Perspective of Molecular Hydrogen in the Treatment of Sepsis

Sepsis is the main cause of death in critically ill patients with no effective treatment. Sepsis is lifethreatening organ dysfunction due to a dysregulated host response to infection. As a novel medical gas, molecular hydrogen (H₂) has a therapeutic effect on many diseases, such as sepsis. H₂ treatment exerts multiple biological effects, which can effectively improve multiple organ injuries caused by sepsis. However, the underlying molecular mechanisms of hydrogen involved in the treatment of sepsis remain elusive, which are likely related to anti-inflammation, anti-oxidation, anti-apoptosis, regulation of autophagy and multiple signaling pathways. This review can help better understand the progress of hydrogen in the treatment of sepsis, and provide a theoretical basis for the clinical application of hydrogen therapy in sepsis in the future.

Sinomenine activation of Nrf2 signaling prevents inflammation and cerebral injury in a mouse model of ischemic stroke

Sinomenine (SINO), which is used clinically to treat rheumatoid arthritis and neuralgia, is derived from the root and stems of Sinomenium acutum. SINO has been reported to exert analgesic, sedative and anti-inflammatory effects, and provides a protective role against shock and organ damage. Studies have suggested that SINO primarily exerts it anti-inflammatory function by inhibiting NF-κB signaling. There is also evidence to indicate that SINO may regulate inflammation Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling. The present study aimed to investigate whether the anti-inflammatory and cerebral protective effects of SINO were induced through Nrf2 both in vitro and in vivo. The results revealed that SINO significantly upregulated Nrf2 protein expression levels, increased Nrf2 nuclear translocation and the upregulated the protein expression levels of downstream factors. The treatment of a middle cerebral artery occlusion model mice with SINO effectively reduced cerebral damage and inflammation, and restored the balance in cerebral oxidative stress. In addition, SINO treatment also promoted Nrf2-dependent microglia M1/M2 polarization and inhibited the phosphorylation of IκBα as well as NF-κB nuclear translocation. This revealed an important upstream event that contributed to its anti-inflammatory and cerebral tissue protective effects. In conclusion, the findings of the present study identified a novel pathway through which SINO may exert its anti-inflammatory and cerebral protective functions, and provided a molecular basis for the potential applications of SINO in the treatment of cerebral inflammatory disorders.

Dexmedetomidine attenuates myocardial ischemia-reperfusion injury in vitro by inhibiting NLRP3 Inflammasome activation

Background

Myocardial ischemia-reperfusion injury (MIRI) is the most common cause of death worldwide. The NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome plays an important role in the inflammatory response to MIRI. Dexmedetomidine (DEX), a specific agonist of α2-adrenergic receptor, is commonly used for sedation and analgesia in anesthesia and critically ill patients. Several studies have shown that dexmedetomidine has a strong anti-inflammatory effect in many diseases. Here, we investigated whether dexmedetomidine protects against MIRI by inhibiting the activation of the NLRP3 inflammasome in vitro.

Methods

We established an MIRI model in cardiomyocytes (CMs) alone and in coculture with cardiac fibroblasts (CFs) by hypoxia/reoxygenation (H/R) in vitro. The cells were treated with dexmedetomidine with or without MCC950 (a potent selective NLRP3 inhibitor). The beating rate and cell viability of cardiomyocytes, NLRP3 localization, the expression of inflammatory cytokines and NLRP3 inflammasome-related proteins, and the expression of apoptosis-related proteins, including Bcl2 and BAX, were determined.

Results

Dexmedetomidine treatment increased the beating rates and viability of cardiomyocytes cocultured with cardiac fibroblasts. The expression of the NLRP3 protein was significantly upregulated in cardiac fibroblasts but not in cardiomyocytes after H/R and was significantly attenuated by dexmedetomidine treatment. Expression of the inflammatory cytokines IL-1β, IL-18 and TNF-α was significantly increased in cardiac fibroblasts after H/R and was attenuated by dexmedetomidine treatment. NLRP3 inflammasome activation induced the increased expression of cleaved caspase1, mature IL-1β and IL-18, while dexmedetomidine suppressed H/R-induced NLRP3 inflammasome activation in cardiac fibroblasts. In addition, dexmedetomidine reduced the expression of Bcl2 and BAX in cocultured cardiomyocytes by suppressing H/R-induced NLRP3 inflammasome activation in cardiac fibroblasts.

Conclusion

Dexmedetomidine treatment can suppress H/R-induced NLRP3 inflammasome activation in cardiac fibroblasts, thereby alleviating MIRI by inhibiting the inflammatory response.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01334-5.

The TSPO-specific Ligand PK11195 Protects Against LPS-Induced Cognitive Dysfunction by Inhibiting Cellular Autophagy

Perioperative neurocognitive disorders (PND) is a common postoperative neurological complication. Neuroinflammation is a major cause that leads to PND. Autophagy, an intracellular process of lysosomal degradation, plays an important role in the development and maintenance of nervous system. PK11195 is a classic translocator protein (TSPO) ligand, which can improve the cognitive function of rats. In this study, we evaluate the protective effect of PK11195 on the learning and memory of rats. A rat model of lipopolysaccharide (LPS)-induced cognitive dysfunction was established by intraperitoneal injection of LPS. Morris Water Maze (MWM), Western blot, qRT-PCR, confocal microscopy and transmission electron microscopy (TEM) were used to study the role of TSPO-specific ligand PK11195 in LPS-activated mitochondrial autophagy in rat hippocampus. We found that PK11195 ameliorated LPS-induced learning and memory impairment, as indicated by decreased escape latencies, swimming distances and increased target quadrant platform crossing times and swimming times during MWM tests. TSPO, ATG7, ATG5, LC3B and p62 protein and mRNA expression increased in the hippocampus of PND model rats. The hippocampal microglia of PND model rats also have severe mitochondrial damage, and a large number of autophagosomes and phagocytic vesicles can be seen. PK11195 pretreatment significantly decreased the expression of TSPO, ATG7, ATG5, LC3B and p62 protein and mRNA, as well as mitochondrial damage. These findings suggested that PK11195 may alleviate the damage of LPS-induced cognitive dysfunction of rats by inhibiting microglia activation and autophagy.

Molecular hydrogen alleviates brain injury and cognitive impairment in a chronic sequelae model of murine polymicrobial sepsis

Sepsis-related encephalopathy (SAE), which causes a series of brain injuries and long-term, potentially irreversible cognitive dysfunction, is closely associated with increased morbidity and mortality. Hydrogen (H2) is a new type of medical gas molecule that has been widely used in the treatment of various diseases in recent years. The aim of the present study was to explore the protective effects of H2 inhalation on brain injury and long-term cognitive impairment in an improved chronic septic mouse model. Male C57BL/6J mice were randomized into four groups: Control, Control + H2, SAE and SAE + H2. The SAE and Control models were established by intraperitoneal injection of human stool suspension or saline in mice. H2 (2%) was inhaled for 60 min at 1 h and 6 h after SAE or Control treatment. The survival rates were recorded for 14 days (days 1-14) and the Morris Water Maze was performed for 7 days (days 8-14). To assess the severity of the brain injury, hematoxylin and eosin staining, Nissl staining, Evans blue (EB) extravasation and the wet/dry weight ratio of brain tissue were detected 24 h after SAE or Control treatment. In addition, inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin 6 (IL-6), high-mobility group box 1 (HMGB1), as well as the protein levels of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), zonula occludens-1 (ZO-1) and Occludin, were measured 6, 12 and 24 h after SAE or Control treatment. The results showed that H2 treatment increased survival rates, mitigated cognitive impairment, reduced hippocampal histological damage, decreased EB and water content, and decreased the levels of TNF-α, IL-6, HMGB1, Nrf2, HO-1, ZO-1 and Occludin, as compared with the SAE group. These data revealed that 2% H2 could suppress brain damage and improve cognitive function in septic mice by inhibiting oxidative stress, inflammatory response and the sepsis-induced blood-brain barrier (BBB) disruption.

iTRAQ-Based Quantitative Proteomic Analysis of Intestines in Murine Polymicrobial Sepsis with Hydrogen Gas Treatment

Objective

Sepsis-associated intestinal injury has a higher morbidity and mortality in patients with sepsis, but there is still no effective treatment. Our research team has proven that inhaling 2% hydrogen gas (H₂) can effectively improve sepsis and related organ damage, but the specific molecular mechanism of its role is not clear. In this study, isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics analysis was used for studying the effect of H₂ on intestinal injury in sepsis.

Methods

Male C57BL/6J mice were used to prepare a sepsis model by cecal ligation and puncture (CLP). The 7-day survival rates of mice were measured. 4-kd fluorescein isothiocyanate-conjugated Dextran (FITC-dextran) blood concentration measurement, combined with hematoxylin-eosinstain (HE) staining and Western blotting, was used to study the effect of H₂ on sepsis-related intestinal damage. iTRAQ-based liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was used for studying the proteomics associated with H₂ for the treatment of intestinal injury.

