Fibroblast growth factor 21 attenuates ventilator-induced lung injury by inhibiting the NLRP3/caspase-1/GSDMD pyroptotic pathway.

BACKGROUND: Ventilator-induced lung injury (VILI) is caused by overdistension of the alveoli by the repetitive recruitment and derecruitment of alveolar units. This study aims to investigate the potential role and mechanism of fibroblast growth factor 21 (FGF21), a metabolic regulator secreted by the liver, in VILI development. METHODS: Serum FGF21 concentrations were determined in patients undergoing mechanical ventilation during general anesthesia and in a mouse VILI model. Lung injury was compared between FGF21-knockout (KO) mice and wild-type (WT) mice. Recombinant FGF21 was administrated in vivo and in vitro to determine its therapeutic effect. RESULTS: Serum FGF21 levels in patients and mice with VILI were significantly higher than in those without VILI. Additionally, the increment of serum FGF21 in anesthesia patients was positively correlated with the duration of ventilation. VILI was aggravated in FGF21-KO mice compared with WT mice. Conversely, the administration of FGF21 alleviated VILI in both mouse and cell models. FGF21 reduced Caspase-1 activity, suppressed the mRNA levels of Nlrp3, Asc, Il-1ß, Il-18, Hmgb1 and Nf-κb, and decreased the protein levels of NLRP3, ASC, IL-1ß, IL-18, HMGB1 and the cleaved form of GSDMD. CONCLUSIONS: Our findings reveal that endogenous FGF21 signaling is triggered in response to VILI, which protects against VILI by inhibiting the NLRP3/Caspase-1/GSDMD pyroptosis pathway. These results suggest that boosting endogenous FGF21 or the administration of recombinant FGF21 could be promising therapeutic strategies for the treatment of VILI during anesthesia or critical care.

Global distribution of publications in anesthesiology : A bibliometric analysis from 1999 to 2018.

PURPOSE: Only few studies have analyzed the global distribution of anesthesia research. This study was designed to reveal the current global research status of anesthesiology. METHODS: Articles published between 1999 and 2018 in international journals in the field of anesthesiology were retrieved from the PubMed database. The top 20 ranked countries were identified. The gross domestic product (GDP) of each country was also retrieved to reveal the correlation between research outputs and the economy. The total outputs and outputs per 10 million inhabitants in each country were calculated and compared. To analyze the quality of publications among the top 10 ranked countries, the impact factor (IF), article influence score (AIS), and immediacy index (ImI) were calculated and analyzed. In addition, the keywords of publications were retrieved to conduct co-occurrence analysis in order to determine the research focus in anesthesiology. RESULTS: A total of 112,918 articles were published in 30 selected journals from 1999 to 2018. There was a positive correlation between research outputs and GDP of 10 countries (p < 0.001, r = 0.825). The USA ranked 1st with 21,703 articles, followed by the UK (8393 articles) and Germany (6504 articles). Canada had the highest number of publications per 10 million inhabitants in 2018. The UK had the highest average IF (4.70), average AIS (1.16), and average ImI (1.64) among the 10 countries. The research highlights in the field of anesthesiology included "mechanism and management of pain", "cardiac anesthesia", "pediatric anesthesia and airway management", "analgesia" and "anesthetic agents". CONCLUSION: Regarding quantity trend, the output of global production in anesthesiology increased continuously as the number of articles from the high-output countries showed an increasing trend; however, there was still a gap between developing and developed countries in research quality. High-quality research should be encouraged in developing countries.

The challenge of safe anesthesia in developing countries: defining the problems in a medical center in Cambodia.

