Lutein Modulates Oxidative Stress, Inflammatory and Apoptotic Biomarkers Related to Di-(2-Ethylhexyl) Phthalate (DEHP) Hepato-Nephrotoxicity in Male Rats: Role of Nuclear Factor Kappa B

Phthalates are widely distributed in our environment due to their usage in many industries, especially in plastic production, which has become an essential part of daily life. This investigation aimed to assess the potential remedial influence of lutein, a naturally occurring carotenoid, on phthalate-triggered damage to the liver and kidneys. When di-(2-ethylhexyl) phthalate (DEHP) was administered to male albino rats over sixty straight days at a dosage of 200 mg/kg body weight, it resulted in a significant increase in the serum activity of liver enzymes (AST, ALT, and GGT), alpha-fetoprotein, creatinine, and cystatin-C, as well as disruptions in the serum protein profile. In addition, intoxication with DEHP affected hepato-renal tissues' redox balance. It increased the content of some proinflammatory cytokines, nuclear factor kappa B (Nf-κB), and apoptotic marker (caspase-3); likewise, DEHP-induced toxicity and decreased the level of anti-apoptotic protein (Bcl-2) in these tissues. Lutein administration at a dose level of 40 mg/kg b.w efficiently facilitated the changes in serum biochemical constituents, hepato-renal oxidative disturbance, and inflammatory, apoptotic, and histopathological alterations induced by DEHP intoxication. In conclusion, it can be presumed that lutein is protective as a natural carotenoid against DEHP toxicity.

Influence of Liver Cirrhosis on Blood Glucose, Insulin Sensitivity and Islet Function in Mice

BACKGROUND

The relationship between cirrhosis and diabetes is controversial. We studied the influence of cirrhosis on glucose levels and islet function and explored its possible mechanisms.

MATERIALS AND METHODS

Cirrhosis was induced in male C57BL/6 mice by bile duct ligation (BDL). Serum biochemical parameters were determined, and oral glucose tolerance tests (OGTT) were performed at 4 and 8 weeks after BDL. Histopathology and phospho-NF-κB-p65/I-kappa B α immunohistochemical staining of the liver and islet were observed. The protein levels of the insulin signaling system and the gene expression of insulin-degrading enzyme (IDE) in the liver and muscle were determined. The activity of glucokinase (GCK) and glucose 6-phosphatase (G6P) and glycogen levels in liver homogenates were measured.

RESULTS

After BDL, the mice developed cirrhosis, and fasting glucose decreased significantly, but 2 h postprandial glucose increased, and the insulin areas under the curves increased. At 4 weeks of BDL, the ratios of phospho-NF-κB-p65/I-kappa B α accumulation in the liver and islet increased, the activity of G6P and the glycogen content in liver homogenates decreased, the insulin signaling system and the gene expression of IDE in the liver was downregulated, and the islet areas were decreased. After 8 weeks, these changes were more severe.

CONCLUSIONS

In different periods of cirrhosis, the levels of fasting glucose and 2 h postprandial glucose changed in different amplitudes. Glycogen concentrations and the activity of G6P in the liver were decreased. The mice developed insulin resistance and the islet areas were decreased. The NF-κB pathway may play a role in the process.

Inflammatory Mechanisms Contributing to Endothelial Dysfunction

Maintenance of endothelial cell integrity is an important component of human health and disease since the endothelium can perform various functions including regulation of vascular tone, control of hemostasis and thrombosis, cellular adhesion, smooth muscle cell proliferation, and vascular inflammation. Endothelial dysfunction is encompassed by complex pathophysiology that is based on endothelial nitric oxide synthase uncoupling and endothelial activation following stimulation from various inflammatory mediators (molecular patterns, oxidized lipoproteins, cytokines). The downstream signaling via nuclear factor-κB leads to overexpression of adhesion molecules, selectins, and chemokines that facilitate leukocyte adhesion, rolling, and transmigration to the subendothelial space. Moreover, oscillatory shear stress leads to pro-inflammatory endothelial activation with increased monocyte adhesion and endothelial cell apoptosis, an effect that is dependent on multiple pathways and flow-sensitive microRNA regulation. Moreover, the role of neutrophil extracellular traps and NLRP3 inflammasome as inflammatory mechanisms contributing to endothelial dysfunction has recently been unveiled and is under further investigation. Consequently, and following their activation, injured endothelial cells release inflammatory mediators and enter a pro-thrombotic state through activation of coagulation pathways, downregulation of thrombomodulin, and an increase in platelet adhesion and aggregation owing to the action of von-Willebrand factor, ultimately promoting atherosclerosis progression.

