Effect of tubastatin A on NLRP3 inflammasome activation in macrophages under hypoxia/reoxygenation conditions.

BACKGROUND: There are currently no effective drugs to mitigate the ischemia/reperfusion injury caused by fluid resuscitation after hemorrhagic shock (HS). The aim of this study was to explore the potential of the histone deacetylase 6 (HDAC6)-specific inhibitor tubastatin A (TubA) to suppress nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation in macrophages under hypoxia/reoxygenation (H/R) conditions. METHODS: The viability of RAW264.7 cells subjected to H/R after treatment with different concentrations of TubA was assessed using a cell-counting kit-8 (CCK8) assay. Briefly, 2.5 µmol/L TubA was used with RAW264.7 cells under H/R condition. RAW264.7 cells were divided into three groups, namely the control, H/R, and TubA groups. The levels of reactive oxygen species (ROS) in the cells were detected using fluorescence microscopy. The protein expression of HDAC6, heat shock protein 90 (Hsp90), inducible nitric oxide synthase (iNOS), NLRP3, gasdermin-D (GSDMD), Caspase-1, GSDMD-N, and Caspase-1 p20 was detected by western blotting. The levels of interleukin-1ß (IL-1ß) and IL-18 in the supernatants were detected using enzyme-linked immunosorbent assay (ELISA). RESULTS: HDAC6, Hsp90, and iNOS expression levels were significantly higher (P<0.01) in the H/R group than in the control group, but lower in the TubA group than in the H/R group (P<0.05). When comparing the H/R group to the control group, ROS levels were significantly higher (P<0.01), but significantly reduced in the TubA group (P<0.05). The H/R group had higher NLRP3, GSDMD, Caspase-1, GSDMD-N, and Caspase-1 p20 expression levels than the control group (P<0.05), however, the TubA group had significantly lower expression levels than the H/R group (P<0.05). IL-1ß and IL-18 levels in the supernatants were significantly higher in the H/R group compared to the control group (P<0.01), but significantly lower in the TubA group compared to the H/R group (P<0.01). CONCLUSION: TubA inhibited the expression of HDAC6, Hsp90, and iNOS in macrophages subjected to H/R. This inhibition led to a decrease in the content of ROS in cells, which subsequently inhibited the activation of the NLRP3 inflammasome and the secretion of IL-1ß and IL-18.

DNALI1 is a prognosis-related biomarker and correlates with immune infiltrates in low grade glioma.

BACKGROUND: Dynein axonemal light intermediate chain 1 (DNALI1) is a component of axonemal dyneins and its role in cancer progression is not known. OBJECTIVE: The influence of DNALI1 expression on the prognosis of low-grade gliomas (LGG) and the possible mechanisms of DNALI1 in promoting the progression of LGG was investigated by applying multiple bioinformatics analyses using datasets from TCGA, GTEx, CPTAC, and CGGA. METHODS: The expression of DNALI1 in different tumor tissues including LGG was investigated. GO functional annotation, KEGG pathway analysis, and GSEA enrichment analysis were performed. The correlation between DNALI1 and prognosis, tumor microenvironment (TME) and immune checkpoints in LGG were assessed. RESULTS: DNALI1 is mainly expressed in malignant cells in the TME of LGG and positively correlated with the development of LGG. DNALI1 expression is negatively correlated with isocitrate dehydrogenase (IDH) mutations and 1p/19q co-deletion. High DNALI1 expression is associated with poor prognosis in LGG. DNALI1 may promote LGG progression through multiple immune-related pathways. The expression of DNALI1 is positively correlated with the infiltration of certain types of immune cells and the expression of some immune checkpoints. CONCLUSIONS: DNALI1 is a potential prognostic marker for LGG, and high expression of DNALI1 may play an important role in maintaining the immunosuppressive microenvironment of LGG.

Traumatic inflammatory response: pathophysiological role and clinical value of cytokines.

Severe trauma is an intractable problem in healthcare. Patients have a widespread immune system response that is complex and vital to survival. Excessive inflammatory response is the main cause of poor prognosis and poor therapeutic effect of medications in trauma patients. Cytokines are signaling proteins that play critical roles in the body's response to injuries, which could amplify or suppress immune responses. Studies have demonstrated that cytokines are closely related to the severity of injuries and prognosis of trauma patients and help present cytokine-based diagnosis and treatment plans for trauma patients. In this review, we introduce the pathophysiological mechanisms of a traumatic inflammatory response and the role of cytokines in trauma patients. Furthermore, we discuss the potential of cytokine-based diagnosis and therapy for post-traumatic inflammatory response, although further clarification to elucidate the underlying mechanisms of cytokines following trauma is warranted.

Characteristics and Risk Factors of Myocardial Injury after Traumatic Hemorrhagic Shock.

