Anti-neuroinflammatory effects of citreohybridonol involving TLR4-MyD88-mediated inhibition of NF-кB and MAPK signaling pathways in lipopolysaccharide-stimulated BV2 cells

Microglial TLR4/NLRP3 Inflammasome Signaling in Alzheimer's Disease

Alzheimer's disease is a pervasive neurodegenerative disease that is estimated to represent approximately 70% of dementia cases worldwide, and the molecular complexity that has been highlighted remains poorly understood. The accumulation of extracellular amyloid-β (Aβ), intracellular neurofibrillary tangles formed by tau hyperphosphorylation, and neuroinflammation are the major pathological features of Alzheimer's disease (AD). Over the years, there has been no apparent breakthrough in drug discovery based on the Aβ and tau hypotheses. Neuroinflammation has gradually become a hot spot in AD treatment research. As the primary cells of innate immunity in the central nervous system, microglia play a key role in neuroinflammation. Toll-like receptor 4 (TLR4) and nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammasomes are vital molecules in neuroinflammation. In the pathological context of AD, the complex interplay between TLR4 and the NLRP3 inflammasomes in microglia influences AD pathology via neuroinflammation. In this review, the effect of the activation and inhibition of TLR4 and NLRP3 in microglia on AD pathology, as well as the cross-talk between TLR4 and the NLRP3 inflammasome, and the influence of essential molecules in the relevant signaling pathway on AD pathology, were expounded. In addition, the feasibility of these factors in representing a potential treatment option for AD has been clarified.

Lumbricus Extract Prevents LPS-Induced Inflammatory Activation of BV2 Microglia and Glutamate-Induced Hippocampal HT22 Cell Death by Suppressing MAPK/NF-κB/NLRP3 Signaling and Oxidative Stress

Microglia-induced inflammatory signaling and neuronal oxidative stress are mutually reinforcing processes central to the pathogenesis of neurodegenerative diseases. Recent studies have shown that extracts of dried Pheretima aspergillum (Lumbricus) can inhibit tissue fibrosis, mitochondrial damage, and asthma. However, the effects of Lumbricus extracts on neuroinflammation and neuronal damage have not been previously studied. Therefore, to evaluate the therapeutic potential of Lumbricus extract for neurodegenerative diseases, the current study assessed the extract's anti-inflammatory and antioxidant activities in BV2 microglial cultures stimulated with lipopolysaccharide (LPS) along with its neuroprotective efficacy in mouse hippocampal HT22 cell cultures treated with excess glutamate. Lumbricus extract dose-dependently inhibited the LPS-induced production of multiple proinflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-6, and IL-1β) and reversed the upregulation of proinflammatory enzymes (inducible nitric oxide synthase and cyclooxygenase-2). Lumbricus also activated the antioxidative nuclear factor erythroid 2-relayed factor 2/heme oxygenase-1 pathway and inhibited LPS-induced activation of the nuclear factor-κB/mitogen-activated protein kinases/NOD-like receptor family pyrin domain containing 3 inflammatory pathway. In addition, Lumbricus extract suppressed the glutamate-induced necrotic and apoptotic death of HT22 cells, effects associated with upregulated expression of antiapoptotic proteins, downregulation of pro-apoptotic proteins, and reduced accumulation of reactive oxygen species. Chromatography revealed that the Lumbricus extract contained uracil, hypoxanthine, uridine, xanthine, adenosine, inosine, and guanosine. Its effects against microglial activation and excitotoxic neuronal death reported herein support the therapeutic potential of Lumbricus for neurodegenerative diseases.

Peniandrastins A-H: Andrastin-type meroterpenoids with immunosuppressive activity from a Penicillium sp

Eight unreported andrastin-type meroterpenoids, namely peniandrastins A-H (1-8), along with six known analogues (9-14), were isolated from the fermentation of a soil-derived fungus Penicillium sp.sb62. Their structures with absolute configurations were elucidated by detailed analyses of the spectroscopic data and single-crystal X-ray diffraction. Compounds 1-4 belong to a rare class of 21-nor-andrastin meroterpenoids, of which 1 bears a 10-hydroperoxyl group, and 2 and 3 feature a 6/6/6/5/5 and a 6/6/6/5/6 pentacyclic systems, respectively. Compounds 5-8 are C25 andrastin-type meroterpenoids, wherein 5 features an unprecedented cyclopentan-1-keton-3-hemiacetal moiety. Additionally, the absolute configuration of compound 9 was corroborated by single-crystal X-ray crystallography for the first time. All isolates were evaluated for their immunosuppressive activities. As a result, compounds 1, 3, 4, 7-9 and 12-14 inhibited concanavalin A-induced T cell proliferation with IC50 values ranging from 7.49 to 36.52 μM, and 1-4, 6-9 and 12-14 inhibited lipopolysaccharide-induced B cell proliferation with IC50 values ranging from 6.73 to 26.27 μM. The preliminary structure-activity relationships (SARs) of those isolates were also discussed.

Fluoxetine alleviates postoperative cognitive dysfunction by attenuating TLR4/MyD88/NF-κB signaling pathway activation in aged mice

OBJECTIVE AND DESIGN

Postoperative cognitive dysfunction (POCD) is a common complication following surgery among elderly patients. Emerging evidence demonstrates that neuroinflammation plays a pivotal role in the pathogenesis of POCD. This study tested the hypothesis that fluoxetine can protect against POCD by suppressing hippocampal neuroinflammation through attenuating TLR4/MyD88/NF-κB signaling pathway activation.

SUBJECTS

Aged C57BL/6 J male mice (18 months old) were studied.

TREATMENT

Aged mice were intraperitoneally injected with fluoxetine (10 mg/kg) or saline for seven days before splenectomy. In addition, aged mice received an intracerebroventricular injection of a TLR4 agonist or saline seven days before splenectomy in the rescue experiment.

METHODS

On postoperative days 1, 3, and 7, we assessed hippocampus-dependent memory, microglial activation status, proinflammatory cytokine levels, protein levels related to the TLR4/MyD88/NF-κB signaling pathway, and hippocampal neural apoptosis in our aged mouse model.

RESULTS

Splenectomy induced a decline in spatial cognition, paralleled by parameters indicating exacerbation of hippocampal neuroinflammation. Fluoxetine pretreatment partially restored the deteriorated cognitive function, downregulated proinflammatory cytokine levels, restrained microglial activation, alleviated neural apoptosis, and suppressed the increase in TLR4, MyD88, and p-NF-κB p65 in microglia. Intracerebroventricular injection of LPS (1 μg, 0.5 μg/μL) before surgery weakened the effect of fluoxetine.

CONCLUSION

Fluoxetine pretreatment suppressed hippocampal neuroinflammation and mitigated POCD by inhibiting microglial TLR4/MyD88/NF-κB pathway activation in aged mice.

