Dexmedetomidine reduces the inflammation and apoptosis of doxorubicin-induced myocardial cells

Thiolutin Alleviates Cardiotoxic Effects of Doxorubicin by Suppressing NLRP3 Inflammasome in the Mouse Model

Doxorubicin (DOX) has a limitation in clinical oncology due to its dose-dependent cardiotoxicity. Thiolutin (THL) can undermine DOX-induced cardiomyocyte injury by inhibiting the NLRP3 inflammasome activation, yet the efficacy of THL in DOX-induced cardiotoxicity (DOXIC) needs to be validated in animal models. DOX-induced mice were treated with THL to evaluate the efficacy of THL. Relative NLRP3 mRNA levels were determined by quantitative PCR. Blood samples were collected from diffuse large B-cell lymphoma (DLBCL) patients with or without DOXIC to validate serum levels of cTnT, IL-1β, CRP, BNP, and IL-18 by enzyme-linked immunosorbent assay. Apoptosis and pyroptosis-related protein levels were analyzed by western blot. Cardiac function and histopathological changes were determined by echocardiography, HE, Masson's, and wheat germ agglutinin staining. In clinical samples, NLRP3 mRNA and/or protein levels were also markedly heightened in peripheral blood mononuclear cells and serum samples from DOXIC patients, along with higher concentrations of IL-18, cTnT, and IL-1β. Importantly, cTnT possessed a positive correlation with NLRP3 mRNA, IL-1β, and IL-18. Moreover, cTnT possessed a positive correlation with NLRP3 mRNA, IL-1β, and IL-18 levels, suggesting a potential link between DOXIC and NLRP3 inflammasome. The outcomes demonstrated that THL reduced LVEF and LVFS, as well as elevated LVESD and LVEDD in DOX-challenged mice, accompanied by elevated serum concentrations of cTnT, CRP, and BNP. In addition, THL attenuated DOX-induced myocardial hypertrophy and cardiac fibrosis in mice, in conjunction with attenuation of DOX-induced upregulation of C-caspase3, Bax, NLRP3, C-caspase-1/Pro-caspase, GSDMD-N/GSDMD, IL-1β, and IL-18 in heart or serum samples. In conclusion, our data supported that THL alleviates the cardiotoxic effects of DOX and suppresses NLRP3 inflammasome in the mouse model, suggesting that THL as a potential drug for DOXIC.

Insight into Cardioprotective Effects and Mechanisms of Dexmedetomidine

PURPOSE

Cardiovascular disease remains the leading cause of death worldwide. Dexmedetomidine is a highly selective α2 adrenergic receptor agonist with sedative, analgesic, anxiolytic, and sympatholytic properties, and several studies have shown its possible protective effects in cardiac injury. The aim of this review is to further elucidate the underlying cardioprotective mechanisms of dexmedetomidine, thus suggesting its potential in the clinical management of cardiac injury.

RESULTS AND CONCLUSION

Our review summarizes the findings related to the involvement of dexmedetomidine in cardiac injury and discusses the results in the light of different mechanisms. We found that numerous mechanisms may contribute to the cardioprotective effects of dexmedetomidine, including the regulation of programmed cell death, autophagy and fibrosis, alleviation of inflammatory response, endothelial dysfunction and microcirculatory derangements, improvement of mitochondrial dysregulation, hemodynamics, and arrhythmias. Dexmedetomidine may play a promising and beneficial role in the treatment of cardiovascular disease.

