Dexmedetomidine Protects Against Septic Liver Injury by Enhancing Autophagy Through Activation of the AMPK/SIRT1 Signaling Pathway

Dexmedetomidine ameliorates x-ray-induced myocardial injury via alleviating cardiomyocyte apoptosis and autophagy

BACKGROUND

Radiotherapy is a primary local treatment for tumors, yet it may lead to complications such as radiation-induced heart disease (RIHD). Currently, there is no standardized approach for preventing RIHD. Dexmedetomidine (Dex) is reported to have cardio-protection effects, while its role in radiation-induced myocardial injury is unknown. In the current study, we aimed to evaluate the radioprotective effect of dexmedetomidine in X-ray radiation-treated mice.

METHODS

18 male mice were randomized into 3 groups: control, 16 Gy, and 16 Gy + Dex. The 16 Gy group received a single dose of 16 Gy X-ray radiation. The 16 Gy + Dex group was pretreated with dexmedetomidine (30 µg/kg, intraperitoneal injection) 30 min before X-ray radiation. The control group was treated with saline and did not receive X-ray radiation. Myocardial tissues were collected 16 weeks after X-ray radiation. Hematoxylin-eosin staining was performed for histopathological examination. Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining was performed to assess the state of apoptotic cells. Immunohistochemistry staining was performed to examine the expression of CD34 molecule and von Willebrand factor. Besides, western blot assay was employed for the detection of apoptosis-related proteins (BCL2 apoptosis regulator and BCL2-associated X) as well as autophagy-related proteins (microtubule-associated protein 1 light chain 3, beclin 1, and sequestosome 1).

RESULTS

The findings demonstrated that 16 Gy X-ray radiation resulted in significant changes in myocardial tissues, increased myocardial apoptosis, and activated autophagy. Pretreatment with dexmedetomidine significantly protects mice against 16 Gy X-ray radiation-induced myocardial injury by inhibiting apoptosis and autophagy.

CONCLUSION

In summary, our study confirmed the radioprotective effect of dexmedetomidine in mitigating cardiomyocyte apoptosis and autophagy induced by 16 Gy X-ray radiation.

THE PROTECTIVE EFFECT OF DEXMEDETOMIDINE ON THE LIVER INJURY IN SEPSIS THROUGH INHIBITION OF NECROPTOSIS

ABSTRACT

Background: Sepsis-induced liver injury leads to extensive necroptosis in hepatocytes, which is the main factor of liver dysfunction. This study aims to investigate the protective effect of dexmedetomidine (DEX) on septic liver and to explore whether its molecular mechanism is related to the modulation of necroptosis. Methods: The model of septic liver injury was induced by cecal ligation and puncture (CLP) in rats. DEX and necrostatin-1(Nec-1), a specific antagonist of necroptosis, were administered 1 h before CLP. The levels of arterial blood gas, serum aspartate aminotransferase, and alanine aminotransferase were measured at 6, 12 and 24 h after CLP. The survival rate was observed 24 h after CLP. Liver pathological changes and apoptosis, the contents of IL-6 and TNF-α in liver tissue homogenates, the ROS content in liver tissue, and the expression levels of RIP1, RIP3, MLKL, and HMGB1 were detected. Results: At 6, 12, and 24 h after CLP, the levels of aspartate aminotransferase, and alanine aminotransferase levels increased, and liver enzyme levels gradually increased with the progression of sepsis. In arterial blood gas analysis, P a O 2 gradually decreased and lactic acid concentration gradually increased during these three periods. The morphological impairment of liver tissues, increased apoptosis, elevated inflammatory factors (IL-6 and TNF-α), increased ROS level, and necroptosis components (RIP1, RIP3, MLKL, and HMGB1) were all observed in sepsis rats. However, these injuries can be ameliorated by pretreatment with DEX. Meanwhile, Nec-1 pretreatment also reduced the expression of RIP1, RIP3, MLKL, HMGB1, and ROS level. Conclusion: Our study suggests that DEX alleviates septic liver injury, and the mechanism is associated with the inhibition of necroptosis.

