Activation Of Nuclear Transcription Factor Research Articles

Cyclooxygenase-2 is Essential for Mediating the Effects of Calcium Ions on Stimulating Phosphorylation of Tau at the Sites of Ser 396 and Ser 404.

Alzheimer's disease (AD) is reported to be associated with the accumulation of calcium ions (Ca2+), which is responsible for the phosphorylation of tau. Although a series of evidence have demonstrated this phenomenon, the inherent mechanisms remain unknown. Using tauP301S and cyclooxygenase-2 (COX-2) transgenic mice and neuroblastoma (n)2a cells as in vivo and in vitro experimental models, we found that Ca2+ stimulates the phosphorylation of tau by activating COX-2 in a prostaglandin (PG) E2-dependent EP receptor-activating manner. Specifically, Ca2+ incubation stimulated COX-2 and PGE2 synthase activity, microsomal PGE synthase 1 and the synthesis of PGE2 by activating the transcriptional activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in n2a cells. Elevated levels of PGE2 were responsible for phosphorylating tau in an EP-1, -2, and -3 but not EP4-dependent glycogen synthase kinase 3-activating manner. These observations were corroborated by results that showed tau was phosphorylated when it colocalized with activated COX-2 in tauP301S and COX-2 transgenic mice or n2a cells. To further validate these observations, treatment of mice with the COX-2 inhibitor rofecoxib decreased the phosphorylation of tau via EP1-3 but not EP4. Collectively, our observations fill the gaps between Ca2+ and the phosphorylation of tau in a COX-2-dependent mechanism, which potentially provides therapeutic targets for combating AD.

Signaling pathway underlying splenocytes activation by polysaccharides from Atractylodis macrocephalae Koidz.

Previous study demonstrated that total polysaccharides isolated from Atractylodis macrocephalae Koidz. (RAMPtp) were effective to eliminate intramammary infection in cows. The present study was designed to investigate the immunomodulatory activity of RAMPtp in mouse splenocytes. Splenocyte proliferation, natural killer (NK) cytotoxicity, productions of NO and cytokines, transcription factor activity as well as the signal pathways and receptor were examined. The results showed that RAMPtp significantly promoted splenocyte proliferation and made the cells enter S and G2/M phases, increased ratios of T/B cells, boosted NK cytotoxicity, enhanced transcriptional activities of nuclear factor of activated T cells (NFAT), nuclear factor κB (NF-κB) and activator protein 1 (AP-1), and stimulated secretions of NO, immunoglobulin G (IgG) and multiple cytokine families (IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-6, IL-10, IL-12p40, IL-12p70, IL-13, IFN-γ, TNF-α, G-CSF, GM-CSF, KC, MIP-1α, MIP-1β, RANTES and Eotaxin). In addition, all the specific inhibitors against the mitogen-activated protein kinases (MAPKs) and NF-κB significantly suppressed the IL-6 production induced by RAMPtp. Moreover, splenocytes from Toll-like receptor 4 (TLR4) deficient mouse responded equally to RAMPtp stimulation as the wild-type. Therefore, RAMPtp might induce splenocytes activation at least in part via the TLR4-independent MAPKs and NF-κB signaling pathways. The present results would be useful to further understand the immunomodulatory mechanisms of RAMPtp in elimination of intramammary infection in cows.

Protective Effects of Fermented Oyster Extract against RANKL-Induced Osteoclastogenesis through Scavenging ROS Generation in RAW 264.7 Cells.

Excessive bone resorption by osteoclasts causes bone loss-related diseases and reactive oxygen species (ROS) act as second messengers in intercellular signaling pathways during osteoclast differentiation. In this study, we explored the protective effects of fermented oyster extract (FO) against receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclast differentiation in murine monocyte/macrophage RAW 264.7 cells. Our results showed that FO markedly inhibited RANKL-induced activation of tartrate-resistant acid phosphatase and formation of F-actin ring structure. Mechanistically, FO has been shown to down-regulate RANKL-induced expression of osteoclast-specific markers by blocking the nuclear translocation of NF-κB and the transcriptional activation of nuclear factor of activated T cells c1 (NFATc1) and c-Fos. Furthermore, FO markedly diminished ROS production by RANKL stimulation, which was associated with blocking the expression of nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1) and its regulatory subunit Rac-1. However, a small interfering RNA (siRNA) targeting NOX1 suppressed RANKL-induced expression of osteoclast-specific markers and production of ROS and attenuated osteoclast differentiation as in the FO treatment group. Collectively, our findings suggest that FO has anti-osteoclastogenic potential by inactivating the NF-κB-mediated NFATc1 and c-Fos signaling pathways and inhibiting ROS generation, followed by suppression of osteoclast-specific genes. Although further studies are needed to demonstrate efficacy in in vivo animal models, FO may be used as an effective alternative agent for the prevention and treatment of osteoclastogenic bone diseases.