Fabrication of apigenin and adenosine-loaded nanoparticles against doxorubicin-induced myocardial infarction by reducing inflammation and oxidative stress

The study's goals are to fabricate PLGA nanoparticles (PNPs) loaded with apigenin (AP) and adenosine (AD) using a microfluidic preparation method to a standard emulsification method and investigate the possible heart-protective effects of AP-AD PNPs made using the emulsification method. Compared to microfluidics, the emulsification method fabricated small-size nanoparticles, which are better at encapsulating drugs, retaining more drugs, and having a low viscosity for the myocardial infarction (MI) injection. TheMI model was developed using SD rats injected under the skin with 85 mg/kg doxorubicin (DOX) for 2 days. The metabolic results showed that our AP-AD PNPs accelerated the blood flow in rats with MI, which increased the amounts of AP and AD in the circulatory system. This led to significant improvements in the cardiac index and lower amounts of AST, LDH, and CK in the blood. A histopathological study using Hematoxylin&eosin, and TUNEL staining showed that cardiac function had improved and apoptosis had decreased. Moreover, tests that checked the amounts of IL-6, TNF-α, NO, GSH, MDA, and SOD showed that AP-AD PNPs may help treat MI by reducing oxidative stress and inflammation, making it a potentially useful therapeutic approach.

Dexmedetomidine alleviates myocardial ischemia-reperfusion injury by down-regulating miR-34b-3p to activate the Jagged1/Notch signaling pathway

BACKGROUND

Myocardial ischemia/reperfusion (I/R) injury is a fatal event that usually occurs after reperfusion therapy for myocardial infarction. Dexmedetomidine (Dex) has been shown to be beneficial in the treatment of myocardial infarction, however, its underlying mechanism for regulating I/R injury is unclear.

METHODS

H9c2 cell and rat models of I/R injury were established via oxygen-glucose deprivation reoxygenation (OGD/R) and occlusion of the left anterior descending branch of coronary artery, respectively. Flow cytometry, MTT, or DHE assay detected cell activity, ROS, or apoptosis, respectively. The expression levels of miR-34b-3p and related mRNAs were determined using qRT-PCR. Related protein expression levels were detected by Western blotting and ELISA test. The interaction between miR-34b-3p and Jagged1 was assessed by dual luciferase reporter and RIP assays. The morphology of cardiac tissue was examined by TTC, HE, and TUNEL labeling.

RESULTS

Dex markedly inhibited the inflammatory damage and apoptosis caused by OGD/R in H9c2 cells. MiR-34b-3p and Jagged1 levels were increased and decreased in myocardial I/R injury model, respectively, while Dex reversed this effect. Moreover, miR-34b-3p was firstly reported to directly bind and decrease Jagged1 expression, thereby inhibiting Notch signaling pathway. Transfection of agomiR-34b-3p or Jagged1 silencing eliminated Dex's defensive impact on OGD/R-induced cardiomyocytes damage. Dex relieved the myocardial I/R injury of rats via inhibiting miR-34b-3p and further activating Notch signaling pathway.

CONCLUSION

Dex protected myocardium from I/R injury via suppressing miR-34b-3p to activate Jagged1-mediated Notch signaling pathway. Our findings revealed a novel mechanism underlying of Dex on myocardial I/R injury.

Dexmedetomidine protects cells from Angiotensin II-induced smooth muscle cell phenotype switch and endothelial cell dysfunction

Abdominal aortic aneurysm (AAA) is a vascular disorder greatly threatening life of the elderly population. Dexmedetomidine (DEX), an α2-adrenergic receptor agonist, has been shown to suppress AAA development. Nevertheless, the signaling pathways that might be mediated by DEX in AAA has not been clarified. Vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) were treated with Angiotensin II (Ang II) to mimic AAA in vitro. BrdU, wound healing, and Transwell assays were utilized for measuring VSMC proliferation and migration. Western blotting was used for evaluating protein levels of contractile VSMC markers, collagens and matrix metalloproteinases (MMPs) in VSMCs as well as apoptosis- and HMGB1/TLR4/NF-κB signaling-related markers in ECs. Cell adhesion molecule expression and monocyte-endothelial adhesion were assessed by immunofluorescence staining and adhesion assays. Flow cytometry was implemented for analyzing EC apoptosis. Hematoxylin-eosin staining and ELISA were used to detect the effect of DEX in vivo. In this study, DEX inhibited Ang II-evoked VSMC phenotype switch and extracellular matrix degradation. DEX suppressed the inflammatory response and apoptosis of ECs induced by Ang II. DEX inhibited HMGB1/TLR4/NF-κB signaling pathway in Ang II-treated ECs. DEX attenuated Ang II-induced AAA and inflammation in mice. Overall, DEX ameliorates Ang II-induced VSMC phenotype switch, and inactivates HMGB1/TLR4/NF-κB signaling pathway to alleviate Ang II-induced EC dysfunction.