Anemonin inhibits sepsis-induced acute kidney injury via mitigating inflammation and oxidative stress

Elevated inflammation and oxidative stress (OS) are the main pathologic features of acute kidney injury (AKI)-caused by sepsis. Here, we made an investigation into the protective effects of the natural compound Anemonin (ANE) on sepsis-induced AKI both in vitro and in vivo. Lipopolysaccharide (LPS) was applied to construct an in vitro AKI model in renal tubular epithelial cells, and the septic C57BL/6J mouse model was constructed via cecal ligation and puncture (CLP). Cell viability and apoptosis were detected. The levels of p53, Bax, Bcl2, Caspase3, Caspase8, Caspase9, AMP-activated protein kinase (AMPK), Sirt-1, and forkhead box O3 were determined by Western Blot or RT-PCR. The reactive oxygen species level and OS markers were measured. Furthermore, the pathological changes of kidneys were evaluated by hematoxylin-eosin staining and immunohistochemistry. As per the information presented, ANE improved LPS-elicited apoptosis, inflammatory response, and OS in a dose-dependent pattern in renal tubular epithelial cells. Besides, ANE activated the AMPK/Sirt-1 pathway, and the AMPK inhibitor (Compound C) and Sirt-1 inhibitor (EX-527) significantly attenuated ANE-mediated protection on renal tubular epithelial cells. In vivo, ANE mitigated the levels of serum creatinine and urea nitrogen in the CLP-induced mouse sepsis model, reduced the renal tissue injury score, and attenuated OS, inflammation, and apoptosis levels in the kidney. Taken together, this study suggested that ANE has protective effects in sepsis-triggered AKI through repressing inflammation, OS, and cell apoptosis by activating the AMPK/Sirt-1 pathway.

Micro electrical fields induced MSC-sEVs attenuate neuronal cell apoptosis by activating autophagy via lncRNA MALAT1/miR-22-3p/SIRT1/AMPK axis in spinal cord injury

Spinal cord injury (SCI) is a traumatic condition of the central nervous system that causes paralysis of the limbs. Micro electric fields (EF) have been implicated in a novel therapeutic approach for nerve injury repair and regeneration, but the effects of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles that are induced by micro electric fields (EF-sEVs) stimulation on SCI remain unknown. The aim of the present study was to investigate whether EF-sEVs have therapeutic effects a rat model of SCI. EF-sEVs and normally conditioned human umbilical cord mesenchymal stem cells-derived small extracellular vesicles (CON-sEVs) were collected and injected intralesionally into SCI model rats to evaluate the therapeutic effects. We detect the expression of candidate long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (lncRNA-MALAT1) in EF-sEVs and CON-sEVs. The targets and downstream effectors of lncRNA-MALAT1 were investigated using luciferase reporter assays. Using both in vivo and in vitro experiments, we demonstrated that EF-sEVs increased autophagy and decreased apoptosis after SCI, which promoted the recovery of motor function. We further confirmed that the neuroprotective effects of EF-sEVs in vitro and in vivo correlated with the presence of encapsulated lncRNA-MALAT1 in sEVs. lncRNA-MALAT1 targeted miR-22-3p via sponging, reducing miR-22-3p's suppressive effects on its target, SIRT1, and this translated into AMPK phosphorylation and increased levels of the antiapoptotic protein Bcl-2. Collectively, the present study identified that the lncRNA-MALAT1 in EF-sEVs plays a neuroprotective role via the miRNA-22-3p/SIRT1/AMPK axis and offers a fresh perspective and a potential therapeutic approach using sEVs to improve SCI.

Metformin Alleviates Sepsis-Associated Myocardial Injury by Enhancing AMP-Activated Protein Kinase/Mammalian Target of Rapamycin Signaling Pathway-Mediated Autophagy