Induction of Oxidative Stress Through Inhibition of Thioredoxin Reductase 1 Is an Effective Therapeutic Approach for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancers worldwide which lacks effective treatment. Cancer cells experience high levels of oxidative stress due to increased generation of reactive oxygen species (ROS). Increased antioxidant-producing capacity is therefore found in cancer cells to counteract oxidative stress. The thioredoxin system is a ubiquitous mammalian antioxidant system which scavenges ROS, and we demonstrate that it is vital for HCC growth as it maintains intracellular reduction-oxidation (redox) homeostasis. Transcriptome sequencing in human HCC samples revealed significant overexpression of thioredoxin reductase 1 (TXNRD1), the cytosolic subunit and key enzyme of the thioredoxin system, with significant correlations to poorer clinicopathological features and patient survival. Driven by the transcriptional activation of nuclear factor (erythroid-derived 2)-like 2, the master protector against oxidative stress, TXNRD1 counteracts intracellular ROS produced in human HCC. Inhibition of TXNRD1 through genetic inhibition hindered the proliferation of HCC cells and induced apoptosis in vitro. Administration of the pharmacological TXNRD1 inhibitor auranofin (AUR) effectively suppressed the growth of HCC tumors induced using the hydrodynamic tail vein injection and orthotopic implantation models in vivo. Furthermore, AUR sensitized HCC cells toward the conventional therapeutic sorafenib. Conclusion: Our study highlights the reliance of HCC cells on antioxidants for redox homeostasis and growth advantage; targeting TXNRD1 resulted in dramatic accumulation of ROS, which was found to be an effective approach for the suppression of HCC tumor growth.

NR4A transcription factors limit CAR T cell function in solid tumours.

T cells expressing chimeric antigen receptors (CAR) targeting human CD19 (huCD19) have exhibited impressive clinical efficacy against B cell malignancies1,2. CAR-T cells have been less effective against solid tumors3–5, in part because they enter a hyporesponsive (“exhausted” or “dysfunctional”) state6–9 triggered by chronic antigen stimulation and characterized by upregulation of inhibitory receptors and loss of effector function. To investigate the function of CAR-T cells in solid tumors, we transferred huCD19-reactive CAR-T cells into huCD19+ tumor-bearing mice. CD8+ CAR+ tumor-infiltrating lymphocytes (TILs) and endogenous TILs expressing inhibitory receptors PD-1 and TIM3 exhibited similar profiles of gene expression and chromatin accessibility, associated with secondary activation of nuclear receptor transcription factors (TFs) Nr4a1 (Nur77), Nr4a2 (Nurr1) and Nr4a3 (Nor1) by the initiating TF NFAT (nuclear factor of activated T cells)10–12. CD8+ T cells from humans with cancer or chronic viral infections13,14,15 expressed high levels of Nr4a TFs and displayed enrichment of Nr4a binding motifs in accessible chromatin regions. CAR-T cells lacking all three Nr4a TFs (Nr4aTKO) promoted tumor regression and prolonged the survival of tumor-bearing mice. Nr4aTKO CAR-TILs displayed phenotypes and gene expression profiles characteristic of CD8+ effector T cells, and chromatin regions uniquely accessible in Nr4aTKO CAR-TILs compared to WT were enriched for binding motifs for NFκB and AP-1, TFs involved in T cell activation. Our data identify Nr4a TFs as major players in the cell-intrinsic program of T cell hyporesponsiveness and point to Nr4a inhibition as a promising strategy for cancer immunotherapy.