Protective Effects of Dexmedetomidine Infusion on Genotoxic Potential of Isoflurane in Patients Undergoing Emergency Surgery

BACKGROUND

Isoflurane (ISO) has been extensively uses in general anesthesia and reported to cause deoxyribonucleic acid (DNA) damage in prolonged surgical procedures. Dexmedetomidine (DEX) is an adrenergic agonist and having antioxidant activity that may reduce the genotoxic potential (DNA damage) and oxidative stress induced by ISO in patients undergoing major neurosurgical procedures. Methods and Findings. Twenty-four patients of ASA (American Society of Anesthesiologists) classes I and II were randomly divided into two groups (n = 12). Group A patients received ISO, while group B patients received DEX infusion for maintenance of anesthesia. Venous blood samples were collected at different time intervals and used to evaluate the oxidative stress marker malondialdehyde (MDA) and endogenous antioxidants superoxide dismutases (SOD) and catalases (CAT). A single-cell gel electrophoresis (SCGE)-comet assay was used to investigate the genotoxic potential of ISO.

CONCLUSION

Increased level of antioxidants and decreased value of MDA and genetic damage index were seen in group B (P < 0.001) in a time-dependent manner. Genetic damage was highest at point T ₂ (0.77 vs. 1.37), and continued to decrease till T ₃ (0.42 vs. 1.19), with respect to negative controls or baseline values following DEX infusion. Significantly, higher level of MDA was recorded in serum of group A (P < 0.001) as compared to group B (1.60 ± 0.33 vs. 0.03 ± 0.001). Enzymatic activities of CAT and SOD were significantly higher in group B than group A (10.11 ± 2.18 vs. 5.71 ± 0.33), (1.04 ± 0.05 vs. 0.95 ± 0.01), respectively. It may play a contributing role in daily anesthesia practice and improve the toxic effects on patients as well as anesthesia personnel. Trial Registration. Ethical Committee of Post Graduate Medical Institute (PGMI), Lahore General Hospital approved the use of humans in this study vide human subject application number ANS-6466 dated February 04, 2019. Furthermore, as the clinical trials required registration from an appropriate registry approved by World Health Organization (WHO), this trail also retrospectively registered at Thai Clinical Trials Registry (an approved WHO registry for clinical trials registration) under reference ID TCTR20211230001 on December 30, 2021.

Piracetam as a Therapeutic Agent for Doxorubicin-Induced Cognitive Deficits by Enhancing Cholinergic Functions and Reducing Neuronal Inflammation, Apoptosis, and Oxidative Stress in Rats

Cancer chemotherapy is known to cause cognitive defects in patients. Our study investigated the effect of piracetam (PIRA; 200 or 400 mg/kg) against doxorubicin (DOX)-induced cognitive deficits in a rat model. The cognitive parameters were analyzed using elevated plus-maze, novel object recognition, and Y-maze tests. Acetylcholinesterase (AChE), neuroinflammatory mediators (cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), nuclear factor-κB (NF-κB), tumor necrosis factor-alpha (TNF-α)), apoptotic proteins (B-cell lymphoma-2 (Bcl-2), Bcl2 associated X protein (Bax), cysteine aspartate specific protease-3 (caspase-3)), oxidative parameters (malondialdehyde (MDA), catalase (CAT), and glutathione (GSH)) were also determined in the brain. PIRA administration offered significant protection against DOX-induced cognitive deficits in all maze tests and restored cholinergic functions via a significant reduction in AChE levels. Additionally, PIRA suppressed DOX-induced neuroinflammatory mediators (COX-2, PGE2, NF-κB, and TNF-α), pro-apoptotic proteins (Bax and caspase-3), and oxidative stress (MDA). Besides, it facilitated antioxidant (CAT and GSH) levels. Hence, our study highlighted that the neuroprotective activity of PIRA against DOX-induced cognitive deficits can be linked to reductions of AChE levels, neuro-inflammatory mediators, pro-apoptotic proteins, and oxidative stress.