Results

H₂ can significantly improve the 7-day survival rates of sepsis mice. The load of blood and peritoneal lavage bacteria was increased, and H₂ treatment can significantly reduce it. CLP mice had significant intestinal damage, and inhalation of 2% hydrogen could significantly reduce this damage. All 4194 proteins were quantified, of which 199 differentially expressed proteins were associated with the positive effect of H₂ on sepsis. Functional enrichment analysis indicated that H₂ may reduce intestinal injury in septic mice through the effects of thyroid hormone synthesis and nitrogen metabolism signaling pathway. Western blot showed that H₂ was reduced by down-regulating the expressions of deleted in malignant brain tumors 1 protein (DMBT1), insulin receptor substrate 2 (IRS2), N-myc downregulated gene 1 (NDRG1) and serum amyloid A-1 protein (SAA1) intestinal damage in sepsis mice.

Conclusion

A total of 199 differential proteins were related with H₂ in the intestinal protection of sepsis. H₂-related differential proteins were notably enriched in the following signaling pathways, including thyroid hormone synthesis signaling pathway, nitrogen metabolism signaling pathways, digestion and absorption signaling pathways (vitamins, proteins and fats). H₂ reduced intestinal injury in septic mice by down-regulating the expressions of SAA1, NDRG1, DMBT1 and IRS2.

Rhein Protects Against Neurological Deficits After Traumatic Brain Injury in Mice via Inhibiting Neuronal Pyroptosis

Neurological dysfunction provoked by traumatic brain injury (TBI) makes a huge impact on individual learning ability, memory level, social participation, and quality of life. Pyroptosis, the caspase-1-dependent cell death, which is associated with the release of numerous pro-inflammatory factors, plays a major role in the pathological process after TBI. Inhibition of pyroptosis has been shown to be an attractive strategy for the treatment of various neurological disorders. Here, we found that Rhein, an anthraquinone derived from the medicinal plant rhubarb, attenuated TBI-induced upregulation of pro-inflammatory cytokines, blood lactate dehydrogenase (LDH), and pyroptosis-related proteins, as well as reduced neurological dysfunction in a mouse TBI model. Consistently, Rhein inhibitd equiaxial stretch-induced neuron pyroptosis, LDH release, and upregulation of pro-inflammatory factors in vitro. Thus, our study suggested that Rhein protected against neurological deficits after TBI via inhibiting neuronal pyroptosis.

iTRAQ-based quantitative proteomic analysis of the therapeutic effects of 2% hydrogen gas inhalation on brain injury in septic mice

Sepsis encephalopathy (SAE) has a high incidence and mortality rate in patients with sepsis; however, there is currently no effective treatment. Our previous studies have reported that 2% hydrogen (H₂) gas inhalation had a protective effect on sepsis and SAE; however, the specific mechanism have not been fully elucidated. In the current study, male Institute of Cancer Research mice were either used to create the cecal ligation and puncture (CLP) model or for sham surgery, followed by 2% H₂ gas inhalation for 60 min beginning at 1 and 6 h following sham or CLP surgeries. The isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, hematoxylin and eosin (H&E) staining, Nissl staining, and western blot analysis were used to investigate the effects of H₂ on brain injury in mice with sepsis. The results of the H&E, and Nissl staining indicated that the CLP mice had a significant brain injury, which was characterized by aggravated pathological damage and was alleviated by 2% H₂ inhalation. Quantitative proteomics based on iTRAQ combined with LC-MS/MS analysis quantified a total of 5317 proteins, of which 39 were connected with the protective mechanism of H₂. In addition, H₂ could regulate the immune and the coagulation systems. Furthermore, western blot analysis revealed that H₂ decreased SAE in septic mice by downregulating the protein expression levels of SMAD4, DPYS, PTGDS and upregulating the expression level of CUL4A. These results provide insights into the mechanism of the positive effect of H₂ on SAE and contribute to the clinical application of H₂ in patients with sepsis.

Coenzyme Q10 alleviates sevoflurane‑induced neuroinflammation by regulating the levels of apolipoprotein E and phosphorylated tau protein in mouse hippocampal neurons

Sevoflurane may exert neurotoxic effects on the developing brain. Coenzyme Q10 (CoQ10) has been reported to reduce sevoflurane anesthesia-induced cognitive deficiency in 6-day-old mice. However, its specific mechanisms remain unknown. Apolipoprotein E (ApoE) has been reported to lead to the initiation of neurodegeneration in patients with Alzheimer's disease (AD) and may serve an important role in anesthesia-induced neurotoxicity. The present study aimed to reveal the role of ApoE in the pathogenesis of tau protein hyperphosphorylation and neuroinflammation enhancement caused by sevoflurane anesthesia, as well as the protective mechanism of CoQ10 in an anesthetic sevoflurane treatment model of primary mouse hippocampal neurons. For that purpose, the neurons were randomly assigned to the following groups: i) Control; ii) sevoflurane; iii) control+corn oil; iv) sevoflurane+corn oil; v) control+CoQ10; and vi) control+CoQ10. CoQ10 or corn oil alone was added to the medium on day 4 of neuron culture. The neurons in the sevoflurane group were treated with 21% O₂, 5% CO₂ and 4.1% sevoflurane for 4 h, whereas the control group only with 21% O₂ and 5% CO₂ on day 5. Samples were collected immediately after anesthesia or control treatment. ATP, superoxidase dismutase (SOD)1, ApoE mRNA, total ApoE, full-length ApoE, ApoE fragments, Tau5, Tau-PS202/PT205 (AT8), Tau-PSer396/404 (PHF1), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β levels were measured with ELISA, quantitative PCR, western blotting and immunocytochemistry. The results of the present study indicated that sevoflurane anesthesia significantly decreased the ATP and SOD levels, but increased ApoE mRNA, total ApoE protein, full-length ApoE, ApoE fragments, phosphorylated tau (AT8 and PHF1) and neuroinflammatory factor (TNF-α, IL-6 and IL-1β) expression levels compared with those in the control group. The use of CoQ10 reversed the expression of these factors. These results suggested that sevoflurane treatment damaged mouse hippocampal neurons, which may be associated with the expression of ApoE and its toxic fragments. CoQ10 improved energy replenishment and inhibited oxidative stress, which may lead to a decrease in ApoE and phosphorylated tau protein expression, thus mitigating the sevoflurane-induced neuroinflammation in mouse hippocampal neurons.

Hydrogen improves cell viability partly through inhibition of autophagy and activation of PI3K/Akt/GSK3β signal pathway in a microvascular endothelial cell model of traumatic brain injury

Objective：Traumatic brain injury (TBI) is one of the most serious public health problems in the world. Hydrogen (H₂), a flammable, colorless, and odorless gas, has been observed to have preventive and therapeutic effects on brain trauma and other neurological disorders, but its exact mechanism has not been fully clarified.Methods: To further study the mechanism underlying the role of hydrogen gas in alleviating BBB damage after TBI, we performed the scratch injury model on cultured brain microvascular endothelial cells (bEnd.3), which formed the microvascular endothelial barrier - an integral part of the highly specialized BBB.Results: In the case of TBI, hydrogen was able to improve the decline of cell viability induced by TBI. More importantly, inhibition of PI3 K/Akt/GSK3β signal pathway or activation of autophagy reduced the protective effect of hydrogen on cell viability, indicating that such protective effect was regulated by PI3 K/Akt/GSK3β signal pathway and was related to the inhibition of autophagy.Conclusion: So we concluded that hydrogen improved the cell viability in a microvascular endothelial cell model of TBI partly through inhibition of autophagy, and inhibitory effect of hydrogen on autophagy was exerted by activating PI3 K/Akt/GSK3β signal pathway. These findings enriched our knowledge about the mechanism of hydrogen therapy against TBI.

Spinal hevin mediates membrane trafficking of GluA1-containing AMPA receptors in remifentanil-induced postoperative hyperalgesia in mice

INTRODUCTION

Hevin, a matricellular protein involved in tissue repair and remodeling, is crucial for initiation and development of excitatory synapses. Besides, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA) is an ionotropic transmembrane receptor for glutamate that mediates fast synaptic transmission in the central nervous system (CNS). This study aimed to investigate the correlation between spinal Hevin and AMPA receptors in remifentanil-induced postoperative hyperalgesia in mice.

METHODS

Remifentanil (1.33 μg/kg/min for 60 min) was subcutaneously injected into a mouse model of postoperative pain. The von Frey and hot plate tests were performed to assess mechanical and thermal hyperalgesia. The gene and protein expression of Hevin and the membrane trafficking of GluA1-containing AMPA receptors in the dorsal horn of spinal cord were detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot analysis. In addition, Hevin-shRNA, exogenous Hevin, and 1-naphtylacetyl-spermine (NASPM) were administrated intrathecally to assess the relationship between spinal Hevin and AMPA receptors.

RESULTS

Perioperative administration of remifentanil can aggravate and prolong incision-induced mechanical and thermal hyperalgesia. Treatment with remifentanil increased the expression of spinal Hevin and the membrane trafficking of AMPA receptors. Additionally, knockdown of spinal Hevin attenuated pain hypersensitivity and downregulated membrane trafficking of AMPA receptors after treatment with remifentanil. Meanwhile, preadministration of NASPM reversed spontaneous pain and membrane trafficking of spinal GluA1-containing AMPA receptors induced by exogenous Hevin in naïve mice.

CONCLUSIONS

Spinal Hevin was involved in the maintenance of remifentanil-induced postoperative hyperalgesia via modulating membrane trafficking of AMPA receptors.

