NLRP3-GABA signaling pathway contributes to the pathogenesis of impulsive-like behaviors and cognitive deficits in aged mice.

BACKGROUND: Perioperative neurocognitive disorders (PND), such as delirium and cognitive impairment, are commonly encountered complications in aged patients. The inhibitory neurotransmitter γ-aminobutyric acid (GABA) is aberrantly synthesized from reactive astrocytes following inflammatory stimulation and is implicated in the pathophysiology of neurodegenerative diseases. Additionally, the activation of NOD-like receptor protein 3 (NLRP3) inflammasome is involved in PND. Herein, we aimed to investigate whether the NLRP3-GABA signaling pathway contributes to the pathogenesis of aging mice's PND. METHODS: 24-month-old C57BL/6 and astrocyte-specific NLRP3 knockout male mice were used to establish a PND model via tibial fracture surgery. The monoamine oxidase-B (MAOB) inhibitor selegiline (1 mg/kg) was intraperitoneally administered once a day for 7 days after the surgery. PND, including impulsive-like behaviors and cognitive impairment, was evaluated by open field test, elevated plus maze, and fear conditioning. Thereafter, pathological changes of neurodegeneration were explored by western blot and immunofluorescence assays. RESULTS: Selegiline administration significantly ameliorated TF-induced impulsive-like behaviors and reduced excessive GABA production in reactive hippocampal astrocytes. Moreover, astrocyte-specific NLRP3 knockout mice reversed TF-induced impulsive-like and cognitive impairment behaviors, decreased GABA levels in reactive astrocytes, ameliorated NLRP3-associated inflammatory responses during the early stage, and restored neuronal degeneration in the hippocampus. CONCLUSIONS: Our findings suggest that anesthesia and surgical procedures trigger neuroinflammation and cognitive deficits, which may be due to NLRP3-GABA activation in the hippocampus of aged mice.

High-grade pivot-shift phenomenon after anterior cruciate ligament injury is associated with asymmetry of lateral and medial compartment anterior tibial translation and lateral meniscus posterior horn tears.

PURPOSE: To investigate whether the high-grade pivot-shift phenomenon is associated with asymmetry of the lateral and medial compartment anterior tibial translation (L-ATT and M-ATT) and lateral meniscus posterior horn (LMPH) tears in anterior cruciate ligament (ACL) injuries. METHODS: A retrospective analysis was performed on 192 consecutive patients who had complete ACL injuries between January 2019 and December 2020. Among these, 156 met the inclusion criteria. L-ATT and M-ATT were measured using preoperative weight-bearing magnetic resonance imaging (MRI), and the differences between L-ATT and M-ATT were calculated. Thirty-five patients who demonstrated excessive differences in L-ATT and M-ATT (> 6.0 mm) were regarded as asymmetric (study group), and 36 patients with minimal or no differences in L-ATT and M-ATT (< 3.0 mm) were allocated to the control group. Demographic data, grade of the pivot-shift test, integrality of LMPH, and medial meniscus posterior horn (MMPH) were compared between the groups. Moreover, predictors of high-grade pivot-shift phenomenon, including asymmetry of L-ATT and M-ATT, integrity of LMPH and MMPH, time from injury to surgery, sex, age, and body mass index (BMI) were assessed using multivariable logistic regression analysis. RESULTS: The difference between L-ATT and M-ATT in the study group was significantly higher than that in the control group (mean ± SD: 8.4 ± 2.1 mm vs. 1.5 ± 1.0 mm, P < 0.001). A higher proportion of patients with high-grade pivot-shift phenomenon (2 + and 3 +) and LMPH tears were identified in the study group (high-grade pivot-shift phenomenon: 25/35 vs. 13/36, P = 0.003; LMPH tears: 18/35 vs. 5/36, P = 0.001). Additionally, asymmetry of L-ATT, M-ATT (odds ratio 5.8; 95% CI 1.7-19.8; P = 0.005), and LMPH tears (odds ratio 3.8; 95% CI 1.3-11.6; P = 0.018) were found to be good predictors of the high-grade pivot-shift phenomenon after ACL injury, whereas MMPH tears, time from injury to surgery, sex, age, and BMI were not. CONCLUSION: In patients with ACL injury, the high-grade pivot-shift phenomenon is associated with asymmetry between L-ATT and M-ATT, and LMPH tears. LEVEL OF EVIDENCE: III.