Endogenous Hydrogen Sulfide Persulfidates Caspase-3 at Cysteine 163 to Inhibit Doxorubicin-Induced Cardiomyocyte Apoptosis

Doxorubicin (DOX) is an efficient antitumor anthracycline drug, but its cardiotoxicity adversely affects the prognosis of the patients. In this study, we explored whether endogenous gasotransmitter hydrogen sulfide (H₂S) could protect against DOX-induced cardiomyocyte apoptosis and its mechanisms. The results indicated that DOX significantly downregulated endogenous H₂S production and endogenous synthetase cystathionine γ-lyase (CSE) expression and obviously stimulated the apoptosis in H9C2 cells. The supplement of H₂S donor sodium hydrosulfide (NaHS) or overexpression of CSE inhibited DOX-induced H9C2 cell apoptosis. DOX enhanced the activities of caspase family members in cardiomyocytes, while NaHS attenuated DOX-enhanced caspase-3, caspase-2, and caspase-9 activities by 223.1%, 73.94%, and 52.29%, respectively. Therefore, taking caspase-3 as a main target, we demonstrated that NaHS or CSE overexpression alleviated the cleavage of caspase-3, suppressed caspase-3 activity, and inhibited the cleavage of poly ADP-ribose polymerase (PARP). Mechanistically, we found that H₂S persulfidated caspase-3 in H9C2 cells and human recombinant caspase-3 protein, while the thiol-reducing agent dithiothreitol (DTT) abolished H₂S-induced persulfidation of caspase-3 and thereby prevented the antiapoptotic effect of H₂S on caspase-3 in H9C2 cells. The mutation of caspase-3 C148S and C170S failed to block caspase-3 persulfidation by H₂S in H9C2 cells. However, caspase-3 C163S mutation successfully abolished the effect of H₂S on caspase-3 persulfidation and the corresponding protection of H9C2 cells. Collectively, these findings indicate that endogenous H₂S persulfidates caspase-3 at cysteine 163, inhibiting its activity and cardiomyocyte apoptosis. Sufficient endogenous H₂S might be necessary for the protection against myocardial cell apoptosis induced by DOX. The results of the study might open new avenues with respect to the therapy of DOX-stimulated cardiomyopathy.

Dexmedetomidine post-conditioning alleviates myocardial ischemia-reperfusion injury in rats by ferroptosis inhibition via SLC7A11/GPX4 axis activation

The SLC7A11/GPX4 axis plays an important role in ferroptosis during cardiac ischemia/reperfusion injury (IRI). The present study was designed to evaluate the impact of dexmedetomidine (DEX) post-conditioning on cardiac IRI and to explore whether the effect was achieved by SLC7A11/GPX4 signaling pathway regulation. Rat myocardial IRI was established by occluding the left anterior descending artery for 30 min followed by 2-h reperfusion. The infarct area was detected by diphenyltetrazolium chloride (TTC) staining; the cardiac function was evaluated by echocardiography. The levels of lipid peroxide biomarkers were measured to estimate the injury caused by lipid peroxide. HE staining and Sirius staining were utilized to assess myocardial damage and fibrosis. The mitochondrial morphology was observed by electron micrography. Western blot and quantitative real-time polymerase chain reaction were employed to measure the relative molecular characteristics. Our results showed that DEX administration at the beginning of reperfusion attenuated IRI-induced myocardial injury, alleviated mitochondrial dysfunction, decreased the level of reactive oxygen species (ROS), alleviated mitochondrial dysfunction, inhibited the activation of SLC7A11/GPX4, and modulated the expression of ferroptosis-related proteins, including SLC7A11, glutathione peroxidase 4 (GPX4), ferritin heavy chain (FTH), and cyclooxygenase-2 (COX-2). Conversely, the ferroptosis activator erastin partly suppressed the DEX-mediated cardio protection. Altogether, these results reveal that DEX inhibits ferroptosis by enhancing the expression of SLC7A11 and GPX4, thereby preventing cardiac I/R injury.