BACKGROUND: The International Standards for a Safe Practice of Anesthesia (ISSPA) were developed on behalf of the World Federation of Societies of Anaesthesiologists and the World Health Organization. It has been recommend as an assessment tool that allows anesthetic providers in developing countries to assess their compliance and needs. This study was performed to describe the anesthesia service in one main public hospital during an 8-month medical mission in Cambodia and evaluate its anesthetic safety issues according to the ISSPA. METHODS: We conduct a retrospective study involving 1953 patients at the Preah Ket Mealea hospital. Patient demographics, anesthetic techniques, and complications were reviewed according to the registers of the anesthetic services and questionnaires. The inadequacies in personnel, facilities, equipment, medications, and conduct of anesthesia drugs were recorded using a checklist based on the ISSPA. RESULTS: A total of 1792 patients received general and regional anesthesia in the operating room, while 161 patients receiving sedation for gastroscopy. The patients' mean age was 45.0 ± 16.6 years (range, 17-87 years). The three most common surgical procedures were abdominal (52.0%; confidence interval [CI], 49.3-54.7), orthopedic (27.6%; CI, 25.2-29.9), and urological surgery (14.7%; CI, 12.8-16.6). General anesthesia, spinal anesthesia, and brachial plexus block were performed in 54.3% (CI, 51.7-56.8), 28.2% (CI, 25.9-30.5), and 9.4% (CI, 7.9-10.9) of patients, respectively. One death occurred. Twenty-six items related to professional aspects, monitoring, and conduct of anesthesia did not meet the ISSPA-recommended standards. A lack of commonly used drugs and monitoring equipment was noted, posing major threats to the safety of anesthesia practice, especially in emergency situations. CONCLUSIONS: This study adds to the scarce literature on anesthesia practice in low- and middle-income countries such as Cambodia. Future medical assistance should help to strengthen these countries' inadequacies, allowing for the adoption of international standards for the safe practice of anesthesia.

Activation of GABAB Receptor Suppresses Diabetic Neuropathic Pain through Toll-Like Receptor 4 Signaling Pathway in the Spinal Dorsal Horn.

Diabetic neuropathic pain (DNP) is a prevalent complication in diabetes patients. Neuronal inflammation and activation of Toll-like receptor 4 (TLR4) are involved in the occurrence of DNP. However, the underlying mechanisms remain unclear. Downregulation of gamma-aminobutyric acid B (GABAB) receptor contributes to the DNP. GABAB receptor interacts with NF-κB, a downstream signaling factor of TLR4, in a neuropathic pain induced by chemotherapy. In this study, we determined the role of TLR4/Myd88/NF-κB signaling pathways coupled to GABAB receptors in the generation of DNP. Intrathecal injection of baclofen (GABAB receptor agonist), LPS-RS ultrapure (TLR4 antagonist), MIP (MyD88 antagonist), or SN50 (NF-κB inhibitor) significantly increased paw withdrawal threshold (PWT) and paw withdrawal thermal latency (PWTL) in DNP rats, while intrathecal injection of saclofen (GABAB receptor blocker) decreased PWT and PWTL in DNP rats. The expression of TLR4, Myd88, NF-κBp65, and their downstream components IL-1 and TNF-α was significantly higher in the spinal cord tissue in DNP rats compared to control rats. Following inhibition of TLR4, Myd88, and NF-κB, the expression of IL-1 and TNF-α decreased. Activation of GABAB receptors downregulated the expression of TLR4, Myd88, NF-κBp65, IL-1, and TNF-α. Blockade of GABAB receptors significantly upregulated expression of TLR4, Myd88, NF-κBp65, IL-1, and TNF-α. These data suggest that activation of the TLR4/Myd88/NF-κB signaling pathway is involved in the occurrence of DNP in rats. Activation of GABAB receptor in the spinal cord may suppress the TLR4/Myd88/NF-κB signaling pathway and alleviate the DNP.

Neuron-Derived ADAM10 Production Stimulates Peripheral Nerve Injury-Induced Neuropathic Pain by Cleavage of E-Cadherin in Satellite Glial Cells.

