Paracoxib Alleviates Ventilator-Induced Lung Injury Through Functional Modulation of Lung-Recruited CD11bloLy6Chi Monocytes

Parecoxib sodium attenuates acute lung injury following burns by regulating M1/M2 macrophage polarization through the TLR4/NF-κB pathway

High temperature-induced burn injury often leads to an excessive inflammatory cascade resulting in multiple organ dysfunction syndrome, such as acute lung injury (ALI), in addition to skin tissue damage. As a specific COX2 inhibitor, parecoxib sodium suppresses the inflammatory response during burn injury. The effect of parecoxib sodium on ALI induced by burn injury and the associated molecular mechanism still need to be investigated. The role of parecoxib sodium in burn injury-induced ALI through the TLR4/NF-κB pathway was explored in the present study. A burn-induced ALI mouse model was constructed, and M1/M2 macrophages in lung tissue and markers involved in the TLR4/NF-κB signalling pathway were evaluated in bronchoalveolar lavage fluid (BALF) and MH-S mouse alveolar macrophages in vitro. The results indicated that parecoxib sodium attenuated lung injury after burn injury, decreased iNOS and TNF-α expression, increased IL-10 expression in BALF, and regulated the CD86-and CD206-mediated polarization of M1/M2 macrophages in lung tissue along with MH-S mouse alveolar macrophages. The effect of parecoxib sodium might be reversed by a TLR4 agonist. Overall, the results suggested that parecoxib sodium can regulate the polarization of M1/M2 macrophages through the TLR4/NF-κB pathway to attenuate ALI induced by skin burns.

Angiotensin Type 2 Receptor Pharmacological Agonist Relieves Neurocognitive Deficits via Reducing Neuroinflammation and Microglial Engulfment of Dendritic Spines

Mechanically ventilated patients suffering critical illness are at high risk of developing neurocognitive impairments. Angiotensin type 2 receptor (AGTR2) has been demonstrated to be anti-inflammatory and neuroprotective. The present study thus aimed to investigate whether AGTR2 can alleviate cerebral dysfunction in mice subjected to cochallenge with lipopolysaccharide (LPS) and mechanical ventilation (MV), and to reveal the underlying mechanism. We utilized a mice model that received a single injection of LPS (1 mg/kg, intraperitoneally) followed 2 h later by MV (10 ml/kg, lasting for 2 h). Pretreatment with the AGTR2 pharmacological agonist C21 (0.03, 0.3, and 3 mg/kg, intraperitoneally, once daily, lasting for 10 days). Locomotor activity and behavioral deficits were evaluated 24 h post-MV by open-field and fear-condition tests. Brain hippocampus and prefrontal cortex tissues were collected for immunofluorescence staining and western blotting to evaluate the resulting impacts on microglia, including morphological traits, functional markers, synaptic engulfment, superoxide production, and signaling molecules. Compared with vehicle-control, pre-administrated C21 reduced the branch endpoints and length of microglia processes in a dose-dependent manner in mice subjected to LPS/MV. The neuroprotective effect of AGTR2 was behaviorally confirmed by the improvement of memory decline in LPS/MV-treated mice following C21 pretreatment. In addition to morphological alterations, C21 reduced microglial functional markers and reduced microglial-dendrite contact and microglial engulfment of synaptic protein markers. In terms of the underlying molecular mechanism, AGTR2 stimulation by C21 leads to activation of protein phosphatase 2A, which subsequently mitigates microglial PKCδ and NF-κB activation, and inhibites NOX2-derived ROS production. The AGTR2 agonist C21 alleviates behavioral deficits in those mice subjected to LPS/MV, via mechanisms that involve reactive microglia and abnormal synaptic plasticity in NOX2-derived ROS and the PKCδ-NFκB pathway.

Significance of Pulmonary Endothelial Injury and the Role of Cyclooxygenase-2 and Prostanoid Signaling

The endothelium plays a key role in the dynamic balance of hemodynamic, humoral and inflammatory processes in the human body. Its central importance and the resulting therapeutic concepts are the subject of ongoing research efforts and form the basis for the treatment of numerous diseases. The pulmonary endothelium is an essential component for the gas exchange in humans. Pulmonary endothelial dysfunction has serious consequences for the oxygenation and the gas exchange in humans with the potential of consecutive multiple organ failure. Therefore, in this review, the dysfunction of the pulmonary endothel due to viral, bacterial, and fungal infections, ventilator-related injury, and aspiration is presented in a medical context. Selected aspects of the interaction of endothelial cells with primarily alveolar macrophages are reviewed in more detail. Elucidation of underlying causes and mechanisms of damage and repair may lead to new therapeutic approaches. Specific emphasis is placed on the processes leading to the induction of cyclooxygenase-2 and downstream prostanoid-based signaling pathways associated with this enzyme.