BAP31 regulates the expression of ICAM-1/VCAM-1 via MyD88/NF-κB pathway in acute lung injury mice model

AIMS

The cell adhesion molecules (CAMs) that mediate neutrophil-endothelium cell adhesion are deeply involved in the pathogenesis of acute lung injury (ALI). B-cell receptor associated protein 31 (BAP31) has been reported to engage in the expression of some CAMs. This study was undertaken to explore whether BAP31 in endotheliocyte affects the pathological process of ALI by regulating CAMs, and its possible mechanism.

MAIN METHODS

Our study used the shBAP31 endothelium cell lines and endothelial-specific BAP31 conditional knockdown mice constructed via Cre/loxP system. Hematoxylin and eosin staining was used to observe the histopathological manifestations. The adhesion of neutrophils to vascular wall was examined by intravital microscopy. The nuclear translocation of NF-κB was observed by immunofluorescence staining assay. Flow cytometric, real-time polymerase chain reaction and Western blot assay were performed to determine the expression of CAMs and key proteins in MyD88/NF-κB-related signaling pathway. Luciferase reporter and chromatin immunoprecipitation assay were analyzed for transcriptional activity of ICAM-1 and VCAM-1.

KEY FINDINGS

Mechanistic investigations indicated that endothelium-specific BAP31 depletion dramatically reduced the capacity of neutrophils adherence to endothelial cells (ECs), which was mainly attributed to the significant downregulation of ICAM-1 (p < 0.05) and VCAM-1 (p < 0.05) expression. Interestingly, BAP31 knockdown apparently deactivated MyD88/TRAF6-mediated TAK1/NF-κB and PI3K/Akt signaling cascades, resulting in the inhibition of NF-κB activation and nuclear translocation.

SIGNIFICANCE

Our data furnished convincing evidence that BAP31 deficiency performs a mitigative effect on ALI by decreasing neutrophils-ECs adhesion. These findings identified BAP31 as a promising protein for regulating the pathogenesis process of ALI.

Neuroprotective and Anti-Neuroinflammatory Properties of Vignae Radiatae Semen in Neuronal HT22 and Microglial BV2 Cell Lines

The important factors in the pathogenesis of neurodegenerative disorders include oxidative stress and neuron-glia system inflammation. Vignae Radiatae Semen (VRS) exhibits antihypertensive, anticancer, anti-melanogenesis, hepatoprotective, and immunomodulatory properties. However, the neuroprotective effects and anti-neuroinflammatory activities of VRS ethanol extract (VRSE) remained unknown. Thus, this study aimed to investigate the neuroprotective and anti-inflammatory activities of VRSE against hydrogen peroxide (H₂O₂)-induced neuronal cell death in mouse hippocampal HT22 cells and lipopolysaccharide (LPS)-stimulated BV2 microglial activation, respectively. This study revealed that VRSE pretreatment had significantly prevented H₂O₂-induced neuronal cell death and attenuated reactive oxygen species generations in HT22 cells. Additionally, VRSE attenuated the apoptosis protein expression while increasing the anti-apoptotic protein expression. Further, VRSE showed significant inhibitory effects on LPS-induced pro-inflammatory cytokines in BV2 microglia. Moreover, VRSE pretreatment significantly activated the tropomyosin-related kinase receptor B/cAMP response element-binding protein, brain-derived neurotrophic factor and nuclear factor erythroid 2-related factor 2, and heme oxygenase-1 signaling pathways in HT22 cells exposed to H₂O₂ and inhibited the activation of the mitogen-activated protein kinase and nuclear factor-κB mechanism in BV2 cells stimulated with LPS. Therefore, VRSE exerts therapeutic potential against neurodegenerative diseases related to oxidative stress and pathological inflammatory responses.

Neuronutraceuticals Combating Neuroinflammaging: Molecular Insights and Translational Challenges—A Systematic Review

Neuropathologies, such as neuroinflammaging, have arisen as a serious concern for preserving the quality of life due to the global increase in neurodegenerative illnesses. Nowadays, neuronutraceuticals have gained remarkable attention. It is necessary to investigate the bioavailability, off-target effects, and mechanism of action of neuronutraceuticals. To comprehend the comprehensive impact on brain health, well-designed randomized controlled trials testing combinations of neuronutraceuticals are also necessary. Although there is a translational gap between basic and clinical research, the present knowledge of the molecular perspectives of neuroinflammaging and neuronutraceuticals may be able to slow down brain aging and to enhance cognitive performance. The present review also highlights the key emergent issues, such as regulatory and scientific concerns of neuronutraceuticals, including bioavailability, formulation, blood–brain permeability, safety, and efficacy.

Isolation, Structure Determination, and Semisynthesis of Diphenazine Compounds from a Deep-Sea-Derived Strain of the Fungus Cystobasidium laryngis and Their Biological Activities

Phenazostatins E-J (1-6), six new diphenazine derivatives, were isolated from the EtOAc extract of the culture broth of a strain of Cystobasidium laryngis derived from deep-sea sediments of the Indian Ocean Ridge. The structures of 1-6 were elucidated based on the HRESIMS and 1D and 2D NMR spectra. The absolute configurations of 1-6, except for 3 and 6, were determined by modified Mosher's method, ECD data analysis, and calculations of optical rotation values. The absolute configurations of 3 and 6 were identified by chemical derivatization and comparing the specific rotation values with those of semisynthetic 3 obtained by the oxidation of 1 and saphenic acid (7). Phenazostatin J (6) was semisynthesized using saphenic acid (7) to prepare additional material for biological testing. During the purification of semisynthetic 6, a side product 9 was obtained from the reaction mixture along with 6. Compounds 1-6, along with previously reported 7 and 8, were assessed for anti-neuroinflammatory activity in LPS-induced BV-2 microglia cells. Compound 6 exhibited the highest anti-neuroinflammatory effect with an IC₅₀ value of 0.30 μM, but it showed cytotoxicity at higher concentrations than 1.0 μM. Accordingly, cytotoxicities of 1-9 were evaluated against six human cancer cell lines. Among tested compounds, 6 and 9 showed potent cytotoxicity (IC₅₀ values: 7.7-72 nM). Especially, 6 exhibited the strongest cytotoxicity with an IC₅₀ value of 7.7 nM against the NUGC-3 (stomach) cell line, displaying 19-fold stronger activity than the positive control, adriamycin.

