海洋真菌Arthrinium sp. UJNMF0008代谢产物的研究

为丰富海洋真菌的化学多样性,发现海洋真菌活性代谢产物,对海洋沉积物来源真菌Arthriniumsp.UJNMF0008的化学成分及其生物活性进行研究,采用硅胶柱色谱、凝胶柱色谱、反向柱色谱和高效液相色谱等方法从海洋沉积物来源真菌Arthriniumsp.UJNMF0008的发酵提取物中分离到5个化合物,通过核磁共振、质谱等方法,结合文献对照,鉴定了化合物的结构分别为arthoneF(1)、arthoneG(2)、sydoxanthoneC(3)、(3R,4R)-cis-4-hydroxymellein(4)和2-(2′S-hydroxypropyl)-5-methyl-7-hydroxychromone(5),其中化合物1和2是新化合物,化合物3首次从该属真菌中分离到。活性测试显示,化合物1~5在50μmoL/L的测试浓度下均没有表现出明显的抗氧自由基活性、抗菌活性以及NO释放抑制活性。     

Cytotoxic Meroterpenoids from the Fungus Alternaria sp. JJY‐32

Two new meroterpenoids, tricycloalternarenes X and Y, together with one known meroterpenoid, tricycloalternarene I, were isolated from the fungus Alternaria sp. JJY‐32. The structures including absolute configurations were established by the comprehensive spectroscopic data, electronic circular dichroism (ECD) spectral analyses, and biosynthesis consideration. Tricycloalternarene X showed cytotoxicity against the HL‐60 and HO8910 cells with IC₅₀ values of 7.54 and 20.32 μm .     

Puerarin attenuates intracerebral hemorrhage-induced early brain injury possibly by PI3K/Akt signal activation-mediated suppression of NF-κB pathway

Intracerebral hemorrhage (ICH) can induce intensively oxidative stress, neuroinflammation, and brain cell apoptosis. However, currently, there is no highly effective treatment available. Puerarin (PUE) possesses excellent neuroprotective effects by suppressing the NF-κB pathway and activating the PI3K/Akt signal, but its role and related mechanisms in ICH-induced early brain injury (EBI) remain unclear. In this study, we intended to observe the effects of PUE and molecular mechanisms on ICH-induced EBI. ICH was induced in rats by collagenase IV injection. PUE was intraperitoneally administrated alone or with simultaneously intracerebroventricular injection of LY294002 (a specific inhibitor of the PI3K/Akt signal). Neurological deficiency, histological impairment, brain edema, hematoma volume, blood–brain barrier destruction, and brain cell apoptosis were evaluated. Western blot, immunohistochemistry staining, reactive oxygen species (ROS) measurement, and enzyme-linked immunosorbent assay were performed. PUE administration at 50 mg/kg and 100 mg/kg could significantly reduce ICH-induced neurological deficits and EBI. Moreover, PUE could notably restrain ICH-induced upregulation of the NF-κB pathway, pro-inflammatory cytokines, ROS level, and apoptotic pathway and activate the PI3K/Akt signal. However, LY294002 delivery could efficaciously weaken these neuroprotective effects of PUE. Overall, PUE could attenuate ICH-induced behavioral defects and EBI possibly by PI3K/Akt signal stimulation-mediated inhibition of the NF-κB pathway, and this made PUE a potential candidate as a promising therapeutic option for ICH-induced EBI.     

Sphingosine kinase, phosphatidylinositol 3-kinase, Akt, NF-kappaB, and p300 are required for CCL5 production in Mycobacterium bovis Bacillus Calmette-Guérin (BCG)-infected epithelial cells

CCL5 is a key in limiting mycobacterial infection. Although NF-κB has been implicated, signaling cascades involved in CCL5 production by epithelial cells following infection with Mycobacterium bovis BCG are still not defined. Here we show that using pharmacological inhibition of sphingosine kinase (SPK), striking inhibition of M. bovis BCG-induced CCL5 protein was observed. Phosphatidylinositol 3-kinase (PI3K) and Akt were also important for CCL5 production by epithelial cells infected with M. bovis BCG. Moreover, there was increased activation of PI3K, IKK/αβ and NF-κB in A549 cells infected with M. bovis BCG. Importantly, the PI3K activation was dependent on SPK. Finally, M. bovis BCG increases the recruitment of p300 with NF-κB in A549 cells. Together, these studies are the first to show that M. bovis BCG-induced CCL5 secretion is dependent on the SPK/PI3K/Akt/NF-κB and p300 signaling pathway. The regulatory pathways of M. bovis BCG-induced CCL5 production can potentially be exploited therapeutically.     

