Anti-Melanogenic and Antioxidant Activity of Bifidobacterium longum Strain ZJ1 Extracts, Isolated from a Chinese Centenarian.

Melanin produced by melanocytes protects our skin against ultraviolet (UV) radiation-induced cell damage and oxidative stress. Melanin overproduction by hyperactivated melanocytes is the direct cause of skin hyperpigmentary disorders, such as freckles and melasma. Exploring natural whitening agents without the concern of toxicity has been highly desired. In this study, we focused on a Bifidobacterium longum strain, ZJ1, isolated from a Chinese centenarian, and we evaluated the anti-melanogenic activity of the distinctive extracts of ZJ1. Our results demonstrated that whole lysate (WL) and bacterial lysate (BL) of ZJ1 ferments efficiently reduce α-melanocyte-stimulating hormone (α-MSH)-induced melanin production in B16-F10 cells as well as the melanin content in zebrafish embryos. BL and WL downregulate melanogenesis-related gene expression and indirectly inhibit intracellular tyrosinase activity. Furthermore, they both showed antioxidant activity in a menadione-induced zebrafish embryo model. Our results suggest that ZJ1 fermentation lysates have application potential as therapeutic reagents for hyperpigmentary disorders and whitening agents for cosmetics.

miR-200a-3p promoted cell proliferation and metastasis by downregulating SOX17 in non-small cell lung cancer cells.

Lung cancer has high mortality and incidence rates in which non-small cell lung cancer (NSCLC) is the primary type of lung cancer that accounts for about 80%-85% of total patients. It has been demonstrated that microRNAs (miRNAs) are critical in the incidence and progression of tumors, while the role and inner mechanism of miR-200a-3p, one type of essential miRNAs, in NSCLC have yet to be revealed. Herein, we investigated the in vitro and vivo pro-/antiproliferative influence of miR-200a-3p on NSCLC cells and utilized bioinformatic programs to further predict the SOX17 gene as miR-200a-3p's potential target. A double luciferase reporter gene experiment was performed to confirm that miR-200a-3p interacts with the SOX17 3'-UTR region specifically. On the basis of the results of Western blot and quantitative reverse-transcription polymerase chain reaction (qRT-PCR), miR-200a-3p impacted the posttranscriptional levels of SOX17 rather than influencing its mRNA expression. In the end, we found that overexpressed SOX17 can reverse miR-200a-3p's impact on NSCLC cell proliferation and metastasis. Therefore, this study demonstrated that miR-200a-3p influences NSCLC cell proliferation and metastasis by modulating the levels of SOX17.

Calunduloside E inhibits HepG2 cell proliferation and migration via p38/JNK-HMGB1 signalling axis.

High-mobility group box 1 (HMGB1), a highly conserved chromosome protein, is considered as a potential therapeutic target and novel biomarker because of its regulation in the proliferation and metastasis of Hepatocellular carcinoma (HCC). Calenduloside E (CE), a natural active product, has been reported to anti-cancer effect. However, the role and underlying molecular mechanism of CE in HCC is still unclear. The purpose of this study is to investigate the effects of CE on the proliferation and migration of HCC, and then explore the possible underlying molecular mechanism. HepG2 cells were treated with CE or transfected with HMGB1 shRNA plasmids, EdU and colony formation assays were used to detect cell proliferation ability. Wound healing and transwell assays were used to determine the role of CE in cell migration. The expression of Cyclins, PCNA, MMPs, HMGB1, N-cadherin, E-cadherin and phosphorylation of p38, ERK and JNK were all detected using Western blotting. Our results showed that CE inhibited HepG2 cells proliferation and migration in a dose dependent manner; reduced the expression levels of Cycins, PCNA, HMGB1, MMPs and N-cadherin; up-regulated E-cadherin expression; enhanced the phosphorylation of p38 and JNK signalling pathways. Blocking the activation of p38 and JNK obviously reversed CE-mediated inhibitory effects on HepG2 cell proliferation and migration; reversed CE-induced down-regulation of Cyclins, PCNA, MMPs, N-cadherin and HMGB1, as well as E-cadherin up-regulation. In conclusion, our study suggested that CE reduces the expression levels of Cyclins, MMPs and epithelial-mesenchymal transformation (EMT) through p38/JNK-HMGB1 signaling axis and then inhibits HepG2 cells proliferation and migration in HepG2 cells. This study provides a new perspective for the anti-tumour molecular mechanism of CE in HCC.

[Dihydromyricetin inhibits proliferation and migration of gastric cancer cells through regulating Akt/STAT3 signaling pathways and HMGB1 expression].