Neuroprotective effects of carvacrol against cadmium-induced neurotoxicity in rats: role of oxidative stress, inflammation and apoptosis

Cadmium (Cd), is a heavy metal reported to be associated with oxidative stress and inflammation. In this paper, we investigated the possible protective effects of carvacrol against Cd-induced neurotoxicity in rats. Adult male Sprague Dawley rats were treated orally with Cd (25 mg/kg body weight) and with carvacrol (25 and 50 mg/kg body weight) for 7 days. Carvacrol decreased the levels of malondialdehyde (MDA), glial fibrillary acidic protein (GFAP) and monoamine oxidase (MAO), and significantly increased the levels of glutathione (GSH) and activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in brain tissue. Additionally, carvacrol alleviated the in levels of inflammation and apoptosis related proteins involving p38 mitogen-activated protein kinase (p38 MAPK), cyclooxygenase-2 (COX-2), nuclear factor kappa B (NF-κB), B-cell lymphoma-3 (Bcl-3), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), myeloperoxidase (MPO), prostaglandin E2 (PGE2), neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), cysteine aspartate specific protease-3 (caspase-3) and Bcl-2 associated X protein (Bax) in the Cd-induced neurotoxicity. Carvacrol also decreased the mRNA expression of matrix metalloproteinases (MMP9 and MMP13), as well as 8-hydroxy-2'-deoxyguanosine (8 - OHdG) level, a marker of oxidative DNA damage. Collectively, our findings indicated that carvacrol has a beneficial effect in ameliorating the Cd-induced neurotoxicity in the brain of rats.

The neurotrophic and antineuroinflammatory effects of phenylpropanoids from Zanthoxylum nitidum var. tomentosum (Rutaceae)

Three novel lignans (1, 5 and 6) and two novel quinic acids (16 and 17) along with 15 known phenylpropanoids were obtained from the ethanol extract of Zanthoxylum nitidum var. tomentosum (Rutaceae). Their structures were confirmed by comprehensive spectroscopic data (NMR and HRESIMS), and the absolute configurations of all novel compounds were elucidated based on electronic circular dichroism (ECD) spectroscopic data. The production of nitric oxide (NO) in BV-2 microglial cells induced through lipopolysaccharide (LPS) was used to evaluate in vitro anti-neuroinflammatory activity of compounds 1-20. Compound 2, 3, 7 and 16 showed excellent inhibition of LPS-induced NO production. The structure-activity relationships of the isolates were investigated. In addition, the mechanism of action of 2 was elucidated by RT-PCR and Western blotting analysis, which indicated that it reduced neuroinflammatory mainly through NLRP3/caspase1 signaling pathways in LPS-induced BV2 microglial cells.

Anti-inflammatory Effects of Sanhuang-Siwu-Tang in Lipopolysaccharide-Stimulated RAW264.7 Macrophages and BV2 Microglial Cells

Sanhuang-Siwu-Tang (SST), composed of seven medicinal herbs, is a well-known herbal formula used for the treatment of gynecologic diseases. To expand the clinical use of SST, we explored the anti-inflammatory or anti-neuroinflammatory effects of SST water extract in lipopolysaccharide-stimulated RAW264.7 macrophages and BV2 microglial cells. According to HPLC analysis, the main components of SST were from Scutellariae Radix, Coptidis Rhizoma, and Paeoniae Radix. SST significantly inhibited pro-inflammatory mediators including lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) as well as protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the production of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in LPS-stimulated RAW264.7 macrophages and BV2 microglial cells. Furthermore, these anti-inflammatory or anti-neuroinflammatory effects of SST were mediated by mitogen-activated protein kinase-related proteins (MAPK) and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB)-related proteins. Overall, this study demonstrated that SST is a potential therapeutic formula for the prevention or treatment of inappropriate inflammation, neuroinflammation, or neurodegenerative diseases.

Protective Role of Natural Products in Glioblastoma Multiforme: A Focus on Nitric Oxide Pathway

In spite of therapeutic modalities such as surgical resection, chemotherapy, and radiotherapy, Glioblastoma Multiforme (GBM) remains an incurable fatal disease. This necessitates further therapeutic options that could enhance the efficacy of existing modalities. Nitric Oxide (NO), a short-lived small molecule, has been revealed to play a crucial role in the pathophysiology of GBM. Several studies have demonstrated that NO is involved in apoptosis, metastasis, cellular proliferation, angiogenesis, invasion, and many other processes implicated in GBM pathobiology. Herein, we elaborate on the role of NO as a therapeutic target in GBM and discuss some natural products affecting the NO signaling pathway.

Mangiferin inhibited neuroinflammation through regulating microglial polarization and suppressing NF-κB, NLRP3 pathway

Inflammation plays important roles in the progress of neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. Microglia is responsible for the homeostasis of the central nervous system (CNS), and involved in the neuroinflammation. Therefore, it could be potential in treatment of neurodegenerative diseases to suppress the microglia-mediated neuroinflammation. Mangiferin, a major glucoside of xanthone in Anemarrhena Rhizome, has anti-inflammatory, anti-diabetes, and anti-oxidative properties. However, the effect of mangiferin on the inflammatary responses of microglia cells are still poorly understand. In this study, we investigated the mechanism by which mangiferin inhibited inflammation in LPS-induced BV₂ microglia cells. BV₂ cells were pretreatment with mangiferin followed by LPS stimulation. In vitro assays, NO and cytokines production were quantified. Western blot and immunocytochemistry were used to examine the effect of mangiferin on the polarization of BV2 cells and signaling pathway. The results showed that mangiferin treatment significantly reduced NO, IL-1β, IL-6 and TNF-α production, also reduced the mRNA and protein of iNOS and COX-2, promoted the polarization of inflammatory toward anti-inflammatory, and inhibited activation of NF-κB and NLRP3 inflammasome. These data suggest that mangiferin has an anti-neuroinflammatory property via regulating microglia macrophage polarization and suppressing NF-κB and NLRP3 signaling pathway, and may act as a potential natural therapeutic candidate for neuroinflammatory diseases.

Discovery of andrastones from the deep-sea-derived Penicillium allii-sativi MCCC 3A00580 by OSMAC strategy

Andrastones are unusual 6,6,6,5-tetracyclic meroterpenoids that are rarely found in nature. Previously, three andrastones were obtained from the rice static fermentation extract of the deep-sea-derived fungus Penicillium allii-sativi MCCC 3A00580. Inspired by one strain many compounds (OSMAC) approach, the oat static fermentation on P. allii-sativi was conducted. As a result, 14 andrastones were isolated by UV-guided isolation. The chemical structures of the nine new compounds (1-9) was established by comprehensive analysis of the NMR, MS, ECD, and X-ray crystallography and the five known ones (10-14) were assigned by comparing their NMR, MS, and OR data with those reported in literature. Compound 1 bears a novel hemiketal moiety while 2 is the first example to possess a novel tetrahydrofuran moiety via C-7 and C-15. All isolates were tested for anti-allergic bioactivity. Compound 10, 3-deacetylcitreohybridonol, significantly decreased degranulation with the IC₅₀ value of 14.8 μM, compared to that of 92.5 μM for the positive control, loratadine. Mechanism study indicated 10 could decrease the generation of histamine and TNF-α by reducing the accumulation of Ca²⁺ in RBL-2H3 cells. These findings indicate andrastones could be potential to discover new anti-allergic candidate drugs.

