Dexmedetomidine protected COPD-induced lung injury by regulating miRNA-146a

The Role of miRNAs in Dexmedetomidine's Neuroprotective Effects against Brain Disorders

There are limited neuroprotective strategies for various central nervous system conditions in which fast and sustained management is essential. Neuroprotection-based therapeutics have become an intensively researched topic in the neuroscience field, with multiple novel promising agents, from natural products to mesenchymal stem cells, homing peptides, and nanoparticles-mediated agents, all aiming to significantly provide neuroprotection in experimental and clinical studies. Dexmedetomidine (DEX), an α2 agonist commonly used as an anesthetic adjuvant for sedation and as an opioid-sparing medication, stands out in this context due to its well-established neuroprotective effects. Emerging evidence from preclinical and clinical studies suggested that DEX could be used to protect against cerebral ischemia, traumatic brain injury (TBI), spinal cord injury, neurodegenerative diseases, and postoperative cognitive disorders. MicroRNAs (miRNAs) regulate gene expression at a post-transcriptional level, inhibiting the translation of mRNA into functional proteins. In vivo and in vitro studies deciphered brain-related miRNAs and dysregulated miRNA profiles after several brain disorders, including TBI, ischemic stroke, Alzheimer’s disease, and multiple sclerosis, providing emerging new perspectives in neuroprotective therapy by modulating these miRNAs. Experimental studies revealed that some of the neuroprotective effects of DEX are mediated by various miRNAs, counteracting multiple mechanisms in several disease models, such as lipopolysaccharides induced neuroinflammation, β-amyloid induced dysfunction, brain ischemic-reperfusion injury, and anesthesia-induced neurotoxicity models. This review aims to outline the neuroprotective mechanisms of DEX in brain disorders by modulating miRNAs. We address the neuroprotective effects of DEX by targeting miRNAs in modulating ischemic brain injury, ameliorating the neurotoxicity of anesthetics, reducing postoperative cognitive dysfunction, and improving the effects of neurodegenerative diseases.

Protective Effect of Nalbuphine Combined With Dexmedetomidine on the Lungs of Children With Atelectasis and Foreign Body in the Bronchus During the Perioperative Period

Objective: The present study aims to explore the protective effect of nalbuphine combined with dexmedetomidine on the lungs of children with atelectasis who have a foreign body in a bronchus during the perioperative period.

Methods: A total of 180 patients whose computed tomography scan showed atelectasis and a foreign body in a bronchus were randomly divided into three groups: group C (conventional anesthesia group), group D (dexmedetomidine group), and group N + D (nalbuphine combined with the dexmedetomidine group). The following indicators were recorded: 1) heart rate (HR) and mean arterial pressure (MAP) prior to induction (T0), at bronchoscope placement (T1), at intubation after surgery (T2), at tube removal (T3), 10 min after tube removal (T4), 20 min after tube removal (T5), and at awaking (T6); 2) monocyte toll-like receptors (TLRs) TLR⁃2, TLR⁃4, tumor necrosis factor α, interleukin 6, oxygenation index, and the B-line sum at T0, T3, 2 h (T7), and 24 h (T8) after tube removal; and 3) hospital stay after surgery.

Results: Compared with group C, in group D and group N + D, 1) the HR and MAP at T1∼T6 were lower; 2) the inflammatory factor indicator and B-line sum were lower, and the oxygenation index was higher at T7 and T8; 3) the agitation and cough scores were decreased during tube removal; and 4) the Ramsay sedation score was higher, and ventilator weaning time was shortened at T4∼T6 (p < 0.05). Compared with group D, in group N + D, 1) the inflammatory factor indicator and B-line sum were lower at T8; 2) the oxygenation index was higher (p < 0.05). Compared with groups C and D, in group N + D, the length of hospital stay was decreased (p < 0.05).

Conclusion: In patients with atelectasis and a foreign body in a bronchus during the perioperative period, nalbuphine combined with dexmedetomidine may be capable of reducing the oxidative stress response, improving the oxygenation index, decreasing the pulmonary fluid content, protecting the lung, and facilitating postoperative recovery.