Eucalyptus kino: a treasure trove of polyphenols eradicating tumors in-vivo by elevating caspase-3 level, inhibiting TGF-β and NF-κb gene expression

30 secondary polyphenolic metabolites were characterised in Eucalyptus kino methanol extract using HPLC-MS/MS. The antitumor activity of the extract in combination with low level ionising radiation in female mice with solid tumors from inoculated Ehrlich ascites carcinoma cells was investigated. Tumor cell-inoculated mice received daily extract doses (100 mg/kg, 200 mg/kgBW) with or without a single exposure to 0.25 Gy γ-rays, and cis-platin as a reference anticancer drug. Changes in the tumor volume, oxidative state, levels of caspase-3, TGF-β and Nf-κB were assessed by q-PCR. Surprisingly, a dose of 200 mg/kg extract together with γ-radiation remarkably reduced the tumor volume, improved the oxidative and apoptotic biomarker levels. In conclusion, results showed that a combination of kino extract with low level γ-radiation synergistically reduced tumor progression due to the antioxidant and anti-proliferative activities of the polyphenolics in the extract.

Undenatured Type II Collagen Ameliorates Inflammatory Responses and Articular Cartilage Damage in the Rat Model of Osteoarthritis

Osteoarthritis (OA) is an age-related joint disease that includes gradual disruption of the articular cartilage and the resulting pain. The present study was designed to test the effects of undenatured type II collagen (UC-II®) on joint inflammation in the monoiodoacetate (MIA) OA model. We also investigated possible mechanisms underlying these effects. Female Wistar rats were divided into three groups: (i) Control; (ii) MIA-induced rats treated with vehicle; (iii) MIA-induced rats treated with UC-II (4 mg/kg BW). OA was induced in rats by intra-articular injection of MIA (1 mg) after seven days of UC-II treatment. UC-II reduced MIA-induced Kellgren-Lawrence scoring (53.3%, P < 0.05). The serum levels of inflammatory cytokines [IL-1β (7.8%), IL-6 (18.0%), TNF-α (25.9%), COMP (16.4%), CRP (32.4%)] were reduced in UC-II supplemented group (P < 0.0001). In the articular cartilage, UC-II inhibited the production of PGE2 (19.6%) and the expression of IL-1β, IL-6, TNF-a, COX-2, MCP-1, NF-κB, MMP-3, RANKL (P < 0.001). The COL-1 and OPG levels were increased, and MDA decreased in UC-II supplemented rats (P < 0.001). UC-II could be useful to alleviate joint inflammation and pain in OA joints by reducing the expression of inflammatory mediators.

The protective effect of 5-O-methylvisammioside on LPS-induced depression in mice by inhibiting the over activation of BV-2 microglia through Nf-κB/IκB-α pathway

BACKGROUND

5-O-methylvisammioside (MeV), also known as 4'-O-β-D-glucosyl-5-O-methylvisamminol, is a conventional marker compound for quality control of roots of Saposhnikovia diviaricata (Radix Saposhnikoviae), which exhibits anti-inflammatory and neuroprotective activities.

PURPOSE

According to the activity of MeV, we speculated that MeV may have antidepressant effect on LPS induced depression, and further explored its mechanism.

STUDY DESIGN

First, to explore the effect and mechanism of MeV on LPS-induced depression in mice, and then to further explore the effect and mechanism of MeV on LPS-activated BV-2 microglia.

METHODS

By the OFT, EPM, TST and FST behavioral tests, to explore the effect of MeV pretreatment on the behavior of LPS-induced depression mice. ELISA and Griess method were used to detect the changes of the serum TNF-α and IL-6 levels, the hippocampus SOD and MDA levels, and the NO, SOD, MDA, TNF-α and IL-6 levels in the culture medium of LPS-stimulated BV-2 microglia. Western blot was used to analyze the protein expression in the Nf-κB/IκB-α and BDNF/TrkB pathway in the hippocampus of mice and BV-2 microglia.

RESULTS

MeV (4 mg/kg, i.p.) pretreatment significantly improves the activity and exploration ability of LPS-induced depression mice, and reduces the immobility time. MeV inhibited the production of pro-inflammatory cytokines in the serum of mice induced by LPS, such as IL-6 and TNF-α. MeV also increased the levels of SOD and reduces the expression of MDA in the hippocampus, thus promoting the alleviation of depressive symptoms in mice. Western blotting analysis showed that the antidepressant activity of MeV was related to the decrease of Nf-κB nuclear transport, the inhibition of IκB-α phosphorylation, and the increase of BDNF and TrkB expression. MeV (40 μM) significantly reduced the contents of NO, MDA, TNF-α and IL-6 in the culture medium of LPS-stimulated BV-2 microglia, and increased the content of SOD.