Myocardial injury increases major adverse cardiovascular events and mortality in patients with traumatic hemorrhagic shock, but its prevalence and risk factors remain unclear. This study aimed to assess the prevalence and risk factors of myocardial injury after traumatic hemorrhagic shock. This was an observational, retrospective cohort study of patients with traumatic hemorrhagic shock at a tertiary university hospital from November 2012 to July 2021. Patient characteristics and clinical variables were recorded in 314 patients. The outcome was the occurrence of myocardial injury after traumatic hemorrhagic shock. Risk factors for myocardial injury were identified using logistic regression. The incidence of myocardial injury after the traumatic hemorrhagic shock was 42.4%, and 95.5% of myocardial injuries occurred within the first three days after trauma. In the multivariate analysis, the independent risk factors for myocardial injury after traumatic hemorrhagic shock included heart rate of >100 beats/min (OR [odds ratio], 3.33; 95% confidence interval [CI], 1.56−7.09; p = 0.002), hemoglobin level of <70 g/L (OR, 3.50; 95% CI, 1.15−10.60; p = 0.027), prothrombin time of >15 s (OR, 2.39; 95% CI, 1.12−5.10; p = 0.024), acute kidney injury (OR, 2.75; 95% CI, 1.27−5.93; p = 0.01), and a higher APACHE II score (OR, 1.08; 95% CI, 1.01−1.15; p = 0.018). The area under the receiver operating characteristic curve for the prediction of myocardial injury after a traumatic hemorrhagic shock was 0.67 (95% CI, 0.68−0.79) for a heart rate of >100 beats/min, 0.67 (95% CI, 0.61−0.73) for hemoglobin level of <70 g/L, 0.66 (95% CI, 0.60−0.73) for prothrombin time of >15 s, 0.70 (95% CI, 0.64−0.76) for acute kidney injury, and 0.78 (95% CI, 0.73−0.83) for APACHE II scores. The incidence rate of myocardial injury in traumatic hemorrhagic shock is high, and heart rates of >100 beats/min, hemoglobin levels of <70 g/L, prothrombin times of >15 s, AKI and higher APACHE II scores are independent risk factors for myocardial injury after traumatic hemorrhagic shock. These findings may help clinicians to identify myocardial injury after traumatic hemorrhagic shock early and initiate appropriate treatment.

Pharmacological inhibition of mitochondrial division attenuates simulated high-altitude exposure-induced cerebral edema in mice: Involvement of inhibition of the NF-κB signaling pathway in glial cells.

High-altitude cerebral edema (HACE) is the severe type of acute mountain sickness, which is still lack of effective therapy. This study investigated for the first time the protective effect of mitochondrial division inhibitor-1 (mdivi-1) against cerebral edema induced by simulated high-altitude exposure in mice. It was found that mdivi-1 effectively inhibited phosphorylation of dynamin-related protein-1 (Drp1), reduced expression of AQP4, decreased secretion of IL-6 and TNF-α, and alleviated cerebral edema in mice. In primary cultured astrocytes or microglia, mdivi-1 significantly decreased the hypoxia-induced Drp1 phosphorylation and mitochondrial fragmentation, inhibited the activation of the NF-κB signaling pathway, reduced the secretion of IL-6 and TNF-α. In addition, mdivi-1 inhibited mitochondrial reactive oxygen species (ROS) generation induced by hypoxia in both astrocytes and microglia. When astrocytes were treated with the conditioned medium of microglia exposed to hypoxia (H-MCM), the protein levels of p-Drp1, p-p65, and AQP4 as well as the mRNA levels of IL-6, TNF-α, and IL-1ß in astrocytes were increased. When the mitochondrial components in H-MCM were removed, the influence of microglia on astrocytes under hypoxia was significantly alleviated. Treated with mdivi-1, the integrity of mitochondria released from microglia induced by hypoxia were significantly improved. In conclusion, pharmacological inhibition of mitochondrial division by mdivi-1 alleviated cerebral edema induced by simulated high-altitude exposure in mice. Inhibition of ROS/NF-κB signaling pathway may contribute to the protective effect of mdivi-1. Under hypoxic conditions, mdivi-1 may attenuate the activation of astrocytes by reducing the release of damaged mitochondria from microglia.

The Role of HDAC6 in Autophagy and NLRP3 Inflammasome.