BACKGROUND: Increasing evidence suggests the potential involvement of metalloproteinase family proteins in the pathogenesis of neuropathic pain, although the underlying mechanisms remain elusive. METHODS: Using the spinal nerve ligation model, we investigated whether ADAM10 proteins participate in pain regulation. By implementing invitro methods, we produced a purified culture of satellite glial cells to study the underlying mechanisms of ADAM10 in regulating neuropathic pain. RESULTS: Results showed that the ADAM10 protein was expressed in calcitonin gene-related peptide (CGRP)-containing neurons of the dorsal root ganglia, and expression was upregulated following spinal nerve ligation surgery invivo. Intrathecal administration of GI254023X, an ADAM10 selective inhibitor, to the rats one to three days after spinal nerve ligation surgery attenuated the spinal nerve ligation-induced mechanical allodynia and thermal hyperalgesia. Intrathecal injection of ADAM10 recombinant protein simulated pain behavior in normal rats to a similar extent as those treated by spinal nerve ligation surgery. These results raised a question about the relative contribution of ADAM10 in pain regulation. Further results showed that ADAM10 might act by cleaving E-cadherin, which is mainly expressed in satellite glial cells. GI254023X reversed spinal nerve ligation-induced downregulation of E-cadherin and activation of cyclooxygenase 2 after spinal nerve ligation. ß-catenin, which creates a complex with E-cadherin in the membranes of satellite glial cells, was also downregulated by spinal nerve ligation surgery in satellite glial cells. Finally, knockdown expression of ß-catenin by lentiviral infection in purified satellite glial cells increased expression of inducible nitric oxide synthase and cyclooxygenase 2. CONCLUSION: Our findings indicate that neuron-derived ADAM10 production stimulates peripheral nerve injury-induced neuropathic pain by cleaving E-cadherin in satellite glial cells.

Fibroblast growth factor 10 protects neuron against oxygen-glucose deprivation injury through inducing heme oxygenase-1.

Fibroblast growth factors (FGFs) are a family of structurally related heparin-binding proteins with diverse biological functions. FGFs participate in mitogenesis, angiogenesis, cell proliferation, development, differentiation and cell migration. Here, we investigated the potential effect of FGF10, a member of FGFs, on neuron survival in oxygen-glucose deprivation (OGD) model. In primary cultured mouse cortical neurons upon OGD, FGF10 treatment (100 and 1000 ng/ml) attenuated the decrease of cell viability and rescued the LDH release. Tuj-1 immunocytochemistry assay showed that FGF10 promoted neuronal survival. Apoptosis assay with Annexin V+PI by flow cytometry demonstrated that FGF10 treatment reduced apoptotic cell proportion. Moreover, immunoblotting showed that FGF10 alleviated the cleaved caspase-3 upregulation caused by OGD. FGF10 treatment also depressed the OGD-induced increase of caspase-3, -8 and -9 activities. At last, we found FGF10 triggered heme oxygenase-1 (HO-1) protein expression rather than hypoxia-inducible factor-1 (HIF-1), AMP-activated protein kinase (AMPK) signaling and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling. Knockdown of HO-1 by siRNA partly abolished the neuroprotection of FGF10 in OGD model. In summary, our observations provide the first evidence for the neuroprotective function of FGF10 against ischemic neuronal injury and suggest that FGF10 may be a promising agent for treatment of ischemic stroke.

Purpurin ameliorated neuropathic allodynia and hyperalgesia by modulating neuronal mitochondrial bioenergetics and redox status in type 1 diabetic mice.