CORM-3 exerts a neuroprotective effect in a rodent model of traumatic brain injury via the bidirectional gut-brain interactions.

OBJECTIVE: Traumatic brain injury (TBI) induced the gastrointestinal inflammation that is associated with TBI-related morbidity and mortality. Carbon monoxide-releasing molecule (CORM)-3 is a water-soluble exogenous carbon monoxide that exerts protective effects against inflammation-induced pyroptosis. We investigated the gastrointestinal inflammation in a rodent model of traumatic brain injury (TBI) with subsequent hemorrhagic shock and resuscitation (HSR), as well as effects of CORM-3 using an intestinal injection on both gut and brain. METHODS: Following exposure to TBI plus HSR, rats were administrated with CORM-3 (8 mg/kg) through an intestinal injection after resuscitation immediately. The pathological changes and pyroptosis in the gut were measured at 24 h and 30 day post-trauma. We also assessed the intestinal and cortical CO content, as well as IL-1ß and IL-18 levels in the serum within 48 h after trauma. We then explored pathological changes in the ventromedial prefrontal cortex (vmPFC) and neurological behavior deficits on 30 day post-trauma. RESULTS: After TBI + HSR exposure, CORM-3-treated rats presented significantly decreased pyroptosis, more CO content in the jejunum, and lower IL-1ß, IL-18 levels in the serum at 24 h after trauma. Moreover, the rats treated with CORM-3 exerted ameliorated jejunal and vmPFC injury, enhanced learning/memory ability and exploratory activity, improved anxiety-like behaviors than the TBI + HSR-treated rats on 30 day post-trauma. CONCLUSION: These experimental data demonstrated and bidirectional gut-brain interactions after TBI, anti-inflammatory effects of CORM-3, which may improve late outcomes after brain injury.

Carbon Monoxide-Releasing Molecule-3 Alleviates Kupffer Cell Pyroptosis Induced by Hemorrhagic Shock and Resuscitation via sGC-cGMP Signal Pathway.

Following hepatic ischemia-reperfusion injury, Kupffer cells could be activated by inflammatory factors released from damaged hepatocytes. Carbon monoxide (CO)-releasing molecule (CORM)-3, a water-soluble transition metal carbonyl, exhibits excellent anti-inflammatory and anti-pyroptosis properties. We investigated whether CORM-3 attenuated hemorrhagic shock and resuscitation (HSR)-induced pyroptosis of Kupffer cells through the soluble guanylate-cyclase (sGC)-cyclic guanosine monophosphate (cGMP) signal pathway. NS2028 (10 mg/kg), a blocker of sGC, was administrated at the onset of hemorrhage, but CORM-3 (4 mg/kg) was infused after resuscitation via femoral vein. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels, tumor necrosis Factor-α (TNF-α), and interleukin-1ß (IL-1ß) were measured at 3, 6, 12, and 24 h after HSR, respectively. Six hours post-HSR, liver injury, pyroptosis of Kupffer cells, and expressions in total caspase-1, cleaved caspase-1, gasdermin D (GSDMD) N-terminal fragment, IL-1ß, and IL-18 were measured by hematoxylin-eosin (H&E), immunofluorescence and western blot assays, respectively (Fig. 1). The rats exposed to HSR exhibited significant upregulated levels of serum ALT, AST, TNF-α, and IL-1ß, elevated liver injury score, increased pyroptosis of Kupffer cells, and accumulated expressions of pyroptosis-associated protein including cleaved caspase-1, GSDMD N-terminal fragment, IL-1ß, and IL-18 than sham-treated rats. However, CORM-3 administration markedly reduced liver injury and pyroptosis of Kupffer cells, whereas these protective effects could be partially blocked by NS2028. CORM-3 can mitigate pyroptosis of Kupffer cells in a blood loss and re-infusion model of rats via sGC-cGMP signal pathway.

Carbon Monoxide-Releasing Molecule-3 Ameliorates Acute Lung Injury in a Model of Hemorrhagic Shock and Resuscitation: Roles of p38MAPK Signaling Pathway.