Autophagy fights against harmful stimuli and degrades cytosolic macromolecules, organelles, and intracellular pathogens. Autophagy dysfunction is associated with many diseases, including infectious and inflammatory diseases. Recent studies have identified the critical role of the NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasomes activation in the innate immune system, which mediates the secretion of proinflammatory cytokines IL-1ß/IL-18 and cleaves Gasdermin D to induce pyroptosis in response to pathogenic and sterile stimuli. Accumulating evidence has highlighted the crosstalk between autophagy and NLRP3 inflammasome in multifaceted ways to influence host defense and inflammation. However, the underlying mechanisms require further clarification. Histone deacetylase 6 (HDAC6) is a class IIb deacetylase among the 18 mammalian HDACs, which mainly localizes in the cytoplasm. It is involved in two functional deacetylase domains and a ubiquitin-binding zinc finger domain (ZnF-BUZ). Due to its unique structure, HDAC6 regulates various physiological processes, including autophagy and NLRP3 inflammasome, and may play a role in the crosstalk between them. In this review, we provide insight into the mechanisms by which HDAC6 regulates autophagy and NLRP3 inflammasome and we explored the possibility and challenges of HDAC6 in the crosstalk between autophagy and NLRP3 inflammasome. Finally, we discuss HDAC6 inhibitors as a potential therapeutic approach targeting either autophagy or NLRP3 inflammasome as an anti-inflammatory strategy, although further clarification is required regarding their crosstalk.

Genome-wide landscape of mRNAs, microRNAs, lncRNAs, and circRNAs in hemorrhagic shock-induced ALI/ARDS in rats.

BACKGROUND: Hemorrhagic shock (HS) can develop into multiple organ dysfunction syndrome, among which acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) usually lead to poor outcomes. The underlying molecular mechanisms of HS-induced ALI/ARDS remain unclear. This study sought to investigate gene expression profiles and predict competing endogenous RNA (ceRNA) regulatory networks in an HS-induced ALI/ARDS preclinical model. METHODS: Sprague Dawley rats were subjected to a fixed volume of hemorrhage (HS, 40% estimated total blood volume) or not (sham) randomly. After 8 hours of observation, left lung tissue was harvested to evaluate lung injury. Right lung was collected for RNA sequencing. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed and the long noncoding RNA (lncRNA)/circular RNA (circRNA)-microRNA (miRNA)-messenger RNA (mRNA) linkages were predicted using the ceRNA theory. Quantitative real-time polymerase chain reaction was used to validate the RNA sequencing findings. RESULTS: Hemorrhagic shock lungs showed noticeable ALI/ARDS features, and 437 mRNAs, 31 miRNAs, 734 lncRNAs, and 29 circRNAs were differentially expressed. In Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses, the differentially expressed transcripts were enriched in the following terms: the metabolic pathways, signal transduction pathways, necroptosis, DNA damage recognition and repair, inflammatory cell migration and chemotaxis, the NOD-like receptor signaling pathway, the Janus kinase/signal transducer and activator of transcription signaling pathway, the mitogen-activated protein kinase signaling pathway, the phosphatidylinositol-3-kinase/protein kinase B signaling pathway, and so on. Also, this study identified lncRNA-miRNA-mRNA linkages with 12 lncRNAs, 5 miRNAs, 15 mRNAs, and circRNA-miRNA-mRNA linkages with 10 circRNAs, 16 miRNAs, 39 mRNAs. These networks might play important regulatory roles. CONCLUSION: This is the first high-throughput analysis of gene expression profiles in HS-induced ALI/ARDS. It shows that metabolism, cell signaling, DNA damage and repair, and necroptosis-related RNAs altered, and inflammatory response-associated RNAs and pathways have pivotal roles in HS-induced ALI/ARDS progression. It also prompts some important RNAs and regulatory networks for future research. LEVEL OF EVIDENCE: Basic science article.

Ultrasonic Characteristics and Severity Assessment of Lung Ultrasound in COVID-19 Pneumonia in Wuhan, China: A Retrospective, Observational Study.

The clinical application of lung ultrasound (LUS) in the assessment of coronavirus disease 2019 (COVID-19) pneumonia severity remains limited. Herein, we investigated the role of LUS imaging in COVID-19 pneumonia patients and the relationship between LUS findings and disease severity. This was a retrospective, observational study at Tongji Hospital in Wuhan, on 48 recruited patients with COVID-19 pneumonia, including 32 non-critically ill patients and 16 critically ill patients. LUS was performed and the respiratory rate oxygenation (ROX) index, disease severity, and confusion, blood urea nitrogen, respiratory rate, blood pressure, and age (CURB-65) score were recorded on days 0-7, 8-14, and 15-21 after symptom onset. Lung images were divided into 12 regions, and the LUS score (0-36 points) was calculated. Chest computed tomography (CT) scores (0-20 points) were also recorded on days 0-7. Correlations between the LUS score, ROX index, and CURB-65 scores were examined. LUS detected COVID-19 pneumonia in 38 patients. LUS signs included B lines (34/38, 89.5%), consolidations (6/38, 15.8%), and pleural effusions (2/38, 5.3%). Most cases showed more than one lesion (32/38, 84.2%) and involved both lungs (28/38, 73.7%). Compared with non-critically ill patients, the LUS scores of critically ill patients were higher (12 (10-18) vs 2 (0-5), p < 0.001). The LUS score showed significant negative correlations with the ROX index on days 0-7 (r = -0.85, p < 0.001), days 8-14 (r = -0.71, p < 0.001), and days 15-21 (r = -0.76, p < 0.001) after symptom onset. However, the LUS score was positively correlated with the CT score (r = 0.82, p < 0.001). The number of patients with LUS-detected lesions decreased from 27 cases (81.8%) to 20 cases (46.5%), and the LUS scores significantly decreased from 4 (2-10) to 0 (0-5) (p < 0.001) from days 0-7 to 17-21. We conclude that LUS can detect lung lesions in COVID-19 pneumonia patients in a portable, real-time, and safe manner. Thus, LUS is helpful in assessing COVID-19 pneumonia severity in critically ill patients.

