Lactate facilitated mitochondrial fission-derived ROS to promote pulmonary fibrosis via ERK/DRP-1 signaling.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic interstitial lung diseases, which mainly existed in middle-aged and elderly people. The accumulation of reactive oxygen species (ROS) is a common characteristic of IPF. Previous research also shown that lactate levels can be abnormally elevated in IPF patients. Emerging evidence suggested a relationship between lactate and ROS in IPF which needs further elucidation. In this article, we utilized a mouse model of BLM-induced pulmonary fibrosis to detect alterations in ROS levels and other indicators associated with fibrosis. Lactate could induce mitochondrial fragmentation by modulating expression and activity of DRP1 and ERK. Moreover, Increased ROS promoted P65 translocation into nucleus, leading to expression of lung fibrotic markers. Finally, Ulixertinib, Mdivi-1 and Mito-TEMPO, which were inhibitor activity of ERK, DRP1 and mtROS, respectively, could effectively prevented mitochondrial damage and production of ROS and eventually alleviate pulmonary fibrosis. Taken together, these findings suggested that lactate could promote lung fibrosis by increasing mitochondrial fission-derived ROS via ERK/DRP1 signaling, which may provide novel therapeutic solutions for IPF.

Lactate accumulation induced by Akt2-PDK1 signaling promotes pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive disease with an abnormal accumulation of fibrotic tissue in the lung parenchyma and elevated glycolysis level in associated cells without effective therapy options. Lactate accumulation in pulmonary fibrotic tissue is a significant factor aggravating IPF development, but the main mechanism regulating glycolysis needs further investigation. In this study, lung fibrosis model was induced by bleomycin (BLM) intratracheally in female C57BL/6 mice. The changes of lactate level and fibrotic markers were detected. For in vitro studies, cell lines of alveolar epithelial cell and lung fibroblast cell were stimulated with TGF-ß1 and BLM respectively, to detect changes in their fibrotic properties. The function of lactate accumulation on facilitating fibrosis was verified. We demonstrated that BLM-induced pulmonary fibrosis is accompanied by lactate accumulation owing to glycolysis upregulation. Significantly high PDK1 expression in lung fibrotic tissue promotes glycolysis. Moreover, PDK1 stimulated trans-differentiation of lung fibroblasts and epithelial-mesenchymal transition (EMT) of alveolar epithelial cells. Furthermore, phosphorylated Akt2 activated PDK1 to cause pulmonary fibrosis and inhibitors of Akt2 and PDK1 could suppress fibrotic process. This study is the first to consider PDK1 facilitated lactate accumulation through glycolysis as a vital factor in pulmonary fibrosis and could be initiated by Akt2. We concluded that the pro-fibrotic properties of PDK1 are associated with Akt2 phosphorylation and thus provide new potential therapeutic targets for pulmonary fibrosis.

Histone lactylation regulates cancer progression by reshaping the tumor microenvironment.

As a major product of glycolysis and a vital signaling molecule, many studies have reported the key role of lactate in tumor progression and cell fate determination. Lactylation is a newly discovered post-translational modification induced by lactate. On the one hand, lactylation introduced a new era of lactate metabolism in the tumor microenvironment (TME), and on the other hand, it provided a key breakthrough point for elucidation of the interaction between tumor metabolic reprogramming and epigenetic modification. Studies have shown that the lactylation of tumor cells, tumor stem cells and tumor-infiltrating immune cells in TME can participate in the development of cancer through downstream transcriptional regulation, and is a potential and promising tumor treatment target. This review summarized the discovery and effects of lactylation, as well as recent research on histone lactylation regulating cancer progression through reshaping TME. We also focused on new strategies to enhance anti-tumor effects via targeting lactylation. Finally, we discussed the limitations of existing studies and proposed new perspectives for future research in order to further explore lactylation targets. It may provide a new way and direction to improve tumor prognosis.

Selective Chiral Recognition between Amino Acids and Growing Gypsum Crystals.