OBJECTIVE: It was reported that carbon monoxide-releasing molecule-3 (CORM-3) administration immediately after hemorrhagic shock and resuscitation (HSR) ameliorates the HSR-induced acute lung injury (ALI); however, the specific mechanism of the protective effects against HSR-induced ALI remains unclear. METHODS: To induce hemorrhagic shock, rats were bled to a mean arterial blood pressure of 30 mm Hg for 45 min and then resuscitated with shed blood via the left vein. CORM-3 (4 mg/kg or 8 mg/kg) was respectively administrated after HSR. Twelve  hours post-HSR, lung injury was assessed by wet/dry (W/D) ratio, hematoxylin-eosin staining staining, and lung ultrasound; the apoptotic and pyroptotic macrophages were measured by immunofluorescence staining; and the expression of phosphorylated p38 mitogen activated protein kinase (p-p38MAPK) and total p38MAPK was measured by western blotting. SB203580 (5 mg/kg), a special inhibitor of p-p38MAPK, was administrated by abdominal cavity to assess the roles of p38MAPK in HSR-induced ALI. RESULTS: Increased B-line score, lung injury score, and W/D ratio indicated the fact of ALI after HSR. Twelve hours post-HSR, CORM-3 administration significantly decreased the B-line score, lung injury score, W/D ratio, apoptotic and pyroptotic macrophages, and the expressions of p-p38MAPK. Further, SB203580 not only reduced HSR-induced ALI, but also enhanced the protective effects of CORM-3 against ALI. CONCLUSION: We identified the protective effects of CORM-3 against HSR-induced ALI. The mechanism might be related to the inhibition of p38MAPK signaling pathway in lung macrophages.

CORM-3 ameliorates neurodegeneration in the amygdala and improves depression- and anxiety-like behavior in a rat model of combined traumatic brain injury and hemorrhagic shock.

OBJECTIVE: Emotional disturbances characterized by depression and anxiety among survivors of traumatic brain injury (TBI) impact the quality of life severely. Currently, there is a lack of effective drug treatment for neurodegeneration induced by TBI, mainly due to failed efficacy of compounds such as corticosteroids, calcium channel blockers, and excitatory amino acid inhibitors. Thus, we sought to continue with our investigation on CORM-3, a water-soluble exogenous carbon monoxide-releasing molecule with excellent anti-inflammatory actions employed in a previous study using a rat model of combined TBI with hemorrhage shock and resuscitation (HSR). METHODS: Rats were administrated with CORM-3 after induction of TBI and HSR and examined depressive and anxiety-like behaviors, along with cerebral function employing functional magnetic resonance imaging (MRI) 30-days post-trauma. Also, the following variables were measured: 1) neuronal pyroptosis and apoptosis 24 h post-trauma, 2) the roles of PKG-ERK1/2 signaling pathways with the use of the protein kinase G (PKG) specific inhibitor, KT5823. RESULTS: CORM-3-treated rats displayed significant ameliorated depression- and anxiety-like behaviors, improved cerebral blood flow, and fractional anisotropy (FA), showed less neuronal pyroptosis and apoptosis in the amygdala, and upregulated the phosphorylation of Vasodilator-stimulated phosphoprotein (VASP) and ERK1/2. However, CORM-3 neuroprotective effects against trauma were only partially reversed by KT5823. CONCLUSION: CORM-3 ameliorated the emotional deficits and neuronal death induced in the amygdala post-TBI and HSR rat model, and PKG-ERK1/2 signaling might be implicated in the underlying mechanism.

CORM-3 improves emotional changes induced by hemorrhagic shock via the inhibition of pyroptosis in the amygdala.

Hemorrhagic shock and resuscitation (HSR) may lead to long-term neurological dysfunction, such as depression and anxiety. Carbon monoxide (CO) has emerged as an excellent neuroprotective agent against caspase-1-associated pyroptosis, following HSR. We evaluated the effects and determined the mechanism through which CO protects against emotional changes in a model of HSR, in rats. We subjected rats to treatments with an exogenous, CO-releasing compound (CORM-3, 4 mg/kg), in vivo, after HSR. We measured sucrose preference and performed tail suspension and open field tests 7 days after HSR, assessed brain magnetic resonance imaging 12 h after HSR and evaluated pyroptosis, and neuronal and astrocyte death in the amygdala 12 h post-HSR. We also measured changes in behavior and pathology, following an injection of recombinant murine interleukin (IL)-18 into the amygdala. HSR-treated rats displayed increased depression-like and anxiety-like behaviors, increased amygdalar injury, as indicated by T2-weighted magnetic resonance imaging (MRI) and cerebral blood flow with arterial spin labeling (CBFASL), associated with both neuronal and astrocytic death and pyroptosis, and upregulated IL-18 expression was observed in astrocytes. CORM-3 administration after resuscitation, via a femoral vein injection, provided neuroprotection against HSR, and this neuroprotective effect could be partially reversed by the injection of recombinant murine IL-18 into the amygdala. Therefore, CORM-3 alleviated HSR-induced neuronal pyroptosis and emotional changes, through the downregulation of IL-18 in astrocytes.