Lactylated Histone H3K18 as a Potential Biomarker for the Diagnosis and Predicting the Severity of Septic Shock.

Objective: To date, there are no studies regarding the lactylation profile and its role in critically ill patients. Thus, we aimed to examine expression of histone H3 lysine 18 (H3K18) lactylation and its role in patients with septic shock. Methods: Thirteen healthy volunteers and 35 critically ill patients from the Department of Surgical Intensive Care Medicine, Beijing Hospital were enrolled in our study. Baseline information and clinical outcomes were obtained prospectively. Lactylation levels of all proteins and H3K18 from peripheral blood mononuclear (PBMC) were determined by western blotting and serum levels of inflammatory cytokines by flow cytometry. Arginase-1 (Arg1) and Krüppel-like factor-4 (Klf4) mRNA expression was evaluated by quantitative real-time PCR (qRT-PCR). Results: Lactylation was found to be an all-protein post-translational modification and was detected in PBMCs from both healthy volunteers and critically ill patients, with a significantly higher relative density in shock patients (t=2.172, P=0.045). H3K18la was expressed in all subjects, including healthy volunteers, with the highest level in septic shock patients (compared with non-septic shock patients, critically ill without shock patients and healthy volunteers P=0.033, 0.000 and 0.000, respectively). Furthermore, H3K18la protein expression correlated positively with APACHE II scores, SOFA scores on day 1, ICU stay, mechanical ventilation time and serum lactate (ρ=0.42, 0.63, 0.39, 0.51 and 0.48, respectively, ρ=0.012, 0.000, 0.019, 0.003 and 0.003, respectively). When we matched patients with septic shock and with non-septic shock according to severity, we found higher H3K18la levels in the former group (t=-2.208, P =0.040). Moreover, H3K18la exhibited a close correlation with procalcitonin levels (ρ=0.71, P=0.010). Patients with high H3K18la expression showed higher IL-2, IL-5, IL-6, IL-8, IL-10, IL-17, IFN-α levels (ρ=0.33, 0.37, 0.62, 0.55, 0.65, 0.49 and 0.374 respectively, P=0.024, 0.011, 0.000, 0.000, 0.000 and 0.000 respectively). H3K18la expression also displayed a positive correlation with the level of Arg1 mRNA (ρ=0.561, P=0.005). Conclusions: Lactylation is an all-protein post-translational modification occurring in both healthy subjects and critically ill patients. H3K18la may reflect the severity of critical illness and the presence of infection. H3K18la might mediate inflammatory cytokine expression and Arg1 overexpression and stimulate the anti-inflammatory function of macrophages in sepsis.

Inhibition of Histone Deacetylase 6 Protects Hippocampal Cells Against Mitochondria-mediated Apoptosis in a Model of Severe Oxygen-glucose Deprivation.

BACKGROUND: Histone deacetylase (HDAC) 6 inhibitors have demonstrated significant protective effects in traumatic injuries. However, their roles in neuroprotection and underlying mechanisms are poorly understood. This study sought to investigate the neuroprotective effects of Tubastatin A (Tub-A), an HDAC6 inhibitor, during oxygenglucose deprivation (OGD) in HT22 hippocampal cells. METHODS: HT22 hippocampal cells were exposed to OGD. Cell viability and cytotoxicity were assessed by cell counting kit-8 (CCK-8) and lactate dehydrogenase (LDH) release assay. Cellular apoptosis was assessed by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Mitochondria membrane potential was detected using JC-1 dye. Expressions of acetylated α-tubulin, α-tubulin, cytochrome c, VDAC, Bax, Bcl- 2, cleaved caspase 3, phosphorylated Akt, Akt, phosphorylated GSK3ß and GSK3ß were analyzed by Western blot analysis. RESULTS: Tub-A induced acetylation of α-tubulin, demonstrating appropriate efficacy. Tub-A significantly increased cell viability and attenuated LDH release after exposure to OGD. Furthermore, Tub-A treatment blunted the increase in TUNEL-positive cells following OGD and preserved the mitochondrial membrane potential. Tub-A also attenuated the release of cytochrome c from the mitochondria into the cytoplasm and suppressed the ratio of Bax/Bcl-2 and cleaved caspase 3. This was mediated, in part, by the increased phosphorylation of Akt and GSK3ß signaling pathways. CONCLUSION: HDAC 6 inhibition, using Tub-A, protects against OGD-induced injury in HT22 cells by modulating Akt/GSK3ß signaling and inhibiting mitochondria-mediated apoptosis.