OBJECTIVE: To investigate the inhibitory effects of dihydromyricetin on the proliferation and migration of gastric cancer BGC-823 cells and explore the molecular mechanisms. METHODS: BGC-823 cells in routine culture were treated with different concentrations of dihydromyricetin (0, 40, 60, 80, 100, and 120 µg/mL) for 24 h, and the changes in cell viability were detected using CCK-8 assay; colony forming assay and Transwell assay were performed to assess the changes in colonyforming and migration abilities of the cells, respectively. The levels of MMP-2 and MMP-9 in the treated cells were determined using ELISA, and Western blotting was used to detect the expressions of E-cadherin, N-cadherin, cyclin D1, cyclin E1, HSP70 and HMGB1 and the phosphorylation levels of Akt and Stat3. RESULTS: CCK-8 assay showed that dihydromyricetin treatment dose-dependently inhibited the viability of BGC-823 cells (P < 0.05). Treatment with dihydromyricetin obviously suppressed the proliferation and migration of BGC-823 cells, significantly reduced the expression levels of cyclin D1, cyclin E1 and Ncadherin, enhanced E-cadherin expression, inhibited the phosphorylation of Akt and stat3, and downregulated HMGB1 expression in the cells. The results of ELISA demonstrated significantly lowered levels of MMP-2 and MMP-9 in dihydromyricetin-treated cells. CONCLUSIONS: Dihydromyricetin inhibits the proliferation and migration of BGC-823 cells through suppressing the activation of Akt/stat3 signaling pathways and HMGB1 expression.

High mobility group box 1 regulates gastric cancer cell proliferation and migration via RAGE-mTOR/ERK feedback loop.

Gastric cancer (GC) is a common malignancy tumour in China. Despite various therapeutic approaches to improve the survival rate of GC patients, the effectiveness of currently available treatments remains unsatisfactory. High mobility group box 1 (HMGB1) is reported to play a role in tumour development. However, the molecular mechanisms involved in HMGB1-mediated regulation of proliferation and migration of GC cells remain unclear. In the present study, we demonstrated that HMGB1 is highly expressed in GC cells and tissue. In HGC-27 GC cells, HMGB1 overexpression or HMGB1 RNA interference both demonstrated that HMGB1 could promote GC cell proliferation and migration. Investigation of the underlying molecular mechanisms revealed that HMGB1 enhanced cyclins expression, induced epithelial-to-mesenchymal transition and matrix metalloproteinase (MMPs) expression and promoted RAGE expression as well as RAGE-mediated activation of Akt/mTOR/P70S6K and ERK/P90RSK/CREB signalling pathways. We also found that inhibition of ERK and mTOR using specific inhibitors reduced recombinant human HMGB1-induced RAGE expression, suggesting that the RAGE-mTOR/ERK positive feedback loop is involved in HMGB1-induced GC cell proliferation and migration. Our study highlights a novel mechanism by which HMGB1 promotes GC cell proliferation and migration via RAGE-mediated Akt-mTOR and ERK-CREB signalling pathways which also involves the RAGE-mTOR/ERK feedback loop. These findings indicate that HMGB1 is a potential therapeutic target for GC.

Aloin Inhibits the Proliferation and Migration of Gastric Cancer Cells by Regulating NOX2-ROS-Mediated Pro-Survival Signal Pathways.

BACKGROUND: Aloin has been reported to have many pharmacological effects including anti-inflammatory, anti-oxidant and anti-tumour activities. However, the precise molecular mechanisms underlying the anti-tumour properties of aloin are yet to be elucidated. METHODS: HGC-27 and BGC-823 gastric cancer cells were treated with aloin. EdU and colony formation assays were used to detect the proliferation ability of cells. The migration of cells was detected using wound healing and transwell assays. Western blotting was used to detect the levels of cyclinD1, cyclin E1, MMPs, N-cadherin, E-cadherin and NOX2. The phosphorylation of Akt, mTOR, P70S6K, S6, Src, stat3 and IκBα were also detected by Western blotting. Flow cytometry was used to detect the cell cycle distribution.The location of p65 in cells was determined by using a confocal microscopy assay. The total amounts of ROS present in cells were measured using an ROS assay kit. RESULTS: Here, we found that aloin inhibited the proliferation and migration of HGC-27 and BGC-823 gastric cancer cells using a combination of EdU, colony formation, wound healing and transwell assays. Further investigations revealed that aloin decreased the protein expression levels of cyclin D1, N-cadherin, and the matrix metalloproteinases (MMP)-2 and MMP-9; increased E-cadherin expression in a dose-dependent manner; inhibited reactive oxygen species (ROS) generation; and mediated the activation of Akt-mTOR, signal transducer and activator of transcription-3 (Stat3), and NF-κB signalling pathways. Our results also indicated that aloin is able to attenuate the expression levels of the two regulatory proteins of nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2), p47phox and p22phox, but had no effect on the level of gp91phox. N-acetylcysteine treatment of gastric cancer cells inhibited ROS production and Akt-mTOR, Stat3, and IκBα phosphorylation. Taken together, our data suggest that aloin inhibits the proliferation and migration of gastric cancer cells by downregulating NOX2-ROS-mediated activation of the Akt-mTOR, Stat3, and NF-κB signalling pathways. CONCLUSION: Our findings suggest a potential role for aloin in the prevention of gastric cancer cell proliferation and migration and provide novel insights into the anti-cancer properties of aloin.