Protective Effects of Hydrogen on Myocardial Mitochondrial Functions in Septic Mice

Enhancement of mitochondrial physiological function prevents sepsis-induced dysfunction. The present study aimed to elucidate the mechanism by which hydrogen (H2) affects mitochondrial function in a wild-type (WT) and homozygous nuclear factor erythroid 2-related factor 2 (Nrf2) knockout (KO, Nrf2-/-) murine model of sepsis. In myocardial tissues with severe sepsis, H2 gas treatment reduced mitochondrial dysfunction, whereas zinc protoporphyrin (ZnPPIX) negated these beneficial effects. H2 treatment upregulated the protein expression of mitofusin-2 (Mfn2), peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α), and protein heme oxygenase-1 (HO-1) in WT mice with severe sepsis but not in their Nrf2-/- counterparts, and this upregulation was inhibited in the presence of ZnPPIX. In conclusion, the mechanism by which H2 limits organ damage in mice with severe sepsis involves HO-1, whereas the mechanism that limits severe sepsis-related mitochondrial dysfunction involves both HO-1 and Nrf2.

[Investigation of treatment and analysis of prognostic risk on enterocutaneous fistula in China: a multicenter prospective study]

Objective: To investigate the diagnosis and treatment for enterocutaneous fistula (ECF) in China, and to explore the prognostic factors of ECF. Methods: A multi-center cross-sectional study was conducted based on the Registration System of Chinese Gastrointestinal Fistula and Intra-Abdominal Infections to collect the clinical data of ECF patients from 54 medical centers in 22 provinces/municipalities from January 1, 2018 to December 31, 2018. The clinical data included patient gender, age, length of hospital stay, intensive care unit (ICU) admission, underlying diseases, primary diseases, direct causes of ECF, location and type of ECF, complications, treatment and outcomes. All medical records were carefully filled in by the attending physicians, and then re-examined by more than two specialists. The diagnosis of ECF was based on the clinical manifestations, laboratory/imaging findings and intraoperative exploration. Results: A total of 1521 patients with ECF were enrolled, including 1099 males and 422 females, with a median age of 55 years. The top three primary diseases of ECF were malignant tumors in 626 cases (41.2%, including 540 gastrointestinal tumors, accounting for 86.3% of malignant tumors), gastrointestinal ulcers and perforations in 202 cases (13.3%), and trauma in 157 cases (10.3%). The direct causes of ECF were mainly surgical operation in 1194 cases (78.5%), followed by trauma in 156 (10.3%), spontaneous fistula due to Crohn's disease in 92 (6.0%), radiation intestinal injury in 41 (2.7%), severe pancreatitis in 20 (1.3%), endoscopic treatment in 13 (0.9%) and 5 cases (0.3%) of unknown reasons. All the patients were divided into three groups: 1350 cases (88.7%) with simple ECF, 150 (9.9%) with multiple ECF, and 21 (1.4%) with combined internal fistula. Among the patients with simple ECF, 438 cases (28.8%) were jejuno-ileal fistula, 313 (20.6%) colon fistula, 170 (11.2%) rectal fistula, 111 (7.3%) duodenal fistula, 76 (5.0%) ileocecal fistula, 65 (4.3%) ileocolic anastomotic fistula, 55 (3.6%) duodenal stump fistula, 36 (2.4%) gastrointestinal anastomotic fistula, 36 (2.4%) esophagogastric/esophagojejunal anastomotic fistula, 29 (1.9%) gastric fistula and 21 (1.4%) cholangiopancreatiointestinal. Among all the simple ECF patients, 991 were tubular fistula and 359 were labial fistula. A total of 1146 patients finished the treatment, of whom 1061 (92.6%) were healed (586 by surgery and 475 self-healing) and 85 (7.4%) died. A total of 1043 patients (91.0%) received nutritional support therapy, and 77 (6.7%) received fistuloclysis. Infectious source control procedures were applied to 1042 patients, including 711 (62.0%) with active lavage and drainage and 331 (28.9%) with passive drainage. Among them, 841 patients (73.4%) underwent minimally invasive procedures of infectious source control (replacement of drainage tube through sinus tract, puncture drainage, etc.), 201 (17.5%) underwent laparotomy drainage, while 104 (9.1%) did not undergo any drainage measures. A total of 610 patients (53.2%) received definitive operation, 24 patients died within postoperative 30-day with mortality of 3.9% (24/610), 69 (11.3%) developed surgical site infection (SSI), and 24 (3.9%) had a relapse of fistula. The highest cure rate was achieved in ileocecal fistula (100%), followed by rectal fistula (96.2%, 128/133) and duodenal stump fistula (95.7%,44/46). The highest mortality was found in combined internal fistula (3/12) and no death in ileocecal fistula. Univariate prognostic analysis showed that primary diseases as Crohn's disease (χ(2)=6.570, P=0.010) and appendicitis/appendiceal abscess (P=0.012), intestinal fistula combining with internal fistula (χ(2)=5.460, P=0.019), multiple ECF (χ(2)=7.135, P=0.008), esophagogastric / esophagojejunal anastomotic fistula (χ(2)=9.501, P=0.002), ECF at ileocecal junction (P=0.012), non-drainage/passive drainage before the diagnosis of intestinal fistula (χ(2)=9.688, P=0.008), non-drainage/passive drainage after the diagnosis of intestinal fistula (χ(2)=9.711, P=0.008), complicating with multiple organ dysfunction syndrome (MODS) (χ(2)=179.699, P<0.001), sepsis (χ(2)=211.851, P<0.001), hemorrhage (χ(2)=85.300, P<0.001), pulmonary infection (χ(2)=60.096, P<0.001), catheter-associated infection (χ(2)=10.617, P=0.001) and malnutrition (χ(2)=21.199, P<0.001) were associated with mortality. Multivariate prognostic analysis cofirmed that sepsis (OR=7.103, 95%CI:3.694-13.657, P<0.001), complicating with MODS (OR=5.018, 95%CI:2.170-11.604, P<0.001), and hemorrhage (OR=4.703, 95%CI: 2.300-9.618, P<0.001) were independent risk factors of the death for ECF patients. Meanwhile, active lavage and drainage after the definite ECF diagnosis was the protective factor (OR=0.223, 95%CI: 0.067-0.745, P=0.015). Conclusions: The overall mortality of ECF is still high. Surgical operation is the most common cause of ECF. Complications e.g. sepsis, MODS, hemorrhage, and catheter-associated infection, are the main causes of death. Active lavage and drainage is important to improve the prognosis of ECF.

Protective effects of hydrogen‑rich saline against experimental diabetic peripheral neuropathy via activation of the mitochondrial ATP‑sensitive potassium channel channels in rats

It has previously been demonstrated that hyperglycemia-induced oxidative stress and inflammation are closely associated with the development of diabetic complications, including diabetic neuropathy. Additionally, mitochondrial ATP-sensitive potassium (Mito-K-ATP) channels play a homeostatic role on blood glucose regulation in organisms. Molecular hydrogen (H₂) exhibits anti-inflammatory, anti-antioxidative and anti-apoptotic properties and can be used to treat more than 71 diseases safely. In addition, the diabetes animal models which are set up using streptozotocin (STZ) injection, is a type of high long-term stability, low animal mortality rate and security method. The aim of the current study was to assess the value of hydrogen-rich saline (HS) in diabetic peripheral neuropathy (DPN) treatment and to determine its associated mechanisms in STZ-induced diabetic experimental rats. Additionally, the effects of the Mito-K-ATP channels, oxidative stress, inflammatory cytokines and apoptosis on DPN were also evaluated. From week 5 of STZ injections, HS (2.5, 5 and 10 ml/kg) was injected into the rat abdominal cavity every day for a period of 4 weeks. The results of the current study demonstrated that HS significantly reduced behavioral, biochemical and molecular effects caused by DPN. However, 5-hydroxydecanoate, a selective Mito-K-ATP channels general pathway inhibitor, partially eliminated the therapeutic effect of HS on DPN. These results indicated that the use of HS may be a novel strategy to treat DPN by activating the Mito-K-ATP pathway and reducing oxidative stress, inflammatory cytokines and apoptosis.

Hydrogen-rich Saline Alleviated the Hyperpathia and Microglia Activation via Autophagy Mediated Inflammasome Inactivation in Neuropathic Pain Rats

Neuropathic pain is a complication after a spinal nerve injury. The inflammasomes are now identified to be responsible for triggering inflammation in neuropathic pain. Autophagy participates in the process of neuropathic pain and can regulate the inflammasome activation in different diseases. Our previous research reported that hydrogen exerted a protective effect against neuropathic pain. Therefore, we focused on the mechanism and role of autophagy and inflammasome, by which hydrogen alleviated the hyperpathia induced by neuropathic pain. The results showed that neuropathic pain stimulated activation of inflammasome NLRP3 and autophagy pathway in the microglial cells of the spinal cord. The inhibition of NLRP3 inhibited the hyperpathia induced by spinal nerve litigation surgery. The absence of autophagy aggravated the inflammasome activity and hyperpathia. Hydrogen promoted autophagy related protein expression, inhibited the inflammasome NLRP3 pathway activation, and relieved the hyperpathia induced by neuropathic pain. Hydrogen treatment could alleviate hyperpathia by autophagy-mediated NLRP3 inactivation.