In nature, selective chiral interactions between biomolecules and minerals provide insight into the mysterious origin of homochirality. Here, we show growing gypsum crystals in a nonequilibrium state can recognize chiral enantiomers of amino acids. The chiral selection for amino acids with different functional groups by growing minerals are distinct. For 11 amino acids, the d-isomer slows dynamic gypsum growth more than the l-isomer, whereas for another 7 amino acids, the opposite was observed. These differences in chiral recognition are attributed to the different stereochemical matching between the chiral amino acids and the dynamic steps of growing gypsum. These stereoselective interactions between amino acid enantiomers and dynamic growing crystals can be applied toward the fabrication of gypsum cements to regulate their structure and mechanical properties. These findings provide insight into understanding the mechanism of the origin of homochirality in nature and suggest a pathway for constructing advanced functional materials.

Astellolides R-W, Drimane-Type Sesquiterpenoids from an Aspergillus parasiticus Strain Associated with an Isopod.

Sesquiterpenoids with a cage-like multiring frame are rarely found in nature. Mining of the isopod-derived fungus Aspergillus parasiticus SDU001 by the one strain-many compounds (OSMAC) strategy unexpectedly led to the discovery of fungal drimane-type sesquiterpenoids astellolide R (1), featuring an unusual cage-like 6/6/5/6/5 pentacyclic ring system, astellolide S (2), possessing a rare nicotinic acid building block, and astellolides T-W (3-6). Their structures were comprehensively assigned by spectroscopic data analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Furthermore, compounds 3 and 5 exhibited anti-inflammatory activity by inhibiting the lipopolyssacharide-induced NO production in RAW264.7 macrophages with IC50 values of 6.1 ± 0.8 and 6.8 ± 0.8 µM, respectively. A putative biosynthetic pathway for 1 is proposed. Our results enlarge the chemical space of the drimane-type sesquiterpenoids generated from endophytic fungi.

Hierarchical flower-like manganese oxide/polystyrene with enhanced oxidase-mimicking performance for sensitive colorimetric detection of glutathione.

Glutathione (GSH) is an important antioxidant and free radical scavenger that converts harmful toxins into harmless substances and excretes them out of the body. In this paper, 3D hierarchical flower-like nanozyme named MnO2/PS (polystyrene) was successfully prepared by template method for the first time. After the systematical studies, MnO2/PS nanozyme was evaluated to possess favorable oxidase activity and direct 3,3',5,5'-tetramethylbenzidine (TMB) catalytic ability in the near-neutral environment at room temperature. With the addition of different concentrations of GSH, oxidized TMB can be reduced to TMB with the whole process from blue to nearly colorless be observed by naked eyes. In addition, there is a good linear relationship in the range 1-50 µM and a detection limit of 0.08 µM. The method proposed can be successfully applied to the detection of reduced GSH in tablets and injections with good selectivity and high sensitivity. The analysis results exhibited good consistency with the results obtained by HPLC.

Feature Selection Based on a Large-Scale Many-Objective Evolutionary Algorithm.

The feature selection problem is a fundamental issue in many research fields. In this paper, the feature selection problem is regarded as an optimization problem and addressed by utilizing a large-scale many-objective evolutionary algorithm. Considering the number of selected features, accuracy, relevance, redundancy, interclass distance, and intraclass distance, a large-scale many-objective feature selection model is constructed. It is difficult to optimize the large-scale many-objective feature selection optimization problem by using the traditional evolutionary algorithms. Therefore, this paper proposes a modified vector angle-based large-scale many-objective evolutionary algorithm (MALSMEA). The proposed algorithm uses polynomial mutation based on variable grouping instead of naive polynomial mutation to improve the efficiency of solving large-scale problems. And a novel worst-case solution replacement strategy using shift-based density estimation is used to replace the poor solution of two individuals with similar search directions to enhance convergence. The experimental results show that MALSMEA is competitive and can effectively optimize the proposed model.