[Calenduloside E inhibits lipopolysaccharide-induced inflammatory response by inhibiting activation of ROS-mediated JAK1-stat3 signaling pathway in RAW264.7 cells].

OBJECTIVE: To investigate the effect of calenduloside E on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 cells and explore the underlying molecular mechanism. METHODS: CCK-8 assay was used to examine the effect of different concentrations of calenduloside E (0-30 µg/mL) on the viability of RAW264.7 cells. The release of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in RAW264.7 cells in response to pretreatment with 6, 8, and 10 µg/mL calenduloside E for 2 h followed by stimulation with 100 ng/mL LPS was detected using enzyme-linked immunosorbent assay (ELISA). The expression levels of iNOS and COX-2 and the activation of JAK-stats, MAPKs and NF-кB signaling pathways in the treated cells were determined using Western blotting. A reactive oxygen species (ROS) detection kit was used to detect ROS production in the cells, and the nuclear translocation of the transcription factor stat3 was observed by laser confocal microscopy. RESULTS: Calenduloside E below 20 µg/mL did not significantly affect the viability of RAW264.7 cells. Calenduloside E dose-dependently decreased the expression levels of iNOS and COX-2 induced by LPS, inhibited LPS-induced release of TNF-α and IL-1ß, and suppressed LPS-induced JAK1-stat3 signaling pathway activation and stat3 nuclear translocation. Calenduloside E also significantly reduced ROS production induced by LPS in RAW264.7 cells. CONCLUSIONS: Calenduloside E inhibits LPS-induced inflammatory response by blocking ROS-mediated activation of JAK1-stat3 signaling pathway in RAW264.7 cells.

The molecular mechanisms of Aloin induce gastric cancer cells apoptosis by targeting High Mobility Group Box 1.

Purpose: Aloin (ALO), a bioactive ingredient extracted from aloe vera, has anti-tumor effects. High Mobility Group Box 1 (HMGB1), a highly conserved nuclear DNA-binding protein, has been implicated in various cancer types. Highly expressed HMGB1 is closely associated with tumor cells apoptosis, proliferation and migration. We investigated the specific molecular mechanisms by which ALO-induced apoptosis by targeting HMGB1 in gastric cancer cells. Materials and methods: Human gastric cancer HGC-27 cells were treated with different doses of ALO (100, 200 and 400 µg/ml) for 24 h, after which DAPI staining was used to observe the nuclear morphology, Annexin V/PI double staining assay was used to determine the rate of apoptosis; Western blotting was used to detect the levels of PARP, pro-caspase3, HMGB1 and RAGE; nuclear translocation of HMGB1 was determined by conducting a nucleoplasm separation experiment. The Enzyme linked immunosorbent assay (ELISA) assay was used to detect release of HMGB1. The HGC-27 cells, transfected with HMGB1 shRNA plasmids, were stimulated with ALO for 24 h, after which a flow cytometry assay was used to detect the rate of apoptosis. HGC-27 cells were pre-treated with or without ALO and then stimulated with rhHMGB1, the phosphorylation of Akt, mTOR, P70S6K, S6, 4EBP1, ERK, P90RSK, cAMP regulatory element binding (CREB) were detected by Western blotting. Results: After different doses of ALO treatment, the nuclei showed morphological changes characteristic of apoptosis. Apoptotic rates were enhanced in a dose dependent manner. The level of cleaved PARP was enhanced and pro-caspase3, HMGB1 and RAGE levels were reduced, HMGB1 nuclear translocation and release were inhibited. The activation of rhHMGB1-induced Akt-mTOR-P70S6K and ERK-CREB signalling pathways was inhibited by ALO. Blocking these signalling pathways by special inhibitors and HMGB1 knockdown could enhance ALO-induced HGC-27 cell apoptosis. Conclusion: ALO- induced HGC-27 cell apoptosis by down-regulating expressions of HMGB1 and RAGE, inhibiting HMGB1 release and then suppressing rhHMGB1-induced activation of Akt-mTOR-P70S6K and ERK-P90RSK-CREB signalling pathways.