Inhibition of histone deacetylase 6 attenuates intestinal inflammation and apoptosis in a rodent model of hemorrhagic shock.

BACKGROUND: Intestinal inflammation is a mediator of multiorgan failure in trauma. We have previously shown that histone deacetylase (HDAC6) inhibitors, including ACY1083, improve survival and preserve intestinal tight junction integrity in a rodent model of hemorrhagic shock (HS). However, mechanisms leading to this alleviation in intestinal injury remain poorly defined. In this study, we sought to determine whether HDAC6 inhibition by ACY1083 can attenuate intestinal inflammation and apoptosis in rats subjected to HS. METHODS: Sprague Dawley rats were subjected to hemorrhage (40% of total blood volume) followed by intravenous injection of either ACY1083 (30 mg/kg) dissolved in cyclodextrin or cyclodextrin only (vehicle group). Three hours after hemorrhage, blood samples were collected, and small bowel was harvested. Histological effects of ACY1083 on small bowel were examined. Myeloperoxidase (MPO) levels were assessed as a marker for neutrophil infiltration. Whole cell lysates were analyzed for acetylated α-tubulin, metalloproteinase (ADAM) 17, TNF-α, IL-6, and cleaved caspase 3 using Western blot. The levels of ADAM17, TNF-α, and IL-6 in serum were also examined using enzyme-linked immunosorbent assay. RESULTS: ACY1083 treatment significantly attenuated HS-induced intestinal injury and MPO production. Both systemic and intestinal TNF-α and IL-6 levels were attenuated following ACY1083 administration. Increased acetylation of α-tubulin was observed in rats treated with ACY1083, along with a significantly decreased expression of cleaved caspase 3 following hemorrhage. CONCLUSION: Inhibition of HDAC6 with ACY1083 provides intestinal protection by attenuating both the inflammatory and apoptotic responses during HS.

Comparative analysis of isoform-specific and non-selective histone deacetylase inhibitors in attenuating the intestinal damage after hemorrhagic shock.

BACKGROUND: Isoform-specific histone deacetylase inhibitors (HDACIs) MC1568 and ACY1083 are comparable to the non-selective HDACI valproic acid (VPA) in improving survival in rodents undergoing lethal hemorrhage. However, the organ-specific properties of isoform-specific HDACIs have not been fully evaluated. Also, whether they can act synergistically is not known. We hypothesized that isoform-specific HDACIs are superior to VPA in attenuating intestinal injury and act synergistically when coadministered. METHODS: Sprague Dawley rats were hemorrhaged (40% of total blood volume) and randomized to receive (n=4 per group) (1) MC1568 (5 mg/kg), (2) ACY1083 (30 mg/kg), (3) MC1568+ACY1083 (combination: 5 mg/kg + 30 mg/kg, respectively), (4) VPA (250 mg/kg), or (5) normal saline (NS; vehicle; 250 µL). Animals were observed for 3 hours, after which blood samples were collected and samples of the ileum were harvested. Expression of interleukin 1 beta (IL-1ß), tumor necrosis factor alpha (TNF-α), and cytokine-induced neutrophil chemoattractant 1 (CINC-1) was assessed in the tissues using enzyme-linked immunosorbent assay. Intestinal cleaved caspase 3 (c-caspase 3) levels were assessed as a marker of apoptosis, and histologic sections of the ileum were examined for signs of bowel injury. Levels of IL-1ß and TNF-α were also measured in the serum as global markers of inflammation. RESULTS: Treatments with MC1568, ACY1083, MC1568+ACY1083, and VPA were associated with decreased IL-1ß levels in the intestine and serum compared with NS. IL-1ß and TNF-α levels were significantly lower in the ACY1083 group compared with the VPA group. CINC-1 levels were significantly lower in the isoform-specific HDACI groups compared with the NS; however, no significant differences were seen with VPA. All treatment groups had a lower expression of intestinal c-caspase 3 compared with NS. Furthermore, MC1568 and ACY1083 groups had lower apoptosis compared with the VPA group. Bowel injury scores were significantly lower in the isoform-specific HDACI groups compared with the NS group; however, the attenuation in the VPA-treated animals did not reach statistical significance. DISCUSSION: Isoform-specific HDACIs provide superior intestinal protection compared with VPA in a rodent model of hemorrhagic shock. LEVEL OF EVIDENCE: Preclinical study.