Circular RNA cerebellar degeneration-related protein 1 antisense RNA (Circ-CDR1as) downregulation induced by dexmedetomidine treatment protects hippocampal neurons against hypoxia/reoxygenation injury through the microRNA-28-3p (miR-28-3p)/tumor necrosis factor receptor-associated factor-3 (TRAF3) axis

Cerebral ischemia/reperfusion (CI/R) injury results in serious brain tissue damage, thereby leading to long-term disability and mortality. It has been reported that dexmedetomidine (DEX) exerted neuroprotective effects in CI/R injury. Herein, we intended to investigate whether and how circular RNA (circRNA) cerebellar degeneration-related protein 1 antisense RNA (circ-CDR1as) was involved in the DEX-mediated protection on hippocampal neurons. In our work, the mouse hippocampal neuronal cells (HT-22) were used to construct a hypoxia/reperfusion (H/R) model for CI/R injury. Cell proliferation and apoptosis were evaluated by CCK-8 and flow cytometry. Gene expressions were detected by RT-qPCR. Levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) were measured by ELISA. The association between miR-28-3p and circ-CDR1as or TRAF3 was verified by dual-luciferase assay. The results indicated that DEX alleviated HT-22 cell dysfunction induced by H/R treatment. In addition, circ-CDR1as was downregulated after DEX treatment and reversed the effects of DEX on the proliferation, apoptosis, and inflammatory responses of H/R-treated HT-22 cells. Circ-CDR1as positively regulated TRAF3 expression via interaction with miR-28-3p in HT-22 cells. Circ-CDR1as aggravated H/R-treated HT-22 cell dysfunction through targeting miR-28-3p. Furthermore, TRAF3 inhibition partly abolished the effect of circ-CDR1as overexpression on cellular activities of H/R-treated HT-22 cells. To sum up, our findings, for the first time, demonstrated that DEX exerted neuroprotective effects on hippocampal neurons against H/R treatment via the circ-CDR1as/miR-28-3p/TRAF3 regulatory network, providing novel therapeutic targets for DEX administration in CI/R treatment.

Long-Chain and Very Long-Chain Ceramides Mediate Doxorubicin-Induced Toxicity and Fibrosis

Doxorubicin (Dox) is a chemotherapeutic agent with cardiotoxicity associated with profibrotic effects. Dox increases ceramide levels with pro-inflammatory effects, cell death, and fibrosis. The purpose of our study was to identify the underlying ceramide signaling pathways. We aimed to characterize the downstream effects on cell survival, metabolism, and fibrosis. Human fibroblasts (hFSF) were treated with 0.7 µM of Dox or transgenically overexpressed ceramide synthase 2 (FLAG-CerS2). Furthermore, cells were pre-treated with MitoTempo (MT) (2 h, 20 µM) or Fumonisin B1 (FuB) (4 h, 100 µM). Protein expression was measured by Western blot or immunofluorescence (IF). Ceramide levels were determined with mass spectroscopy (MS). Visualizations were conducted using laser scanning microscopy (LSM) or electron microscopy. Mitochondrial activity was measured using seahorse analysis. Dox and CerS2 overexpression increased CerS2 protein expression. Coherently, ceramides were elevated with the highest peak for C24:0. Ceramide- induced mitochondrial ROS production was reduced with MT or FuB preincubation. Mitochondrial homeostasis was reduced and accompanied by reduced ATP production. Our data show that the increase in pro-inflammatory ceramides is an essential contributor to Dox side-effects. The accumulation of ceramides resulted in a lipotoxic shift and subsequently mitochondrial structural and functional damage, which was partially reversible following inhibition of ceramide synthesis.