ABSTRACT

Sepsis-associated myocardial injury is one of the main causes of death in intensive care units, and current clinical treatments have not been satisfactory. Therefore, finding an effective intervention is an urgent requirement. Metformin, an anti-type 2 diabetes drug, has been reported to be an autophagic activator agent that confers protection in some diseases. However, it is unclear whether it can provide defense against sepsis-associated myocardial injury. In this study, we investigated the cardioprotective effects of metformin pretreatment against lipopolysaccharide (LPS)-induced myocardial injury in C57BL/6J mice or H9c2 cells and the possible underlying mechanisms. Metformin was administered at a dose of 100 mg/kg for a week before LPS intraperitoneal injection. Twenty-four hours after LPS intervention, echocardiographic evaluation, reactive oxygen species measurement, Hoechst staining, western blotting, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay were performed. Inhibitors of autophagy and AMP-activated protein kinase (AMPK) were used to further clarify the mechanisms involved. Metformin pretreatment effectively attenuated cardiac dysfunction, reduced the levels of myocardial enzymes, and alleviated cardiac hydroncus in LPS-treated mice. In addition, metformin restored the LPS-disrupted antioxidant defense and activated LPS-reduced autophagy by modulating the AMPK/mammalian target of rapamycin (AMPK/mTOR) pathway both in vivo and in vitro. The antioxidant effects of metformin on cardiomyocytes were abolished by the autophagy inhibitor 3-methyladenine (3-MA). Treatment with compound C, an AMPK inhibitor, reversed the metformin-induced autophagy in LPS-treated H9c2 cells. In conclusion, metformin pretreatment alleviates LPS-induced myocardial injury by activating AMPK/mTOR pathway-mediated autophagy.

Hepatocyte CD36 modulates UBQLN1-mediated proteasomal degradation of autophagic SNARE proteins contributing to septic liver injury

Macroautophagy/autophagy plays a protective role in sepsis-induced liver injury. As a member of class B scavenger receptors, CD36 plays important roles in various disorders, such as atherosclerosis and fatty liver disease. Here we found that the expression of CD36 in hepatocytes was increased in patients and a mouse model with sepsis, accompanied by impaired autophagy flux. Furthermore, hepatocyte cd36 knockout (cd36-HKO) markedly improved liver injury and the impairment of autophagosome-lysosome fusion in lipopolysaccharide (LPS)-induced septic mice. Ubqln1 (ubiquilin 1) overexpression (OE) in hepatocyte blocked the protective effect of cd36-HKO on LPS-induced liver injury in mice. Mechanistically, with LPS stimulation, CD36 on the plasma membrane was depalmitoylated and distributed to the lysosome, where CD36 acted as a bridge molecule linking UBQLN1 to soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and hence promoting the proteasomal degradation of SNARE proteins, resulting in fusion impairment. Overall, our data reveal that CD36 is essential for modulating the proteasomal degradation of autophagic SNARE proteins in a UBQLN1-dependent manner. Targeting CD36 in hepatocytes is effective for improving autophagic flux in sepsis and therefore represents a promising therapeutic strategy for clinical treatment of septic liver injury.Abbreviations: AAV8: adeno-associated virus 8; AOSC: acute obstructive suppurative cholangitis; ATP1A1: ATPase, Na+/K+ transporting, alpha 1 polypeptide; CASP3: caspase 3; CASP8: caspase 8; CCL2: chemokine (C-C motif) ligand 2; cd36-HKO: hepatocyte-specific cd36 knockout; Co-IP: co-immunoprecipitation; CQ: chloroquine; Cys: cysteine; GOT1: glutamic-oxaloacetic transaminase 1, soluble; GPT: glutamic-pyruvic transaminase, soluble; IL1B: interleukin 1 beta; IL6: interleukin 6; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LDH, lactate dehydrogenase; LPS: lipopolysaccharide; LYPLA1: lysophospholipase 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; OE: overexpression; qPCR: quantitative polymerase chain reaction; SNAP29: synaptosome associated protein 29; SNARE: soluble N-ethylmaleimide-sensitive factor attachment protein receptor; SQSTM1/p62: sequestosome 1; STX17: syntaxin 17; TNF: tumor necrosis factor; TRIM: tripartite motif-containing; UBA: ubiquitin-associated; UBL: ubiquitin-like; UBQLN: ubiquilin; VAMP8: vesicle associated membrane protein 8; WT: wild-type.

Stachydrine Relieved the Inflammation and Promoted the Autophagy in Diabetes Retinopathy Through Activating the AMPK/SIRT1 Signaling Pathway

Background

Diabetes retinopathy (DR) is a chronic, progressive, and potentially harmful retinal disease associated with persistent hyperglycemia. Autophagy is a lysosome-dependent degradation pathway that widely exists in eukaryotic cells, which has recently been demonstrated to participate in the DR development. Stachydrine (STA) is a water-soluble alkaloid extracted from Leonurus heterophyllus. This study aimed to explore the effects of STA on the autophagy in DR progression in vivo and in vitro.