Inhibition of ROS-mediated activation Src-MAPK/AKT signaling by orientin alleviates H2O2-induced apoptosis in PC12 cells.

PURPOSE: Reactive oxygen species (ROS) are considered a direct cause of neurodegenerative diseases (NDDs). Drugs developed to target ROS are effective for the treatment of NDDs. Orientin is a pyrone glucoside extracted from Polygonum orientale, and it exhibits many pharmacological activities. In this study, we aimed to determine whether orientin could relieve hydrogen peroxide (H2O2)-induced neuronal apoptosis and to investigate the specific target of orientin. MATERIALS AND METHODS: In this study, the neuroprotective effect and its possible mechanisms of orientin in mouse pheochromocytoma cell line (PC12) cells stimulated by H2O2, establishing an oxidative stress model, were investigated. And we further tested the role of ROS in the neuroprotective effects of orientin. RESULTS: Orientin (5-100 µg/mL) did not cause toxicity in PC12 cells but significantly decreased H2O2-induced reduction in PC12 cell viability, cell apoptosis rates, and nuclear condensation. It also inhibited the activation of caspase-3 and degradation of poly(ADP-ribose) polymerase (PARP). Under the stimulation of H2O2, MAPKs (ERK, JNK, and p38), AKT, and Src signaling proteins in PC12 cells were activated in a time-dependent manner. The application of inhibitors that were specific for MAPKs, AKT, and Src effectively alleviated H2O2-induced cell apoptosis. In addition, the Src inhibitor decreased the activation of MAPKs and AKT signaling. More importantly, orientin effectively decreased H2O2-induced phosphorylation of MAPKs, AKT, and Src signaling proteins. Finally, we confirmed that orientin effectively inhibited H2O2-induced accumulation of ROS in cells. In addition, ROS inhibitors blocked the Src-MAPKs/AKT signaling pathway-dependent cell apoptosis stimulated by H2O2. CONCLUSION: These results indicate that alleviation of H2O2-induced cell apoptosis by orientin is Src-MAPKs/AKT dependent. Overall, our study confirms that orientin alleviates H2O2-induced cell apoptosis by inhibiting the ROS-mediated activation of Src-MAPKs/AKT signaling.

[Aloin induces apoptosis via regulating the activation of MAPKs signaling pathway in human gastric cancer cells in vitro].

OBJECTIVE: To investigate the effect of aloin on apoptosis of human gastric cancer cells and explore the molecular mechanism. METHODS: Gastric cancer MKN-28 and HGC-27 cells were cultured routinely in 1640 medium supplemented with 10% fetal bovine serum and 10% non-essential amino acids (for HGC-27 cells) and treated with different concentrations of aloin for different durations. The cell viability, cell nuclear morphology, and apoptotic rate of the cells were detected using CCK-8 assay, DAPI staining and AnnexinV-FITC/PI, respectively; Western blotting was used to detect the expression levels of PARP, procaspase 3 and the phosphorylation of p38, ERK and JNK. The cells were treated with specific inhibitors of p38, ERK and JNK, and the inhibitory effects on these pathways were detected with Western blotting; DAPI staining was used to detect the effects of inhibitors on apoptosis of gastric cancer cells. RESULTS: Aloin dose-dependently inhibited the viability and induced apoptosis of HGC-27 and MKN-28 cells. Alion treatment obvious enhanced the phosphorylation of p38 and JNK but decreased ERK phosphorylation in the cells. Blocking ERK activation with the ERK inhibitor obviously enhanced aloin-induced cell apoptosis, where inhibiting p38 and JNK activation partly reversed alion-induced apoptosis in the cells. CONCLUSIONS: Aloin induces apoptosis of human gastric cancer cells in vitro by activating p38 and JNK signaling pathways and inhibiting ERK signaling pathway.

[Chrysin promotes SMMC-7721 cell apoptosis by regulating MAPKs signaling pathway].