Targeting MAPKs,NF-κB,and PI3K/AKT pathways by methyl palmitate ameliorates ethanol-induced gastric mucosal injury in rats

Excessive drinking of alcohol has been frequently associated with gastric injury; however, its underlying molecular mechanisms have been inadequately investigated. Methyl palmitate (MP) has demonstrated marked hepato-, cardio- and pulmonary protective features; however, its effects on ethanol-induced gastric injury have not been studied. The aim of the present study was to evaluate the potential gastroprotective activity of MP against ethanol-evoked gastric mucosal damage in rats and associated molecular mechanisms, for example, mitogen-activated protein kinases (MAPKs), nuclear factor κB (NF-κB), and phosphoinositide 3 kinase/protein kinase B (PI3K/AKT) pathways. The rat stomachs were examined in terms of the inflammatory, oxidative, and apoptotic perturbations. Current data demonstrated that pretreatment with MP attenuated the gross gastric damage, scores of ulcer index, area of mucosal lesions and histopathology outcomes; actions which were similar to the reference antiulcer omeprazole. MP inhibited NF-κB expression, its nuclear translocation, and the expression of its downstream signals, for example, tumor necrosis factor-α and myeloperoxidase besides restoration of interleukin-10 levels. Western blot analysis revealed that MP counteracted the disruption of MAPKs signaling via lowering p-c-Jun N-terminal kinase 1/2 (p-JNK1/2) expression and restoring the phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2) levels without affecting p-p38MAPK levels. Additionally, MP improved the antioxidant milieu via diminishing lipid peroxides and enhancing glutathione, glutathione peroxidase, total antioxidant capacity and mucosal nitric oxide. In the context of apoptosis, MP inhibited the cleavage of caspase-3 and poly(ADP-ribose)polymerase (PARP) and Bax protein expression with upregulating B cell lymphoma-2 expression (Bcl-2), thus, promoting gastric cellular survival. This was confirmed by MP activation of the PI3K/AKT pathway manifested by enhanced expression of PI3K p110α and p-AKT. Together, the present findings report the gastroprotective actions of MP mediated via its anti-inflammatory, antioxidant, and antiapoptotic actions. The underlying molecular mechanisms involve, at least partly, the modulation of MAPKs, NF-κB and PI3K/AKT transduction.     

The TRAF3 adaptor protein drives proliferation of anaplastic large cell lymphoma cells by regulating multiple signaling pathways

T cells devoid of tumor necrosis factor receptor associated factor-3 (Traf3) exhibit decreased proliferation, sensitivity to apoptosis, and an improper response to antigen challenge. We therefore hypothesized that TRAF3 is critical to the growth of malignant T cells. By suppressing TRAF3 protein in different cancerous T cells, we found that anaplastic large cell lymphoma (ALCL) cells require TRAF3 for proliferation. Since reducing TRAF3 results in aberrant activation of the noncanonical nuclear factor-κB (NF-κB) pathway, we prevented noncanonical NF-κB signaling by suppressing RelB together with TRAF3. This revealed that TRAF3 regulates proliferation independent of the noncanonical NF-κB pathway. However, suppression of NF-κB-inducing kinase (NIK) along with TRAF3 showed that high levels of NIK have a partial role in blocking cell cycle progression. Further investigation into the mechanism by which TRAF3 regulates cell division demonstrated that TRAF3 is essential for continued PI3K/AKT and JAK/STAT signaling. In addition, we found that while NIK is dispensable for controlling JAK/STAT activity, NIK is critical to regulating the PI3K/AKT pathway. Analysis of the phosphatase and tensin homolog (PTEN) showed that NIK modulates PI3K/AKT signaling by altering the localization of PTEN. Together our findings implicate TRAF3 as a positive regulator of the PI3K/AKT and JAK/STAT pathways and reveal a novel function for NIK in controlling PI3K/AKT activity. These results provide further insight into the role of TRAF3 and NIK in T cell malignancies and indicate that TRAF3 differentially governs the growth of B and T cell cancers.     

Luteolin attenuates TGF-β1-induced epithelial–mesenchymal transition of lung cancer cells by interfering in the PI3K/Akt–NF-κB–Snail pathway

Aims

Luteolin is a natural flavonoid that possesses a variety of pharmacological activities, such as anti-inflammatory and anti-cancer abilities. Whether luteolin regulates the transformation ability of lung cancer cells remains unclear. The current study aims to uncover the effects and underlying mechanisms of luteolin in regulation of and epithelial–mesenchymal transition of lung cancer cells.

Main methods

The lung adenocarcinoma A549 cells were used in this experiment; the cells were pretreated with luteolin followed by administration with TGF-β1. The expression levels of various cadherin and related upstream regulatory modules were examined.

Key findings

Pretreatment of luteolin prevented the morphological change and downregulation of E-cadherin of A549 cells induced by TGF-β1. In addition, the activation of PI3K–Akt–IκBa–NF-κB–Snail pathway which leads to the decline of E-cadherin induced by TGF-β1 was also attenuated under the pretreatment of luteolin.

Significance

We provide the mechanisms about how luteolin attenuated the epithelial–mesenchymal transition of A549 lung cancer cells induced by TGF-β1. This finding will strengthen the anti-cancer effects of flavonoid compounds via the regulation of migration/invasion and EMT ability of various cancer cells.     