CONCLUSION

MeV can regulate the neurotrophic factors in the mouse brain, reduce the content of inflammatory factors by the Nf-κB/IκB-α pathway, improve oxidative stress, and inhibit the excessive activation of LPS-stimulated BV -2 microglia. It effectively reversed the depression-like behAavior induced by LPS in mice.

Downregulation of miR-146a-5p Inhibits Choroidal Neovascularization via the NF-κB Signaling Pathway by Targeting OTUD7B

PURPOSE

Choroidal neovascularization (CNV) is the key pathological change caused by irreversible blindness resulting from neovascular AMD (nAMD). However, the pathological mechanisms underlying CNV remain largely unknown. Here, we aimed to investigate the role of miR-146a-5p in CNV formation.

MATERIALS AND METHODS

At the cellular level, we overexpressed or downregulated miR-146a-5p in an umbilical vein endothelial cell line (EA.hy926) by transfecting cells with either a miR-146a-5p mimic or an inhibitor. CCK8, wound healing, and Matrigel assays were performed to examine the proliferation, migration, and tube formation of endothelial cells (EA.hy926). Target relationship between miR-146a-5p and OTUD7B was verified using a double luciferase reporter experiment. An experimental CNV model was established by treating fundi of male C57BL/6 J mice with 810 nm laser. Fundus fluorescein angiography (FFA) was performed to evaluate the leakage of CNV on day 7 after miR-146a-5p antagomir intravitreal injection. The CNV volume was measured using Choroidal Flatmounts in a confocal study. The expression levels of VEGF, ICAM1, and NF-κB (p50 and p65) were detected both in vitro and in vivo.

RESULTS

The expression of miR-146a-5p was increased in LPS-stimulated endothelial cells and in experimental CNV RPE-choroidal complexes in mouse models. LPS-induced proliferation, migration, and tube formation were inhibited by the miR-146a-5p inhibitor. The miR-146a-5p antagomir attenuated CNV formation and fluorescent leakage in the vivo CNV model. In the LPS-stimulated endothelial cells and the CNV mouse model, the NF-κB signaling pathway was activated and the expression of VEGF and ICAM1 increased. Conversely, downregulation of miR-146a-5p inactivated the NF-κB signaling pathway and reduced the expression of VEGF and ICAM1.

CONCLUSIONS

Our results indicated that downregulation of miR-146a-5p inhibited experimental CNV formation via inactivation of the NF-κB signaling pathway.

Anti-inflammatory effect of bee venom in phthalic anhydride-induced atopic dermatitis animal model

Globally, many people have been affected with atopic dermatitis (AD), a chronic inflammatory skin disease. AD is associated with multiple factors such as genetic, inflammatory, and immune factors. Bee venom (BV) is now widely used for the treatment of several inflammatory diseases. However, its effect on 5% phthalic anhydride (PA)-induced AD has not been reported yet. We investigated the anti-inflammatory and anti-AD effects of BV in a PA-induced animal model of AD. Balb/c mice were treated with topical application of 5% PA to the dorsal skin and ears for induction of AD. After 24 h, BV was applied on the back and ear skin of the mice three times a week for 4 weeks. BV treatment significantly reduced the PA-induced AD clinical score, back and ear epidermal thickness, as well as IgE level and infiltration of immune cells in the skin tissues compared to those of control mice. The levels of inflammatory cytokines in the serum were significantly decreased in BV-treated group compared to PA-treated group. In addition, BV inhibited the expression of iNOS and COX-2 as well as the activation of mitogen-activated protein kinase (MAPK) and NF-ҡB induced by PA in the skin tissues. We also found that BV abrogated the lipopolysaccharide or TNF-α/IFN-γ-induced NO production, expression of iNOS and COX-2, as well as MAPK and NF-ҡB signaling pathway in RAW 264.7 and HaCaT cells. These results suggest that BV may be a potential therapeutic macromolecule for the treatment of AD.

