Corrigendum: Interferon-induced transmembrane protein 3 in the hippocampus: a potential novel target for the therapeutic effects of recombinant human brain natriuretic peptide on sepsis-associated encephalopathy.

[This corrects the article DOI: 10.3389/fnmol.2023.1182005.].

Interferon-induced transmembrane protein 3 in the hippocampus: a potential novel target for the therapeutic effects of recombinant human brain natriuretic peptide on sepsis-associated encephalopathy.

Objective: This study aims to explore whether interferon-induced transmembrane protein 3 (IFITM3) is involved in recombinant human brain natriuretic peptide (rhBNP)-mediated effects on sepsis-induced cognitive dysfunction in mice. Methods: The cellular localization and expression level of IFITM3 in the hippocampus were detected. The IFITM3 overexpression was achieved using an intracranial stereotactic system to inject an adeno-associated virus into the hippocampal CA1 region of mice. Field experiments, an elevated plus maze, and conditioned fear memory tests assessed the cognitive impairment in rhBNP-treated septic mice. Finally, in the hippocampus of septic mice, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining and Immunoblot were used to detect changes in the protein expression of cleaved Caspase-8 and cleaved Caspase-3 in apoptosis-related pathways, and toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) p65 in inflammatory pathways. Results: Fourteen days after cecal ligation and puncture (CLP) surgery, IFITM3 localized in the plasma membrane and cytoplasm of the astrocytes in the hippocampus of septic mice, partially attached to the perivascular and neuronal surfaces, but not expressed in the microglia. The expression of IFITM3 was increased in the astrocytes and neurons in the hippocampus of septic mice, which was selectively inhibited by the administration of rhBNP. Overexpression of IFITM3 resulted in elevated anxiety levels and long-term learning and memory dysfunction, completely abolished the therapeutic effect of rhBNP on cognitive impairment in septic mice, and induced an increase in the number of neuronal apoptosis in the hippocampal CA1 region. The expression levels of cleaved Caspase-3 and cleaved Caspase-8 proteins were significantly increased in the hippocampus, but the expression levels of TLR4 and NF-κB p65 were not increased. Conclusion: The activation of IFITM3 may be a potential new target for treating sepsis-associated encephalopathy (SAE), and it may be one of the key anti-apoptotic mechanisms in rhBNP exerting its therapeutic effect, providing new insight into the clinical treatment of SAE patients.

Therapeutic effects of recombinant human brain natriuretic peptide on sepsis-associated encephalopathy in mice.

There is little information in the sepsis treatment guidelines on the prevention and treatment of cognitive dysfunction after sepsis. This study aimed to explore whether Recombinant human brain natriuretic peptide (rhBNP) has protective effects against sepsis-associated encephalopathy (SAE) in a mouse model. The results showed that 50 µg/kg of rhBNP significantly improved the 14-day survival of cecal ligation and puncture (CLP)-induced septic mice and mitigated cognitive dysfunction and anxiety. Fourteen days after CLP surgery, septic mice showed increased BBB permeability and neuronal apoptosis. rhBNP treatment significantly reduced pathological changes in the brain of CLP mice. Meanwhile, rhBNP therapy also reduced the level of inflammatory cytokines in the hippocampus, possibly via inhibiting the TLR4-NF-κB pathway. These results indicate that rhBNP may be a promising drug for the treatment of SAE.

Combined administration of a sedative dose sevoflurane and 60% oxygen reduces inflammatory responses to sepsis in animals and in human PMBCs.

Our study aims to investigate the effects of the inhalation of subanesthestic doses of sevoflurane combined with oxygen on sepsis. Male Sprague-Dawley rats or Male ICR/Km mice underwent caecal ligation and puncture (CLP) or intraperitoneal injection of lipopolysccharide (LPS) to induce sepsis, while sham rats were used as control. Then, rats were treated with the inhalation of sevoflurane in oxygen; and air or 100% oxygen was used as control. Seven-day survival, lung injury and inflammatory factors were assessed. In this in vitro experiment, we obtained RAW264.7 macrophages and human peripheral blood mononuclear cells (PBMCs) incubated by LPS or plasma from septic patients to explore the NF-κB pathway in the effect of the inhalation of sevoflurane combined with oxygen in sepsis. In this study, we found that the inhalation of 0.5 MAC of sevoflurane in 60% oxygen was the best protocol for protecting against lethality resulting from sepsis and ALI, and there was a time window for these protective effects. We also founded that 0.5 MAC of sevoflurane in 60% oxygen inhibited the nuclear translocation of NF-κB in human PBMCs induced by LPS or plasma from septic patients. The subanesthesia dose sevoflurane in 60% oxygen may reduce sepsis-induced inflammatory responses in animals and in PBMCs, and the inhibition to the activation of the NF-κB pathway may contribute to this protection.