Dexmedetomidine alleviates myocardial ischemia/reperfusion-induced injury and Ca2+ overload via the microRNA-346-3p/CaMKIId axis

Myocardial ischemia/reperfusion (MI/R) may impair cardiac functions. Dexmedetomidine (DEX) is protective in various clinical cases. Therefore, this study investigated the role and mechanism of DEX in MI/R. The myocardial infarct size, apoptosis, and levels of myocardial enzymes, SOD, ROS, Ca²⁺, and inflammatory factors in DEX-treated MI/R rats were measured. Differentially expressed microRNAs (miRs) in DEX-treated MI/R rats were detected. miR-346-3p was intervened to assess the effects of DEX on MI/R rats. The targeted binding relationship between miR-346-3p and CaMKIId was predicted and verified. DEX effect on hypoxia/reoxygenation (H/R)-induced cell model was evaluated. The role of CaMKIId in DEX protection was assessed after CaMKIId overexpression in H/R cells. NF-κB pathway and NLRP3 inflammasome-related protein levels were detected. DEX alleviated the myocardial injury and Ca²⁺ overload in MI/R rats, as evidenced by reduced infarct size, apoptosis and levels of myocardial enzymes, ROS, Ca²⁺, and inflammatory factors. DEX promoted miR-346-3p expression in MI/R rats, and miR-346-3p knockdown reversed DEX protection on MI/R rats. miR-346-3p targeted CaMKIId. DEX improved H/R-induced cell injury and Ca²⁺ overload and inhibited NF-κB/NLRP3 inflammasome-related protein levels, which were all reversed by CaMKIId overexpression. DEX alleviated injury and Ca²⁺ overload in MI/R via regulating the miR-346-3p/CaMKIId axis and inhibiting the NF-κB/NLRP3 inflammasome pathway.

The Emerging Role of TXNIP in Ischemic and Cardiovascular Diseases; A Novel Marker and Therapeutic Target

Thioredoxin interacting protein (TXNIP) is a metabolism- oxidative- and inflammation-related marker induced in cardiovascular diseases and is believed to represent a possible link between metabolism and cellular redox status. TXNIP is a potential biomarker in cardiovascular and ischemic diseases but also a novel identified target for preventive and curative medicine. The goal of this review is to focus on the novelties concerning TXNIP. After an overview in TXNIP involvement in oxidative stress, inflammation and metabolism, the remainder of this review presents the clues used to define TXNIP as a new marker at the genetic, blood, or ischemic site level in the context of cardiovascular and ischemic diseases.

The effect of dexmedetomidine on gastric ischemia reperfusion injury in rats. Biochemical and histopathological evaluation

Purpose:

To evaluate the protective effect of dexmedetomidine on gastric injury induced by ischemia reperfusion (I/R) in rats.

Methods:

A total of 18 male albino Wistar rats were divided groups as: gastric ischemia reperfusion (GIR), gastric ischemia reperfusion and 50 μg/kg dexmedetomidine (DGIR) and sham operation (HG) group. After the third hour of reperfusion, the biochemical and histopathological examinations were performed on the removed stomach tissue.

Results:

Malondialdehyde (MDA) and myeloperoxidase (MPO) levels were found to be significantly higher in GIR compared to HG (p < 0.05). A statistically significant decrease was observed at the DGIR compared to the GIR for oxidants levels. Total glutathione (tGSH) and superoxide dismutase (SOD) levels were statistically significantly decreased at the GIR, and antioxidants levels were found to be significantly higher in the DGIR (p < 0.05) There was no significant difference between HG and DGIR in terms of SOD (p = 0.097). The DGIRs’ epitheliums, glands and vascular structures were close to normal histological formation.