NRF2 and NF-қB interplay in cerebrovascular and neurodegenerative disorders: Molecular mechanisms and possible therapeutic approaches

Electrophiles and reactive oxygen species (ROS) play a major role in modulating cellular defense mechanisms as well as physiological functions, and intracellular signaling. However, excessive ROS generation (endogenous and exogenous) can create a state of redox imbalance leading to cellular and tissue damage (Ma and He, 2012) [1]. A growing body of research data strongly suggests that imbalanced ROS and electrophile overproduction are among the major prodromal factors in the onset and progression of several cerebrovascular and neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS), stroke, Alzheimer's disease (AD), Parkinson's disease (PD), and aging (Ma and He, 2012; Ramsey et al., 2017; Salminen et al., 2012; Sandberg et al., 2014; Sarlette et al., 2008; Tanji et al., 2013) [1-6]. Cells offset oxidative stress by the action of housekeeping antioxidative enzymes (such as superoxide dismutase, catalase, glutathione peroxidase) as well direct and indirect antioxidants (Dinkova-Kostova and Talalay, 2010) [7]. The DNA sequence responsible for modulating the antioxidative and cytoprotective responses of the cells has been identified as the antioxidant response element (ARE), while the nuclear factor erythroid 2-related factor (NRF2) is the major regulator of the xenobiotic-activated receptor (XAR) responsible for activating the ARE-pathway, thus defined as the NRF2-ARE system (Ma and He, 2012) [1]. In addition, the interplay between the NRF2-ARE system and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB, a protein complex that controls cytokine production and cell survival), has been further investigated in relation to neurodegenerative and neuroinflammatory disorders. On these premises, we provide a review analysis of current understanding of the NRF2-NF-ĸB interplay, their specific role in major CNS disorders, and consequent therapeutic implication for the treatment of neurodegenerative and cerebrovascular diseases.

Long noncoding RNA CASC2 regulates hepatocellular carcinoma cell oncogenesis through miR-362-5p/Nf-κB axis

The long non-coding RNA segment cancer susceptibility candidate 2 (CASC2) has been shown to suppress tumor growth in a variety of cancers, including hepatocellular carcinoma (HCC). However, the mechanism by which CASC2 exerts control over HCC has yet to be established. In the present study, we first demonstrated that CASC2 is downregulated in human HCC tissues and HCC cell lines as compared to adjacent non-tumor tissues (NTTs) and a liver cell line, respectively. After finding that CASC2 knockdown significantly promotes HCC cells migration and invasion as well as that CASC2 overexpression inhibits cell migration and invasion, we identified the microRNA miR-362-5p as an endogenous target of CASC2. Through the use of wild type and mutant CASC2 binding sites inserted into psiCHECK-2 luciferase reporter plasmids, as well as qRT-PCR, we determined that CASC2 overexpression reduces miR-362-5p expression levels, while inhibiting CASC2 activity increases miR-362-5p expression. Past research has shown that miR-362-5p stimulates the NF-κB pathway, which has been implicated in the survival and proliferation of a variety of cancer cells. We therefore investigated the effects of CASC2 expression on NF-κB pathway activity. Ultimately, we determined that CASC2 regulates HCC cell activity by targeting miR-362-5p and thus inhibiting the NF-κB pathway. The present study not only identifies CASC2 as an important HCC cell regulator, but also suggests its mechanism of action. It therefore provides the basis for designing strategies to target CASC2 activity and thereby inhibit HCC growth and progression.

Bacteroides fragilis Toxin Coordinates a Pro-carcinogenic Inflammatory Cascade via Targeting of Colonic Epithelial Cells

Pro-carcinogenic bacteria have the potential to initiate and/or promote colon cancer, in part via immune mechanisms that are incompletely understood. Using ApcMin mice colonized with the human pathobiont enterotoxigenic Bacteroides fragilis (ETBF) as a model of microbe-induced colon tumorigenesis, we show that the Bacteroides fragilis toxin (BFT) triggers a pro-carcinogenic, multi-step inflammatory cascade requiring IL-17R, NF-κB, and Stat3 signaling in colonic epithelial cells (CECs). Although necessary, Stat3 activation in CECs is not sufficient to trigger ETBF colon tumorigenesis. Notably, IL-17-dependent NF-κB activation in CECs induces a proximal to distal mucosal gradient of C-X-C chemokines, including CXCL1, that mediates the recruitment of CXCR2-expressing polymorphonuclear immature myeloid cells with parallel onset of ETBF-mediated distal colon tumorigenesis. Thus, BFT induces a pro-carcinogenic signaling relay from the CEC to a mucosal Th17 response that results in selective NF-κB activation in distal colon CECs, which collectively triggers myeloid-cell-dependent distal colon tumorigenesis.