Sub-anesthesia Dose of Isoflurane in 60% Oxygen Reduces Inflammatory Responses in Experimental Sepsis Models.

BACKGROUND: Sepsis is a major cause of mortality in Intensive Care Units. Anesthetic dose isoflurane and 100% oxygen were proved to be beneficial in sepsis; however, their application in septic patients is limited because long-term hyperoxia may induce oxygen toxicity and anesthetic dose isoflurane has potential adverse consequences. This study was scheduled to find the optimal combination of isoflurane and oxygen in protecting experimental sepsis and its mechanisms. METHODS: The effects of combined therapy with isoflurane and oxygen on lung injury and sepsis were determined in animal models of sepsis induced by cecal ligation and puncture (CLP) or intraperitoneal injection of lipopolysaccharide (LPS) or zymosan. Mouse RAW264.7 cells or human peripheral blood mononuclear cells (PBMCs) were treated by LPS to probe mechanisms. The nuclear factor kappa B (NF-κB) signaling molecules were examined by Western blot and cellular immunohistochemistry. RESULTS: The 0.5 minimum alveolar concentration (MAC) isoflurane in 60% oxygen was the best combination of oxygen and isoflurane for reducing mortality in experimental sepsis induced by CLP, intraperitoneal injection of LPS, or zymosan. The 0.5 MAC isoflurane in 60% oxygen inhibited proinflammatory cytokines in peritoneal lavage fluids (tumor necrosis factor-alpha [TNF-ß]: 149.3 vs. 229.7 pg/ml, interleukin [IL]-1ß: 12.5 vs. 20.6 pg/ml, IL-6: 86.1 vs. 116.1 pg/ml, and high-mobility group protein 1 [HMGB1]: 323.7 vs. 449.3 ng/ml; all P< 0.05) and serum (TNF-ß: 302.7 vs. 450.7 pg/ml, IL-1ß: 51.7 vs. 96.7 pg/ml, IL-6: 390.4 vs. 722.5 pg/ml, and HMGB1: 592.2 vs. 985.4 ng/ml; all P< 0.05) in septic animals. In vitro experiments showed that the 0.5 MAC isoflurane in 60% oxygen reduced inflammatory responses in mouse RAW264.7 cells, after LPS stimulation (all P< 0.05). Suppressed activation of NF-κB pathway was also observed in mouse RAW264.7 macrophages and human PBMCs after LPS stimulation or plasma from septic patients. The 0.5 MAC isoflurane in 60% oxygen also prevented the increases of phospho-IKKß/ß, phospho-IκBß, and phospho-p65 expressions in RAW264.7 macrophages after LPS stimulation (all P< 0.05). CONCLUSION: Combined administration of a sedative dose of isoflurane with 60% oxygen improves survival of septic animals through reducing inflammatory responses.

Anesthetic isoflurane posttreatment attenuates experimental lung injury by inhibiting inflammation and apoptosis.

We investigated the effect of 1.4% isoflurane (ISO) on the development of inflammation and apoptosis caused by zymosan (ZY) in mice. We found that ZY-challenged mice exhibited significant body weight loss, markedly high mortality, and significant lung injury characterized by the deterioration of histopathology, histologic scores, and wet-to-dry ratio after ISO treatment. ISO dramatically attenuated ZY-induced lung neutrophil recruitment and inflammation, as evidenced by the reduced levels of total cells, neutrophils, and proinflammatory cytokines (i.e., tumor necrosis factor- α , interleukin- (IL-) 1 ß , IL-6, and macrophage inflammatory protein-2) in bronchoalveolar lavage fluid and of their mRNA expression in lung tissues. ISO also inhibited ZY-induced expression and activation of nuclear factor-kappaB p65 and inducible nitric oxide synthase in pulmonary tissue. ZY administration also resulted in the upregulation of heme oxygenase-1 expression and activity in the lung, which was further enhanced by ISO treatment. Moreover, ISO markedly prevented ZY-induced pulmonary cell apoptosis in mice, as reflected by the decrease in expression of procaspase-8, procaspase-3, cleaved caspase-8, and cleaved caspase-3, as well as in caspase-3 activity and Bcl-2-associated X/B-cell lymphoma 2 ratio. These results indicate that ISO is a potential therapeutic drug for treating ZY-induced lung injury, and further investigations are warranted.