Valproic Acid and Neural Apoptosis, Inflammation, and Degeneration 30 Days after Traumatic Brain Injury, Hemorrhagic Shock, and Polytrauma in a Swine Model.

BACKGROUND: A single-dose (150 mg/kg) of valproic acid (VPA) has been shown to decrease brain lesion size and improve neurologic recovery in preclinical models of traumatic brain injury (TBI). However, the longer-term (30 days) impact of single-dose VPA treatment after TBI has not been well evaluated. STUDY DESIGN: Yorkshire swine were subjected to TBI (cortical impact), hemorrhagic shock, and polytrauma. Animals remained in hypovolemic shock for 2 hours before resuscitation with normal saline (NS; volume = 3× hemorrhaged volume) or NS + VPA (150 mg/kg) (n = 5/cohort). Brain samples were harvested 30 days after injuries. The cerebral cortex adjacent to the site of cortical impact was evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, immunohistochemistry, and Western blot analysis. Neural apoptosis, inflammation, degeneration, plasticity, and signaling pathways were evaluated. RESULTS: For apoptosis, VPA treatment significantly decreased (p < 0.05) the number of TUNEL (+) cells and expression of cleaved-caspase 3. For inflammation and degeneration, expression of ionized calcium binding adaptor molecule-1, glial fibrillary acid protein, amyloid-ß, and phosphorylated-Tau protein were significantly attenuated (p < 0.05) in the VPA-treated animals compared with the NS group. For, plasticity, VPA treatment also increased expression of brain-derived neurotrophic factor significantly (p < 0.05) compared with the NS group. For signaling pathways, nuclear factor-κB was decreased significantly (p < 0.05) and cytosolic IκBα expression was increased significantly (p < 0.05) in the VPA-treated animals compared with the NS group. CONCLUSIONS: Administration of a single dose of VPA (150 mg/kg) can decrease neural apoptosis, inflammation, and degenerative changes, and promote neural plasticity at 30 days after TBI. In addition, VPA acts, in part, via regulation of nuclear factor-κB and IκBα pathways.

Traumatic brain injury may worsen clinical outcomes after prolonged partial resuscitative endovascular balloon occlusion of the aorta in severe hemorrhagic shock model.

BACKGROUND: The use of partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) in combined hemorrhagic shock (HS) and traumatic brain injury (TBI) has not been well studied. We hypothesized that the use of pREBOA in the setting of TBI would be associated with worse clinical outcomes. METHODS: Female Yorkshire swine were randomized to the following groups: HS-TBI, HS-TBI-pREBOA, and HS-pREBOA (n = 5/cohort). Animals in the HS-TBI group were left in shock for a total of 2 hours, whereas animals assigned to pREBOA groups were treated with supraceliac pREBOA deployment (60 minutes) 1 hour into the shock period. All animals were then resuscitated, and physiologic parameters were monitored for 6 hours. Further fluid resuscitation and vasopressors were administered as needed. At the end of the observation period, brain hemispheric swelling (%) and lesion size (mm) were assessed. RESULTS: Mortality was highest in the HS-TBI-pREBOA group (40% [2/5] vs. 0% [0/5] in the other groups, p = 0.1). Severity of shock was greatest in the HS-TBI-pREBOA group, as defined by peak lactate levels and pH nadir (p < 0.05). Fluid resuscitation and norepinephrine requirements were significantly higher in the HS-TBI-pREBOA group (p < 0.05). No significant differences were noted in brain hemispheric swelling and lesion size between the groups. CONCLUSION: Prolonged application of pREBOA in the setting of TBI does not contribute to early worsening of brain lesion size and edema. However, the addition of TBI to HS-pREBOA may worsen the severity of shock. Providers should be aware of the potential physiologic sequelae induced by TBI.

Mesenchymal Stem Cell-Derived Exosomes Provide Neuroprotection and Improve Long-Term Neurologic Outcomes in a Swine Model of Traumatic Brain Injury and Hemorrhagic Shock.

Combined traumatic brain injury (TBI) and hemorrhagic shock (HS) remains a leading cause of preventable death worldwide. Mesenchymal stem cell-derived exosomes have demonstrated promise in small animal models of neurologic injury. To investigate the effects of exosome treatment in a clinically realistic large animal model, Yorkshire swine underwent TBI and HS. Animals were maintained in shock for 2 h before resuscitation with normal saline (NS). Animals were then resuscitated either with NS (3 × volume of shed blood) or with the same volume of NS with delayed exosome administration (1 × 1013 particles/4 mL) (n = 5/cohort). Exosomes were administered 9 h post-injury, and on post-injury days (PID) 1, 5, 9, and 13. Neurologic severity scores (NSS) were assessed for 30 days, and neurocognitive functions were objectively measured. Exosome-treated animals had significantly lower NSS (p < 0.05) during the first five days of recovery. Exosome-treated animals also had a significantly shorter time to complete neurologic recovery (NSS = 0) compared with animals given NS alone (days to recovery: NS = 16.8 ± 10.6; NS + exosomes = 5.6 ± 2.8; p = 0.03). Animals treated with exosomes initiated neurocognitive testing earlier (days to initiation: NS = 9.6 ± 0.5 vs. NS + exosomes = 4.2 ± 0.8; p = 0.008); however, no difference was seen in time to mastery of tasks. In conclusion, treatment with exosomes attenuates the severity of neurologic injury and allows for faster neurologic recovery in a clinically realistic large animal model of TBI and HS.