The effect of parecoxib sodium on postoperative delirium in elderly patients with hip arthroplasty

Objective: This study aimed to clarify the effect of parecoxib sodium on the occurrence of postoperative delirium and to investigate its possible mechanism. Methods: A total of 80 patients who underwent elective hip arthroplasty in our hospital between December 2020 and December 2021 were selected and randomly divided into two groups: a parecoxib sodium group (group P, n = 40) and a control group (group C, n = 40). Patients in group P were intravenously injected with 40 mg of parecoxib sodium 30 min before anesthesia and at the end of the surgery. Patients in group C were intravenously injected with the same volume of normal saline at the same time points. The primary endpoint was the incidence of POD, and the secondary endpoints were the levels of inflammatory factors (tumor necrosis factor- α [TNF-α], interleukin [IL]-1β, IL-6, and IL-10), nerve injury-related factors (brain-derived neurotrophic factor [BDNF], S-100β protein, neuron-specific enolase [NSE], and neurofilament light chain [NfL]), and antioxidant factors (heme oxygenase-1 [HO-1]), as well as the Visual Analogue Scale (VAS) and Confusion Assessment Method-Chinese Reversion (CAM-CR) scores. Results: The incidence of POD was 10% in group P and 27.5% in group C. Intergroup comparison revealed that the levels of TNF-α, IL-1β, S-100β, NfL, and NSE were lower, and BDNF was higher, in group P than in group C at each postoperative time point. The levels of IL-6 were lower, and the levels of IL-10 and HO-1 were higher, in group P than in group C at 1 h and 1 day postoperatively (p < 0.05). Three days after surgery, the differences in the levels of IL-6, IL-10, and HO-1 were not statistically significant between the two groups (p > 0.05). The VAS and CAM-CR scores were lower at each postoperative time point in group P than in group C (p < 0.05). Conclusion: Parecoxib sodium could reduce postoperative pain, decrease the plasma levels of inflammatory and nerve injury-related factors, upregulate HO-1 levels, and reduce the incidence of POD. The results of this study suggest that parecoxib sodium may reduce the occurrence of POD through the effects of anti-inflammation, analgesia, and antioxidants.

Cyclooxygenase-2 deficiency attenuates lipopolysaccharide-induced inflammation, apoptosis, and acute lung injury in adult mice

Many lung diseases are caused by an excessive inflammatory response, and inflammatory lung diseases are often modeled using lipopolysaccharide (LPS) in mice. Cyclooxygenase-2 (COX-2) encoded by the Ptgs2 gene is induced in response to inflammatory stimuli including LPS. The objective of this study was to test the hypothesis that mice deficient in COX-2 (Ptgs2-/-) will be protected from LPS-induced lung injury. Wild-type (WT; CD1 mice) and Ptgs2-/- mice (on a CD1 background) were treated with LPS or vehicle for 24 h. LPS treatment resulted in histological evidence of lung injury, which was attenuated in the Ptgs2-/- mice. LPS treatment increased the mRNA levels for tumor necrosis factor-α, interleukin-10, and monocyte chemoattractant protein-1 in the lungs of WT mice, and the LPS-induced increases in these levels were attenuated in the Ptgs2-/- mice. The protein levels of active caspase-3 and caspase-9 were lower in the LPS-treated lungs of Ptgs2-/- mice than in LPS-treated WT mice, as were the number of terminal deoxynucleotide transferase dUTP nick end labeling-positive cells in lung sections. LPS exposure resulted in a greater lung wet-to-dry weight ratio (W/D) in WT mice, suggestive of pulmonary edema, while in LPS-treated Ptgs2-/- mice, the W/D was not different from controls and less than in LPS-treated WT mice. These results demonstrate that COX-2 is involved in the inflammatory response to LPS and suggest that COX-2 not only acts as a downstream participant in the inflammatory response, but also acts as a regulator of the inflammatory response likely through a feed-forward mechanism following LPS stimulation.

Antioxidants as Therapeutic Agents in Acute Respiratory Distress Syndrome (ARDS) Treatment-From Mice to Men

Acute respiratory distress syndrome (ARDS) is a major cause of patient mortality in intensive care units (ICUs) worldwide. Considering that no causative treatment but only symptomatic care is available, it is obvious that there is a high unmet medical need for a new therapeutic concept. One reason for a missing etiologic therapy strategy is the multifactorial origin of ARDS, which leads to a large heterogeneity of patients. This review summarizes the various kinds of ARDS onset with a special focus on the role of reactive oxygen species (ROS), which are generally linked to ARDS development and progression. Taking a closer look at the data which already have been established in mouse models, this review finally proposes the translation of these results on successful antioxidant use in a personalized approach to the ICU patient as a potential adjuvant to standard ARDS treatment.

Ventilator-induced lung-injury in mouse models: Is there a trap?

Ventilator-induced lung injury (VILI) is a serious acute injury to the lung tissue that can develop during mechanical ventilation of patients. Due to the mechanical strain of ventilation, damage can occur in the bronchiolar and alveolar epithelium resulting in a cascade of events that may be fatal to the patients. Patients requiring mechanical ventilation are often critically ill, which limits the possibility of obtaining patient samples, making VILI research challenging. In vitro models are very important for VILI research, but the complexity of the cellular interactions in multi-organ animals, necessitates in vivo studies where the mouse model is a common choice. However, the settings and duration of ventilation used to create VILI in mice vary greatly, causing uncertainty in interpretation and comparison of results. This review examines approaches to induce VILI in mouse models for the last 10 years, to our best knowledge, summarizing methods and key parameters presented across the studies. The results imply that a more standardized approach is warranted.