Methods

High glucose-treated human retinal microvascular endothelial cells (HRMECs) and STA-treated rats were used to establish DR model. The reactive oxygen species (ROS) and inflammatory factor levels (TNF-α, IL-1β, and IL-6) were determined using corresponding kits. Additionally, the cell growth was analyzed using CCK-8 and EdU assays. Besides, LC3BII, p62, p-AMPKα, AMPKα, and SIRT1 protein levels were measured using Western blot. The LC3BII and SIRT1 expressions were also determined using immunofluorescence.

Results

The results showed that STZ decreased the ROS and inflammatory factor levels in the HG-treated HRMECs. Besides, after STA treatment, the beclin-1, LC3BII, p-AMPKα, and SIRT1 levels were increased, and p62 was decreased in the HG-treated HRMECs and the retinal tissue of STZ-treated rats.

Conclusion

In conclusion, this study demonstrated that STA effectively relieved the inflammation and promoted the autophagy in DR progression in vivo and in vitro through activating the AMPK/SIRT1 signaling pathway.

Dexmedetomidine Alleviates Abdominal Aortic Aneurysm by Activating Autophagy Via AMPK/mTOR Pathway

BACKGROUND

Abdominal aortic aneurysms (AAA) are a critical global health issue with increasing prevalence. Dexmedetomidine (DEX) is a highly selective α2-adrenoceptor agonist that has previously been shown to play a protective role in AAA. Nevertheless, the mechanisms underlying its protection effect remain not fully understood.

METHODS

A rat AAA model was established via intra-aortic porcine pancreatic elastase perfusion with or without DEX administration. The abdominal aortic diameters of rats were measured. Hematoxylin-eosin and Elastica van Gieson staining were conducted for histopathological observation. TUNEL and immunofluorescence staining were utilized to detect cell apoptosis and α-SMA/LC3 expression in the abdominal aortas. Protein levels were determined using western blotting.

RESULTS

DEX administration repressed the dilation of aortas, alleviated pathological damage and cell apoptosis, and suppressed phenotype switching of vascular smooth muscle cells (VSMCs). Moreover, DEX activated autophagy and regulated the AMP-activated protein kinase/mammalian target of the rapamycin (AMPK/mTOR) signaling pathway in AAA rats. Administration of the AMPK inhibitor attenuated the DEX-mediated ameliorative effects on AAA in rats.

CONCLUSION

DEX ameliorates AAA in rat models by activating autophagy via the AMPK/mTOR pathway.

Deficiency of S100A9 Alleviates Sepsis-Induced Acute Liver Injury through Regulating AKT-AMPK-Dependent Mitochondrial Energy Metabolism

Acute liver injury (ALI) is recognized as a serious complication of sepsis in patients in intensive care units (ICUs). S100A8/A9 is known to promote inflammation and immune responses. However, the role of S100A8/A9 in the regulation of sepsis-induced ALI remains known. Our results indicated that S100A8/A9 expression was significantly upregulated in the livers of septic mice 24 h after cecal ligation and a puncture (CLP) operation. Moreover, S100A9-KO in mice markedly attenuated CLP-induced liver dysfunction and injury, promoting the AMPK/ACC/GLUT4-mediated increases in fatty acid and glucose uptake as well as the improvement in mitochondrial function and ATP production. In contrast, treatment with the AMPK inhibitor Compound C reversed the inhibitory effects of S100A9 KO on CLP-induced liver dysfunction and injury in vivo. Finally, the administration of the S100A9 inhibitor Paquinimod (Paq) to WT mice protected against CLP-induced mortality, liver injury and mitochondrial dysfunction. In summary, our findings demonstrate for the first time that S100A9 plays an important pro-inflammatory role in sepsis-mediated ALI by regulating AKT-AMPK-dependent mitochondrial energy metabolism and highlights that targeting S100A9 may be a promising new approach for the prevention and treatment of sepsis-related liver injury.