C. tropicalis promotes chemotherapy resistance in colon cancer through increasing lactate production to regulate the mismatch repair system.

Due to chemotherapeutic drug resistance, tumor recurrence is common in patients with colorectal cancer (CRC) and chemo-resistant patients are often accompanied by defects in the mismatch repair system (MMR). Our previous study has shown that Candida tropicalis (C. tropicalis) is closely related to the occurrence and development of colorectal cancer, but whether this conditional pathogenic fungus is involved in chemotherapy needs further investigation. Here we found that C. tropicalis promoted chemotherapy resistance of colon cancer to oxaliplatin. Compared with oxaliplatin-treated group, the expression of functional MMR proteins in tumors were decreased in C.tropicalis/oxaliplatin -treated group, while the glycolysis level of tumors was up-regulated and the production of lactate was significantly increased in C.tropicalis/oxaliplatin -treated group. Inhibiting lactate production significantly alleviated the chemoresistance and rescued the decreased expression of MMR caused by C. tropicalis. Furthermore, we found that lactate down-regulated the expression of MLH1 through the GPR81-cAMP-PKA-CREB axis. This study clarified that C. tropicalis promoted chemoresistance of colon cancer via producing lactate and inhibiting the expression of MLH1, which may provide novel ideas for improving CRC chemotherapy effect.

Mass spectrometry-based serum lipidomics strategy to explore the mechanism of Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves in the treatment of ischemic stroke.

Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves (ESL) were reported to have neuroprotective function and are also used to treat cranial and cerebral traumas as a traditional Chinese medicine and food herbage plant. However, there has been no previous study on ESL treatment for stroke at the level of lipid disorders. To clarify the mechanism of ESL in treating ischemic stroke, this study was carried out from 3 aspects, namely, the regulation of lipid disorders, protection of the nervous system, as well as anti-inflammatory and antioxidant actions. This study established a lipidomics research strategy that was developed by UPLC-Q-TOF/MS analysis. The quantification of neurotransmitters in the serum and brain tissue of rats was performed using UPLC-TQ/MS. Also, we quantified the oxidative stress and inflammatory reaction by measuring the contents of SOD, MDA, TNF-α, IL-6, and IL-10 via the ELISA kits for serum and brain tissue. According to UPLC-Q-TOF/MS-based lipidomics analysis, 27 lipidomics biomarkers were identified in this study, including PC, PE, SM, and TG, which were distributed in various lipid metabolic pathways, including glycerophospholipid, linoleic acid, alpha-linolenic acid, glycerolipid, sphingolipid, and arachidonic acid metabolism pathways. By reversing the changes in the lipid content caused by the disease, ESL has a therapeutic effect on ischemic stroke. Furthermore, quantitative results of neurotransmitters indicated that they can be regulated by ESL. Finally, the results of ELISA showed that ESL can treat ischemic stroke to a certain extent by reducing the oxidative and inflammatory damage. Therefore, ESL may play a therapeutic role in the treatment of ischemic stroke in different ways. This research preliminarily revealed the mechanism of ESL in the treatment of ischemic stroke and provided support for the further application of ESL.

17ß-Estradiol promotes LC3B-associated phagocytosis in trained immunity of female mice against sepsis.

Sepsis is a common serious clinical infectious disease accompanied by more severe injuries and higher mortality rates in men than women. The much higher level of 17ß-estradiol (E2) in female is one of the significant reasons for better sepsis resistance ability. Trained immunity is a novel way to fight against infection by improving innate immunity. However, whether ß-glucan-induced trained immunity can promote macrophage phagocytosis to clear infections in early sepsis has not been clarified. And whether E2 involved in this process needs further investigation. Symptoms among male, female and ovariectomized (OVX) C57BL/6 mice in early sepsis were detected. The effect of trained immunity on macrophage LC3B-associated phagocytosis (LAP) and the mechanism of E2 functioned in this process have also been explored. We demonstrated compared with male mice, female has significantly more mild symptoms and more reactive oxygen species (ROS) production and stronger NADPH oxidase 2 (NOX2) expression in the macrophage of major organs. In contrary, these characteristics are disappeared in OVX mice. Furthermore, in macrophage cell lines and primary bone marrow- derived macrophages (BMDMs), ß-glucan-induced trained immunity can increase ROS production by activating NOX2 to promote macrophage LAP. E2 can up-regulate RUBICON through estrogen receptor α (ERα) to further facilitate macrophage LAP. These results indicated that trained immunity can improve sepsis resistance ability by stimulating macrophage LAP. E2 can boost ROS production and RUBICON expression to further promote macrophage LAP, which can provide a new perspective to recognize the mechanism of trained immunity in gender differences when responding to sepsis.