[Effects of hydrogen gas inhalation on serum high mobility group box 1 levels in severe septic mice].

OBJECTIVE: To investigate the effect of hydrogen gas inhalation on survival rate and serum high mobility group box 1 (HMGB1) levels in severe septic mice. METHODS: Severe sepsis was induced by cecal ligation and puncture (CLP) operation in mice.A total of 248 mice were randomly divided into four groups: sham operation group (sham), sham operation with hydrogen gas inhalation group (sham+H2), severe CLP group (severe CLP) and severe CLP with hydrogen gas inhalation group (severe CLP+H2). Hydrogen gas inhalation was given for 1 h at 1st and 6th h after CLP or sham operation, respectively. The survival rates and serum HMGB1 levels of all groups at different time points were measured. RESULT: The 7-d survival rates of severe CLP mice was 0 % (Compared with Sham group, P <0.05), and the serum HMBG1 levels from h2 to h32 after CLP operation were significantly increased in severe CLP mice (Compared with Sham group, P <0.05). Hydrogen gas treatment increased the 7-d survival rate of severe CLP mice to 60 % (Compared with severe sepsis group, P <0.05) and significantly reduced the serum HMGB1 levels at different time points (Compared with severe sepsis group, P <0.05). CONCLUSION: Hydrogen gas inhalation can decrease the serum HMGB1 levels and increase the survival rate of rats with severe sepsis.

CB1 cannabinoid receptor participates in the vascular hyporeactivity resulting from hemorrhagic shock in rats.

BACKGROUND: Vascular hyporeactivity, which occurs in the terminal stage of hemorrhagic shock, is believed to be critical for treating hemorrhagic shock. The present study was designed to examine whether the CB1 cannabinoid receptor (CB1R) was involved in the development of vascular hyporeactivity in rats suffering from hemorrhagic shock. METHODS: Sixteen animals were randomly divided into two groups (n = 8 in each group): sham-operated (Sham) and hemorrhagic shock (HS) groups. Hemorrhagic shock was induced by bleeding. The mean arterial pressure (MAP) was reduced to and stabilized at (25 +/- 5) mmHg for 2 hours. The vascular reactivity was determined by the response of MAP to norepinephrine (NE). In later experiments another twelve animals were used in which the changes of CB1R mRNA and protein in aorta and superior mesenteric artery (SMA) were analyzed by RT-PCR and Western blotting. In addition, we investigated the effects of a CB1R antagonist on the vascular hyporeactivity and survival rates in rats with hemorrhagic shock. Survival rates were analyzed by the Fisher's exact probability test. The MAP response was analyzed by one-way analysis of variance (ANOVA). RESULTS: Vascular hyporeactivity developed in all animals suffering from hemorrhagic shock. The expression of CB1R mRNA and protein in aorta and 2 - 3 branches of the SMA were significantly increased in the HS group after the development of vascular hyporeactivity when compared to those in Sham group. When SR141716A or AM251 was administered, the MAP response to NE was (41.75 +/- 4.08) mmHg or (44.78 +/- 1.80) mmHg respectively, which was higher than that in saline groups with (4.31 +/- 0.36) mmHg (P < 0.01). We also showed an increased 4-hour survival rate in the SR141716A or AM251-treated group with 20% or 30%, but with a statistically significant difference present between the AM251-treated and saline groups (P < 0.05). CONCLUSIONS: CB1R is involved in vascular hyporeactivity resulting from hemorrhagic shock in rats, and CB1R antagonist may be useful in treating patients with traumatic, hemorrhagic shock who need field-rescue or initial treatment.