Effects of dexmedetomidine on oxidative stress, programmed cell death, liver function, and expression of peripheral immune cells in patients with primary liver cancer undergoing hepatectomy

Study background: Primary liver cancer is a severe health issue that imposes a significant health burden on families. Oxidation and subsequent cell death impair liver function and provoke an immune response. The present article investigates the effect of Dexmedetomidine on oxidation, cell death, the expression of peripheral immune cells, and liver function. The clinical data will represent the facts and evidence of the effects of this intervention. Methods: We analyzed clinical data reporting various accounts of the effects of Dexmedetomidine on oxidation, cell death, the expression of peripheral immune cells, and liver function among patients who underwent hepatectomy. The surgical procedure reported the differences in cell death as procedural outcomes among pre- and post-treatment records were compared and contrasted. Results: We found decreased cell apoptosis in the treatment group: the number of incisions to remove dead cells was lower in the treatment group than in the pre-treatment group. Likewise, lower oxidation was reported in pre-treatment than in post-treatment records. The expression of peripheral immune cells was higher in the pre-treatment clinical data than in post-treatment, suggesting a reduction in oxidation following dexmedetomidine treatment. Liver function was a function of oxidation and cell death outcomes. In the pre-treatment clinical data, liver function was poor, whereas improved functions were reported in the post-treatment clinical data. Discussion: We found compelling evidence of Dexmedetomidine's effects on oxidative stress and programmed cell death. The intervention suppresses the production of reactive oxygen species and the consequential apoptosis. Additionally, liver functions improve due to the decrease in hepatocyte apoptosis. Since the peripheral immune cells are expressed against tumors, a decrease in the progression of primary liver cancer decreased the expression of the peripheral immune cells. Conclusion: Dexmedetomidine's positive effects stood out in the present research article. The intervention reduced oxidation by balancing the production of reactive oxygen species and the detoxification processes. Reduced oxidation induced reduced cell death through apoptosis, resulting in a low expression of peripheral immune cells and improved liver functions.

Dexmedetomidine ameliorates liver injury and maintains liver function in patients with hepatocellular carcinoma after hepatectomy: a retrospective cohort study with propensity score matching

Background

Although dexmedetomidine (DEX) is widely used during the perioperative period in patients with hepatocellular carcinoma (HCC), its clinical effects on liver function and postoperative inflammation are unclear. This study aimed to explore effects of DEX on postoperative liver function and inflammation in patients with HCC after hepatectomy.

Methods

A retrospective cohort study with propensity score matching was performed. A total of 494 patients who underwent hepatectomy from June 2019 to July 2020 and fulfilled the eligibility criteria were included in this study. Baseline data, liver function indexes and inflammation-related biomarkers were collected and compared between the two groups. Survival analysis was conducted to investigate the effects of DEX on the overall survival (OS) of patients. Propensity score matching (PSM) was used to minimize bias between the two groups.

Results

The study cohort comprised 189 patients in the DEX-free group and 305 patients in the DEX group. Patients in the DEX group had lower levels of alanine transaminase (ALT, P = 0.018) and lactate dehydrogenase (LDH, P = 0.046) and higher level of serum albumin (ALB, P < 0.001) than patients in the DEX-free group before discharge. A total of 107 pairs of patients were successfully matched by PSM. Results consistently suggested that ALT and LDH levels were significantly lower (P = 0.044 and P = 0.046, respectively) and ALB levels were significantly higher (P = 0.002) in the DEX group than in the DEX-free group in the early postoperative period. No significant differences of inflammation-related biomarkers were observed between two groups after PSM. Neither the Kaplan-Meier survival analysis nor the multiple Cox regression survival analysis identified DEX as a contributing factor that would affect the OS of patients after PSM.

Conclusion

DEX exerts protective effects on liver function while has little effects on inflammation-related biomarkers in the early postoperative period in patients undergoing hepatectomy due to HCC.