[Effects of hydrogen on lung injury in wild-type and Nrf2 gene knockout mice: relationship with Nrf2/HO-1/HMGB1 pathway]

OBJECTIVE

To investigate the key role of nuclear factor E2-related factor 2 (Nrf2) in the treatment of lung injury in sepsis mice by regulating Nrf2/heme oxygenase-1 (HO-1)/high mobility group protein B1 (HMGB1) pathway.

METHODS

120 male wild type (WT) and 120 Nrf2 knockout (Nrf2-KO) ICR mice were randomly divided into Sham group, H₂ control group (Sham+H₂ group), cecal ligation and puncture (CLP) induced sepsis model group (CLP group) and H₂ intervention group (CLP+H₂ group), with 30 mice in each group. The sepsis model was reproduced by CLP. The same operation was done in Sham group and Sham+H₂ group except CLP. The mice in Sham+H₂ group and CLP+H₂ group were challenged by 2% H₂ for 1 hour at 1 hour and 6 hours after operation respectively, while the mice in Sham group and CLP group only inhaled air. Twenty mice in each group were collected to observe the 7-day survival. The other mice were sacrificed at 24 hours after the reproduction of model, and the lung tissues were harvested. The activities of superoxide dismutase (SOD) and catalase (CAT) and malondialdehyde (MDA) contents were determined by enzyme-linked immunosorbent assay (ELISA). The expressions of HO-1 and HMGB1 were determined by Western Blot, and the positive expression of HO-1 was also detected by immunofluorescence.

RESULTS

Compared with Sham groups, the 7-day survival rates of WT and Nrf2-KO mice in CLP groups were significantly lowered [WT: 0% (0/20) vs. 100% (20/20), Nrf2-KO: 0% (0/20) vs. 100% (0/20), both P < 0.05]; the 7-day survival rates of CLP+H₂ group in WT mice were significantly higher than those of CLP group [40% (8/20) vs. 0% (0/20), P < 0.05], but there was no significant difference between CLP+H₂ group and CLP group in Nrf2-KO mice [0% (0/20) vs. 0% (0/200), P > 0.05]. In WT mice, compared with Sham group, the activities of SOD and CAT in lung tissue of CLP group were decreased significantly [SOD (kU/g): 131.30±28.21 vs. 251.00±22.84, CAT (kU/g): 13.43±1.52 vs. 20.76±1.63, both P < 0.01], the MDA content, the expressions of HO-1 and HMGB1 were increased significantly [MDA (μmol/g): 6.26±1.18 vs. 4.16±0.58, HO-1/β-actin: 0.160±0.045 vs. 0.023±0.005, HMGB1/β-actin: 0.656±0.055 vs. 0.005±0.001, all P < 0.05]. Compared with CLP group, the activities of SOD, CAT and HO-1 expression in lung tissue of CLP+H₂ group were significantly increased [SOD (kU/g): 220.32±35.06 vs. 131.30±28.21, CAT (kU/g): 18.95±2.49 vs. 13.43±1.52, HO-1/β-actin: 0.376±0.025 vs. 0.160±0.045, all P < 0.01], while the MDA contents and HMGB1 expressions were significantly decreased [MDA (μmol/g): 4.26±0.75 vs. 6.26±1.18, HMGB1/β-actin: 0.343±0.040 vs. 0.656±0.055, both P < 0.05]. In Nrf2-KO mice, compared with Sham group, the activity of CAT in CLP group was significantly lowered (kU/g: 12.28±1.49 vs. 19.11±1.53, P < 0.01), MDA contents and the expressions of HO-1 and HMGB1 were significantly increased [MDA (μmol/g): 6.85±0.54 vs. 4.59±0.50, HO-1/β-actin: 0.063±0.005 vs. 0.021±0.003, HMGB1/β-actin: 0.713±0.035 vs. 0.005±0.001, all P < 0.01], while there was no significant difference in SOD activity (kU/g: 114.19±9.94 vs. 135.75±28.10, P > 0.05). There was no significant difference in above parameters between CLP+H₂ group and CLP group.

CONCLUSIONS

H₂ inhibits lung injury in septic mice through Nrf2/HO-1/HMGB1 pathway. Nrf2 plays a major role in the treatment of septic lung injury by H₂.

The role of PI3K-mediated AMPA receptor changes in post-conditioning of propofol in brain protection

Background

We aimed to study the role of amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) glutamate receptor 2 (GluR2) subunit trafficking, and activity changes in short-term neuroprotection provided by propofol post-conditioning. We also aimed to determine the role of phosphoinositide-3-kinase (PI3K) in the regulation of these processes.

Methods

Rats underwent 1 h of focal cerebral ischemia followed by 23 h of reperfusion were randomly divided into 6 groups (n = 36 per group): sham- operation (S), ischemia–reperfusion (IR), propofol (P group, propofol 20 mg/kg/h at the onset of reperfusion for 2 h after 60 min of occlusion), and LY294002 (PI3K non-selective antagonist) + sham (L + S, LY294002 of 1.5 mg/kg was infused 30 min before sham operation), LY294002+ ischemia–reperfusion (L + IR, LY294002 of 1.5 mg/kg was infused 30 min before middle cerebral artery occlusion), LY294002 + IR + propofol (L + P, LY294002 of 1.5 mg/kg was infused 30 min before middle cerebral artery occlusion and propofol 20 mg/kg/h at the onset of reperfusion for 2 h after 60 min of occlusion).

Results

Compared with group IR, rats in group P had significant lower neurologic defect scores and infarct volume. Additionally, consistent with enhanced expression of PI3K-AMPAR GluR2 subunit complex substances in ipsilateral hippocampus, GluR2 subunits showed increased levels in both the plasma and postsynaptic membranes of neurons, while pGluR2 expression was reduced in group P. Furthermore, LY294002, the PI3K non-selective antagonist, blocked those effects.

Conclusion

These observations demonstrated that propofol post-conditioning revealed acute neuroprotective role against transient MCAO in rats. The short-term neuroprotective effect was contributed by enhanced GluR2 subunits trafficking to membrane and postsynaptic membranes of neurons, as well as down-regulated the expression of pGluR2 in damaged hippocampus. Finally, the above-mentioned protective mechanism might be contributed by increased combination of PI3K to AMPAR GluR2 subunit, thus maintained the expression and activation of AMPAR GluR2 in the ipsilateral hippocampus.

Hydrogen alleviates mitochondrial dysfunction and organ damage via autophagy‑mediated NLRP3 inflammasome inactivation in sepsis

Sepsis is a highly heterogeneous syndrome that is caused by a dysregulated host response to infection. The disproportionate inflammatory response to invasive infection is a triggering event inducing sepsis. The activation of inflammasomes in sepsis can amplify inflammatory responses. It has been reported that damaged mitochondria contribute to NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome-related sepsis. Our previous study revealed that hydrogen (H₂) exerts anti-inflammatory effects in sepsis but the detailed mechanism remains to be elucidated. In the present study, septic mice induced by cecal ligation and puncture (CLP) and macrophages induced by lipopolysaccha-ride (LPS) were used as models of sepsis in vivo and in vitro, respectively. An inducer and inhibitor of autophagy and the NLRP3 inflammasome were administered to investigate the detailed mechanism of action of H₂ treatment in sepsis. The results demonstrated that LPS and ATP led to NLRP3 inflammasome pathway activation, excessive cytokine release, mitochondrial dysfunction and the activation of autophagy. CLP induced organ injury and NLRP3 pathway activation. H₂ treatment ameliorated vital organ damage, the inflammatory response, mitochondrial dysfunction and NLRP3 pathway activation, and promoted autophagy in macrophages induced by LPS and in CLP mice. However, the inhibitor of autophagy and the inducer of NLRP3 reversed the protective effect of H₂ against organ damage, the inflammatory response and mitochondrial dysfunction in vivo and in vitro. Collectively, the results demonstrated that H₂ alleviated mitochondrial dysfunction and cytokine release via autophagy-mediated NLRP3 inflammasome inactivation.

Hydrogen-rich saline alleviates inflammation and apoptosis in myocardial I/R injury via PINK-mediated autophagy

Ischemia/reperfusion (I/R)-induced inflammatory reaction is one of the most important elements in myocardial I/R injury. In addition, autophagy serves an important role in normal cardiac homeostasis, and obstructions to the autophagy process lead to severe consequences for the heart. Hydrogen exerts an effective therapeutic role in numerous diseases associated with I/R injury via its anti-inflammation, anti-apoptosis and anti-oxidative properties. Therefore, the present study investigated the effect of hydrogen on the myocardial inflammation response and apoptosis in myocardial ischemic/reperfusion (MI/R) injury, and further explored the mechanism of PTEN-induced kinase 1 (PINK1)/Parkin-induced mitophagy in the protection of hydrogen on MI/R injury. MI/R injury was performed by surgical ligation of the left coronary artery in vivo and H9C2 cell injury was performed by hypoxia/reoxygenation (H/R) in vitro. Hydrogen-rich saline was administered twice through intraperitoneal injection at a daily dose of 10 ml/kg following the operation in the in vivo model, and hydrogen-rich medium culture was used for cells instead of normal medium in vitro. The infarction size of hearts, the levels of creati-nine kinase-muscle/brain (CK-MB) and cardiac troponin I (cTnI), cardiac function, cell viability and lactate dehydrogenase (LDH) release, levels of cytokines, apoptosis and the expression of autophagy-associated proteins were detected in the different treatment groups in vivo and in vitro. The results demonstrated that treatment with hydrogen improved the myocardial infarction size of hearts, cardiac function, apoptosis and cytokine release following MI/R in rats. In vitro, hydrogen improved cell viability and LDH release following hypoxia/reoxygenation in myocardial cells. In addition, it was demonstrated that hydrogen exerted an anti-inflammatory and anti-apoptotic effect in myocardial cells induced by H/R via PINK1/Parkin mediated autophagy. These results suggested that hydrogen-rich saline alleviated the inflammation response and apoptosis induced by MI/R or H/R in vivo or in vitro, and that hydrogen-rich saline contributed to the increased expression of proteins associated with autophagy. In summary, the present study indicated that treatment with hydrogen-rich saline improved the inflammatory response and apoptosis in MI/R via PINK1/Parkin-mediated mitophagy.