Severity of sepsis is correlated with the elevation of serum high-mobility group box 1 in rats.

BACKGROUND: Sepsis is a leading cause of death in the intensive care units. The late inflammatory cytokine, high-mobility group box 1 (HMGB1), plays a critical role in sepsis. In the present study, we investigated the association between the serum HMGB1 levels and the severity of organ injury in the lipopolysaccharide-induced sepsis in rats. METHODS: To produce an animal model of sepsis with different degree of organ injury, animals were treated with three different doses of lipopolysaccharide (4, 8 and 16 mg/kg), and the animals in control group were treated with the same volume of the vehicle (saline). The levels of serum HMGB1 were measured at 0, 2, 4, 8, 16, 24, 32 and 48 hours after lipopolysaccharide (LPS) or vehicle injection, meanwhile the biochemical and histopathological indicators for the severity of organ injury were assessed. RESULTS: The level of HMGB1 had a positive, high correlation with the abnormal changes of serum cardiac troponin I, alanine aminotransferase, aspartate aminotransferase, creatinine and blood urea nitrogen, as well as the pathologic scores of heart, lung, liver and kidney. CONCLUSIONS: The level of serum HMGB1 is highly correlated with the severity of sepsis in rats, suggesting that HMGB1 could serve as a valuable adjunct in the diagnosis and management of sepsis.

[Neuroprotective effect of preconditioning with cannabinoid receptor agonist WIN 55, 212 - 2 on focal cerebral ischemia: experiment with rats].

OBJECTIVE: To investigate the neuroprotective effect of preconditioning with cannabinoid (CB) receptor agonist WIN 55, 212 - 2 on focal cerebral ischemia. METHODS: Fifty male SD rats were randomly assigned to 5 equal groups: control group undergoing middle cerebral artery occlusion (MCAO) for 2 h only without any preconditioning; 3 WIN 55, 212 - 2 preconditioning groups (WIN1-3) injected intraperitoneally with WIN 55, 212 - 2 at the doses of 0.3, 1, and 3 mg/kg respectively 24 h before MCAO for 2 h, and DMSO group injected intraperitoneally with dimethyl sulfoxide (DMSO), solvent of WIN 55, 212 - 2 24 h before MCAO for 2 h. 24, 48, and 72 hours after reperfusion the neurological function score (NFS) was evaluated the rats were then decapitated with their brains taken out. Brain infarct volume was evaluated with 2% 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. RESULTS: The NFS values of the rats in WIN 55, 212 - 2 preconditioning groups were all significantly higher than those of the control and DMSO groups (all P < 0.05) while the infarct volumes of the WIN 55, 212 - 2 preconditioning groups were all significantly smaller than those of the control and DMSO groups (all P < 0.05) 24, 48, and 72 h after reperfusion. The infarct volumes of the WIN2 and WIN3 groups were both significantly smaller than that of the WIN1 group (both P < 0.05). However, there was no significant difference in the infarct volume between WIN2 and WIN3 groups (P = 0.928). CONCLUSION: WIN 55, 212 - 2 preconditioning has neuroprotective effect on focal cerebral ischemia with a dose-dependent manner.

[Analysis of full-length molecule of human lipopolysaccharide responsed gene and its expression in four cell lines].

AIM: To clone full-length human lipopolysaccharide responsive gene(hlrp) and predict its function by bioinformatics analysis; to observe full-length hlrp protein and quantify its relative gene expression in four cell lines. METHODS: Total RNA was extracted from LPS-stimulated human embryonic kidney cells HEK293 and the full-length hlrp was obtained by RT-PCR. Function of hlrp was predicted by bioinformatics analysis with Internet and GenBank database. Expression full-length hlrp protein in HEK293, HepG2, HeLa and PDC was observed by laser scanning confocal fluorescence microscope and compared. RESULTS: Full-length hlrp of 2 045 bp was amplified and sequenced. Leucine zipper was found in the hlrp series that may have an important function. hlrp gene have been mapped to a particular chromosome location in Xp22.2. Laser scanning confocal fluorescence microscope showed hlrp protein was expressed in the cell lines (HEK293, HepG2, HeLa and PDC). CONCLUSION: hlrp has been successfully cloned and its function has been predicted. Expression of hlrp has been detected in 4 cell lines. Present result would provide data for the further study of hlrp.