Peripheral tumors alter neuroinflammatory responses to lipopolysaccharide in female rats

Cancer is associated with an increased prevalence of depression. Peripheral tumors induce inflammatory cytokine production in the brain and depressive-like behaviors. Mounting evidence indicates that cytokines are part of a pathway by which peripheral inflammation causes depression. Neuroinflammatory responses to immune challenges can be exacerbated (primed) by prior immunological activation associated with aging, early-life infection, and drug exposure. This experiment tested the hypothesis that peripheral tumors likewise induce neuroinflammatory sensitization or priming. Female rats with chemically-induced mammary carcinomas were injected with either saline or lipopolysaccharide (LPS, 250μg/kg; i.p.), and expression of mRNAs involved in the pathway linking inflammation and depression (interleukin-1beta [Il-1β], CD11b, IκBα, indolamine 2,3-deoxygenase [Ido]) was quantified by qPCR in the hippocampus, hypothalamus, and frontal cortex, 4 or 24h post-treatment. In the absence of LPS, hippocampal Il-1β and CD11b mRNA expression were elevated in tumor-bearing rats, whereas Ido expression was reduced. Moreover, in saline-treated rats basal hypothalamic Il-1β and CD11b expression were positively correlated with tumor weight; heavier tumors, in turn, were characterized by more inflammatory, necrotic, and granulation tissue. Tumors exacerbated CNS proinflammatory gene expression in response to LPS: CD11b was greater in hippocampus and frontal cortex of tumor-bearing relative to tumor-free rats, IκBα was greater in hippocampus, and Ido was greater in hypothalamus. Greater neuroinflammatory responses in tumor-bearing rats were accompanied by attenuated body weight gain post-LPS. The data indicate that neuroinflammatory pathways are potentiated, or primed, in tumor-bearing rats, which may exacerbate future negative behavioral consequences.

Comparison of in vitro tests for antioxidant and immunomodulatory capacities of compounds

Oxidative stress is considered to be critically involved in the normal aging process but also in the development and progression of various human pathologies like cardiovascular and neurodegenerative diseases, as well as of infections and malignant tumors. These pathological conditions involve an overwhelming production of reactive oxygen species (ROS), which are released as part of an anti-proliferative strategy during pro-inflammatory immune responses. Moreover, ROS themselves are autocrine forward regulators of the immune response. Most of the beneficial effects of antioxidants are considered to derive from their influence on the immune system. Due to their antioxidant and/or radical scavenging nature, phytochemicals, botanicals and herbal preparations can be of great importance to prevent oxidation processes and to counteract the activation of redox-regulated signaling pathways. Antioxidants can antagonize the activation of T-cells and macrophages during the immune response and this anti-inflammatory activity could be of utmost importance for the treatment of above-mentioned disorders and for the development of immunotolerance. Herein, we provide an overview of in vitro assays for the measurement of antioxidant and anti-inflammatory activities of plant-derived substances and extracts, by discussing possibilities and limitations of these methods. To determine the capacity of antioxidants, the oxygen radical absorbance capacity (ORAC) assay and the cell-based antioxidant activity (CAA) assay are widely applied. To examine the influence of compounds on the human immune response more closely, the model of mitogen stimulated human peripheral blood mononuclear (PBMC) cells can be applied, and the production of the inflammatory marker neopterin as well as the breakdown of the amino acid tryptophan in culture supernatants can be used as readout to indicate an immunomodulatory potential of the tested compound. These two biomarkers of immune system activation are robust and correlate with the course of cardiovascular, neurodegenerative and malignant tumor diseases, but also with the normal aging process, and they are strongly predictive. Thus, while the simpler ORAC and CAA assays provide insight into one peculiar chemical aspect, namely the neutralization of peroxyl radicals, the more complex PBMC assay is closer to the in vivo conditions as the assay comprehensively enlights several properties of immunomodulatory test compounds.

Insect antiviral innate immunity: pathways, effectors, and connections

Insects are infected by a wide array of viruses some of which are insect restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. The medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. The interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. The major mechanism of antiviral defense is the small, interfering RNA pathway that responds through the detection of virus-derived double-stranded RNA to suppress virus replication. However, other innate antimicrobial pathways such as Imd, Toll, and Jak-STAT and the autophagy pathway have also been shown to play important roles in antiviral immunity. In this review, we provide an overview of the current understanding of the main insect antiviral pathways and examine recent findings that further our understanding of the roles of these pathways in facilitating a systemic and specific response to infecting viruses.