FoxO3 transcription factor promotes autophagy after transient cerebral ischemia/reperfusion

Aim: Autophagy was activated after cerebral ischemia reperfusion (I/R) injury. However, the molecular mechanisms underlying regulation of autophagy in cerebral I/R injury were not completely understood. Studies reported that Forked-box class O (FoxO) transcription factors involved in autophagy and might be the regulator of autophagy in multiple cells. In this study, we investigated the effects of FoxO3 on regulating autophagy after cerebral I/R injury.Materials and methods: Rats were subjected to MCAO for 2 h and reperfusion for different times, western blot was used to examine the expression of p-FoxO3, FoxO3 and the autophagic marker LC3 and Beclin-1 in penumbral region. Then rats were injected with WT-FoxO3 or TM-FoxO3 adenovirus by lateral cerebral ventricle to increase the function of FoxO3, western blot was used to examine the expression of LC3 and Beclin-1 in penumbral region. TTC and HE staining were used to evaluate the effects of increased FoxO3 activation on I/R induced brain damage.Results: Our studies showed that I/R injury resulted in induction of autophagy in penumbral brain tissue with concomitant dephosphorylation of FoxO3, consistent with increased activity of nuclear FoxO3 transcription factor. Increased FoxO3 activation led to autophagy significantly increased and had a protective effects on I/R injury.Conclusion: These data revealed an important role of FoxO3 in regulating autophagy in brain, and provided a new approach for further prevention and treatment of cerebral ischemia.

Shear stress regulates eNOS signaling in human umbilical vein endothelial cells via SRB1-PI3KAP1 pathway

Background: The occurrence and development of atherosclerosis are closely related to shear stress on the endothelial cells. However, related molecular mechanisms of controlling mechanical signal transduction in endothelial cells remain largely unknown. Aim of the Study: To obtain this goal, here, a parallel-plate flow chamber was used to impose laminar shear stress (8.4 dyne/cm2 ) on endothelial cells for 0 minute (min), 10 min, 30 min, 60 min, and 120 min. Subjects and Methods: The RNA interference was employed to down-regulate scavenger receptor class B1 (SRB1) and LY294002 was performed to block the phosphorylation status of the phosphoinositide 3-kinase pathway. Then, the cell status was observed under the microscope, followed by detection of phosphorylated phosphoinositide 3-kinase (PI3K), p38, extracellular signal-regulated protein kinases 1 and 2 and the binding activities of activator protein 1, nuclear factorκB and endothelial nitric oxide synthase (eNOs) by western blot. The results showed that shear stress (8.4 dyne/cm2 ) for 60 min induced obvious cell morphologic changes. Meanwhile, PI3K phosphorylation and eNOS expression were significantly increased by shear stress while reversed by SRB1 si-RNA and LY294002. Additionally, shear stress caused the enhanced binding activity of nuclear transcription factor activator protein 1 (AP-1) to DNA from 10 to 120 min, while only at 30 and 60 min for NF-κB. After treatment with SRB1 si-RNA and LY294002 inhibitor, the binding activities of AP-1 and DNA was significantly decreased, however, there was no effect on NF-κB binding activity. Results: Therefore, SRB1 plays a crucial role in mediating shear stress-induced eNOS activation in endothelial cells via PI3K-AP1 pathway. These findings will provide an important understanding of shear stress-induced cell alterations in clinic detection

Protective Effects of Euphrasia officinalis Extract against Ultraviolet B-Induced Photoaging in Normal Human Dermal Fibroblasts

Ultraviolet (UV) radiation induces skin photoaging, which is associated with the elevation of matrix metalloproteinases (MMPs) and the impairment of collagen. The Euphrasia species play a well-known role in the treatment of certain eye disorders through their anti-oxidative and anti-inflammatory activities. However, their protective activity toward UVB-induced damage remains unclear. In the present study, we investigated the protective effect of Euphrasia officinalis (95% ethanol extract) on UVB-irradiated photoaging in normal human dermal fibroblasts (NHDFs). Our results show that Euphrasia officinalis extract exhibited obvious reactive oxygen species (ROS) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, enhanced NHDF cell migration, and reduced UVB-induced apoptosis. The UVB-induced increases in MMP-1 and MMP-3 and decrease in type I procollagen were ameliorated by Euphrasia officinalis treatment, which worked by suppressing the mitogen-activated protein kinase (MAPK) and nuclear transcription factor activator protein 1 (AP-1) signaling pathways. Taken together, our data strongly suggest that Euphrasia officinalis ethanol extract could reduce UVB-induced photoaging by alleviating oxidative stress, proinflammatory activity, and cell apoptosis.