Effect of dopamine and metaraminol on the renal function of patients with septic shock.

BACKGROUND: Vasoactive drugs are often necessary for reversing hypotension in patients with severe infection. The standard for evaluating effects of vasoactive drugs should not only be based on the increase of arterial blood pressure, but also on the blood flow perfusion of internal organs. The effects of dopamine and metaraminol on the renal function of the patients with septic shock were investigated retrospectively in this study. METHODS: Ninety-eight patients with septic shock were divided into three groups according to the highest infusing rate of metaraminol, with the lightest infusing rate of (0.1 - 0.5, 0.6 - 1.0, > 1.0) microgxkg(-1)xmin(-1) in group A, B and C respectively. Urine output, mean arterial blood pressure (MAP), heart rate (HR), urine output, blood urea nitrogen (BUN), creatinine (CRE), urine albumin (U-ALB), urine beta(2)-microglubulin (Ubeta(2)-MG) and Apache III scores were recorded. RESULTS: Before antishock therapy, hypotension, tachycardia and oliguria occurred to all the 98 patients with septic shock and CRE, BUN, U-ALB, Ubeta(2)-MG and Apache III scoring were abnormal in most cases. With the antishock therapy, MAP, HR, urine output, BUN and CRE in all patients returned gradually to normal (P < 0.05 or < 0.01 compared to those before antishock therapy). U-ALB, Ubeta(2)-MG output and Apache III scoring also reverted but remained abnormal (P < 0.01 compared to those before antishock therapy). No statistically significant differences in the changes of these indices with the time existed among the three groups (P > 0.05). CONCLUSION: Dopamine and metaraminol when applied to the patients with septic shock could effectively maintain the circulatory stability and promote restoration of renal function.

[Effect of dopamine combined with norepinephrine on the renal function in patients with septic shock].

OBJECTIVE: To investigate the effects of dopamine and norepinephrine on the renal function in the patients with septic shock. METHODS: Eighty-seven patients with septic shock were divided into three groups (group A, B, C) according to the biggest infusing rate of norepinephrine, with the infusing rate of 0.5 - 0.9, 1.0 - 1.5, 1.6 - 2.0 microg x kg(-1) x min(-1), respectively. Mean arterial blood pressure (MAP), heart rate (HR), urine output, blood urea nitrogen (BUN), creatinine (CRE), urine albumin (U-ALB) and urine beta(2)-microglobulin (Ubeta(2)-MG) as well as APACHE III score in all the patients were detected. RESULTS: Before anti-shock therapy was given, hypotension, tachycardia and oliguria occurred in all the 87 patients, and CRE, BUN, U-ALB, Ubeta(2)-MG and APACHE III score were abnormal in most cases. With the anti-shock therapy, MAP, HR, urine output and BUN, CRE in all patients returned to normal levels gradually, and U-ALB, Ubeta(2)-MG levels and APACHE III score also restored but still remained abnormal. CONCLUSIONS: The first aim of treating septic shock should be restoring the organ blood supply, and based on volume resuscitation, dopamine, noradrenaline and other vasoactive drugs could be combined to maintain circulatory stability.

[Cantharidin regulates intracellular ATP in G1/S-phase renal tubule epithelial cells].

OBJECTIVE: To study the mechanism of cantharidin in protecting F-actin microfilaments from disruption by hypoxic damage by observing the effects of cantharidin on intracellular ATP metabolism in G(1)/S-phase renal tubule epithelial cells (RTECs). METHODS: G1-phase RTECs were divided into cantharidin-treated group, exposed to sodium cyanide (CN) and cantharidin, hypoxic-group with CN exposure and non-treated control group. ATP levels were measured in the 3 groups with high-performance liquid chromatography. RESULTS: The concentration of CN exposure for 1 h, ATP level in the RTECs with cantharidin treatment were significantly higher than that in both hypoxic and non-treated control groups (14.50+/-0.26 mmol/g protein, 4.25+/-0.11 mmol/g protein, 8.58+/-0.13 mmol/g protein, respectively, P<0.01). CONCLUSION: Cantharidin prevents the disruption of the actin cytoskeleton in hypoxic damage by preventing abnormal intracellular ATP metabolism.