Penicillospirone from a marine isolate of Penicillium sp. (SF-5292) with anti-inflammatory activity

Chemical investigation of the EtOAc extract of a marine-derived fungal isolate Penicillium sp. SF-5292 yielded a new polyketide-type metabolite, penicillospirone (1). The structure of 1 was determined by analysis of spectroscopic data such as 1D and 2D NMR spectra and MS data, and the final structure including absolute configuration was unambiguously established by single-crystal X-ray diffraction analysis. In the evaluation of its anti-inflammatory effects, 1 inhibited the overproduction of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and BV2 microglia, and these inhibitory effects were correlated with the suppressive effect of 1 against overexpressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, 1 also inhibited the production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-12. Overall, the anti-inflammatory effect of 1 was suggested to be mediated through the negative regulation of NF-κB pathway.     

Inhibition of PI3K/Akt/NF-κB signaling with leonurine for ameliorating the progression of osteoarthritis: In vitro and in vivo studies

Osteoarthritis (OA) is characterized as the degeneration and destruction of articular cartilage. In recent decades, leonurine (LN), the main active component in medical and edible dual purpose plant Herba Leonuri, has been shown associated with potent anti-inflammatory effects in several diseases. In the current study, we examined the protective effects of LN in the inhibition of OA development as well as its underlying mechanism both in vitro and in vivo experiments. In vitro, interleukin-1 beta (IL-1β) induced over-production of prostaglandin E2, nitric oxide, inducible nitric oxide synthase, cyclooxygenase-2, interleukin-6 and tumor necrosis factor alpha were all inhibited significantly by the pretreatment of LN at a dose-dependent manner (5, 10, and 20 µM). Moreover, the expression of thrombospondin motifs 5 (ADAMTS5) and metalloproteinase 13 (MMP13) was downregulated by LN. All these changes led to the IL-1β induced degradation of extracellular matrix. Mechanistically, the LN suppressed IL-1β induced activation of the PI3K/Akt/NF-κB signaling pathway cascades. Meanwhile, it was also demonstrated in our molecular docking studies that LN had strong binding abilities to PI3K. In addition, LN was observed exerting protective effects in a surgical induced model of OA. To sum up, this study indicated LN could be applied as a promising therapeutic agent in the treatment of OA.     

Arthpyrone L,a New Pyridone Alkaloid from a Deep-Sea Arthrinium sp., Inhibits Proliferation of MG63 Osteosarcoma Cells by Inducing G0/G1 Arrest and Apoptosis

Fractionation of the ethanol extract of a marine fungus, Arthrinium sp., afforded a new pyridone alkaloid (arthpyrone L ( 1 )), the structure with absolute configuration of which was established by comprehensive spectroscopic analyses. In vitro cell viability assays revealed that compound 1 showed antiproliferative effects toward human A549 (lung), MG63, U2OS (bone), MCF-7 and MDA-MB-231 (breast) cancer cells. MG63 cell lines were chosen for further biological evaluations and presented apoptosis and cell cycle arrest (G0/G1 phase) upon treatment of 1 . Subsequent mechanism studies demonstrated that the growth inhibition of 1 against MG63 cells was via activation of caspase-modulated apoptotic pathway and inhibition of PI3K/Akt pathway.     

Phragmalin-type limonoids with NF-κB inhibition from Chukrasia tabularis var. velutina

Chemical investigation on Chukrasia tabularis var. velutina led to the identification of eight new phragmalin-type limonoids (1–8), as well as 20 known analogues. Compounds 1–4 are a rare class of C-15-acyl phragmalin-type limonoids, and particularly compounds 2–4 also possess a δ-lactone ring formed between C-16 and C-30. All the isolates were evaluated for inhibitory effects on NF-κB production, and four of which showed significant inhibitions.     

Chaetochromones A – C,Three New Polyketides from Mangrove Plant Derived Endophytic Fungus Phomopsis sp. SCSIO 41006

Three new polyketides, chaetochromones A – C ( 1  –  3 ), together with a chromone ( 4 ), were isolated from the ethyl acetate extract of mangrove‐derived fungus Phomopsis sp. SCSIO 41006. Their structures were elucidated by means of spectroscopic techniques (UV, IR, MS, 1D‐ and 2D‐NMR). The absolute configurations of the new compounds were established by CD data.     

Chemical constituents from Vietnamese mangrove Calophyllum inophyllum and their anti-inflammatory effects

In a search for anti-inflammatory activity in resources from Vietnamese mangroves, we found that a methanolic extract from the leaves of Calophyllum inophyllum (CIL) showed significant anti-inflammatory effects in vitro. Using various chromatographic techniques, we subsequently isolated 12 compounds (1–12) from a methanolic extract of CIL, including two novel compounds (1–2). The inhibitory effects of these compounds on lipopolysaccharide-induced nitric oxide (NO) production in RAW264.7 cells were also evaluated. Compound 1 significantly suppressed NO production (IC₅₀ = 2.44 ± 0.88 µM), the secretion of pro-inflammatory cytokines (including interleukin-1 beta and tumor necrosis factor alpha), and the expression of inducible nitric oxide synthase through downregulation of nuclear factor-kappa-B signaling cascades. These results suggest that C. inophyllum leaves might be a useful resource for the development of drugs for the treatment of inflammation.