Selenium deficiency aggravates bisphenol A-induced autophagy in chicken kidney through regulation of nitric oxide and adenosine monophosphate activated protein kinase/mammalian target of rapamycin signaling pathway

Bisphenol A (BPA), a phenolic compound, is harmful to humans and animals as its residue in the water threatens multiple organs, especially the kidney. Low selenium (Se) diets are consumed in many regions of the world, and poor Se status has exacerbating effect on toxicity of several environmental chemicals. Here, we described the discovery path of Se deficiency aggravation on autophagy in BPA treated chicken kidney through regulating nitric oxide (NO) and adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathways. The actual dietary Se intake for chickens was 0.30 mg/kg in control group and 0.03 mg/kg in Low-Se group, and BPA exposure concentration for chickens was 0.05 g/kg. Chicken embryo kidney (CEK) cells were used in vitro and the BPA exposure concentration for CEK cells was 150 nM. We found that BPA significantly increased levels of NO and inducible nitric oxide synthase, activated AMPK/mTOR signaling pathways, thereby triggering p62/LC3/Beclin1 signaling, resulting in formations of autophagosome and autolysosome, and finally stimulating autophagy in the chicken kidney. Additionally, Se deficiency promoted the occurrence of autophagy in BPA-treated kidneys. Altogether, our findings showed that Se deficiency exacerbates BPA-induced renal autophagy in chickens via regulation of NO and AMPK/mTOR signaling pathways. These findings will improve our understandings of the mechanisms of nephrotoxicity of BPA and detoxification by Se in chickens. In addition, further work is required to determine if Se status of exposed populations needs to be considered in future epidemiological assessments.

Protective effects of dexmedetomidine in vital organ injury: crucial roles of autophagy

Vital organ injury is one of the leading causes of global deaths. Accumulating studies have demonstrated that dexmedetomidine (DEX) has an outstanding protective effect on multiple organs for its antiinflammatory and antiapoptotic properties, while the underlying molecular mechanism is not clearly understood. Autophagy, an adaptive catabolic process, has been found to play a crucial role in the organ-protective effects of DEX. Herein, we present a first attempt to summarize all the evidence on the proposed roles of autophagy in the action of DEX protecting against vital organ injuries via a comprehensive review. We found that most of the relevant studies (17/24, 71%) demonstrated that the modulation of autophagy was inhibited under the treatment of DEX on vital organ injuries (e.g. brain, heart, kidney, and lung), but several studies suggested that the level of autophagy was dramatically increased after administration of DEX. Albeit not fully elucidated, the underlying mechanisms governing the roles of autophagy involve the antiapoptotic properties, inhibiting inflammatory response, removing damaged mitochondria, and reducing oxidative stress, which might be facilitated by the interaction with multiple associated genes (i.e., hypoxia inducible factor-1α, p62, caspase-3, heat shock 70 kDa protein, and microRNAs) and signaling cascades (i.e., mammalian target of rapamycin, nuclear factor-kappa B, and c-Jun N-terminal kinases pathway). The authors conclude that DEX hints at a promising strategy in the management of vital organ injuries, while autophagy is crucially involved in the protective effect of DEX.

Recent Advances in the Clinical Value and Potential of Dexmedetomidine

Dexmedetomidine, a highly selective α2-adrenoceptor agonist, has sedative, anxiolytic, analgesic, sympatholytic, and opioid-sparing properties and induces a unique sedative response which shows an easy transition from sleep to wakefulness, thus allowing a patient to be cooperative and communicative when stimulated. Recent studies indicate several emerging clinical applications via different routes. We review recent data on dexmedetomidine studies, particularly exploring the varying routes of administration, experimental implications, clinical effects, and comparative advantages over other drugs. A search was conducted on the PubMed and Web of Science libraries for recent studies using different combinations of the words “dexmedetomidine”, “route of administration”, and pharmacological effect. The current routes, pharmacological effects, and application categories of dexmedetomidine are presented. It functions by stimulating pre- and post-synaptic α2-adrenoreceptors within the central nervous system, leading to hyperpolarization of noradrenergic neurons, induction of an inhibitory feedback loop, and reduction of norepinephrine secretion, causing a sympatholytic effect, in addition to its anti-inflammation, sleep induction, bowel recovery, and sore throat reduction effects. Compared with similar α2-adrenoceptor agonists, dexmedetomidine has both pharmacodynamics advantage of a significantly greater α2:α1-adrenoceptor affinity ratio and a pharmacokinetic advantage of having a significantly shorter elimination half-life. In its clinical application, dexmedetomidine has been reported to present a significant number of benefits including safe sedation for various surgical interventions, improvement of intraoperative and postoperative analgesia, sedation for compromised airways without respiratory depression, nephroprotection and stability of hypotensive hemodynamics, reduction of postoperative nausea and vomiting and postoperative shivering incidence, and decrease of intraoperative blood loss. Although the clinical application of dexmedetomidine is promising, it is still limited and further research is required to enhance understanding of its pharmacological properties, patient selection, dosage, and adverse effects.