Electroacupuncture alleviates morphine‑induced hyperalgesia by regulating spinal CB1 receptors and ERK1/2 activity

Electroacupuncture (EA), a traditional Chinese therapeutic technique, is considered an effective method for treating certain painful neuropathies induced by various neuropathological damage. The current study investigated the effect of EA on intrathecal (IT) morphine-induced hyperalgesia (MIH) and examined the hypothesis that activation of cannabinoid receptor 1 (CB1) could enhance the antinociceptive effect of EA on MIH via regulation of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. Using a rat model of IT MIH, mechanical and thermal hyperalgesia were evaluated by an electronic von Frey filament and hotplate at baseline (1 day before IT administration) and at days 1, 3, 5 and 7 after IT administration. Rats received IT normal saline, IT morphine or IT morphine + EA at ST36-GB34. The protein levels of ERK1/2, phosphorylated (p)-ERK1/2 and CB1 in the spinal cord were assayed by western blotting. Furthermore, the effect of IT injection of the CB1 agonist WIN 55,212-2 and the CB1 antagonist SR141716 on the antinociceptive effect of EA in rats with MIH was investigated. Nociceptive behavior and ERK1/2, phosphorylated (p)-ERK1/2 and CB1 protein levels were evaluated as mentioned above. The results revealed that chronic IT injections of morphine induced a significant decrease in mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) accompanied with remarkable upregulation of p-ERK1/2 in the spinal cord, which could be attenuated by EA at the ST36-GB34 acupoints. In the rat model of MIH, IT injection of WIN 55,212-2 combined with EA induced a significant increase in MWT and TWL accompanied with a significant decrease in p-ERK1/2 and a significant increase in CB1 protein level compared with EA alone, while SR141716 induced the opposite results. The present study suggests that EA alleviates hyperalgesia induced by IT injection of morphine partially through the inhibition of ERK1/2 activation. Activation of the CB1 receptor enhances the antinociceptive effect of EA in rats with MIH partly through the regulation of the spinal CB1-ERK1/2 signaling pathway.

Sevoflurane induces temporary spatial working memory deficits and synaptic ultrastructure impairments in the hippocampus of neonatal rats

OBJECTIVE

Exposure to volatile anesthetics in neonatal rats could induce neurotoxicity, learning deficits and abnormal social behaviors. The aim of this study is to investigate the potential neurotoxicity induced by sevoflurane.

MATERIALS AND METHODS

Postnatal day 7 (P7) Sprague-Dawley (SD) rats were continuously exposed to 2% sevoflurane plus 40% oxygen/air for 2 h. We used Morris water maze (MWM) to examine subsequent neurobehavioral performance. Transmission electron microscopy (TEM) was used to observe the histopathological changes in the hippocampus.

RESULTS

Neonatal exposure to 2% sevoflurane for 2 hours impaired short-term spatial working memory but not reference memory at P25. It induced synaptic ultrastructure impairments in the CA3 region of hippocampal, including fewer numbers of synapses, thinner thickness of postsynaptic dense, broader synaptic cleft width and smaller synaptic curvature. Our results also showed that all synaptic ultrastructure impairments and neurocognitive deficits had almost completely recovered at P53.

CONCLUSIONS

We showed that a single sevoflurane exposure to neonatal rats led to temporary spatial working memory deficits. It might be associated with synaptic ultrastructure impairments in the CA3 region of the hippocampus, including fewer numbers of synapses, thinner thickness of PSD and broader synaptic cleft width. Fortunately, all the neurotoxicity and neurocognitive deficits were reversible.

[Effect of autophagy on N-methy-D-aspartate receptor and hyperalgesia in a rat model of neuropathic pain]

OBJECTIVE

To investigate the effects of autophagy on N-methy-D-aspartate (NMDA) receptor and its subunit NR2B and behavioral test in a rat model of neuropathic pain (NP).

METHODS

Male Sprague-Dawley (SD) rats were divided into sham group, NP group, autophagy inhibitor 3-methyladenine (3-MA) pretreatment group (3-MA+NP group) and autophagy inducer rapamyein (Rap) group (Rap+NP group) by random number table with 22 rats in each group. NP animal model was reproduced by ligating sciatic nerve, while sciatic nerve of the rats in the sham group were only exposed but not ligated. The rats in two pretreatment groups were intraperitoneally challenged with 3-MA 15 mg/kg or Rap 10 mg/kg injection 1 hour before operation. Mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured before and 1, 3, 7, 14 days after operation in each group. Spinal cord tissues were harvested at 1 day and 7 days after operation for autophagosome observation by electron microscope. The expressions of autophagy protein microtubule-associated protein 1 light chain 3-II (LC3-II), Beclin1, and NMDA, NR2B were determined by Western Blot. The positive expression of LC3 was detected by immunofluorescence.

RESULTS

Compared with sham group, the MWT and TWL of rats in NP group were decreased gradually with the prolongation of operation time, the number of autophagosome, the expressions of LC3-II, Beclin1, NMDA, NR2B, and the positive expression of LC3 in spinal cord were significantly increased at 1 day after operation and till 7 days, which indicated that NP led to hyperpathia and autophagy activation. Compared with NP group, MWT was significantly further decreased, TWL was further shortened, the number of autophagosome was decreased, the expressions of LC3-II and Beclin1 in spinal cord were decreased, and NMDA and NR2B expressions were further increased after 3-MA pretreatment, with significant differences at 1 day after operation [MWT (g): 29.4±2.4 vs. 42.5±6.6, TWL (s): 7.2±1.0 vs. 8.8±1.1, LC3-II/β-actin: 0.38±0.03 vs. 0.52±0.07, Beclin1/β-actin: 0.29±0.06 vs. 0.59±0.05, NMDA/β-actin: 0.62±0.06 vs. 0.50±0.06, NR2B/β-actin: 0.57±0.03 vs. 0.46±0.03, all P < 0.05]. Immunofluorescence staining confirmed that the positive expression of LC3 was significantly decreased. Rap pretreatment could increase MWT, TWL and the number of autophagosome, increase LC3-II and Beclin1 expressions in spinal cord, and decrease NMDA and NR2B expressions in NP rats, and significant differences at 1 day after operation were found as compared with those in NP group [MWT (g): 49.4±4.4 vs. 42.5±6.6, TWL (s): 10.5±1.2 vs. 8.8±1.1, LC3-II/β-actin: 0.67±0.09 vs. 0.52±0.07, Beclin1/β-actin: 0.71±0.08 vs. 0.59±0.05, NMDA/β-actin: 0.40±0.05 vs. 0.50±0.06, NR2B/β-actin: 0.34±0.04 vs. 0.46±0.03, all P < 0.05], and immunofluorescence showed that the positive expression of LC3 was increased and lasted for 7 days. It indicated that Rap could increase the activity of autophagy, alleviate the occurrence of hyperalgesia, and reduce the expressions of NMDA receptor and its NR2B subunit.

CONCLUSIONS

NP could regulate the variety of NMDA/NR2B and hyperalgesia via increasing autophagy.

Erythropoietin Ameliorates Lung Injury by Accelerating Pulmonary Endothelium Cell Proliferation via Janus Kinase-Signal Transducer and Activator of Transcription 3 Pathway After Kidney Ischemia and Reperfusion Injury

BACKGROUND/AIMS

Kidney ischemia and reperfusion injury could cause microvascular barrier dysfunction, lung inflammatory cascades activation, and programmed cell death of pulmonary endothelium, leading to acute lung injury. Our study aimed at determining whether erythropoietin (EPO) can ameliorate lung dysfunction following renal ischemia and reperfusion (IR) injury and explored the underlying mechanisms.

METHODS

In vivo, C57BL/6 mice received EPO (6000 U/kg) before right renal vascular pedicles clamping for 30 minutes, followed by 24 hours of reperfusion. The lung histopathologic changes and inflammatory cytokines expression were assessed. In vitro, cultured human umbilical vein endothelial cells were treated with EPO, and apoptosis rate, proliferation capacity, and phosphorylation status of the Janus kinase-signal transducer and activator of transcription 3 (Jak-STAT3) pathway were measured respectively in the presence or absence of lipopolysaccharide stimulation.

RESULTS

In vivo, EPO remarkably attenuated pulmonary interstitial and alveolar epithelial edema caused by renal IR injury. In vitro, the proliferation capacity of human umbilical vein endothelial cells was significantly increased under EPO stimulation, which correlated with changes in Jak-STAT3 signaling.

CONCLUSION

Our data indicated that EPO is able to ameliorate acute lung tissue damage induced by renal IR, and at least in part, via the Jak-STAT3 pathway.