Single-Atom Fe-Anchored Nano-Diamond With Enhanced Dual-Enzyme Mimicking Performance for H2O2 and Glutathione Detection.

Glutathione (GSH) is an important antioxidant and free radical scavenger that converts harmful toxins into harmless substances and excretes them out of the body. In the present study, we successfully prepared single-atom iron oxide-nanoparticle (Fe-NP)-modified nanodiamonds (NDs) named Fe-NDs via a one-pot in situ reduction method. This nanozyme functionally mimics two major enzymes, namely, peroxidase and oxidase. Accordingly, a colorimetric sensing platform was designed to detect hydrogen peroxide (H2O2) and GSH. Owing to their peroxidase-like activity, Fe-NDs can oxidize colorless 3,3',5,5'-tetramethylbenzidine (TMB) into blue with sufficient linearity at H2O2 concentrations of 1-60 µM and with a detection limit of 0.3 µM. Furthermore, using different concentrations of GSH, oxidized TMB can be reduced to TMB, and the color change from blue to nearly colorless can be observed by the naked eye (linear range, 1-25 µM; detection limit, 0.072 µM). The established colorimetric method based on oxidase-like activity can be successfully used to detect reduced GSH in tablets and injections with good selectivity and high sensitivity. The results of this study exhibited reliable consistency with the detection results obtained using high-performance liquid chromatography (HPLC). Therefore, the Fe-NDs colorimetric sensor designed in this study offers adequate accuracy and sensitivity.

17ß-Estradiol Promotes Trained Immunity in Females Against Sepsis via Regulating Nucleus Translocation of RelB.

Sepsis is more common among males than females, and the unequal estrogen levels have been suspected to play a vital role in gender differences. Recently, trained immunity is reported to be a novel strategy for the innate immune system to fight infection. However, it has not been clarified whether ß-glucan-induced trained immunity causes different responses to early sepsis between male and female mice. In this study, sepsis was induced in mice by intraperitoneal injection of Escherichia coli (E. coli). The changes of inflammatory cytokines expression, and macrophage polarization in male, female, and ovariectomized C57BL/6 mice in sepsis model were investigated. For in vitro studies, different macrophages were treated with LPS. The function of estradiol (E2) on macrophage cell lines was verified and the mechanism of E2 affecting trained immunity was explored. We demonstrated that ß-glucan-induced trained immunity was more resistant to sepsis in female than male mice. Macrophage polarization toward the M1 phenotype, which exhibited enhanced trained immunity, was related to the difference in sepsis resistance between female and male mice. Moreover, ovariectomized (OVX) mice manifested serious sepsis consequences with a weaker trained immunity effect than female mice. Female bone marrow-derived macrophages (BMDMs) were also apt to be polarized to the M1 phenotype in response to trained immunity in vitro. Furthermore, E2 promoted trained immunity in macrophage cell lines J774 and RAW264.7. E2 was also verified to facilitate trained immunity in primary BMDMs from female and male mice. Mechanistically, we found that E2 inhibited the nuclear translocation of RelB, which is a member of non-canonical pathway of NFκB and contributes to macrophage polarization to change the intensity of trained immunity. This study is the first to indicate the role of E2 in the trained immunity induced by ß-glucan to protect against E. coli-induced sepsis via the non-canonical NFκB pathway. These results improve our understanding of the molecular mechanisms governing trained immunity in gender differences.