Crystal structure of (E)-2-(4-fluoro-2-(trifluoromethyl)benzylidene)-7-methoxy-3,4-dihydronaphthalen-1(2H)-one, C19H14F4O2

C19H14F4O2, monoclinic, C2/c (no. 15), a = 17.1519(13) Å, b = 13.9810(8) Å, c = 15.2299(9) Å, β = 123.031(7)°, V = 3061.9(4) Å3, Z = 8, R gt (F) = 0.0410, wR ref (F 2) = 0.1010, T = 100(1) K.

A Cautionary Tale and Update on Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL)

Breast implant-associated anaplastic large T-cell lymphoma (BIA-ALCL) was first recognized by the World Health Organization in 2016. The total number of cases worldwide continues to increase, with >800 cases confirmed through a combination of Food and Drug Administration data, verified reports, and registries. To date, 33 deaths have been reported. Typical presentation includes a late seroma containing monoclonal T cells that are CD30 positive and anaplastic lymphoma kinase negative. We present a review of the current literature and report on 3 cases of BIA-ALCL at our institution, which serve to illustrate our approach to diagnosis and management of this disease. In 2 cases, the diagnosis of BIA-ALCL was not initially confirmed due to an incomplete workup but was recognized upon explantation. The seroma fluid was sent for flow cytometry. Initially, the cells were reported as morphologically suspicious for malignancy with phenotypically normal T cells based on standard CD3+ T-cell gating. Subsequent cytology specimens were reported as consistent with recurrent adenocarcinoma. However, upon regating of flow-cytometry data, a population of CD30+, CD3- T cells was noted and the diagnosis of BIA-ALCL was confirmed by immunohistochemical stains of the excised breast capsule specimen. Given the increasing incidence of this disease, as plastic surgeons we must stay informed to order the correct workup to avoid misdiagnosis and be prepared to appropriately refer affected patients to centers with multidisciplinary teams experienced in the management of BIA-ALCL.

LEVEL OF EVIDENCE: 4

Neuroprotective effect of chrysin on isoniazid-induced neurotoxicity via suppression of oxidative stress, inflammation and apoptosis in rats

Isoniazid (INH) is among the most important anti-tuberculosis agents widely prescribed. However, its clinical use is restricted due to its severe side effects associated with neurotoxicity. The aim of the present study was to investigate the neuroprotective effects of chrysin (CR), a natural antioxidant, against INH-induced neurotoxicity in rats. The rats were treated orally with INH (400 mg/kg body weight) alone or with CR (25 and 50 mg/kg body weight) for 7 consecutive days. INH administration significantly increased brain lipid peroxidation and resulted in a significant decrease in antioxidant biomarkers including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH). INH treatment also increased levels of nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), glial fibrillary acidic protein (GFAP) and activities of p38α mitogen-activated protein kinase (p38α MAPK) while decreasing levels of neural cell adhesion molecule (NCAM). Double immunofluorescence expressions of c-Jun N-terminal kinase (JNK) and Bcl-2 associated X protein (Bax) in brain tissues were increased after INH administration. Furthermore, INH increased mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf-2), heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase 1 (NQO1), glutamate-cysteine ligase modifier subunit (Gclm), glutamate cysteine ligase catalytic subunit (Gclc), NF-κB, TNF-α, interleukin-1β (IL-1β), interleukin-6 (IL-6) and GFAP in rat brain tissues. Co-treatment with CR increased anti-oxidant capacity as well as regulated inflammation and apoptosis in brain. Additionally, molecular docking results showed that CR had the potential to interact with the active sites of TNF-α and NFκ-B. In conclusion, CR improved INH-induced brain oxidative damage, inflammation and apoptosis, possibly through their antioxidant properties.

Environmental enrichment rescues cognitive impairment with suppression of TLR4-p38MAPK signaling pathway in vascular dementia rats

Increasing evidence demonstrated the promising effects of environmental enrichment (EE) on brain recovery and cognitive performance in animal models of various diseases. However, the effect and molecular mechanisms of EE on vascular dementia (VD) remain to be studied. The aim of this study was to explore the effect of EE on cognitive decline and its mechanism. Sprague-Dawley rats underwent 2-vessel occlusion (2-VO) surgery or sham operation. Subsequently, rats were kept in EE for 4 weeks. In Morris water maze (MWM) test, we demonstrated that EE significantly improved cognitive function in rats with VD. HE staining exhibited morphological changes of neurons and quantitative analysis of TUNEL showed increased apoptotic neurons in hippocampal CA1 region following 2-VO. Results from RT-qPCR showed up-regulation of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) after 2-VO. Western blotting analysis revealed enhanced toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MYD88) and phosphorylated p38 mitogen-activated protein kinase (p-p38MAPK) in 2-VO rats. Whereas administration of EE reduced apoptotic neurons, down-regulated inflammatory factors. Moreover, EE suppressed protein expression of TLR4-p38MAPK pathway. Spearman correlation analysis showed that improved cognitive function was associated with decreased expression of TLR4 and p-p38MAPK proteins. Thus, our study proved that EE has a prominent effect on cognitive impairment and neuronal damage following 2-VO by attenuating inflammation and apoptosis, which may be realized via inhibiting the TLR4-P38MAPK signaling pathway.

A Review of Terpenes from Marine-Derived Fungi: 2015-2019

Marine-derived fungi are a significant source of pharmacologically active metabolites with interesting structural properties, especially terpenoids with biological and chemical diversity. In the past five years, there has been a tremendous increase in the rate of new terpenoids from marine-derived fungi being discovered. In this updated review, we examine the chemical structures and bioactive properties of new terpenes from marine-derived fungi, and the biodiversity of these fungi from 2015 to 2019. A total of 140 research papers describing 471 new terpenoids of six groups (monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, triterpenes, and meroterpenes) from 133 marine fungal strains belonging to 34 genera were included. Among them, sesquiterpenes, meroterpenes, and diterpenes comprise the largest proportions of terpenes, and the fungi genera of Penicillium, Aspergillus, and Trichoderma are the dominant producers of terpenoids. The majority of the marine-derived fungi are isolated from live marine matter: marine animals and aquatic plants (including mangrove plants and algae). Moreover, many terpenoids display various bioactivities, including cytotoxicity, antibacterial activity, lethal toxicity, anti-inflammatory activity, enzyme inhibitor activity, etc. In our opinion, the chemical diversity and biological activities of these novel terpenoids will provide medical and chemical researchers with a plenty variety of promising lead compounds for the development of marine drugs.