Conclusions:

Dexmedetomidine is found to prevent oxidative damage on the stomach by increasing the antioxidant effect. These results indicate that dexmedetomidine may be useful in the treatment of ischemia-reperfusion-related gastric damage.

Investigation of the Therapeutic Effects of Chloroquine in Adriamycin-Induced Hepatotoxicity

The aim of this study is to investigate the therapeutic effects of Chloroquine (CLQ) against Adriamycin (ADR) induced hepatotoxicity. ADR is a chemotherapeutic agent used in the treatment of many cancer types, but it causes hepatotoxicity. CLQ is used as an anti-inflammatory drug in the treatment of malaria, rheumatoid arthritis, and pneumonia caused by Covid-19. Rats were divided into four groups: Control group, ADR group (2 mg/kg Adriamycin, one in three days for 30 days, i.p.), CLQ group (50 mg/kg Chloroquine, per day for 30 days, i.p.), ADR+CLQ (2 mg/kg Adriamycin, one in three days for 30 days, i.p. and 50 mg/ kg Chloroquine, per day for 30 days, i.p.). Animals were sacrificed, and liver tissues were extracted for further examinations. Histopathological changes in liver tissues were scored and IL-17 immunostaining was performed to determine the expression levels among experimental groups. Bodyweights in the ADR group decreased significantly compared to the Control group and CLQ group. Furthermore, bodyweight in ADR+CLQ group was significantly higher compared to ADR group. The histopathological score was significantly higher in ADR group when compared to Control and CLQ group while CLQ administrations reduced the damage induced by ADR in the ADR+CLQ group. IL-17 immunoreactivity was considerably increased in the ADR group. On the other hand, IL-17 expressions of ADR+CLQ were substantially less compared to ADR group. We suggest that CLQ can be used as a therapeutic agent to reduce the detrimental effects of ADR, thanks to its anti-inflammatory properties.

Dexmedetomidine alleviates non-ventilation associated lung injury via modulating immunology phenotypes of macrophages

AIMS

We aimed to evaluate the effect of Dexmedetomidine (Dex) on immunology function of macrophages and inflammatory reactions in non-ventilated lung tissues from both humans and rats.

MAIN METHODS

Patients scheduled for lung lobectomy were randomly assigned to traditional anesthesia group or Dex anesthesia group, 15 subjects in each group. CD68, CD86 and CD206 were used to mark activate and polarized macrophages using immunofluorescence staining in human lung tissues. Sprague-Dawley rats were used to set lung injury model and randomly divided into Control group, one-lung ventilation group (CLI group) and CLI + Dex group. Lung tissues and bronchoalveolar lavage fluid (BALF) from non-ventilated lungs were collected. The acquired lung tissues were subjected to hematoxylin-eosin (H&E) staining and the inflammatory cells in BALF were calculated. Levels of cytokines and chemokines were detected by enzyme-linked immunosorbent assays (ELISA).

KEY FINDINGS

Results from humans showed that anesthesia with Dex decreased the number of both CD68 positive cells and CD86 positive cells and down-regulated level of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and monocyte chemotactic protein 1 (MCP-1) in human lung. Results from rats demonstrated that treatment with Dex reversed the increased inflammatory cells in lung and the increased levels of TNF-α, interleukin-1β (IL-β), MCP-1 and chemokine (C-X-C motif) ligand 1 (CXCL1) resulted from non-ventilation; Dex increased the anti-inflammatory cytokine interleukin-10 (IL-10) in BALF from non-ventilated lung.

SIGNIFICANCE

This study showed that Dex modulated the activation and immunological function of macrophages in non-ventilated lung and revealed a protective role in collapsed lung injury.