Trichostatin A improves the inflammatory response and liver injury in septic mice through the FoxO3a/autophagy signaling pathway

BACKGROUND

Sepsis-induced liver injury is a fatal complication of sepsis. Trichostatin A (TSA) regulates inflammation and autophagy in some human diseases, and forkhead box O3a (FoxO3a) has been shown to regulate autophagy. The present study aims to investigate whether TSA exerts its effects on septic liver injury through the FoxO3a/autophagy signaling pathway.

METHODS

A sepsis mouse model was constructed by the cecal ligation and puncture (CLP) method, and AML12 cells were pretreated with lipopolysaccharide (LPS) (1 μg/mL) to establish a sepsis cell model. Forty mice were divided into four groups, namely control group, TSA group, CLP group, and CLP+TSA group, with 10 mice in each group. Cells were divided into control group, TSA group, LPS group, and LPS+TSA group. Hematoxylin-eosin (H&E) staining and biochemical methods were used to evaluate liver tissue injury. Enzyme-linked immunosorbent assay (ELISA) was applied to detect the expression of proinflammatory cytokines, and Western blotting and immunofluorescence were used to measure autophagy-related protein expression.

RESULTS

Compared with the CLP group (mice), the proinflammatory cytokines (interleukin-β [IL-β] 2,665.27±324.90 pg/mL to 2,080.26±373.66 pg/mL; interleukin-6 [IL-6] 399.01±60.98 pg/mL to 221.90±46.89 pg/mL) and the hepatocyte injury markers (aspartate transaminase [AST] from 198.18±27.07 U/L to 128.42±20.55 U/L; alanine aminotransferase [ALT] from 634.98±74.10 U/L to 478.60±32.56 U/L) were notably decreased after TSA intervention. Moreover, LC3 II and FoxO3a showed an obvious increase and P62 showed an obvious decrease in the CLP+TSA group. Cell experiment results showed the similar trend. After FoxO3a gene was knocked down in AML12 cells, the promotion of autophagy and the improvement of liver enzyme index and inflammation by TSA were weakened.

CONCLUSION

TSA may improve the inflammatory response and liver injury in septic mice through FoxO3a/autophagy.

2-Amino-3-Methylimidazo[4,5-f]quinoline Triggering Liver Damage by Inhibiting Autophagy and Inducing Endoplasmic Reticulum Stress in Zebrafish (Danio rerio)

It is important to note that 2-Amino-3-methylimidazole[4,5-f]quinoline (IQ) is one of the most common heterocyclic amines (HCAs), which is a class of mutagenic/carcinogenic harmful compounds mainly found in high-protein thermal processed foods and contaminated environments. However, the pre-carcinogenic toxicity of IQ to the liver and its mechanism are poorly understood, further research is needed. In light of this, we exposed zebrafish to IQ (0, 8, 80, and 800 ng/mL) for 35 days, followed by comprehensive experimental studies. Histopathological and ultrastructural analysis showed that hepatocytes were damaged. TUNEL results showed that IQ induced apoptosis of liver cells, the expression of apoptosis factor gene was significantly increased, and the expression of Bcl-2 protein was significantly decreased. In addition, upregulated expression of the 78-kDa glucose-regulated protein (GRP78) and C/EBP homologous protein (CHOP) and endoplasmic reticulum stress (ERS)-related factors transcription levels were elevated obviously, suggesting that IQ induced ERS. Decreased protein expression of autophagy-related 5 (Atg5)-Atg12, Beclin1, and LC3-II, increased protein expression of p62, and autophagy-related factors transcription levels were significantly decreased, suggesting that IQ inhibited autophagy. Overall, our research showed that the potential harm of IQ to the liver before the occurrence of liver cancer was related to ERS and its mediated autophagy and apoptosis pathways.