Plant Polyphenols in Obesity and Obesity-Associated Metabolic Disorders: A Narrative Review of Resveratrol and Flavonoids Upon the Molecular Basis of Inflammation

Background: The epidemic of obesity, metabolic syndrome, type 2 diabetes and non-alcoholic fatty liver disease is currently unsustainable for Public Health systems, and preventive and therapeutic approaches are urgently sought to improve health outcomes for affected individuals. Aim: In this study, we aim to further explore and synthetize available evidence on the effects of selected plant polyphenols (PP) upon molecular mechanisms associated with oxidative stress and inflammatory pathways. We also aim to briefly discuss PP supplementation as therapeutic tool for the prevention and management of prevalent obesity-associated metabolic disorders. Methods: This narrative review was performed in the PubMed database in June 2018 without restriction of publication period. Results: PP influence a broad range of cell signalling pathways; by modulating the activity of nuclear transcription factors, PP modulate gene expression and antioxidant responses, as well as inflammation and its resolution. Several interventional studies have investigated the effects of PP supplementation in a variety of sample populations, but no consensus has yet been reached regarding composition, dosage or course of treatment for therapeutic purposes. However, overall results tend to suggest a positive effect of PP in either improving metabolic profile or minimizing negative disease outcomes. Careful consideration on PP supplementation is paramount; adverse effects have already been described. Conclusion: The successful prevention and management or treatment of obesity-associated metabolic disorders may be achieved through an effective multidisciplinary approach to tackle their modifiable risk factors. A balanced diet, which includes naturally occurring sources of PP associated with lower consumption of ultra-processed foods, is a relevant approach for the positive health outcomes desired.

Abstract P152: Exercise Training Upregulates Nrf2 Gene Expression in the RVLM of Mice With Heart failure

Sympatho-excitation is an important hallmark in the heart failure (HF) state. It is known that HF is associated with global oxidative stress, which contributes to pathogenesis of sympatho-excitation. Central reactive oxygen species (ROS) accumulate within neurons and evoke alterations in protein function, leading to an enhanced neuronal excitability, thereby evoking the higher level of sympathetic activation in HF. On the other hand, exercise training (ExT) is associated with a reduction of oxidative stress, in part by upregulation of antioxidant enzymes. However, the link between ExT and antioxidants in the brain of animals with HF has not been explored. In this study, we hypothesized ExT enhances transcriptional activation of Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a master transcription factor that modulates a wide array of antioxidant enzyme gene expression, in the rostral ventrolateral medulla (RVLM). Sham and coronary artery ligation-induced HF mice were divided into either sedentary (Sed) or ExT groups. After 6 weeks of treadmill training, maximal exercise tolerance, urinary norepinephrine (NE) and Nrf2 as well as NAD(P)H dehydrogenase [quinone] 1 (NQO1) gene expression were evaluated by real time RT-PCR. We found that: (1) HF mice displayed significantly lower maximal distance than Sham mice, which was improved by ExT (maximal distance: Sham- Sed 255 ± 34 m (n = 6), HF Sed 148 ± 37 (n = 5), HF ExT 304 ± 34 (n = 6), p<0.05 HF Sed vs HF ExT); (2) urinary NE concentration was significantly higher in HF Sed group which was attenuated by ExT (urinary NE: Sham Sed 442 ± 38 (n = 6), HF Sed 596 ± 41 (n = 5), HF ExT 465 ± 38 ng/ml (n = 6), p<0.05); (3) ExT attenuated HF- induced lower Nrf2 and NQO1 gene expression and also upregulated gene expression of these two proteins in Sham mice (Nrf2: Sham Sed 0.92 ± 0.10 (n = 6), Sham ExT 1.32 ± 0.10 (n = 6), HF Sed 0.60 ± 0.11 (n = 5), HF ExT 0.95 (n = 6), p<0.05), (NQO1: Sham Sed 0.98 ± 0.12 (n = 6), sham ExT 1.39 ± 0.12 (n = 6), HF Sed 0.60 ± 0.13 (n = 5), HF ExT 1.07 ± 0.12 (n = 6), p < 0.05). These data suggest that upregulation of Nrf2 gene expression could be a mechanism by which ExT exerts its beneficial effects on sympathetic tone in HF. Further studies are required to investigate how ExT-induced Nrf2 upregulation alters sympathetic nerve activity in HF.

Desoxo-narchinol A and Narchinol B Isolated from Nardostachys jatamansi Exert Anti-neuroinflammatory Effects by Up-regulating of Nuclear Transcription Factor Erythroid-2-Related Factor 2/Heme Oxygenase-1 Signaling.