OBJECTIVE: To study the effect of chrysin in inducing apoptosis of human hepatic carcinoma cells and explore the possible mechanism. METHODS: Human hepatic carcinoma SMMC-7721 cells treated with DMSO or chrysin at different concentrations (5-200 µg/mL) were examined for changes in the cell proliferation using CCK-8 assay. The morphological changes of SMMC-7721 cells were observed in response to treatment with 5, 10, or 20 µg/mL chrysin, and the changes in the cell nuclei were observed using DAPI nuclear staining. Annexin Ⅴ-FITC/PI flow cytometry was used to determine the cell apoptosis rate. The changes in the apoptosis-related proteins (PARP and caspase-3) and MAPKs signal pathway were detected with Western blotting. RESULTS: Chrysin treatment obviously suppressed the proliferation of SMMC-7721 cells in a dose-dependent manner below the concentration of 60 µg/mL. Chrysin (20 µg/mL) also caused significantly increased cell apoptosis and significant cleavage of PARP and caspase-3. Chrysin significantly activated MAPKs signaling pathway in a time-and dose-dependent manner, with the peak activation level occurring at 15 min. Pretreatment of the cells with specific inhibitors of the MAPKs pathway obviously inhibited the effect of chrysin in inducing cell apoptosis. CONCLUSIONS: Chrysin inhibits the proliferation and promotes apoptosis of SMMC-7721 cells by regulating the activation of MAPKs signaling.

Salidroside inhibits the proliferation and migration of gastric cancer cells via suppression of Src­associated signaling pathway activation and heat shock protein 70 expression.

Salidroside, an active ingredient extracted from the Rhodiola rosea plant, has potential anti­tumor effects. However, the effects of salidroside on gastric cancer cell proliferation and migration remain unclear. In the present study, the inhibitory effects of salidroside on gastric cancer cell proliferation, migration and invasion and the molecular mechanisms underlying these effects were investigated. The human gastric cancer cell line, BGC­823, was treated with different concentrations of salidroside (200, 400 and 600 µg/ml). Cell proliferation was determined with Cell Counting Kit­8 and colony formation assays, and the migration and invasion of cells was detected by a wound healing and Transwell assay, respectively. Western blotting was performed to detect the levels of N­cadherin, E­cadherin and heat shock protein (HSP)70. In addition, the phosphorylation of proto­oncogene tyrosine­protein kinase Src (Src), protein kinase B (Akt), mitogen activated protein kinase 1 (ERK), signal transducer and activator of transcription (STAT)3 and focal adhesion kinase 1 (FAK) was examined by western blotting. The levels of matrix metalloproteinase (MMP)­2 and MMP­9 were determined by enzyme­linked immunosorbent assay kits. Levels of reactive oxygen species (ROS) in cells were measured by a fluorescence plate reader with dichloro­dihydro­fluorescein diacetate. The results indicated that salidroside significantly suppressed cell proliferation and colony formation, inhibited cell migration and invasion, increased E­cadherin expression and decreased N­cadherin, MMP­2 and MMP­9 expression. Furthermore, salidroside suppressed ROS production and subsequently reduced the phosphorylation of Src, Akt, ERK and FAK. Salidroside also inhibited HSP70 expression, and HSP70 overexpression reversed the inhibitory effects of salidroside on BGC­823 cell proliferation, migration and invasion. In conclusion, the present study revealed that salidroside inhibited the proliferation, migration and invasion of BGC­823 cells by downregulating ROS­mediated Src­associated signaling pathway activation and HSP70 expression.

[Chrysin inhibits lipopolysaccharide-induced inflammatory responses of macrophages via JAK-STATs signaling pathway].

OBJECTIVE: To investigate the mechanism of chrysin in regulating lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells. METHODS: RAW264.7 cells were treated with different concentrations (0, 5, 10, 20, 40, 60, 80, 100, 150, and 200 µg/mL) of chrysin for 24 h, and the cell viability was measured using CCK-8. RAW264.7 cells were pre-treated with 10, 30, or 60 µg/mL chrysin for 2 h before stimulation with LPS for different times. The levels of TNF-α, IL-6 and MCP-1 were detected by ELISA, and Western blotting was used to detect the phosphorylation of JAK- 1, JAK-2, STAT-1 and STAT-3. The level of reactive oxygen species in RAW264.7 cells was detected by CM-H2DCFDA fluorescence probe. The effect of ROS on LPS-induced JAK-STATs signal and the inflammatory response of RAW264.7 cells was detected by ROS scavenger NAC. The transcription factors STAT-1 and STAT-3 nuclear translocation were observed by laser confocal microscopy. RESULTS: Chrysin below 60 µg/mL did not significantly affect the viability of RAW264.7 cells. At 10, 30, and 60 µg/mL, chrysin dose-dependently inhibited the expression of iNOS induced by LPS. Chrysin treatment also inhibited LPS-induced phosphorylation of JAK-STATs, nuclear translocation of STAT1 and STAT3, release of TNF-α, IL-6 and MCP-1, and the production of ROS in RAW264.7 cells; ROS acted as an upstream signal to mediate the activation of JAK-STATs signaling pathway. CONCLUSION: Chrysin blocks the activity of JAK-STATs mediated by ROS to inhibit LPS-induced inflammatory response in RAW264.7 cells.

miR-24-3p promotes cell migration and proliferation in lung cancer by targeting SOX7.