Animal models of emphysema

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease of human beings characterized by not fully reversible airflow limitation. Emphysema is the main pathological feature of COPD which causes high mortality worldwide every year and consumes a large amount of medical expenses. This paper was to review the establishment and evaluation methods of animal models of emphysema or COPD, and put forward some new ideas on animal selection, method of modeling, and model evaluation.

DATA SOURCES

The author retrieved information from the PubMed database up to July 2019, using various combinations of search terms, including emphysema, model, and animal.

STUDY SELECTION

Original articles, reviews, and other articles were searched and reviewed for animal models of emphysema.

RESULTS

This review summarized animal models of emphysema from the perspectives of animal selection, emphysema mechanism, modeling method and model evaluation, and found that passive smoking is the classic method for developing animal model of emphysema, mice are more suitable for experimental study on emphysema. Compared with pulmonary function indicators, airway inflammation indicators and oxidative stress indicators, pathomorphological indicators of lung tissue are the most important parameters for evaluating the establishment of the animal model of emphysema.

CONCLUSIONS

Mice model induced by passive smoking is the classic animal model of emphysema. Pathomorphological indicators are the most important parameters for evaluating the establishment of the animal model of emphysema.

Identification of Candidate Genes and Pathways in Dexmedetomidine-Induced Cardioprotection in the Rat Heart by Bioinformatics Analysis

Dexmedetomidine (DEX), a highly selective alpha2 adrenergic receptor agonist, directly protects hearts against ischemia/reperfusion (I/R) injury. However, the detailed mechanism has not been fully elucidated. We studied differentially expressed mRNAs and miRNAs after DEX administration in rat hearts by comprehensive analysis. Additionally, bioinformatics analysis was applied to explore candidate genes and pathways that might play important roles in DEX-induced cardioprotection. The results of microarray analysis showed that 165 mRNAs and 6 miRNAs were differentially expressed after DEX administration. Through bioinformatics analysis using differentially expressed mRNAs, gene ontology (GO) terms including MAP kinase tyrosine/serine/threonine phosphatase activity and pathways including the p53 pathway were significantly enriched in the down-regulated mRNAs. Dusp1 and Atm were associated with the GO term of MAP kinase tyrosine/serine/threonine phosphatase activity and the p53 pathway, respectively. On the other hand, no significant pathway was found in the target mRNAs of deregulated miRNAs. The results indicated some possible key genes and pathways that seem to be of significance in DEX-induced cardioprotection, although miRNAs seem to be unlikely to contribute to cardioprotection induced by DEX.

Geriatric Anesthesia-related Morbidity and Mortality in China: Current Status and Trend

Objective:

The population of elderly patients and the amount of geriatric anesthesia have been growing rapidly in China. Thus, understanding the morbidity and mortality associated with geriatric anesthesia in China is critical to the improvement of anesthesia quality and outcome. The aim of the review was to discuss the geriatric anesthesia-related morbidity and mortality in China, as well as to point out the future trend.

Data Sources:

Articles in this review were all searched from Wanfang, China National Knowledge Infrastructure (CNKI), VIP, PubMed, and Web of Science databases, based on the reports originated in China from January 2011 to December 2016.

Study Selection:

A total of 57 studies were selected for further study, including 12 retrospective studies, 35 prospective studies, 3 meta-analyses, 4 reviews, 1 viewpoint, and 2 case reports. Of the total studies, 42 studies were in Chinese while 15 were in English.

Results:

The mortality and morbidity associated with geriatric anesthesia in China are not yet completely reported. Some factors have been recognized, while some are yet to be identified and confirmed. Several studies addressed postoperative cognitive dysfunction and postoperative delirium, whereas only a few studies can be found on renal complications. Thus, a nationwide registry is essential for geriatric anesthesia-associated adverse outcomes. The mortality associated with geriatric anesthesia in China should be reported promptly. In the future, the perspective of geriatric anesthesia needs to be expanded into perioperative geriatric medicine to improve the perioperative management strategy based on the postoperative outcome-directed concept transformation.

Conclusions:

Anesthesiologists should evaluate the physiological and medical status and focus on the prevention of potential complications in the perioperative setting with the goal to enhance elderly patients’ long-term well-being and survival quality.