Hydrogen gas reduces HMGB1 release in lung tissues of septic mice in an Nrf2/HO-1-dependent pathway

BACKGROUND

Lung injury is a vital contributor of mortality in septic patients. Our previous studies have found that molecular hydrogen (H₂), which has anti-oxidant, anti-inflammatory, and anti-apoptosis effects, had a therapeutic effect on a septic animal model through increasing expression of nuclear factor-erythroid 2-related factor 2 (Nrf2). The aim of this research was to investigate the effects of 2% H₂ gas inhalation on sepsis-induced lung injury and its underlying mechanisms.

METHODS

Male wild-type (WT) and Nrf2-knockout (Nrf2-KO) ICR mice underwent sham or cecal ligation and puncture (CLP) operation. Two percent of H₂ gas was inhaled for 60 min beginning at both 1 h and 6 h after sham or CLP surgery. To assess the severity of septic lung injury, the 7-day survival rate, wet/dry (W/D) weight ratio of lung tissue, lung histopathologic score, pro-inflammatory cytokines (tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), high-mobility group box 1 (HMGB1)), anti-inflammatory cytokine (interleukin 10 (IL-10)), antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and heme oxygenase 1 (HO-1)), and an oxidative product (malondialdehyde (MDA)) were detected after sham or CLP operation. The histopathologic changes were observed in lung tissues by hematoxylin and eosin (HE) staining, and pro-inflammatory cytokines (TNF-α and IL-6), anti-inflammatory cytokine (IL-10), antioxidant enzymes (SOD and CAT), and MDA were detected in lung tissues by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

The results indicated that 2% H₂ gas treatment increased the survival rates, decreased the W/D weight ratio and the lung injury score, alleviated the injuries caused by oxidative stress and inflammation, and induced HO-1 level but reduced HMGB1 level in WT but not Krf2-KO mice. These data reveal that H₂ gas could suppress lung injury in septic mice through regulation of HO-1 and HMGB1 expression and that Nrf2 plays a main role in the protective effects of H₂ gas on lung damage caused by sepsis.

Dietary Supplementation With High Fiber Alleviates Oxidative Stress and Inflammatory Responses Caused by Severe Sepsis in Mice Without Altering Microbiome Diversity

In this study, we demonstrated the effects of a high-fiber diet on intestinal lesions, oxidative stress and systemic inflammation in a murine model of endotoxemia. C57BL/6 mice were randomly assigned to four groups: the control group (CONTROL), which received a commercial normal-fiber rodent diet comprising normal fiber; a CLP group, which received a commercial normal-fiber rodent diet and underwent caecal ligation puncture (CLP); a high-fiber group (HFG), which received a commercial high-fiber rodent diet; and a high fiber + CLP group (HFCLP) which received a commercial high-fiber rodent diet and underwent CLP (30%). The sepsis model was created via CLP after 2 weeks of dietary intervention. Notably, dietary high-fiber supplementation in HFCLP group improved survival rates and reduced bacterial loads, compared with CLP alone. In the HFCLP group, dietary fiber supplementation decreased the serum concentrations of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6) and high-mobility group protein 1 (HMG-1) but raised the concentration of interleukin 10 (IL-10), compared with the levels in CLP mice. Meanwhile, high-fiber supplementation increased the relative proportions of Akkermansia and Lachnospiraceae. These data show that dietary high-fiber supplementation may be therapeutic for sepsis-induced lesions.

Hemopexin alleviates cognitive dysfunction after focal cerebral ischemia-reperfusion injury in rats

Background

Ischemia-reperfusion (I/R) is a critical pathophysiological basis of cognitive dysfunction caused by ischemia stroke. Heme-oxygenase-1 (HO-1) is the rate-limiting enzyme for the elimination of excessive free heme by combining with hemopexin (HPX), a plasma protein that contributes to eliminating excessive free heme during ischemia stroke. This study aimed to elucidate whether HPX could alleviate cognitive dysfunction in rats subjected to cerebral I/R.

Methods

Rats were randomly divided into five groups: sham, MCAO, Vehicle, HPX and HPX + protoporphyrin IX (ZnPPIX). Cerebral I/R was induced by MCAO. Saline, vehicle, HPX and HPX + ZnPPIX were injected intracerebroventricularly at the moment after reperfusion. Morris water maze (MWM) test was used to detect the learning and cognitive function. Western blot was used to detect the expression of HO-1 in ischemic penumbra. CD31/vWF double labeling immunofluorescence was used to detect the neovascularization in the penumbra hippocampus. The structure and function of blood-brain barrier (BBB) was detected by the permeability of Evans Blue (EB), water content of the brain tissue, the Ang1/Ang2 and VE-cadherin expression.

Results

Our study verified that HPX improved the learning and memory capacity. Hemopexin up-regulated HO-1 protein expression, the average vessel density in the penumbra hippocampus and the VE- cadherin expression but decreased the permeability of EB, the water content of brain tissue and the ratio of Ang1/Ang2. The effects were reversed by ZnPPIX, an inhibitor of HO-1.

Conclusion

HPX can maintain the integrity of the blood-brain barrier and alleviate cognitive dysfunction after cerebral I/R through the HO-1 pathway.

Sevoflurane-induced learning deficits and spine loss via nectin-1/corticotrophin-releasing hormone receptor type 1 signaling

In recent years, the neurotoxicity of general anesthetics in the developing brain has been studied and raised great concern as a major health issue to the public and physicians. Sevoflurane inhalation may induce neurotoxicity expressed as memory and learning impairment in young animals. In the current study, we investigated the role of nectin-1 and corticotrophin-releasing hormone receptor type 1 (CRHR1) in sevoflurane-induced learning deficits and dendritic spines loss in neonatal mice. Neonatal mice (P7) were treated with 3% sevoflurane with 60% O₂ or 60% O₂ for 6 h. Cognitive function was evaluated by Y Maze, Object recognition test, and Morris Water Maze. Hippocampal nectin-1 and L-afadin expression assessed using western blot analysis. The dendritic spines morphology of the hippocampus was determined using Golgi impregnation on 7 d and 2 months old. Sevoflurane exposed to neonatal mice decreased hippocampal nectin-1 levels from 1 h to 2 months after sevoflurane inhalation and attenuated working and spatial memory and spinal number in adulthood, which could be reversed by nectin-1 overexpression and CRHR1 antagonist Antalarmin. Nectin-1 knockdown caused spatial learning deficits and dendritic spine loss and lower L-afadin protein expression. Sevoflurane-induced nectin-1 and L-afadin expression decrease was mediated by CRHR1 signaling in the hippocampus. This information can be used to develop targeted intervention aimed at decreasing the neurotoxicity of sevoflurane inhalation.

Effect of autophagy on allodynia, hyperalgesia and astrocyte activation in a rat model of neuropathic pain

Primary damage or dysfunction of the nervous system may cause or initiate neuropathic pain. However, it has been difficult to establish an effective treatment for neuropathic pain, as the mechanisms responsible for its pathology remain largely unknown. Autophagy is closely associated with the pathological process of neurodegenerative diseases, neuropathic injury and cancer, among others. The aim of the present study was to examine the changes in the autophagy-lysosomal pathway and discuss the effects of autophagy on allodynia, hyperalgesia and astrocyte activation in neuropathic pain. A neuropathic pain model was induced by chronic constriction injury (CCI) in rats. Inducers and inhibitors of autophagy and lysosomes were used to assess autophagy, allodynia, hyperalgesia and astrocyte activity. Neuropathic pain was found to induce an increase in the levels of the autophagy-related proteins, LC3II and Beclin 1 and, and in those of the lysosomal proteins, lysosomal-associated membrane protein type 2 (LAMP2) and Ras-related protein Rab-7a (RAB7), whereas p62 levels were found to decrease from day 1 to 14 following CCI. The autophagy inducer, rapamycin, further increased the LC3II, Beclin 1, lysosomal-associated membrane protein 2 (LAMP2) and Ras-related protein Rab-7a (RAB7) expression levels, and decreased the p62 expression levels, which were accompanied by alleviation of allodynia, hyperalgesia and astrocyte activation in the rats subjected to CCI; the autophagy inhibitor, 3-methyladenine, reversed these effects. The use of the lysosomal inhibitors, bafilomycin and chloroquine, resulted in the accumulation of LC3II and Beclin 1, a decrease in the levels of LAMP2 and RAB7, and the exacerbation of allodynia, hyperalgesia and astrocyte activation in rats with neuropathic pain. On the whole, the findings of this study indicate that neuropathic pain activates autophagy, which alleviates mechanical and thermal hyperalgesia and suppresses astrocyte activity. Therefore, neuropathic pain induced by CCI in rats appears to be mediated via the autophagy-lysosomal pathway.