Circumdatin D Exerts Neuroprotective Effects by Attenuating LPS-Induced Pro-Inflammatory Responses and Downregulating Acetylcholinesterase Activity In Vitro and In Vivo

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder with multifactorial causes, of which systemic inflammation may play a key role to promote neurodegeneration, and acetylcholinesterase (AChE) is a target protein to induce cholinergic transmission. Inhibitors toward inflammation and targeting AChE are regarded to promote cholinergic signaling of the central nervous system in AD therapy. During the search for neuroprotection agents from marine-derived compounds, seven circumdatin-type alkaloids from a coral-associated fungus Aspergillus ochraceus LZDX-32-15 showed potent inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) production and activation of NF-κB report gene along with anti-AChE activities. Among the tested compounds, circumdatin D showed the most potent inhibitory effect against AChE activity and NO production. In vivo experiments using AD-like nematode models demonstrated that circumdatin D effectively delayed paralysis of CL4176 worms upon temperature up-shift via suppression of AChE activity and inflammatory-related gene expression. Moreover, circumdatin D interfered with inflammatory response by inhibiting the secretion of pro-inflammatory cytokines in LPS-induced BV-2 and primary microglia cells. Mechanistically, circumdatin D modulated Toll-like receptor 4 (TLR4)-mediated NF-κB, MAPKs and JAK/STAT inflammatory pathways in LPS-stimulated BV-2 cells, and protected primary neurons cells from LPS-induced neurotoxicity. Thus, circumdatin D is a potential agent for neuroprotective effects by the multi-target strategy.

Anti-Inflammatory and Protein Tyrosine Phosphatase 1B Inhibitory Metabolites from the Antarctic Marine-Derived Fungal Strain Penicillium glabrum SF-7123

A chemical investigation of the marine-derived fungal strain Penicillium glabrum (SF-7123) revealed a new citromycetin (polyketide) derivative (1) and four known secondary fungal metabolites, i.e, neuchromenin (2), asterric acid (3), myxotrichin C (4), and deoxyfunicone (5). The structures of these metabolites were identified primarily by extensive analysis of their spectroscopic data, including NMR and MS data. Results from the initial screening of anti-inflammatory effects showed that 2, 4, and 5 possessed inhibitory activity against the excessive production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated BV2 microglial cells, with IC₅₀ values of 2.7 µM, 28.1 µM, and 10.6 µM, respectively. Compounds 2, 4, and 5 also inhibited the excessive production of NO, with IC₅₀ values of 4.7 µM, 41.5 µM, and 40.1 µM, respectively, in LPS-stimulated RAW264.7 macrophage cells. In addition, these compounds inhibited LPS-induced overproduction of prostaglandin E₂ in both cellular models. Further investigation of the most active compound (2) revealed that these anti-inflammatory effects were associated with a suppressive effect on the over-expression of inducible nitric oxide synthase and cyclooxygenase-2. Finally, we showed that the anti-inflammatory effects of compound 2 were mediated via the downregulation of inflammation-related pathways such as those dependent on nuclear factor kappa B and p38 mitogen-activated protein kinase in LPS-stimulated BV2 and RAW264.7 cells. In the evaluation of the inhibitory effects of the isolated compounds on protein tyrosine phosphate 1B (PTP1B) activity, compound 4 was identified as a noncompetitive inhibitor of PTP1B, with an IC₅₀ value of 19.2 µM, and compound 5 was shown to inhibit the activity of PTP1B, with an IC₅₀ value of 24.3 µM, by binding to the active site of the enzyme. Taken together, this study demonstrates the potential value of marine-derived fungal isolates as a bioresource for bioactive compounds.

Phenolic Glycosides from the Roots of Ficus hirta Vahl. and Their Antineuroinflammatory Activities

Ficus hirta Vahl. (Wuzhimaotao) is an edible functional food used for the soup cooking and health products. Seven undescribed phenolic glycosides (1-7), along with 20 analogues, were isolated from the roots of Ficus hirta. Their structures were determined by comprehensive spectroscopic methods (UV, IR, HRESIMS, and NMR), while the absolute configuration of 1 was established by comparison of the experimental and calculated ECD data. The antineuroinflammatory effects of all the compounds were examined by Western blot. Compounds 1 and 11 attenuated the phosphorylation of AKT, JNK, and ERK1/2. In addition, compound 11 inhibited the NF-κB p65 phosphorylation. Our results indicated that compounds 1 and 11 decreased the occurrence of neuroinflammation in BV2 microglia cells, which might be regulated by inhibiting the activity of proteins in NF-κB, MAPK (JNK and ERK1/2), or AKT signaling pathways. Thus, 1 and 11 might exhibit antineuroinflammatory activities and show promise in treating neurodegenerative diseases.

Attenuation of paraquat-induced inflammation by inhibitors of phosphorylation of mitogen-activated protein kinases in BV2 microglial cells

Paraquat has dopaminergic neurotoxicity and potentially contributes to Parkinson's disease (PD) as a risk factor. However, the cellular and molecular mechanisms of PQ-induced neurodegeneration have not been clearly elucidated. Studies have shown that PQ induces microglial neuroinflammation through toll-like receptor 4 (TLR4)-nuclear factor-κB pathway, resulting in neuronal cell loss. Mitogen-activated protein kinases (MAPKs) are involved in the production of pro-inflammatory cytokines in microglia, and in this study, the role of MAPKs in PQ-activated microglial inflammation was investigated. Murine BV₂ microglial cells were treated with 40 μM of PQ following pretreatment of the cells with selective inhibitor of MAPKs phosphorylation for blockage of the phosphorylation of ERK, JNK and P38, or a specific TLR4 inhibitor for blocking the activation of TLR4. The protein expression of phosphorylated ERK, JNK and p38, and the transcription expression of pro-inflammatory mediators were assessed with Western blotting and qRT-PCR technique, respectively. The results indicated that PQ significantly induced the phosphorylation of ERK, JNK and P38 in microglia, while MAPKs inhibitors suppressed PQ-induced phosphorylation of ERK, JNK and P38, and reduced the transcription level of pro-inflammatory cytokines. PQ-stimulated phosphorylation of ERK, JNK and P38 was also reduced by TLR4 inhibitor. The inhibited intensity in the level of pro-inflammatory cytokine transcription was obviously greater in TLR4 inhibitor + PQ group than in each MAPK inhibitor + PQ group. Taken together, inhibition of MAPKs phosphorylation partially attenuates PQ-induced microglial inflammation, which may become a potential intervention strategy for PQ neurotoxicity.