Ganoderma lucidum fruiting body extracts inhibit colorectal cancer by inducing apoptosis, autophagy, and G0/G1 phase cell cycle arrest in vitro and in vivo.

Although previous studies have found that Ganoderma lucidum extracts have the ability to directly resist tumor proliferation and reduce metastasis and invasion, the effect of the extracts of Ganoderma lucidum fruiting body (GLE) on cancer is not clarified. This study intends to investigate the anticancer role of GLE on HCT116 colorectal cancer cells in vitro and in vivo. The effects of GLE on the proliferation, apoptosis, autophagy and cell cycle arrest of HCT116 cells were detected by cell counting kit-8 (CCK-8), flow cytometry, electron microscope, quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot assay. Xenografted mouse models were used to evaluate the tumor growth inhibition effect of GLE in vivo. GLE could significantly inhibit the viability of four tumor cell lines (A549, SW1990, SKOV3 and HCT116) and HCT116 cells were more sensitive to GLE treatment with a half inhibitory concentration of 106 µg/mL. GLE treatment induced apoptosis of HCT116 cells by downregulating of the ratio of Bcl-2 to Bax and increasing cleaved caspase-3 and poly ADP-ribose polymerase (PARP) protein expression. Autophagy of HCT116 cells also increased after GLE treatment, as shown by observation of autophagosomes formation and altered protein expressions in the mTOR pathway. In addition, GLE treatment led to G0/G1 cell cycle arrest as evidenced by flow cytometry analysis and changes in cell-cycle-related gene expressions at the mRNA levels. Of note, in vivo evaluation indicated that GLE significantly inhibited tumor weight and tumor volume and decreased Ki67 expression. In summary, GLE has potential to be developed as an anticancer agent against colorectal cancer, and further evaluation is needed.

Ferumoxytol Attenuates the Function of MDSCs to Ameliorate LPS-Induced Immunosuppression in Sepsis.

Sepsis-induced immunosuppression is recognized as one of the main features responsible for therapeutic failures. Myeloid-derived suppressor cells (MDSCs), which are mainly characterized by their suppressive properties, have been reported to be expanded in sepsis. Ferumoxytol (FMT), an FDA-approved iron supplement, has been shown to possess immune-modulatory properties in tumors. However, it is unclear whether FMT alters the functions of MDSCs to reduce late-sepsis immunosuppression. Here, we showed an immunomodulatory effect of FMT on MDSCs to ameliorate lipopolysaccharide (LPS)-induced immunosuppression in the late stage of sepsis. Separation of cells with internalized FMT and detection of the intracellular iron content showed that MDSCs could uptake FMT. Low doses of FMT had no effects on the cell viability of MDSCs, but FMT inhibited the expansion of MDSCs in vitro. Moreover, FMT significantly downregulated the expression levels of Arg-1, S100A8, S100A9, and p47phox as well as ROS production in MDSCs. FMT decreased the percentage of granulocytic MDSCs (G-MDSCs) and promoted the differentiation of MDSCs into macrophages. Furthermore, FMT reduced white blood cell recruitment and alveolar wall thickening in the lungs and areas of necrosis in the liver as well as some biochemical markers of liver dysfunction. FMT decreased the percentage of G-MDSCs and monocytic MDSCs (M-MDSCs) in the spleens of LPS-induced septic mice. Of note, FMT reduced the T cell immunosuppressive functions of both G-MDSCs and M-MDSCs. Expectedly, FMT also significantly reduced Arg-1 and p47phox gene expression in splenic CD11b+Gr-1+ cells isolated from LPS-challenged mice. These data indicate that FMT decreased the immunosuppressive functions of MDSCs by decreasing Arg-1 and ROS production, suggesting that FMT may reduce long-term immunosuppression in the late stage of sepsis.