Changes in body composition in children with acute graft-versus-host disease within the first 100 days after hematopoietic stem cell transplantation.

BACKGROUND: Acute graft-versus-host-disease (aGVHD) is one of the main complications of hematopoietic stem cell transplantation (HSCT). This study investigated the changes in body composition of pediatric patients with aGVHD during the first 100 days after HSCT. METHODS: Fifty-five children receiving HSCT were divided into two groups (aGVHD and non-aGVHD). Body mass index Z-scores (BMI-z), arm muscle area index (AMAI), fat mass index (FMI), and fat-free mass index (FFMI) were measured on the day of transplantation (H0), and on the 30th (H30), 60th (H60), and 100th day (H100) after the transplantation. The correlative factors on body composition were evaluated. RESULTS: In the aGVHD group, the rates of absolute change of BMI-z at H30, H60, and H100 showed a significant increase as compared to that at H0, especially at H30 which was remarkably higher than that of the non-aGVHD group (P = 0.008). AMAI showed a continuous decrease from H0 to H100 in the aGVHD group; also FFMI was found to be lower than that of the non-aGVHD group during the first 100 days after transplantation, however, no significant differences were found between the two groups. At H60 and H100, FFMI in the aGVHD group was lower than that in the non-aGVHD group (P = 0.014, P = 0.032, respectively). Glucocorticoid treatment and the occurrence of mucositis were the key factors for changes in body composition in the aGVHD group. CONCLUSIONS: Changes in body composition are characterized by a lean reduction in body mass and increase in adipose tissues in the early stage of post-transplantation in the aGVHD children. Glucocorticoid treatment and occurrence of mucositis are the two important factors that were found to affect body composition after HSCT.

Histone deacetylase inhibitors: Isoform selectivity improves survival in a hemorrhagic shock model.

BACKGROUND: Hemorrhage is a leading preventable cause of death. Nonselective histone deacetylase inhibitors (HDACIs), such as valproic acid (VPA), have been shown to improve outcomes in hemorrhagic shock (HS). The HDACs can be divided into four functional classes (I, IIa/IIb, III, and IV). Classes I, IIa/IIb, and III have previously been implicated in the pathophysiology of HS. This study aimed to determine which HDAC class, or classes, are responsible for the survival benefit observed with nonselective HDACIs. METHODS: Survival study: Sprague-Dawley rats were subjected to lethal HS (50% hemorrhage) and randomized to the following groups (n = 8): (1) no treatment, (2) normal saline vehicle, (3) cyclodextrin vehicle, (4) MS275 (class I HDACI), (5) VPA (class I/IIa HDACI), (6) MC1568 (class IIa HDACI), (7) ACY1083 (class IIb HDACI), and (8) EX527 (class III HDACI). Survival was monitored for 24 hours. Mechanistic study: Sprague-Dawley rats were subjected to sublethal HS (40% hemorrhage) and randomized to the same groups (n = 3), excluding EX527, based on results of the survival study. Tissues were harvested at 3 hours posttreatment, and expression of phosphorylated-AKT, ß-catenin, acetylated histones H3 and H4, and acetylated α-tubulin were analyzed in myocardial tissue. RESULTS: Survival rate was 12.5% in the untreated group, and did not improve with vehicle or MS275 treatment. EX527 improved survival to 50%, although this did not achieve statistical significance (p = 0.082). However, treatment with VPA, MC1568, and ACY1083 improved survival rates to 87.5%, 75%, and 75%, respectively (p < 0.05). The VPA-induced acetylation of both histones H3 and H4, while MC1568 and ACY1083 increased acetylation of histone H4. ACY1083 also induced acetylation of α-tubulin. All treatment groups, except MS275, increased phosphorylated-AKT, and ß-catenin. CONCLUSION: Inhibition of HDAC classes IIa or IIb, but not class I, activates prosurvival pathways, which may be responsible for the improved outcomes in rodent models of HS.

Transcriptomic changes following valproic acid treatment promote neurogenesis and minimize secondary brain injury.