Ethyl pyruvate inhibits LPS induced IPEC-J2 inflammation and apoptosis through p38 and ERK1/2 pathways

The endotoxin of Gram-negative bacteria threatens the intestinal health of livestock. Ethyl pyruvate (EP) has been shown to regulate intestinal immunity and protect against cell and tissue damage. In this study, it was first verified that EP could reduce the secretion of IL-8, TNF-α, IL-6 and IL-1β in LPS-induced IPEC-J2 cells. Then, we used RNA sequencing (RNA-seq) to analyze the differentially expressed genes (DEGs) of inflammatory factors induced by LPS in IPEC-J2 cells. It was found that LPS induced the upregulation of 377 genes and the downregulation of 477 genes compared to Vehicle; LPS+EP induced the upregulation of 258 genes and the downregulation of 240 genes compared to Vehicle; and LPS+EP induced the upregulation of 373 genes and the downregulation of 188 genes compared to LPS (fold change > 1.5 and FDR < 0.01). Their enrichment pathways included the MAPK signaling pathway, PI3K-Akt signaling pathway, Toll-like receptor signaling pathway, and other pathways. Furthermore, the mRNA level of cytokines associated with inflammation and apoptosis enriched in the MAPK pathway was verified by qRT-PCR. Western blots and immunofluorescence revealed that EP significantly inhibited phosphorylated p38 and phosphorylated-ERK1/2 protein expression levels (P < 0.05). The apoptosis due to LPS reduced by EP was significantly inhibited, as shown by Annexin V-FITC/PI staining. According to the results, EP inhibited the expression of IL-8, TNF-α, IL-6 and IL-1β as well as apoptosis by inhibiting the phosphorylation of p38 and ERK1/2 in LPS-induced IPEC-J2 cells.

A Systematic Review of Recently Reported Marine Derived Natural Product Kinase Inhibitors

Protein kinases are validated drug targets for a number of therapeutic areas, as kinase deregulation is known to play an essential role in many disease states. Many investigated protein kinase inhibitors are natural product small molecules or their derivatives. Many marine-derived natural products from various marine sources, such as bacteria and cyanobacteria, fungi, animals, algae, soft corals, sponges, etc. have been found to have potent kinase inhibitory activity, or desirable pharmacophores for further development. This review covers the new compounds reported from the beginning of 2014 through the middle of 2019 as having been isolated from marine organisms and having potential therapeutic applications due to kinase inhibitory and associated bioactivities. Moreover, some existing clinical drugs based on marine-derived natural product scaffolds are also discussed.

Atractylodis Rhizoma Alba Attenuates Neuroinflammation in BV2 Microglia upon LPS Stimulation by Inducing HO-1 Activity and Inhibiting NF-κB and MAPK

Microglial activation and the resulting neuroinflammation are associated with a variety of brain diseases, such as Alzheimer’s disease and Parkinson’s disease. Thus, the control of microglial activation is an important factor in the development of drugs that can treat or prevent inflammation-related neurodegenerative disorders. Atractylodis Rhizoma Alba (ARA) has been reported to exhibit antioxidant, gastroprotective, and anti-inflammatory effects. However, the effects of ARA ethanolic extract (ARAE) on microglia-mediated neuroinflammation have not been fully elucidated. In this work, we explored the anti-neuroinflammatory properties and underlying molecular mechanisms of ARAE in lipopolysaccharide (LPS)-stimulated microglial BV2 cells. Our results showed that ARAE significantly attenuates the production of nitric oxide (NO) and inflammatory cytokines induced by LPS. ARAE treatment also inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 without causing cytotoxicity. ARAE markedly attenuated the transcriptional activities of nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPK) phosphorylation, and induced heme oxygenase (HO)-1 expression. High-performance liquid chromatography (HPLC) analysis showed that ARAE contains three main components—atractylenolide I, atractylenolide III, and atractylodin—all compounds that significantly inhibit the production of inflammatory factors. These findings indicate that ARAE may be a potential therapeutic agent for the treatment of inflammation-related neurodegenerative diseases.

Toxicocladosporium aquimarinum sp. nov. and Toxicocladosporium qatarense sp. nov., isolated from marine waters of the Arabian Gulf surrounding Qatar

The Arabian Gulf surrounding Qatar is distinct from other marine ecosystems due to its high salinity (35-75 PSU) and extreme water temperature fluctuations (11-40 °C). Furthermore, in the last decade, Qatar has been witnessing an industrial boom as well as extensive infrastructure construction activities. Marine micro-organisms, including fungi, remain largely unexplored in the Arabian Gulf. During a 3 year study, we investigated the diversity of marine fungi in coastal waters around Qatar. As a result, two new Toxicocladosporium species were isolated from the Qatari marine environment. Molecular and phylogenetic analyses of rRNA gene sequences of five loci, namely the internal transcribed spacer 1 and 2 regions and the D1/D2 domains of the large subunit rRNA, actin, RNA polymerase second largest subunit and beta-tubulin genes, were used to confirm the identity of the novel species for which we propose the names Toxicocladosporium aquimarinum sp. nov. and Toxicocladosporium qatarense sp. nov.

Oceans as a Source of Immunotherapy

Marine flora is taxonomically diverse, biologically active, and chemically unique. It is an excellent resource, which offers great opportunities for the discovery of new biopharmaceuticals such as immunomodulators and drugs targeting cancerous, inflammatory, microbial, and fungal diseases. The ability of some marine molecules to mediate specific inhibitory activities has been demonstrated in a range of cellular processes, including apoptosis, angiogenesis, and cell migration and adhesion. Immunomodulators have been shown to have significant therapeutic effects on immune-mediated diseases, but the search for safe and effective immunotherapies for other diseases such as sinusitis, atopic dermatitis, rheumatoid arthritis, asthma and allergies is ongoing. This review focuses on the marine-originated bioactive molecules with immunomodulatory potential, with a particular focus on the molecular mechanisms of specific agents with respect to their targets. It also addresses the commercial utilization of these compounds for possible drug improvement using metabolic engineering and genomics.

Anti-inflammatory effects of Ang-(1-7) via TLR4-mediated inhibition of the JNK/FoxO1 pathway in lipopolysaccharide-stimulated RAW264.7 cells

Targeting inflammation is considered a challenging pharmacological strategy to prevent or delay the development of inflammatory diseases, such as severe asthma, Crohn's disease, and rheumatoid arthritis. The angiotensin-(1-7) -Mas axis ((Ang-(1-7)-Mas axis) was confirmed to antagonize the effects of the Angiotensin II-AT₁ receptor axis and the latter is reported to regulate cardiovascular and renal function, as well as contribute to the inflammatory process. In this paper, we aim to explore the crucial effect of Ang-(1-7) in inflammation and disclose the mechanisms in lipopolysaccharide (LPS)-induced murine macrophages RAW264.7. We found that Ang-(1-7) inhibited the production and secretion of tumor necrosis factor-α and interleukin-6 in a concentration-dependent manner in LPS-induced macrophages. The overexpression of TLR4, phospho-JNK, and FoxO1 induced by LPS were also inhibited by incubation with Ang-(1-7). These inhibitory effects were reversed by A-779. Moreover, we also used a selective JNK inhibitor Sp600125 to further corroborate the involvement of TLR4, JNK, and FoxO1 in the anti-inflammatory action of Ang-(1-7). Our research reveals a new mechanism that Ang-(1-7) may drive anti-inflammatory effects via the Mas receptor through inhibition of the TLR4-mediated JNK/FoxO1 signaling pathway in LPS-induced macrophages. Our findings open new perspectives of Ang-(1-7)-Mas axis in local inflammation.