Lung cancer (LC) is one of the leading causes of cancer-related death in the world. miR-24-3p plays critical roles in many cancer types, including LC. In this study, we first investigated whether miR-24-3p promoted LC cell migration and proliferation in vitro. We used three bioinformatics algorithms to predict the miR-24-3p target gene to study the molecular mechanism by which miR-24-3p contributes to LC progression. Then, we used the luciferase reporter assay to identify whether SOX7 was a direct target of miR-24-3p. Moreover, Western blotting and a quantitative real time-polymerase chain reaction analysis showed that miR-24-3p downregulated SOX7 protein expression by a post-transcriptional mechanism. Finally, we determined that SOX7 had opposing effects to those of miR-24-3p on LC cell proliferation and migration, suggesting that miR-24-3p promotes cell proliferation and migration by directly targeting SOX7. Furthermore, miR-24-3p accelerated tumor growth in xenograft mice by targeting SOX7. These results provide the first clue that miR-24-3p could play a role as an oncomiR in LC by regulating SOX7.

Ly6G+ neutrophil-derived miR-223 inhibits the NLRP3 inflammasome in mitochondrial DAMP-induced acute lung injury.

MicroRNA (miRNA) mediates RNA interference to regulate a variety of innate immune processes, but how miRNAs coordinate the mechanisms underlying acute lung injury/acute respiratory distress syndrome (ALI/ARDS) in patients with pulmonary inflammatory injury is still unknown. In this study, we demonstrated that miR-223 limits the number of Ly6G+ neutrophils and inhibits the activity of the NLRP3 inflammasome to alleviate ALI induced by mitochondrial damage-associated molecular patterns (DAMPs) (MTDs). miR-223 expression is increased in the lungs of MTD-induced mice or ARDS patients following trauma/transfusion or following the physiological remission of ALI/ARDS. miR-223-/+ mice exhibited more severe ALI and cytokine dysregulation. Other studies have shown that MTD-induced increases in miR-223 expression are mainly contributed by Ly6G+ neutrophils from the haematopoietic system. miR-223 blocks bone marrow-derived Ly6G+ neutrophil differentiation and inhibits peripheral cytokine release. In addition, MTD-induced miR-223 expression activates a negative feedback pathway that targets the inhibition of NLRP3 expression and IL-1ß release; therefore, miR-223 deficiency can lead to the sustained activation of NLRP3-IL-1ß. Finally, elimination of peripheral Ly6G+ neutrophils and pharmacological blockade of the miR-223-NLRP3-IL-1ß signalling axis could alleviate MTD-induced ALI. In summary, miR-223 is essential for regulating the pathogenesis of DAMP-induced ALI.

Myricitrin Modulates NADPH Oxidase-Dependent ROS Production to Inhibit Endotoxin-Mediated Inflammation by Blocking the JAK/STAT1 and NOX2/p47phox Pathways.

Myricitrin, a naturally occurring polyphenol hydroxy flavonoid, has been reported to possess anti-inflammatory properties. However, the precise molecular mechanism of myricitrin's effects on LPS-induced inflammation is unclear. In the present study, myricitrin significantly alleviated acute lung injury in mice. Myricitrin also markedly suppressed the production of NO, TNF-α, IL-6, and MCP-1 in RAW264.7 macrophage cells. The inhibition of NO was concomitant with a decrease in the protein and mRNA levels of iNOS. The phosphorylation of JAKs and STAT-1 was abrogated by myricitrin. Furthermore, myricitrin inhibited the nuclear transfer and DNA binding activity of STAT1. The JAK-specific inhibitor ruxolitinib simulated the anti-inflammatory effect of myricitrin. However, myricitrin had no impact on the MAPK signalling pathway. Myricitrin attenuated the generation of intracellular ROS by inhibiting the assembly of components of the gp91phox and p47phox. Suppression of ROS generation using NAC or apocynin or by silencing gp91phox and p47phox all demonstrated that decreasing the level of ROS inhibited the LPS-induced inflammatory response. Collectively, these results confirmed that myricitrin exhibited anti-inflammatory activity by blocking the activation of JAKs and the downstream transcription factor STAT1, which may result from the downregulation of NOX2-dependent ROS production mediated by myricitrin.