A substantial proportion of diabetic patients suffer a debilitating and persistent pain state, known as peripheral painful neuropathy that necessitates improved therapy or antidote. Purpurin, a natural anthraquinone compound from Rubia tinctorum L., has been reported to possess antidepressant activity in preclinical studies. As antidepressants have been typically used as standard agents against persistent neuropathic pain, this study aimed to probe the effect of purpurin on neuropathic pain associated with streptozotocin-induced type 1 diabetes in male C57BL6J mice. The Hargreaves test and the von Frey test were used to assess the pain-like behaviors, shown as heat hyperalgesia and mechanical allodynia respectively. Chronic treatment of diabetic mice with purpurin not only ameliorated the established symptoms of heat hyperalgesia and mechanical allodynia, but also arrested the development of these pain states given preemptively at low doses. Although purpurin treatment hardly impacted on metabolic disturbance in diabetic mice, it ameliorated exacerbated oxidative stress in pain-associated tissues, improved mitochondrial bioenergetics in dorsal root ganglion neurons and restored nerve conduction velocity in sciatic nerves. Notably, the analgesic actions of purpurin were modified by pharmacologically manipulating redox status and mitochondrial bioenergetics. These findings unveil the analgesic activity of purpurin, an effect that is causally associated with its bioenergetics-enhancing and antioxidant effects, in mice with type 1 diabetes.

Transient early neurotrophin release and delayed inflammatory cytokine release by microglia in response to PAR-2 stimulation.

Activated microglia exerts both beneficial and deleterious effects on neurons, but the signaling mechanism controlling these distinct responses remain unclear. We demonstrated that treatment of microglial cultures with the PAR-2 agonist, 2-Furoyl-LIGRLO-NH2, evoked early transient release of BDNF, while sustained PAR-2 stimulation evoked the delayed release of inflammatory cytokines (IL-1 ß and TNF-α) and nitric oxide. Culture medium harvested during the early phase (at 1 h) of microglial activation induced by 2-Furoyl-LIGRLO-NH2 (microglial conditioned medium, MCM) had no deleterious effects on cultured neurons, while MCM harvested during the late phase (at 72 h) promoted DNA fragmentation and apoptosis as indicated by TUNEL and annexin/PI staining. Blockade of PAR-1 during the early phase of PAR-2 stimulation enhanced BDNF release (by 11%, small but significant) while a PAR-1 agonist added during the late phase (24 h after 2-Furoyl-LIGRLO-NH2 addition) suppressed the release of cytokines and NO. The neuroprotective and neurotoxic effects of activated microglial exhibit distinct temporal profiles that are regulated by PAR-1 and PAR-2 stimulation. It may be possible to facilitate neuronal recovery and repair by appropriately timed stimulation and inhibition of microglial PAR-1 and PAR-2 receptors.

Postreperfusion syndrome during orthotopic liver transplantation: a single-center experience.

BACKGROUND: Marked hemodynamic alteration, commonly referred to as postreperfusion syndrome (PRS), often occurs after revascularization of the donor organ during orthotopic liver transplantation (OLT) and is associated with poor outcomes. This study aimed to investigate the incidence, predictive factors and clinical outcomes of PRS in Chinese patients following OLT at a liver transplantation center in China. METHODS: Over a 5-year period, 330 consecutive patients who had undergone OLT for hepatocellular carcinoma or cirrhosis were included in this retrospective study. PRS was defined as a >30% decrease in the mean arterial pressure compared with that before revascularization for more than 1 minute during the first 5 minutes of graft reperfusion. The patients were divided into 2 groups according to the development of PRS: group 1 (patients with PRS, n=56) and group 2 (patients without PRS, n=274). The demographic characteristics, operative and postoperative courses, and outcomes of the patients were analyzed using SPSS version 18.0. RESULTS: Multivariate regression analysis showed that left ventricular diastolic dysfunction determined by echocardiography and prolonged cold ischemia time were the independent risk factors for PRS. More patients in group 1 showed postoperative renal dysfunction than those in group 2 (19.23% vs 8.4%). Moreover, patients in group 1 also had higher intraoperative (7.14% vs 0%) and postoperative mortalities (26.92% vs 12.04%). CONCLUSION: Left ventricular diastolic dysfunction and prolonged cold ischemia time contribute to a high incidence of PRS, which is associated with adverse outcomes in Chinese patients following OLT.