Intermedin in Paraventricular Nucleus Attenuates Sympathoexcitation and Decreases TLR4-Mediated Sympathetic Activation via Adrenomedullin Receptors in Rats with Obesity-Related Hypertension

Intermedin/adrenomedullin-2 (IMD/AM2), a member of the calcitonin gene-related peptide/AM family, plays an important role in protecting the cardiovascular system. However, its role in the enhanced sympathoexcitation in obesity-related hypertension is unknown. In this study, we investigated the effects of IMD in the paraventricular nucleus (PVN) of the hypothalamus on sympathetic nerve activity (SNA), and lipopolysaccharide (LPS)-induced sympathetic activation in obesity-related hypertensive (OH) rats induced by a high-fat diet for 12 weeks. Acute experiments were performed under anesthesia. The dynamic alterations of sympathetic outflow were evaluated as changes in renal SNA and mean arterial pressure (MAP) in response to specific drugs. Male rats were fed a control diet (12% kcal as fat) or a high-fat diet (42% kcal as fat) for 12 weeks to induce OH. The results showed that IMD protein in the PVN was downregulated, but Toll-like receptor 4 (TLR4) and plasma norepinephrine (NE, indicating sympathetic hyperactivity) levels, and systolic blood pressure were increased in OH rats. LPS (0.5 µg/50 nL)-induced enhancement of renal SNA and MAP was greater in OH rats than in obese or control rats. Bilateral PVN microinjection of IMD (50 pmol) caused greater decreases in renal SNA and MAP in OH rats than in control rats, and inhibited LPS-induced sympathetic activation, and these were effectively prevented in OH rats by pretreatment with the AM receptor antagonist AM22-52. The mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) inhibitor U0126 in the PVN partially reversed the LPS-induced enhancement of SNA. However, IMD in the PVN decreased the LPS-induced ERK activation, which was also effectively prevented by AM22-52. Chronic IMD administration resulted in significant reductions in the plasma NE level and blood pressure in OH rats. Moreover, IMD lowered the TLR4 protein expression and ERK activation in the PVN, and decreased the LPS-induced sympathetic overactivity. These results indicate that IMD in the PVN attenuates SNA and hypertension, and decreases the ERK activation implicated in the LPS-induced enhancement of SNA in OH rats, and this is mediated by AM receptors.

Synergistic anti-inflammatory effects of quercetin and catechin via inhibiting activation of TLR4-MyD88-mediated NF-κB and MAPK signaling pathways

The synergistic anti-inflammatory effect of quercetin and catechin was investigated using lipopolysaccharide (LPS)-stimulated macrophage RAW 264.7 cells. Results showed that the combined treatment of quercetin with catechin synergistically attenuated LPS-stimulated increase of some proinflammatory molecules, including nitric oxide, tumor necrosis factor α, interleukin-1β, nitric oxide synthase, and cyclooxygenase-2. Moreover, it exhibited significantly (p < 0.05) stronger inhibitory effect on nuclear translocation of nuclear factor-κB (NF-κB) by suppressing the phosphorylation of NF-κB p65 and p50 submits and on the phosphorylation of ETS domain-containing protein and c-Jun N-terminal kinase than any of quercetin or catechin alone. Besides, the cotreatment of quercetin with catechin significantly (p < 0.05) restored the impaired expression of toll-like receptor 4, myeloid differentiation primary response gene 88, and some downstream effectors (IRAK1, TRAF6, and TAK1). These results suggest that quercetin and catechin possessed synergistic anti-inflammatory effects, which may be attributed to their roles in suppressing the activation of TLR4-MyD88-mediated NF-κB and mitogen-activated protein kinases signaling pathways.

A synthetic diosgenin primary amine derivative attenuates LPS-stimulated inflammation via inhibition of NF-κB and JNK MAPK signaling in microglial BV2 cells

Diosgenin, a precursor of steroid hormones in plants, is known to exhibit diverse pharmacological activities including anti-inflammatory properties. In this study, (3β, 25R)‑spirost‑5‑en‑3‑oxyl (2‑((2((2‑aminoethyl)amino)ethyl)amino)ethyl) carbamate (DGP), a new synthetic diosgenin derivative incorporating primary amine was used to investigate its anti-inflammatory effects and underlying mechanisms of action in lipopolysaccharide (LPS)-stimulated microglial BV2 cells. Pretreatment with DGP resulted in significant inhibition of nitric oxide (NO) synthesis, and down-regulation of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated microglial BV2 cells. In addition, DGP decreased the production of reactive oxygen species (ROS) and pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α). The inhibitory effects of DGP on these inflammatory mediators in LPS-stimulated microglial BV2 cells were regulated by NF-κB signaling through blocking p65 nuclear translocation and NF-κB p65/DNA binding activity. DGP also blocked the phosphorylation of c-Jun amino-terminal kinase (JNK), but not p38 kinase or extracellular signal-regulated kinases (ERK). The NF-κB inhibitor JSH-23 and JNK-specific inhibitor SP600125 significantly decreased NO production and IL-6 release in LPS-stimulated BV2 cells, respectively. The overall results demonstrate that DGP has anti-inflammatory effects on LPS-stimulated BV2 cells via inhibition of NF-κB and JNK activation, suggesting that DGP is a potential prophylactic agent in various neurodegenerative disorders.

Marine-derived protein kinase inhibitors for neuroinflammatory diseases

Neuroinflammation is primarily characterized by overexpression of proinflammatory mediators produced by glial activation or immune cell infiltration. Several kinases have been shown to be critical mediators in neuroinflammation. One of the largest groups of kinases is protein kinases, which have been the second most studied group of drug targets after G-protein-coupled receptors. Thus far, most of the approved kinase inhibitor drugs are adenosine triphosphate-competitive inhibitors with various off-target liabilities because of cross-reactivities; however, marine-derived compounds provide opportunities for discovering allosteric kinase inhibitors. This review summarizes the potential of marine-derived protein kinase inhibitors in the field of neuroinflammatory diseases, such as Parkinson disease, Alzheimer disease, multiple sclerosis, and pain. The previous studies from 1990 to 2017 in this review have shown that marine-derived protein kinase inhibitors have great potential to elicit anti-neuroinflammatory or neuroprotective responses in in vitro and in vivo models of neuroinflammatory diseases. This suggests that further exploration and investigation of these marine-derived protein kinase inhibitors on neuroinflammatory diseases are warranted. Therefore, this review may inspire further discovery of new protein kinase inhibitors from a marine origin and additional neuroscience studies focusing on these valuable marine-derived protein kinase inhibitors.