Salidroside Inhibits HMGB1 Acetylation and Release through Upregulation of SirT1 during Inflammation.

HMGB1, a highly conserved nonhistone DNA-binding protein, plays an important role in inflammatory diseases. Once released to the extracellular space, HMGB1 acts as a proinflammatory cytokine that triggers inflammatory reaction. Our previous study showed that salidroside exerts anti-inflammatory effect via inhibiting the JAK2-STAT3 signalling pathway. However, whether salidroside inhibits the release of HMGB1 is still unclear. In this study, we aim to study the effects of salidroside on HMGB1 release and then investigate the potential molecular mechanisms. In an experimental rat model of sepsis caused by CLP, salidroside administration significantly attenuated lung injury and reduced the serum HMGB1 level. In RAW264.7 cells, we investigated the effects of salidroside on LPS-induced HMGB1 release and then explored the underlying molecular mechanisms. We found that salidroside significantly inhibited LPS-induced HMGB1 release, and the inhibitory effect was correlated with the HMGB1 acetylation levels. Mechanismly, salidroside inhibits HMGB1 acetylation through the AMPK-SirT1 pathway. In addition, SirT1 overexpression attenuated LPS-induced HMGB1 acetylation and nucleocytoplasmic translocation. Furthermore, in SirT1 shRNA plasmid-transfected cells, salidroside treatment enhanced SirT1 expression and reduced LPS-activated HMGB1 acetylation and nucleocytoplasmic translocation. Collectively, these results demonstrated that salidroside might reduce HMGB1 release through the AMPK-SirT1 signalling pathway and suppress HMGB1 acetylation and nucleocytoplasmic translocation.

[Neuroprotective effect of Nogo-66 receptor silencing in preterm rats with brain injury caused by intrauterine infection].

OBJECTIVE: To investigate the effect of Nogo-66 receptor (NgR) silencing with specific small interfering RNA (siRNA) on brain injury repair in preterm rats with brain injury caused by intrauterine infection and related mechanism of action. METHODS: The pregnant Sprague-Dawley rats (with a gestational age of 15 days) were selected, and premature delivery was induced by RU486 or lipopolysaccharide (LPS). The preterm rats delivered by those treated with RU486 were selected as the control group. The preterm rats with brain injury caused by intrauterine infection induced by LPS were divided into model, empty vector, and NgR-siRNA groups, with 36 rats in each group. The rats in the control and model groups were given routine feeding only, and those in the empty vector and NgR-siRNA groups were given an injection of lentiviral empty vector or NgR-siRNA lentivirus via the lateral ventricle on postnatal day 1 (P1) and then fed routinely. On P3, P7, and P14, 8 rats in each group were randomly selected and sacrificed to harvest the brain tissue. RT-PCR was used to measure the mRNA expression of NgR. Western blot was used to to measure the protein expression of active RhoA. The immunofluorescence histochemistry was used to determine the degree of activation of microglial cells and the morphology of oligodendrocyte precursor cells (OPCs). Hematoxylin and eosin staining was used to observe the pathological changes in brain tissue. The behavioral score was evaluated on P30. RESULTS: On P3, the NgR-siRNA group had significantly lower mRNA expression of NgR and protein expression of active RhoA in brain tissue than the model and empty vector groups (P<0.05). In each group, the mRNA expression of NgR was positively correlated with the protein expression of active RhoA (P<0.05). The results of immunofluorescence histochemistry showed that on P3, the NgR-siRNA group had a significantly reduced fluorescence intensity of the microglial cells labeled with CD11b compared with the model and empty vector groups (P<0.05). The OPCs labeled with O4 antibody in the four groups were mainly presented with tripolar cell morphology. The results of pathological examination showed a normal structure of white matter with clear staining in the periventriclar area in the control group, a loose structure of white matter with disorganized fibers and softening lesions in the model and empty vector groups, and a loose structure of white matter with slightly disorganized fibers, slight gliocyte proliferation, and no significant necrotic lesions in the NgR-siRNA group. As for the behavioral score, compared with the model and empty vector groups, the NgR-siRNA group had a higher score in the suspension test, a longer total activity distance, and greater mean velocity and number of squares crossed, as well as a shorter time of slope test and a shorter time and distance of activity in the central area (P<0.05), while there were no significant differences in these parameters between the NgR-siRNA and control groups (P>0.05). CONCLUSIONS: NgR silencing with specific siRNA can effectively silence the expression of NgR in pertem rats with brain injury caused by interauterine infection and has a significant neuroprotective effect in brain injury repair.