SPIONs enhances IL-10-producing macrophages to relieve sepsis via Cav1-Notch1/HES1-mediated autophagy.

BACKGROUND: Sepsis is a life-threatening condition caused by dysregulated host responses to infection. Macrophages, which recognize microbial infections through identification of bacterial markers such as lipopolysaccharide (LPS), are crucial to the pathogenesis of sepsis-associated liver injury. However, the understanding of the SPIONs-mediated modulation of macrophage responses in LPS-induced sepsis and liver injury is limited. MATERIALS AND METHODS: Superparamagnetic iron oxide nanoparticles (SPIONs) of γ-Fe2O3 nanoparticles were prepared, and their morphology and magnetic properties were characterized. RESULTS: Using a murine model of LPS-induced sepsis and liver injury, we found that SPIONs alleviated LPS-induced sepsis, preventing infiltration of inflammatory cells into the liver. SPIONs also increased the level of interleukin-10 (IL-10) in liver macrophages, while SPIONs's effect on LPS-induced sepsis was abrogated in IL-10-/- mice, indicating that the protective effect of SPIONs is dependent on IL-10+ macrophages. Moreover, SPIONs activated macrophage autophagy to increase IL-10 production, which was markedly attenuated by autophagy inhibition. Furthermore, SPIONs upregulated the expression of Caveolin-1 (Cav1) in macrophages, which plays a role in cellular uptake of metallic nanoparticles. Interestingly, activation of Cav1 and Notch1/HES1 signaling was involved in SPIONs-induced autophagy in both RAW 264.7 cells and bone marrow-derived macrophages (BMDMs). Our data reveal a novel mechanism for SPIONs -induced autophagy in macrophages, which occurs through activation of the Cav1-Notch1/HES1 signaling pathway, which promotes the production of IL-10 in macrophages, leading to inhibition of inflammation in LPS-induced sepsis and liver injury. CONCLUSION: Our results suggest that SPIONs may represent a potential therapeutic agent for the treatment of sepsis and sepsis-induced liver injury.

Mass spectrometry-based urinary metabolomics for the investigation on the mechanism of action of Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves against ischemic stroke in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: As a traditional Chinese medicine, Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves (ESL) can treat ischemic, neurasthenia, and hypertension diseases. However, only few studies have been conducted on the mechanism of action of ESL for ischemic disease treatment. AIM OF THE STUDY: This study aimed to discover the potential biomarkers in the rats caused by ischemic stroke and build a gene-enzyme-biomarker network to explore the mechanism of ESL treatment on ischemic stroke further. MATERIALS AND METHODS: The urinary metabolomics strategy was developed by combining UPLC-Q-TOF/MS with multivariate data analysis. The gene-enzyme-biomarker network was built by Cytoscape 3.6.0 on the basis of the potential biomarkers filtered out via urinary metabolomic analysis. Then, the potential target enzymes of ESL in the treatment of ischemic stroke were selected for further validation analysis via the ELISA kits. RESULTS: A total of 42 biomarkers associated with ischemic stroke have been identified, among which 38 species can be adjusted by ESL, including 5'-methylthioadenosine, prostaglandin A2, l-methionine, aldosterone, 11b-hydroxyprogesterone, prostaglandin E3, dehydroepiandrosterone, taurine, 5-methoxyindoleacetate, and p-cresol glucuronide. These biomarkers were involved in several metabolic pathways, including taurine and hypotaurine, arachidonic acid, cysteine and methionine, steroid hormone biosynthesis, tryptophan, and tyrosine metabolism pathways. The gene-enzyme-biomarker network was built, and three predicted target proteins, including cyclooxygenase-2 (COX-2), monoamine oxidase (MAO), and nitric oxide synthase (NOS), were selected as the potential target enzymes for ESL in ischemic stroke treatment. CONCLUSIONS: All results showed that ESL can play a therapeutic role in treating ischemic stroke through different pathways. This study will provide an overall view of the mechanism underlying the action of ESL against ischemic stroke.