Exogenous carbon monoxide protects against mitochondrial DNA­induced hippocampal pyroptosis in a model of hemorrhagic shock and resuscitation.

Carbon monoxide­releasing molecule­3 (CORM­3), which is an exogenous carbon monoxide (CO) compound, slowly releases CO under physiological conditions; this exerts neuroprotective effects against incomplete ischemia/reperfusion injury. The objective of the present study was to investigate whether the administration of CORM­3 protects against nucleotide­binding oligomerization domain­like receptor pyrin domain­3 (NLRP3) inflammasome formation and neuronal pyroptosis in the hippocampus following hemorrhagic shock and resuscitation (HSR). To establish this, an HSR model was created. Hemorrhagic shock was induced in adult male Sprague­Dawley rats under sevoflurane anesthesia by bleeding using a heparinized syringe to maintain a mean arterial pressure of 30±5 mmHg for 60 min. Resuscitation was performed by reperfusion of the blood and, if necessary, administering sterile saline to achieve the baseline arterial pressure. Following resuscitation, CORM­3 (4 mg/kg) was injected via the femoral vein. Neuronal pyroptosis in the hippocampus, mitochondrial morphology, mitochondrial DNA (mtDNA), brain magnetic resonance imaging, expression levels of NLRP3 and the interaction of pro­caspase­1 and apoptosis­associated speck­like protein containing a CARD domain (ASC) were examined 12 h after HSR; locomotor activity was assessed 7 days after HSR. Compared with HSR­treated rats, CORM­3 administration resulted in a lower level of neuronal pyroptosis in the hippocampus, improved mitochondrial morphology, a lower mtDNA level, steadier levels of metabolites, decreased expression levels of NLRP3 and pro­caspase­1 interacting with ASC and enhanced locomotor activity. In conclusion, treatment with CORM­3 ameliorated impairments of locomotor and exploratory activities in a rat model of HSR. The mechanism may be associated with the inhibition of mitochondrial DNA­induced pyroptosis via improvements in cell metabolism.

Low-Dose, Early Fresh Frozen Plasma Transfusion Therapy After Severe Trauma Brain Injury: A Clinical, Prospective, Randomized, Controlled Study.

BACKGROUND: To investigate role of Low-dose, Early Fresh frozen plasma Transfusion (LEFT) therapy in preventing perioperative coagulopathy and improving long-term outcome after severe traumatic brain injury (TBI). METHODS: A prospective, single-center, parallel-group, randomized trial was designed. Patients with severe TBI were eligible. We used a computer-generated randomization list and closed opaque envelops to randomly allocate patients to treatment with fresh frozen plasma (5 mL/kg body weight; LEFT group) or normal saline (5 mL/kg body weight; NO LEFT group) after admission in the operating room. RESULTS: Between January 1, 2018, and November 31, 2018, 63 patients were included and randomly allocated to LEFT (n = 28) and NO LEFT (n = 35) groups. The final interim analysis included 20 patients in the LEFT group and 32 patients in the NO LEFT group. The study was terminated early for futility and safety reasons because a high proportion of patients (7 of 20; 35.0%) in the LEFT group developed new delayed traumatic intracranial hematoma after surgery compared with the NO LEFT group (3 of 32; 9.4%) (relative risk, 5.205; 95% confidence interval, 1.159-23.384; P = 0.023). Demographic characteristics and indexes of severity of brain injury were similar at baseline. CONCLUSIONS: LEFT therapy was associated with a higher incidence of delayed traumatic intracranial hematoma than normal fresh frozen plasma transfusion in patients with severe TBI. A restricted fresh frozen plasma transfusion protocol, in the right clinical setting, may be more appropriate in patients with TBIs.