Daphnetin protects oxidative stress-induced neuronal apoptosis via regulation of MAPK signaling and HSP70 expression.

Neurodegenerative disorders are characterized by progressive degeneration and loss of neurons in the brain. Oxidative stress is implicated in the pathogenesis of neurological disorders, although the pathological mechanism remains unelucidated. Daphnetin, an active ingredient extracted from Changbai daphne (Daphne Korean Nakai), exhibits various pharmacological effects, including anti-inflammatory, anti-oxidative and anti-tumor effects. However, the neuroprotective effects, as well as the specific mechanisms of daphnetin, remain unclear. Neuronal-like rat pheochromocytoma PC12 cells were pretreated with daphnetin for 2 h, then treated with or without H2O2 for various times. Cell morphology was detected using an inverted microscope, the apoptotic ratio was determined by Annexin V fluorescein isothiocyanate/propidium iodide assay, nuclear morphology was observed and photographed using a fluorescence microscope following 4',6-diamidino-2-phenylindole staining. The levels of pro-caspase 3, cleavage of poly ADP-ribose polymerase and caspase 3 were detected by western blotting. In addition, the activation of mitogen-activated protein kinase (MAPK) signal pathway and the expression of HSP70 were detected by western blotting. The present study demonstrated that daphnetin attenuated hydrogen peroxide (H2O2)-induced apoptosis in a concentration-dependent manner, reduced the cleavage of poly ADP ribose polymerase and caspase 3, and inhibited the phosphorylation of p38 MAPK and c-Jun N-terminal kinases (JNK) in H2O2-induced PC12 cells. In addition, daphnetin induced the expression of HSP70 in a dose- and time-dependent manner, and daphnetin-induced HSP70 expression was reduced by extracellular signal-regulated kinase (ERK) 1/2 inhibitor U0126 in PC12 cells. Therefore, the present results indicate that daphnetin protects PC12 cells against oxidative stress injury by regulating p38 MAPK and JNK signaling and increasing the expression of HSP70 via ERK signaling. This suggests that daphnetin may have the potential to treat certain neurodegenerative diseases. The present results not only provide insight into the potential use of daphnetin in H2O2-induced PC12 cell apoptosis, but also highlight the potential role of HSP70 in neuroprotection.

ß-arrestin2 regulates TRAIL-induced HepG2 cell apoptosis via the Src-extracellular signal-regulated signaling pathway.

ß-arrestins, including ß-arrestin1 and ß­arrestin2, two ubiquitously expressed members of the arrestin family in various types of tissue, are adaptor proteins that modulate the desensitization and trafficking of seven membrane­spanning receptors. Recently, ß­arrestins have been shown to bind to numerous signaling molecules, including c­Src and mitogen­activated protein kinase family members. In addition, accumulating evidence has suggested that ß­arrestins are involved in the anti­apoptosis signaling pathway by associating with kinases, such as Akt and ERK, and altering their activities. However, the role of ß­arrestins in tumor necrosis factor­related apoptosis­inducing ligand (TRAIL)­induced apoptosis remains unclear. In the present study, ß­arrestin2, but not ß­arrestin1, was observed to modulate TRAIL­triggered HepG2 cell apoptosis by regulating activation of the Src­extracellular signal­regulated kinase (ERK) signaling pathway. Using overexpression and RNA interference experiments, ß­arrestin2 was demonstrated to prevent TRAIL­induced HepG2 cell apoptosis. Additionally, ß­arrestin2 exerted an additive effect on TRAIL­induced activation of Src and ERK. Furthermore, downregulating ß­arrestin2 expression attenuated the TRAIL­induced activation of Src and ERK survival signaling and enhanced TRAIL­induced apoptosis. PP2, a pharmacological inhibitor of Src, reduced activation of the Src­ERK signaling pathway and enhanced TRAIL­induced HepG2 cell apoptosis. Co-immunoprecipitation experiments demonstrated a physical association between ß­arrestin2 and Src, and TRAIL stimulation resulted in enhanced quantities of the ß­arrestin2/Src complex. A notable interaction was identified between ß­arrestin2 and death receptors (DR)4 and 5, but only in the presence of TRAIL stimulation. To the best of our knowledge, these findings are the first to demonstrate that ß­arrestin2 mediates TRAIL­induced apoptosis by combing with DRs and Src, and regulates the activation of Src­ERK signaling in HepG2 cells. It is hypothesized that the formation of a signaling complex comprising DR, ß­arrestin2 and Src is required for the action of TRAIL on HepG2 cell apoptosis, which provides a novel insight into analyzing the effects of ß­arrestin2 on protecting cells from TRAIL­induced apoptosis.