We previously reported that desoxo-narchinol A and narchinol B from Nardostachys jatamansi DC (Valerianaceae) inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2), and the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 protein in lipopolysaccharide (LPS)-stimulated BV2 and primary microglial cells. In this study, we aimed to elucidate the molecular mechanism underlying the anti-neuroinflammatory effects of desoxo-narchinol A and narchinol B. These two compounds inhibited the nuclear factor (NF)-κB pathway, by repressing the phosphorylation and degradation of inhibitor kappa B (IκB)-α, nuclear translocation of the p65/p50 heterodimer, and DNA-binding activity of the p65 subunit. Furthermore, both compounds induced heme oxygenase-1 (HO-1) protein expression, which was mediated by the activation of nuclear transcription factor erythroid-2-related factor 2 (Nrf2). Activation of the Nrf2/HO-1 pathway by desoxo-narchinol A was shown to be regulated by increased phosphorylation of p38 and extracellular signal-regulated kinase (ERK), whereas only p38 was involved in narchinol B-induced activation of the Nrf2/HO-1 pathway. In addition, phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling was also involved in the activation of HO-1 by desoxo-narchinol A and narchinol B. These compounds also increased the phosphorylation of glycogen synthase kinase 3 beta (GSK3β) at serine-9 residue, following phosphorylation of Akt. The anti-neuroinflammatory effect of desoxo-narchinol A and narchinol B was partially blocked by a selective HO-1 inhibitor, suggesting that this effect is partly mediated by HO-1 induction. In addition, both compounds also induced HO-1 protein expression in rat-derived primary microglial cells, which was correlated with their anti-neuroinflammatory effects in LPS-stimulated primary microglial cells. In conclusion, desoxo-narchinol A and narchinol B are potential candidates for the development of preventive agents for the regulation of neuroinflammation in neurodegenerative diseases.

The Antioxidant and Anti-Inflammatory Activities of 8-Hydroxydaidzein (8-HD) in Activated Macrophage-Like RAW264.7 Cells.

8-Hydroxydaidzein (8-HD) is a daidzein metabolite isolated from soybeans. This compound has been studied for its anti-proliferation, depigmentation, and antioxidant activities. However, the anti-inflammatory activities of 8-HD are not well-understood. Through its antioxidant effects in ABTS and DPPH assays, 8-HD reduces the production of sodium nitroprusside (SNP)-induced radical oxygen species (ROS). By triggering various Toll-like receptors (TLRs), 8-HD suppresses the inflammatory mediator nitric oxide (NO) without cytotoxicity. We examined the regulatory mechanism of 8-HD in lipopolysaccharide (LPS)-induced conditions. We found that 8-HD diminishes inflammatory gene expression (e.g., inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and tumor necrosis factor (TNF)-α) by regulating the transcriptional activities of nuclear factor (NF)-κB and activator protein 1 (AP-1). To find the potential targets of 8-HD, signaling pathways were investigated by immunoblotting analyses. These analyses revealed that 8-HD inhibits the activation of TAK1 and that phosphorylated levels of downstream molecules decrease in sequence. Together, our results demonstrate the antioxidant and anti-inflammatory actions of 8-HD and suggest its potential use in cosmetics or anti-inflammatory drugs.

Theaflavin alleviates inflammatory response and brain injury induced by cerebral hemorrhage via inhibiting the nuclear transcription factor kappa β-related pathway in rats.

ObjectiveIntracerebral hemorrhage (ICH) is one of the most common acute cerebrovascular diseases with high mortality. Numerous studies have shown that inflammatory response played an important role in ICH-induced brain injury. Theaflavin (TF) extracted from black tea has various biological functions including anti-inflammatory activity. In this study, we investigated whether TF could inhibit ICH-induced inflammatory response in rats and explored its mechanism.Materials and methodsICH rat models were induced with type VII collagenase and pretreated with TF by gavage in different doses (25 mg/kg–100 mg/kg). Twenty-four hours after ICH attack, we evaluated the rats’ behavioral performance, the blood–brain barrier (BBB) integrity, and the formation of cerebral edema. The levels of reactive oxygen species (ROS) and inflammatory cytokines were examined by 2′,7′-dichlorofluorescin diacetate and enzyme-linked immunosorbent assay. Nissl staining and transferase dUTP nick end labeling (TUNEL) were aimed to detect the neuron loss and apoptosis, the mechanism of which was explored by Western blot.ResultsIt was found that in the pretreated ICH rats TF significantly alleviated the behavioral defects, protected BBB integrity, and decreased the formation of cerebral edema and the levels of ROS as well as inflammatory cytokines (including interleukin-1 beta [IL-1β], IL-18, tumor nectosis factor-alpha, interferon-γ, transforming growth factor beta, and (C-X-C motif) ligand 1 [CXCL1]). Nissl staining and TUNEL displayed TF could protect against the neuron loss and apoptosis via inhibiting the activation of nuclear transcription factor kappa-β-p65 (NF-κβ-p65), caspase-1, and IL-1β. We also found that phorbol 12-myristate 13-acetate, a nonspecific activator of NF-κβ-p65, weakened the positive effect of TF on ICH-induced neural defects and neuron apoptosis by upregulating NF-κβ-related signaling pathway.ConclusionTF could alleviate ICH-induced inflammatory responses and brain injury in rats via inhibiting NF-κβ-related pathway, which may provide a new way for the therapy of ICH.