A paternal methyl donor-rich diet altered cognitive and neural functions in offspring mice

Dietary intake of methyl donors, such as folic acid and methionine, shows considerable intra-individual variation in human populations. While it is recognized that maternal departures from the optimum of dietary methyl donor intake can increase the risk for mental health issues and neurological disorders in offspring, it has not been explored whether paternal dietary methyl donor intake influences behavioral and cognitive functions in the next generation. Here, we report that elevated paternal dietary methyl donor intake in a mouse model, transiently applied prior to mating, resulted in offspring animals (methyl donor-rich diet (MD) F1 mice) with deficits in hippocampus-dependent learning and memory, impaired hippocampal synaptic plasticity and reduced hippocampal theta oscillations. Gene expression analyses revealed altered expression of the methionine adenosyltransferase Mat2a and BK channel subunit Kcnmb2, which was associated with changes in Kcnmb2 promoter methylation in MD F1 mice. Hippocampal overexpression of Kcnmb2 in MD F1 mice ameliorated altered spatial learning and memory, supporting a role of this BK channel subunit in the MD F1 behavioral phenotype. Behavioral and gene expression changes did not extend into the F2 offspring generation. Together, our data indicate that paternal dietary factors influence cognitive and neural functions in the offspring generation.

Hydrogen ameliorates oxidative stress via PI3K-Akt signaling pathway in UVB-induced HaCaT cells

Chronic ultraviolet (UV) exposure-induced oxidative stress is associated with the pathogenesis of skin damage. However, the nuclear factor erythroid‑2‑related factor 2 (Nrf2) pathway is a critical factor in protecting cells against UVB‑induced injury through inhibiting oxidative stress. Furthermore, Nrf2 activation requires the involvement of the phosphoinositide-3 kinase (PI3K)/protein kinase B (AKT) pathway, which has a major role in survival of various cell types. Molecular hydrogen exerts protective effects on UV‑induced injury, but the underlying mechanisms have remained elusive. The present study assessed the protective effects of hydrogen against oxidative stress‑induced injury caused by UVB irradiation and investigated the molecular mechanisms. In vitro, UVB‑induced HaCaT cells were collected for the detection of reactive oxygen species, 8‑iso‑prostaglandin F2α, malondialdehyde via fluorescence spectrometry and ELISA; cell activity and cytotoxicity by MTT and lactate dehydrogenase assays, respectively. Additionally, the expression level of PI3K, Akt, Nrf2 and heme oxygenase‑1 (HO‑1) were investigated using western blot, etc. All of the results indicated that hydrogen decreased the levels of reactive oxygen species, 8‑iso‑prostaglandin F2α and malondialdehyde, and promoted the UVB exposure‑induced expression of PI3K, Akt, Nrf2 and heme oxygenase‑1 in HaCaT cells. Of note, PI3K inhibition partially reversed the effects of hydrogen on UVB‑induced HaCaT cells. Therefore, hydrogen effectively protects cells from UVB radiation‑induced oxidative stress by inhibiting Nrf2/HO‑1 activation through the PI3K/Akt signaling pathway.

Hemopexin promotes angiogenesis via up-regulating HO-1 in rats after cerebral ischemia-reperfusion injury

BACKGROUND

Ischemia-reperfusion (I/R) is a critical pathophysiological change of ischemic stroke. Heme-oxygenase-1 (HO-1) is a rate-limiting enzyme of eliminating excessive free heme by combining with hemopexin (HPX), a plasma protein contributing to alleviating infarct size due to ischemia stroke. This study was to investigate whether HPX could improve angiogenesis after cerebral ischemia-reperfusion via up-regulating HO-1.

METHODS

Rats were randomly divided into five groups: sham, MCAO, MCAO + Vehicle, MCAO + HPX and MCAO + HPX + protoporphyrin IX (ZnPPIX, an HO-1 inhibitor). Cerebral I/R was induced by MCAO. Saline, vehicle, HPX and HPX + ZnPPIX were respectively given to MCAO group, MCAO + Vehicle group, MCAO + HPX group and MCAO + HPX + ZnPPIX group at the moment after reperfusion by intracerebroventricular injection. Neurological behavioral scores(NBS) was assessed at 24 h and 7d after I/R. Real-time polymerase chain reaction (RT-PCR) was used to analyze the mRNA level of HO-1. Angiogenesis in penumbra area was assessed by immunofluorescence detection at 7d after I/R. Serum endothelial nitric oxide synthase (eNOS) was assessed by enzyme linked immunosorbent assay (ELISA) at 24 h and 7d after I/R.

RESULTS

Compared with sham group, the NBS and the mRNA levels of HO-1 at 24 h and 7d after I/R in MCAO group decreased notably (P < 0.05), the new vessel density in ischemia penumbra increased notably at 7d after I/R (P < 0.05), the serum eNOS level increased at 24 h and 7d after I/R (P < 0.05). MCAO group and MCAO + Vehicle group showed no significant differences (P > 0.05). In the MCAO + HPX group, compared with MCAO + Vehicle group, the NBS and the mRNA levels of HO-1 increased drastically at 24 h and 7d after I/R (P < 0.05), the new vessel density in ischemia penumbra increased significantly at 7d after I/R (P < 0.05), the serum eNOS level at 24 h and 7d after I/R ascended notably (P < 0.05). Compared with MCAO + HPX group, the NBS assessment, new vessel density and serum eNOS level decreased at corresponding time points after I/R in MCAO + HPX+ ZnPPIX group (P < 0.05).

CONCLUSION

HPX can promote angiogenesis after cerebral ischemia-reperfusion injury in rats via up-regulating HO-1.

Improved apple latent spherical virus-induced gene silencing in multiple soybean genotypes through direct inoculation of agro-infiltrated Nicotiana benthamiana extract

BACKGROUND

Virus induced gene silencing (VIGS) is a powerful genomics tool for interrogating the function of plant genes. Unfortunately, VIGS vectors often produce disease symptoms that interfere with the silencing phenotypes of target genes, or are frequently ineffective in certain plant genotypes or tissue types. This is especially true in crop plants like soybean [Glycine max (L.) Merr]. To address these shortcomings, we modified the inoculation procedure of a VIGS vector based on Apple latent spherical virus (ALSV). The efficacy of this new procedure was assessed in 19 soybean genotypes using a soybean Phytoene desaturase (GmPDS1) gene as the VIGS target. Silencing of GmPDS1 was easily scored as photo-bleached leaves and/or stems.

RESULTS

In this report, the ALSV VIGS vector was modified by mobilizing ALSV cDNAs into a binary vector compatible with Agrobacterium tumefaciens-mediated delivery, so that VIGS-triggering ALSV variants could be propagated in agro-infiltrated Nicotiana benthamiana leaves. Homogenate of these N. benthamiana leaves was then applied directly onto the unifoliate of young soybean seedlings to initiate systemic gene silencing. This rapid inoculation method bypassed the need for a particle bombardment apparatus. Among the 19 soybean genotypes evaluated with this new method, photo-bleaching indicative of GmPDS1 silencing was observed in nine, with two exhibiting photo-bleaching in 100% of the inoculated individuals. ALSV RNA was detected in pods, embryos, stems, leaves, and roots in symptomatic plants of four genotypes.

CONCLUSIONS

This modified protocol allowed for inoculation of soybean plants via simple mechanical rubbing with the homogenate of N. benthamiana leaves agro-infiltrated with ALSV VIGS constructs. More importantly, inoculated plants showed no apparent virus disease symptoms which could otherwise interfere with VIGS phenotypes. This streamlined procedure expanded this functional genomics tool to nine soybean genotypes.

[Effect of combination therapy with propofol and hydrogen-rich saline on organ damage and cytokines in a murine model of sepsis]

OBJECTIVE

To investigate the effect of combining propofol with hydrogen on organ damage and inflammation of sepsis in cecal ligation and puncture (CLP) mice model.

METHODS

One hundred and forty male C57BL/6 mice were randomly divided into groups (n = 28): sham group, CLP group, propofol group, H₂ group, and propofol and H₂ group. The sepsis was induced by CLP operation. Mice in sham group did the same operation with ligation and puncture. The mice of propofol group and propofol and H₂ group were given 50 mg/kg propofol through tail vein at 1 hour and 6 hours after CLP and the mice of H2 group and propofol and H₂ group were given 5 mL/kg H₂-rich saline i.p. at 1 hour and 6 hours after CLP. The survival rates were observed during 7 days in twenty mice of each group. Inferior vena cava blood and part lung, liver and kidney tissue were collected for detection of the concentration of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and high mobility group box 1 (HMGB1) at 24 hours after CLP in the 40 animals left (each n = 8). Then, the rest tissue of lung, liver and kidney tissue were harvested to test histopathology and histological score.