Systemic Sympathoexcitation Was Associated with Paraventricular Hypothalamic Phosphorylation of Synaptic CaMKIIα and MAPK/ErK

Systemic administration of adrenergic agonist (Isoproterenol; ISOP) is known to facilitate cardiovascular changes associated with heart failure through an upregulation of cardiac toll-like receptor 4 (TLR4). Furthermore, previous studies have shown that cardiac tissue-specific deletion of TLR4 protects the heart against such damage. Since the autonomic regulation of systemic cardiovascular function originates from pre-autonomic sympathetic centers in the brain, it is unclear how a systemically driven sympathetic change may affect the pre-autonomic paraventricular hypothalamic nuclei (PVN) TLR4 expression. Here, we examined how change in PVN TLR4 was associated with alterations in the neurochemical cytoarchitecture of the PVN in systemic adrenergic activation. After 48 h of intraperitoneal 150 mg/kg ISOP treatment, there was a change in PVN CaMKIIα and MAPK/ErK expression, and an increase in TLR4 in expression. This was seen as an increase in p-MAPK/ErK, and a decrease in synaptic CaMKIIα expression in the PVN (p < 0.01) of ISOP treated mice. Furthermore, there was an upregulation of vesicular glutamate transporter (VGLUT 2; p < 0.01) and a decreased expression of GABA in the PVN of Isoproterenol (ISOP) treated WT mice (p < 0.01). However, after a PVN-specific knockdown of TLR4, the effect of systemic administration of ISOP was attenuated, as indicated by a decrease in p-MAPK/ErK (p < 0.01) and upregulation of CaMKIIα (p < 0.05). Additionally, loss of inhibitory function was averted while VGLUT2 expression decreased when compared with the ISOP treated wild type mice and the control. Taken together, the outcome of this study showed that systemic adrenergic activation may alter the expression, and phosphorylation of preautonomic MAPK/ErK and CaMKIIα downstream of TLR4. As such, by outlining the roles of these kinases in synaptic function, we have identified the significance of neural TLR4 in the progression, and attenuation of synaptic changes in the pre-autonomic sympathetic centers.

New endophytic Toxicocladosporium species from cacti in Brazil, and description of Neocladosporium gen. nov

Brazil harbours a unique ecosystem, the Caatinga, which belongs to the tropical dry forest biome. This region has an important diversity of organisms, and recently several new fungal species have been described from different hosts and substrates within it. During a survey of fungal endophyte diversity from cacti in this forest, we isolated cladosporium-like fungi that were subjected to morphological and multigene phylogenetic analyses including actA, ITS, LSU, rpb2 and tub2 gene sequences. Based on these analyses we identified two new species belonging to the genus Toxicocladosporium, described here as T. cacti and T. immaculatum spp. nov., isolated from Pilosocereus gounellei subsp. gounellei and Melocactus zehntneri, respectively. To improve the species recognition and assess species diversity in Toxicocladosporium we studied all ex-type strains of the genus, for which actA, rpb2 and tub2 barcodes were also generated. After phylogenetic reconstruction using five loci, we differentiated 13 species in the genus. Toxicocladosporium velox and T. chlamydosporum are synonymized based on their phylogenetic position and limited number of unique nucleotide differences. Six strains previously assigned to T. leucadendri, including the ex-type strain (CBS 131317) of that species, were found to belong to an undescribed genus here named as Neocladosporium gen. nov., with N. leucadendri comb. nov. as type species. Furthermore, this study proposes the actA, ITS, rpb2 and tub2 as main phylogenetic loci to recognise Toxicocladosporium species.

TLR4 is a link between diabetes and Alzheimer's disease

Recently, more and more studies have shown that there is an essential link between diabetes mellitus (DM) and Alzheimer's disease (AD). In addition, innate immunity plays an important role in the occurrence and development of DM and AD, which increase the risk of developing type 2 diabetes (T2D) and AD. Although the pathogenesis of those diseases is still a matter of debate, the important role of Toll-like receptor 4 (TLR4) in the two diseases has been receiving much attention at present. TLR4 and insulin resistance do have close ties, and chronic TLR4 activation may contribute to the insulin resistance. Aside from this, TLR4-mediated chronic inflammation also causes many DM complications such as diabetic nephropathy, diabetic retinopathy and diabetic neuropathy and has a profound impact on the internal environment of the body and brain's microenvironment. In parallel, TLR4 is widely distributed in the brain and also has an important role in the central nervous system (CNS) via regulation of neuroinflammation. The cerebrum under the circumstances of insulin resistance may lead to mitochondrial dysfunction in neurons. Interestingly, in the initial stage, the activation of TLR4 has a useful scavenging effect on amyloid beta (Aβ), but chronic long-term activation leads to Aβ deposition in the brain. Therefore we speculate that the TLR4 signaling pathway may be a potential link between DM and AD.

Anthocyanins protect against LPS-induced oxidative stress-mediated neuroinflammation and neurodegeneration in the adult mouse cortex

Several studies provide evidence that reactive oxygen species (ROS) are key mediators of various neurological disorders. Anthocyanins are polyphenolic compounds and are well known for their anti-oxidant and neuroprotective effects. In this study, we investigated the neuroprotective effects of anthocyanins (extracted from black soybean) against lipopolysaccharide (LPS)-induced ROS-mediated neuroinflammation and neurodegeneration in the adult mouse cortex. Intraperitoneal injection of LPS (250 μg/kg) for 7 days triggers elevated ROS and oxidative stress, which induces neuroinflammation and neurodegeneration in the adult mouse cortex. Treatment with 24 mg/kg/day of anthocyanins for 14 days in LPS-injected mice (7 days before and 7 days co-treated with LPS) attenuated elevated ROS and oxidative stress compared to mice that received LPS-injection alone. The immunoblotting results showed that anthocyanins reduced the level of the oxidative stress kinase phospho-c-Jun N-terminal Kinase 1 (p-JNK). The immunoblotting and morphological results showed that anthocyanins treatment significantly reduced LPS-induced-ROS-mediated neuroinflammation through inhibition of various inflammatory mediators, such as IL-1β, TNF-α and the transcription factor NF-_kB. Anthocyanins treatment also reduced activated astrocytes and microglia in the cortex of LPS-injected mice, as indicated by reductions in GFAP and Iba-1, respectively. Anthocyanins also prevent overexpression of various apoptotic markers, i.e., Bax, cytosolic cytochrome C, cleaved caspase-3 and PARP-1. Immunohistochemical fluoro-jade B (FJB) and Nissl staining indicated that anthocyanins prevent LPS-induced neurodegeneration in the mouse cortex. Our results suggest that dietary flavonoids, such as anthocyanins, have antioxidant and neuroprotective activities that could be beneficial to various neurological disorders.