The effect of dexmedetomidine on inflammatory inhibition and microglial polarization in BV-2 cells.

OBJECTIVE: Microglia have different phenotypic and functional states: M1 is associated with inflammatory responses, whereas M2 results in anti-inflammatory effects. The cellular state of microglia plays an important role in brain inflammation associating with many neuroinflammatory diseases. The purpose of this study was to detect the effect of dexmedetomidine (Dex) on inflammatory inhibition and microglial polarization in BV-2 cells. MATERIALS AND METHODS: Dex exerts anti-inflammatory effects in various experimental models. The BV-2 microglial cell line was treated with liposaccharide in the presence or absence of Dex. The M1 and M2 markers were evaluated by quantitative real-time PCR (qRT-PCR) and western blot. RESULTS: We found that Dex exerted a potent anti-inflammatory effect by reducing the expression of M1 marker genes such as tumor necrosis factor alpha (P < 0.05), interleukin-1ß (IL-1ß) (P < 0.001) and IL-6 (P < 0.001). Importantly, Dex improved the expression of microglia M2 markers arginase-1 (Arg-1) (P < 0.01), Flt3-interacting zinc finger protein 1 (Fizz-1) (P < 0.001) and CD206) (P < 0.001). Further, Dex enhanced the activation of Akt pathway. DISCUSSION: Our results indicated that Dex promotes microglia from the M1 phenotype to the M2 phenotype. Therefore, Dex may be a potential novel therapeutic drug for treating brain inflammation-associated diseases not only because of its anti-inflammatory property but also because it can remodel M1 phenotype microglia to M2 phenotype microglia.

Propane-2-sulfonic acid octadec-9-enyl-amide, a novel PPARα/γ dual agonist, protects against ischemia-induced brain damage in mice by inhibiting inflammatory responses.

Propane-2-sulfonic acid octadec-9-enyl-amide (N15), an analogue of oleoylethanolamide (OEA), is a novel PPARα/γ dual agonist. Our previous studies verified the positive effects of OEA on the acute and delayed stages of cerebral ischemia. However, it is not clear whether N15 is effective against ischemic cerebral injury. In the present study, male Kunming mice were subjected to middle cerebral artery occlusion (MCAO). To evaluate its preventive effects, N15 (50, 100 or 200mg/kg, ip) was administered for 3days before ischemia. To evaluate its therapeutic effects, N15 (200mg/kg, ip) was administered 1h before reperfusion or 0, 1, 2 or 4h after reperfusion. Neurological deficit scores, infarct volume and the degree of brain oedema were determined at 24h after reperfusion. Blood brain barrier (BBB) disruption was evaluated by Evans blue (EB) and FITC-dextran leakages at 6h after reperfusion. The activation/inflammatory responses of microglia/macrophages were detected using immunohistochemistry and western blot. N15 pretreatment improved neurological dysfunction, reduced infarct volume and alleviated brain oedema in a dose-dependent manner; the most effective dose was 200mg/kg. The therapeutic time window was within 2h after reperfusion. N15 treatment preserved the BBB integrity and suppressed the activation of microglia/macrophages. N15 inhibited inflammatory cytokine expression not only in MCAO mice but also in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Additionally, N15 markedly decreased the phosphorylation levels of NF-κBp65, STAT3, and ERK1/2 both in vivo and in vitro. Furthermore, the PPARα antagonist MK886 or PPARγ antagonist T0070907 respectively partly abolished the anti-inflammatory effects of N15 in vitro. Our findings demonstrated that N15 can exert neuroprotective effects against cerebral ischemic insult. Moreover, the neuroprotective effects of N15 on cerebral ischemia may be attributed to its anti-inflammatory properties, at least in part, by enhancing PPARα/γ dual signaling and inhibiting the activation of the NF-κB, STAT3, and ERK1/2 signaling pathways. These findings suggest that N15 may be a potential therapeutic choice for the prevention and treatment of ischemic stroke.