The group VIA calcium-independent phospholipase A2 and NFATc4 pathway mediates IL-1β-induced expression of chemokines CCL2 and CXCL10 in rat fibroblasts.

Chemokines are secreted proteins that regulate cell migration and are involved in inflammatory and immune responses. Here, we sought to define the functional crosstalk between the lipid signaling and chemokine signaling. We obtained evidence that the induction of some chemokines is regulated by group VIA calcium-independent phospholipase A2 β (iPLA2 β) in IL-1β-stimulated rat fibroblastic 3Y1 cells. Treatment of 3Y1 cells with IL-1β elicited an increased release of chemotactic factor(s) for monocytic THP-1 cells into culture medium in a time-dependent manner. Inhibitor studies revealed that an intracellular PLA2 inhibitor, arachidonoyl trifluoromethyl ketone (AACOCF3 ), but not the cyclooxygenase inhibitor indomethacin, attenuated the release of chemotactic factor(s). The chemotactic activity was inactivated by treatment with either heat or proteinase K, suggesting this chemotactic factor(s) is a proteinaceous factor(s). We purified the chemotactic factor(s) from the conditioned medium of IL-1β-stimulated 3Y1 cells using a heparin column and identified several chemokines, including CCL2 and CXCL10. The inducible expressions of CCL2 and CXCL10 were significantly attenuated by pretreatment with AACOCF3 . Gene silencing using siRNA revealed that the inductions of CCL2 and CXCL10 were attenuated by iPLA2 β knockdown. Additionally, the transcriptional activation of nuclear factor of activated T-cell proteins (NFATs), but not nuclear factor-κB, by IL-1β stimulation was markedly attenuated by the iPLA2 inhibitor bromoenol lactone, and NFATc4 knockdown markedly attenuated the IL-1β-induced expression of both CCL2 and CXCL10. Collectively, these results indicated that iPLA2 β plays roles inIL-1β-induced chemokine expression, in part via NFATc4 signaling.

PSRC1 overexpression attenuates atherosclerosis progression in apoE−/− mice by modulating cholesterol transportation and inflammation

AimsHuman genome-wide association studies (GWAS) have found that proline/serine-rich coiled-coil 1 (PSRC1) encodes a protein that is associated with serum lipid levels and coronary artery disease. In addition, our previous study showed that the cholesterol efflux capacity is decreased in macrophages following a treatment silencing Psrc1, indicating that PSRC1 has anti-atherosclerotic effects. However, the role of PSRC1 in the development of atherosclerosis is unknown. This study aims to explore the effect of PSRC1 on atherosclerosis and its underlying mechanisms. Method and resultsA recombinant adenovirus expressing Psrc1 (Ad-PSRC1) was constructed and transfected in RAW264.7 cells as well as injected intravenously into apoE−/− mice. The in vitro study showed that PSRC1 overexpression reduced the cellular cholesterol content, increased the cholesterol efflux capacity and inhibited foam cell formation by upregulating the expression of peroxisome proliferator-activated receptor γ (PPAR-γ) and liver X receptor α (LXR-α), which are key cholesterol transportation-related proteins. Infecting apoE−/− mice with Ad-PSRC1 inhibited the development of atherosclerotic lesions and enhanced atherosclerotic plaque stability. Consistent with these results, PSRC1 overexpression in apoE−/− mice decreased the plasma levels of TC, TG, LDL-C, TNF-α, IL-1β and IL-6, increased the plasma HDL-C levels and improved HDL function. Similarly, the PPAR-γ and LXR-α expression levels were upregulated in the liver and in peritoneal macrophages of PSRC1-overexpressing apoE−/− mice. Finally, the liver and peritoneal macrophages of apoE−/− mice displayed elevated expression of β-catenin, which is a direct downstream gene of PSRC1 and an upstream gene of PPAR-γ and LXR-α, but decreased activity of nuclear transcription factor (NF-κB), which acts as a key gene in the regulation of inflammation. ConclusionsPSRC1 protects against the development of atherosclerosis and enhances the stability of plaques by modulating cholesterol transportation and inflammation in macrophages and the liver of apoE−/− mice.