RESULTS

The 1, 2, 3, 5, 7 days survival rate of septic mice were 80%, 40%, 20%, 10%, and 0%, respectively. The survival rate of animals increased significantly after propofol or hydrogen-rich treatment, and the combined treatment can further increase survival rate to 90%, 75%, 60%, 55%, and 55%, respectively. Compared with the sham group, inflammatory factors were significantly increased in blood and organ tissues, cell degeneration, necrosis, congestion and inflammatory cell infiltration in lung, liver and kidney, and tissues histological scores were significantly increased. The levels of inflammatory factors were reduced in blood and tissues, cell degeneration, necrosis, congestion and inflammatory cell infiltration were alleviated in lung, liver and kidney, and tissues histological scores were decreased after propofol or hydrogen-rich treatment compared with CLP group; these indicators were further improved in propofol and H₂ group compared with propofol group or H2 group [2, 3, 5, 7-day survival rate: 75% vs. 60%, 65%; 60% vs. 50%, 50%; 55% vs. 45%, 40%; 55% vs. 40%, 40%; blood TNF-α (ng/L): 367±74 vs. 612±132, 588±117; blood IL-1β (ng/L): 321±68 vs. 502±95, 476±86; blood HMGB1 (μg/L): 4.6±0.9 vs. 7.0±1.4, 6.8±1.3; lung TNF-α (ng/g): 307±70 vs. 512±132, 488±102; lung IL-1β (ng/g): 367±77 vs. 571±108, 466±89; lung HMGB1 (μg/g): 5.1±1.0 vs. 7.8±1.7, 7.1±1.5; liver TNF-α (ng/g): 247±57 vs. 431±112, 389±87; liver IL-1β (ng/g): 267±58 vs. 417±85, 399±76; liver HMGB1 (μg/g): 4.2±1.1 vs. 7.1±1.6, 6.6±1.2; kidney TNF-α (ng/g): 257±41 vs. 480±89, 448±82; kidney IL-1β (ng/g): 258±39 vs. 409±68, 411±66; kidney HMGB1 (μg/g): 3.9±0.7 vs. 6.8±1.2, 5.7±1.0; histological scores: lung: 1.22±0.28 vs. 2.61±0.49, 2.58±0.44; liver: 1.38±0.32 vs. 2.76±0.51, 2.62±0.46; kidney: 1.19±0.25 vs. 2.43±0.41, 2.36±0.40; all P < 0.05].

CONCLUSIONS

Both propofol and H² can improve the survival rate of sepsis, reduce tissue damage and the release of cytokines, and combined application of the two treatment was better.

[Hydrogen-rich saline attenuates hyperalgesia and reduces cytokines in rats with post-herpetic neuralgia via activating autophagy]

OBJECTIVE

To investigate the role of autophagy in hydrogen-rich saline attenuating post-herpetic neuralgia( PHN) in rats.

METHODS

A total of 100 male SD rats were randomly divided into the five groups( n = 20) : control group,PHN group,PHN group treated with hydrogen-rich saline( PHN-H2group),PHN group treated with hydrogen-rich saline and3-MA( PHN-H2-3-MA group),PHN group treated with hydrogen-rich saline and rapamycin( PHN-H2-Rap group). PHN models were established by varicella-zoster virus( VZV) inoculation. After modeling,15 mg / kg 3-MA or 10 mg / kg rapamycin were intraperitoneally injected in corresponding rats with PHN once two days for 3 times. Hydrogen-rich saline( 10 m L / kg)was injected intraperitoneally twice a day for 7 consecutive days in PHN-H2 group,PHN-H2-3-MA group and PHN-H2-Rap group after VZV injection. The paw withdrawal thresholds( PWT) of 50 rats were detected at 3,7,14 and 21 days after modeling. Spinal cord enlargements of the other 50 rats were collected to examine tumor necrosis factor α( TNF-α),interleukine 1β( IL-1β) and IL-6 by ELISA and autophagy protein microtubule-associated protein 1 light chain 3( LC3),beclin 1and P62 by Western blotting.

RESULTS

Compared with the control group,the rats in the PHN group presented with decreased PWT,increased levels of TNF-α,IL-1β,IL-6,LC3Ⅱ and beclin 1,and down-regulated P62 expression. Compared with PHN group,the rats in the PHN-H2 group and PHN-H2-Rap group showed increased PWT,decreased levels of TNF-α,IL-1β and IL-6,further up-regulated expressions of LC3 and beclin 1 as wel as P62 expression. Compared with PHN-H2 group,the rats in the PHN-H2-3-MA group had reduced PWT,elevated expressions of TNF-α,IL-1β and IL-6,suppressed expressions of LC3 and beclin 1,and enhanced p62 expression.

CONCLUSION

Hydrogen-rich saline attenuated PWT and inhibited the release of cytokines TNF-α,IL-1β,IL-6 in rats with PHN via activating autophagy.

Trithiocarbonates as intrinsic photoredox catalysts and RAFT agents for oxygen tolerant controlled radical polymerization

In this study, we reported on the discovery that trithiocarbonates (RAFT agents) can act as intrinsic photocatalyst to significantly reduce the oxygen level in a controlled radical polymerization under visible light irridation.

H2 Treatment Attenuated Pain Behavior and Cytokine Release Through the HO-1/CO Pathway in a Rat Model of Neuropathic Pain

Neuropathic pain (NP) is characterized by persistent pain, tactile allodynia, or hyperalgesia. Peripheral nerve injury contributes to rapid progress of inflammatory response and simultaneously generates neuropathic pain. Hydrogen (H2) has anti-inflammation, anti-apoptosis, and anti-oxidative stress effects. Therefore, we hypothesized that H2 treatment could alleviate allodynic and hyperalgesic behaviors and the release of inflammatory factors in rats with neuropathic pain. Peripheral neuropathic pain was established by chronic constriction injury of sciatic nerve in rats. H2 was given twice through intraperitoneal injection at a daily dose of 10 mL/kg during days 1-7 after the operation. Hyperalgesia and allodynia were tested, pro-inflammatory factors of dorsal root ganglia (DRG) and the spinal cord were measured by enzyme-linked immunosorbent assay (ELISA) during days 1-14 after the operation, and heme oxygenase (HO)-1 messenger RNA (mRNA) and protein expression and activities were measured at day 14 after sciatic nerve injury in rats. After Sn (IV) protoporphyrin IX dihydrochloride (SnPP)-IX, hemin, and carbon monoxide-releasing molecule (CORM)-2 had been given for chronic constriction injury (CCI) in rats, the above indicators were assessed. We found that H2 clearly inhibited hyperalgesia and allodynia in neuropathic pain and also attenuated the pro-inflammatory cytokines TNF-α, IL-1β, and high-mobility group box (HMGB) 1. H2 improved HO-1 mRNA and protein expression and activities in the process of pain. SnPP-IX reversed the inhibitory effect of H2 on hyperalgesia and allodynia and on pro-inflammatory cytokines in DRG and the spinal cord. The antinociceptive and anti-inflammatory effects of H2 were involved in the activation of HO-1/CO signaling during neuropathic pain in rats.

[Role of Nrf2 in the protective effects of hydrogen against cerebral dysfunction in septic mice]

OBJECTIVE

To investigate the role of nuclear factor erythroid 2-related factor 2 (Nrf2) in the protective effects of hydrogen against cerebral dysfunction in a mouse model of sepsis.

METHODS

Male ICR mice were randomly divided into sham operation group, hydrogen control group, sepsis group and hydrogen treatment group, with 20 in each group. Sepsis model was reproduced by cecal ligation and puncture (CLP). 2% hydrogen inhalation was given for 1 hour at 1 hour and 6 hours after operation in hydrogen treatment group. The brain tissues were obtained at 24 hours after operation. The histopathologic changes and neuron apoptosis in the hippocampus were observed under the microscope. The expressions of nucleus and total Nrf2 in hippocampus were detected by Western Blot. The activities of superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and 8-iso-prostaglandin F2α (8-iso-PGF2α) in hippocampus were also detected. The changes of learning and memory abilities were observed by Morris water maze test at day 4 to 9 after operation.

RESULTS

Compared with the sham operation and hydrogen control groups, in the sepsis group, the number of normal pyramidal neurons in the hippocampal CA1 region was markedly reduced, the apoptotic index was marked increased, the expressions of nucleus and total Nrf2 were partly increased, the activities of SOD and CAT in the hippocampus were significantly decreased, and the levels of MDA and 8-iso-PGF2α were markedly increased, the escape latency at day 4 to 8 after operation was significantly extended, and there was no difference in swimming speed, the percentage of time in the target quadrant and the times of the platform crossing were significantly decreased on probe day. Compared with the sepsis group, in the hydrogen treatment group, the number of normal pyramidal neurons in the hippocampal CA1 region was markedly increased (67.33 ± 6.89 vs. 42.33 ± 6.02, P<0.01), the apoptotic index was dramatically reduced [(30.00 ± 4.77)% vs. (80.50 ± 6.99)%, P<0.01], the expressions of nucleus and total Nrf2 were significantly increased [nucleus Nrf2 (A value): 5.07 ± 0.35 vs. 3.04 ± 0.34, total Nrf2 (A value): 4.24 ± 0.58 vs. 2.91 ± 0.37, both P<0.01], the activities of SOD and CAT in the hippocampus were significantly increased [SOD (U/mg): 120.96 ± 13.44 vs. 81.16 ± 12.28, CAT (U/mg): 9.11 ± 1.28 vs. 5.64 ± 1.88, both P<0.01], and the levels of MDA and 8-iso-PGF2α were markedly reduced [MDA (nmol/mg): 16.12 ± 1.49 vs. 27.64 ± 1.87, 8-iso-PGF2α (pg/mg): 183.43 ± 13.07 vs. 864.07 ± 49.92, both P<0.01], the escape latency at day 5 to 8 after operation was significantly shortened, and there was no difference in swimming speed, the percentage of time in the target quadrant [(37.06 ± 1.16)% vs. (24.42 ± 1.82)%, P<0.01] and the times of the platform crossing (7.13 ± 0.98 vs. 4.88 ± 0.99, P<0.01) were significantly increased on probe day. There was no statistical difference in above indexes between sham operation group and hydrogen control group.

CONCLUSIONS

Hydrogen inhalation can ameliorate pathological injury in brain and impairment of learning and memory abilities of septic mice, which may be associated with the up-regulation of Nrf2, the increase of antioxidant enzymes activities and the decrease of oxidative products.