BACKGROUND: Early treatment with valproic acid (VPA) has demonstrated benefit in preclinical models of traumatic brain injury, including smaller brain lesion size, decreased edema, reduced neurologic disability, and faster recovery. Mechanisms underlying these favorable outcomes are not fully understood. We hypothesized that VPA treatment would upregulate genes involved in cell survival and proliferation and downregulate those associated with cell death and the inflammatory response. METHODS: Ten female swine were subjected to a protocol of traumatic brain injury and hemorrhagic shock. They were assigned to two groups (n = 5): normal saline (NS; 3× volume of shed blood), or NS + VPA (150 mg/kg). Following 6 hours of observation, brain tissue was harvested to evaluate lesion size and edema. Brain tissue was processed for RNA sequencing. Gene set enrichment and pathway analysis was performed to determine the differential gene expression patterns following injury. RESULTS: Animals treated with VPA were noted to have a 46% reduction in brain lesion size and a 57% reduction in ipsilateral brain edema. Valproic acid significantly upregulated genes involved in morphology of the nervous system, neuronal development and neuron quantity. The VPA treatment downregulated pathways related to apoptosis, glial cell proliferation, and neuroepithelial cell differentiation. Ingenuity Pathway Analysis identified VPA as the top upstream regulator of activated transcription, supporting it as a direct cause of these transcriptional changes. Master transcriptional regulator NEUROD1 was also significantly upregulated, suggesting that VPA may induce additional transcription factors. CONCLUSION: Administration of VPA attenuated brain lesion size, reduced brain edema, and induced significant changes in the transcriptome of injured brain within 6 hours. Patterns of differential expression were consistent with the proposed neurogenic and prosurvival effects of VPA treatment.

Histone Deacetylase Inhibition Attenuates Cardiomyocyte Hypoxia-Reoxygenation Injury.

BACKGROUND: Cardiac reperfusion injury can have devastating consequences. Histone deacetylase (HDAC) inhibitors are potent cytoprotective agents, but their role in the prevention of cardiac injury remains ill-defined. OBJECTIVE: We sought to determine the therapeutic potential of HDAC inhibitors in an in vitro model of cardiomyocyte hypoxia-reoxygenation (H/R). METHOD: H9c2 cardiomyocytes were subjected to H/R and treated with various classspecific and pan-HDAC inhibitors in equal concentrations (5µM). Biological activity of inhibitors was determined, as a proxy for concentration adequacy, by Western blot for acetylated histone H3 and α-tubulin. Cell viability and cytotoxicity were measured by methyl thiazolyl tetrazolium and lactate dehydrogenase assays, respectively. Mechanistic studies were performed to better define the effects of the most effective agent, Tubastatin-A (Tub-A), on the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway effectors, and on the degree of autophagy. RESULTS: All inhibitors acetylated well-known target proteins (histone H3 and α-tubulin), suggesting that concentrations were adequate to induce a biological effect. Improved cell viability and decreased cell cytotoxicity were noted in cardiomyocytes exposed to Tub-A, whereas the cytoprotective effects of other HDAC inhibitors were inconsistent. Pro-survival mediators in the PI3K/mTOR pathway were up-regulated and the degree of autophagy was significantly attenuated in cells that were treated with Tub-A. CONCLUSION: HDAC inhibitors improve cell viability in a model of cardiomyocyte H/R, with Class IIb inhibition (Tub-A) demonstrating superior cellular-level potency and effectiveness. This effect is, at least in part, related to an increased expression of prosurvival mediators and a decreased degree of autophagy.

Complete and Partial Aortic Occlusion for the Treatment of Hemorrhagic Shock in Swine.

Hemorrhage remains the leading cause of preventable deaths in trauma. Endovascular management of non-compressible torso hemorrhage has been at the forefront of trauma care in recent years. Since complete aortic occlusion presents serious concerns, the concept of partial aortic occlusion has gained a growing attention. Here, we present a large animal model of hemorrhagic shock to investigate the effects of a novel partial aortic balloon occlusion catheter and compare it with a catheter that works on the principles of complete aortic occlusion. Swine are anesthetized and instrumented in order to conduct controlled fixed-volume hemorrhage, and hemodynamic and physiological parameters are monitored. Following hemorrhage, aortic balloon occlusion catheters are inserted and inflated in the supraceliac aorta for 60 min, during which the animals receive whole-blood resuscitation as 20% of the total blood volume (TBV). Following balloon deflation, the animals are monitored in a critical care setting for 4 h, during which they receive fluid resuscitation and vasopressors as needed. The partial aortic balloon occlusion demonstrated improved distal mean arterial pressures (MAPs) during the balloon inflation, decreased markers of ischemia, and decreased fluid resuscitation and vasopressor use. As swine physiology and homeostatic responses following hemorrhage have been well-documented and are like those in humans, a swine hemorrhagic shock model can be used to test various treatment strategies. In addition to treating hemorrhage, aortic balloon occlusion catheters have become popular for their role in cardiac arrest, cardiac and vascular surgery, and other high-risk elective surgical procedures.