Effects of Toll-like receptor blockers on intestinal mucosal injury in mice with endotoxemia

To investigate the effects of Toll-like receptor blockers TLR2-Ab and TLR4-Ab on the tight junction protein ZO-1 in intestinal epithelial cells in mice, as well as their effects on nuclear factor-kappa B (NF-κB) and tumor necrosis factor-α (TNF-α). A total of 32 BALB/C mice were divided into control group, model group, TLR4 treatment group, and TLR2 treatment group, with 8 mice in each group. A mouse model of endotoxemia was established by intraperitoneal injection of lipopolysaccharide. The mice in the TLR4 treatment group and the TLR2 treatment group were given intraperitoneal injection of TLR4 antibody and TLR2 antibody (10 μg each mouse), respectively, and those in the control group were given normal saline. The distal small intestinal tissue was collected, and RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α. Compared with the control group, the model group had significantly lower mRNA and protein expression of ZO-1 and significantly higher mRNA expression of NF-κBp65 and TNF-α (P<0.05). Compared with the model group, the TLR4 treatment group and the TLR2 treatment group had significantly higher mRNA and protein expression of ZO-1 and significantly lower mRNA and protein expression of NF-κBp65 and TNF-α (P<0.05). There were no significant differences in the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α between the TLR4 treatment group and the TLR2 treatment group (P>0.05). Anti-TLR2 and anti-TLR4 monoclonal antibodies can reduce the activation of nuclear transcription factors, inhibit the secretion of inflammatory factors, and protect tight junction protein, which is expected to provide new ideas for the treatment of enterogenous infectious diseases.

Anti-Aging Effect of &amp;lt;i&amp;gt;Cynara cardunculus&amp;lt;/i&amp;gt; L. var. &amp;lt;i&amp;gt;Cynara scolymus&amp;lt;/i&amp;gt; L. Extract in D-Galactose-Induced Skin Aging Model in Rats

The aim of the study was to evaluate the efficacy of 2% Cynara scolymus L. extracts in reverse disturbances of collagen metabolism and inflammation in D-galactose induced skin aging model in rats. D-galactose induced aging reproduced in 48 animals of main group, and 12 rats in control group. All animals in main group were randomized for 4 groups: I. aging + saline, II - IV. different manufacturers 2% artichoke extracts (with content of chlorogenic acid < 2.5%) in a dose of intradermal injection 0.13 mg twice at weeks during 4 weeks. Influence of artichoke extracts restored skin relative weight and led to an increase of solubility in neutral salt and acid, and decreased pepsin solubility collagen fraction, restored the hexosamine/collagen (hydroxyproline) ratio and decreased the activity of nuclear transcription factor (NF-kB). Local prolonged treatment with artichoke extracts improved collagen metabolism and attenuated the progression of inflammation in D-galactose induced skin aging model.

Modified Ginseng Extract Induces Apoptosis in HepG2 Cancer Cells by Blocking the CXCL8-Mediated Akt/Nuclear Factor-[Formula: see text]B Signaling Pathway.

The cytokine C-X-C motif chemokine ligand 8 (CXCL8) is produced in the tumor microenvironment and has an important role in cancer pathogenesis. CXCL8 activates the nuclear factor (NF)-[Formula: see text]B signaling. However, the role of NF-[Formula: see text]B inactivation in apoptosis induced by negative regulation of CXCL8 remains unclear. Here, we assessed the effects of MRGX on the transcriptional activity of NF-[Formula: see text]B and the expression of tumor necrosis factor (TNF)-[Formula: see text]-stimulated target genes in liver cancer cells. Furthermore, we found that modified regular ginseng extract (MRGX)-mediated inhibition of NF-[Formula: see text]B signaling induced apoptosis. Importantly, MRGX exerted strong activity, inhibiting TNF-[Formula: see text]-induced expression of Akt and NF-[Formula: see text]B in a concentration-dependent manner. Furthermore, MRGX inhibited the TNF-[Formula: see text]-induced expression of genes encoding CXCL8, CXCL1, inducible nitric oxide synthase and intercellular adhesion molecule 1. MRGX also dowregulated Akt activation, and there was a significant decrease in Akt activation in HepG2 cells treated with CXCL8 siRNA. Conversely, CXCL8 overexpression increased Akt activation in MRGX-treated HepG2 cells. When Akt was silenced, MRGX treatment of HepG2 cells overexpressing CXCL8 decreased nuclear translocation of NF-[Formula: see text]B, whereas Akt overexpression increased nuclear translocation of NF-[Formula: see text]B in MRGX-treated HepG2 cells. Moreover, MRGX negatively regulated the TNF-[Formula: see text]-mediated I[Formula: see text]B/NF-[Formula: see text]B pathway to promote Bax activation, resulting in caspase-3 activation and apoptosis. Taken together, these results indicated that MRGX inhibited CXCL8-mediated Akt/NF-[Formula: see text]B signaling, which upregulated Bax activation and consequently induced apoptosis in HepG2 cells.