Carbon monoxide-releasing molecule-3 protects against cortical pyroptosis induced by hemorrhagic shock and resuscitation via mitochondrial regulation.

OBJECTIVE: Carbon monoxide (CO) releasing molecule (CORM)-3, a water-soluble CORM, has protective effects against inflammatory and ischemia/reperfusion injury. We determined the effect of CORM-3 against neuronal pyroptosis in a model of hemorrhagic shock and resuscitation (HSR) in rats via mitochondrial regulation. METHODS: Rats were treated with CORM-3 (4 mg/kg) in vitro after HSR. We measured cortical CO content 3-24 h after HSR; assessed neuronal pyroptosis, mitochondrial morphology, ROS production, and mitochondrial membrane potential at 12 h after HSR; and evaluated brain magnetic resonance imaging at 24 h after HSR and learning ability 30 days after HSR. We also measured soluble guanylate-cyclase (sGC)-cyclic guanosine monophosphate (cGMP) signaling pathway activity using a blocker of sGC, NS2028, and 125I-cGMP assay. RESULTS: Among rats that underwent HSR, CORM-3-treated rats had more CO in the cortical tissue than sham- and iCORM-3-treated rats. CORM-3-treated rats had significantly less neuronal pyroptosis in the cortical tissue; higher sGC activity and cGMP content; lower ROS production; better mitochondrial morphology, function, and membrane potential; and enhanced learning/memory ability than HSR-treated rats. However, these neuroprotective effects of CORM-3 were partially inhibited by NS2028. CONCLUSION: CORM-3 may alleviate neuronal pyroptosis and improve neurological recovery in HSR through mitochondrial regulation mediated by the sGC-cGMP pathway. Thus, CO administration could be a promising therapeutic strategy for hemorrhagic shock.

[Quantitative estimation of evapotranspiration from Tahe forest ecosystem, Northeast China].

Evapotranspiration (ET) is an important parameter of agriculture, meteorology and hydrology research, and also an important part of the global hydrological cycle. This paper applied the improved DHSVM distributed hydrological model to estimate daily ET of Tahe area in 2007 using leaf area index and other surface data extracted TM remote sensing data, and slope, aspect and other topographic indices obtained by using the digital elevation model. The relationship between daily ET and daily watershed outlet flow was built by the BP neural network, and a water balance equation was established for the studied watershed, together to test the accuracy of the estimation. The results showed that the model could be applied in the study area. The annual total ET of Tahe watershed was 234.01 mm. ET had a significant seasonal variation. The ET had the highest value in summer and the average daily ET value was 1.56 mm. The average daily ET in autumn and spring were 0.30, 0.29 mm, respectively, and winter had the lowest ET value. Land cover type had a great effect on ET value, and the broadleaf forest had a higher ET ability than the mixed forest, followed by the needle leaf forest.

[Simulation of leaf inclination angle distribution of main tree species in Daxing'an Mountains of China based on the Campbell ellipsoid distribution function].

Leaf inclination angle distribution directly decides the amount of radiation interception by vegetation canopy, and also, decides the size and direction of the incident radiation, being the key parameter in quantitative remote sensing. This paper simulated the leaf inclination angle distribution of the main tree species in Daxing'an Mountains forest region based on the Campbell ellipsoid distribution model and iterative method, and quantitatively analyzed the fitting results of canopy with and without leaf stratification as well as the effects of tree age group on the leaf inclination angle distribution. For the test 6 main tree species, the leaf inclination angle distribution was in planophile shape, and the mean leaf inclination angle was smaller for coniferous tree than for broadleaved tree. Whether with or without stratify, the fitting result and the measured result were basically identical. For Betula platyphylla and Larix gmelinii, the correlation coefficient between the simulated and measured values was 0.8268 and 0.8192, and the root mean square error was 3.7% and 4.3% respectively, indicating that the Campbell model was reliable applied for forest canopy. Considering the effects of tree age group, though the leaf inclination angle distribution trend with leaf stratification had no correlation with age group, the mean leaf inclination angle of young L. gmelinii was relatively smaller than that mature one, suggesting that age group had positive effects on the numerical design of leaf inclination angle distribution and negative effects on the numerical design of extinction coefficient.