Caffeic acid and resveratrol ameliorate cellular damage in cell and Drosophila models of spinocerebellar ataxia type 3 through upregulation of Nrf2 pathway.

Polyglutamine (polyQ)-expanded mutant ataxin-3 protein, which is prone to misfolding and aggregation, leads to cerebellar neurotoxicity in spinocerebellar ataxia type 3 (SCA3), an inherited PolyQ neurodegenerative disease. Although the exact mechanism is unknown, the pathogenic effects of mutant ataxin-3 are associated with dysregulation of transcription, protein degradation, mitochondrial function, apoptosis, and antioxidant potency. In the present study we explored the protective role and possible mechanism of caffeic acid (CA) and resveratrol (Res) in cells and Drosophila expressing mutant ataxin-3. Treatment with CA and Res increased the levels of antioxidant and autophagy protein expression with consequently corrected levels of reactive oxygen species, mitochondrial membrane potential, mutant ataxin-3, and the aggregation of mutant ataxin-3 in SK-N-SH-MJD78 cells. Moreover, in SK-N-SH-MJD78 cells, CA and Res enhanced the transcriptional activity of nuclear factor erythroid-derived-2-like 2 (Nrf2), a master transcription factor that upregulates the expression of antioxidant defense genes and the autophagy gene p62. CA and Res improved survival and motor performance in SCA3 Drosophila. Additionally, the above-mentioned protective effects of CA were also observed in CA-supplemented SCA3 Drosophila. Notably, blockade of the Nrf2 pathway by use of small interfering RNA annulled the health effects of CA and Res on SCA3, which affirmed the importance of the increase in Nrf2 activation by CA and Res. Additional studies are need to dissect the protective role of CA and Res in modulating neurodegenerative progression in SCA3 and other polyQ diseases.

Inhibitory effects of Dianthi Herba ethanolic extract on inflammatory and nociceptive responses in murine macrophages and mouse models of abdominal writhing and ear edema

Ethnopharmacological relevanceDianthi Herba is a traditional herbal medicine used to treat inflammatory-related diseases including acute pyelonephritis, cystitis, laryngopharyngitis, and urethritis. Aim of the studyWe investigated the effects of Dianthi Herba ethanolic extract (DH) on lipopolysaccharide (LPS)-mediated inflammatory responses in murine macrophages including RAW 264.7 cell line and mouse peritoneal macrophages as well as nociceptive and edema mouse models. Materials and methodsThe biological effects of DH on inflammatory cytokine, mediator, and related protein production were assessed using enzyme-linked immunosorbent assay (ELISA), Western blotting, and real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). Additionally, Western blotting was performed to investigate intracellular signaling pathways, and the anti-nociceptive activity of three doses of DH (100, 200, and 300mg/kg) against acetic acid-induced writhing responses and its inhibitory effects on xylene-induced ear edema were researched in mice through oral administration. ResultsDH treatment significantly inhibited nitric oxide (NO) secretion and inflammatory cytokine production in RAW 264.7 cells and mouse peritoneal macrophages and induced heme oxygenase (HO)−1 expression. DH strongly inhibited the transcriptional activity of nuclear factor (NF)-κB and phosphorylation of mitogen-activated protein kinases (MAPK) in LPS-stimulated macrophages. Meanwhile, DH exerted anti-nociceptive effects on writhing responses and anti-edema effects in mice. ConclusionWe confirmed the anti-inflammatory activities and inhibitory mechanism of DH in macrophages and clarified its inhibitory effects in vivo. These findings illustrate the therapeutic potential of DH as a natural anti-inflammatory agent.