Activation AMPK in Hypothalamic Paraventricular Nucleus Improves Renovascular Hypertension Through ERK1/2-NF-κB Pathway.

Hypertension is a globally prevalent disease, but the pathogenesis remains largely unclear. AMP-activated protein kinase (AMPK) is a nutrition-sensitive signal of cellular energy metabolism, which has a certain influence on the development of hypertension. Previously, we found a down-regulation of the phosphorylated (p-) form of AMPK, and the up-regulation of the angiotensin II type 1 receptor (AT1-R) and that of p-ERK1/2 in the hypothalamic paraventricular nucleus (PVN) of hypertensive rats. However, the exact mechanism underlying the relationship between AMPK and AT1-R in the PVN during hypertension remains unclear. Thus, we hypothesized that AMPK modulates AT1-R through the ERK1/2-NF-κB pathway in the PVN, thereby inhibiting sympathetic nerve activity and improving hypertension. To examine this hypothesis, we employed a renovascular hypertensive animal model developed via two-kidney, one-clip (2K1C) and sham-operated (SHAM). Artificial cerebrospinal fluid (aCSF), used as vehicle, or 5-amino-1-ß-D-ribofuranosyl-imidazole-4-carboxamide (AICAR, an AMPK activator, 60 µg/day) was microinjected bilaterally in the PVN of these rats for 4 weeks. In 2K1C rats, there an increase in systolic blood pressure (SBP) and circulating norepinephrine (NE). Also, the hypertensive rats had lowered expression of p-AMPK and p-AMPK/AMPK, elevated expression of p-ERK1/2, p-ERK1/2/ERK1/2 and AT1-R, increased NF-κB p65 activity in the PVN compared with the levels of these biomarkers in SHAM rats. Four weeks of bilateral PVN injection of AMPK activator AICAR, attenuated the NE level and SBP, increased the expression of p-AMPK and p-AMPK/AMPK, lessened the NF-κB p65 activity, decreased the expression of p-ERK1/2, p-ERK1/2/ERK1/2 and AT1-R in the PVN of 2K1C rats. Data from this study imply that the activation of AMPK within the PVN suppressed AT1-R expression through inhibiting the ERK1/2-NF-κB pathway, decreased the activity of the sympathetic nervous system, improved hypertension.

Structures, Biosynthesis, and Bioactivity of Oligomycins from the Marine-Derived Streptomyces sp. FXY-T5.

Oligomycins are potent antifungal and antitumor agents. Mass spectrometry (MS)- and nuclear magnetic resonance (NMR)-based metabolomic fingerprinting analysis of marine-derived actinomycetes in our in-house library provided an oligomycin-producing strain, Streptomyces sp. FXY-T5. Chemical investigation led to the discovery of five new oligomycins, 24-lumooligomycin B (1), 4-lumooligomycin B (2), 6-lumooligomycin B (3), 40-homooligomycin B (4), and 15-hydroxy-oligomycin B (5), together with seven biosynthetically related known derivatives. Their structures were assigned by MS, NMR, electronic circular dichroism (ECD), and single-crystal X-ray diffraction analyses. The biosynthesis pathway of oligomycins was first proposed based on the analysis of a type I modular polyketide synthase (PKS) system and targeted gene disruption. As expected, the isolated oligomycins showed significant antiagricultural fungal pathogen activity and antiproliferative properties from which the possible structure-activity relationships were first suggested. More importantly, oligomycins induced significant G1-phase cell cycle arrest on cancer cells and significantly attenuated their Cyclin D1 and PCNA expression through a ß-catenin signaling pathway.

Exercise Training Attenuates Hypertension via Suppressing ROS/MAPK/NF-κB/AT-1R Pathway in the Hypothalamic Paraventricular Nucleus.

BACKGROUND: Aerobic exercise training (ExT) is beneficial for hypertension, however, its central mechanisms in improving hypertension remain unclear. Since the importance of the up-regulation of angiotensin II type 1 receptor (AT-1R) in the paraventricular nucleus (PVN) of the hypothalamic in sympathoexcitation and hypertension has been shown, we testified the hypothesis that aerobic ExT decreases blood pressure in hypertensive rats by down-regulating the AT-1R through reactive oxygen species (ROS)/mitogen-activated protein kinase (MAPK)/nuclear factors κB (NF-κB) pathway within the PVN. METHODS: Forty-eight male Sprague-Dawley (SD) rats were assigned to the following groups: sham operation (SHAM) + kept sedentary (Sed), SHAM + exercise training (ExT), two kidney-one clamp (2K1C) + Sed, and 2K1C + ExT groups. RESULTS: The 2K1C + Sed hypertensive rats showed higher systolic blood pressure (SBP), upregulated ROS, phosphorylated (p-) p44/42 MAPK, p-p38 MAPK, NF-κB p65 activity, and AT-1R expression in the PVN, and increased circulating norepinephrine (NE) than those of SHAM rats. After eight weeks of aerobic ExT, the 2K1C + ExT hypertensive rats showed attenuated NE and SBP levels, suppressed NF-κB p65 activity, and reduced expression of ROS, p-p44/42 MAPK, p-p38 MAPK, and AT-1R in the PVN, relatively to the 2K1C + Sed group. CONCLUSIONS: These data are suggestive of beneficial effects of aerobic ExT in decreasing SBP in hypertensive rats, via down-regulating the ROS/MAPK/NF-κB pathway that targets AT-1R in the PVN, and eventually ameliorating 2K1C-induced hypertension.

Resveratrol in the Hypothalamic Paraventricular Nucleus Attenuates Hypertension by Regulation of ROS and Neurotransmitters.

BACKGROUND: The hypothalamic paraventricular nucleus (PVN) is an important nucleus in the brain that plays a key role in regulating sympathetic nerve activity (SNA) and blood pressure. Silent mating-type information regulation 2 homolog-1 (sirtuin1, SIRT1) not only protects cardiovascular function but also reduces inflammation and oxidative stress in the periphery. However, its role in the central regulation of hypertension remains unknown. It is hypothesized that SIRT1 activation by resveratrol may reduce SNA and lower blood pressure through the regulation of intracellular reactive oxygen species (ROS) and neurotransmitters in the PVN. METHODS: The two-kidney one-clip (2K1C) method was used to induce renovascular hypertension in male Sprague-Dawley rats. Then, bilaterally injections of vehicle (artificial cerebrospinal fluid, aCSF, 0.4 µL) or resveratrol (a SIRT1 agonist, 160 µmol/L, 0.4 µL) into rat PVN were performed for four weeks. RESULTS: PVN SIRT1 expression was lower in the hypertension group than the sham surgery (SHAM) group. Activated SIRT1 within the PVN lowered systolic blood pressure and plasma norepinephrine (NE) levels. It was found that PVN of 2K1C animals injected with resveratrol exhibited increased expression of SIRT1, copper-zinc superoxide dismutase (SOD1), and glutamic acid decarboxylase (GAD67), as well as decreased activity of nuclear factor-kappa B (NF-κB) p65 and NAD(P)H oxidase (NOX), particularly NOX4. Treatment with resveratrol also decreased expression of ROS and tyrosine hydroxylase (TH). CONCLUSION: Resveratrol within the PVN attenuates hypertension via the SIRT1/NF-κB pathway to decrease ROS and restore the balance of excitatory and inhibitory neurotransmitters.

The roles of exosomal immune checkpoint proteins in tumors.

Targeting immune checkpoints has achieved great therapeutic effects in the treatment of early-stage tumors. However, most patients develop adaptive resistance to this therapy. The latest evidence demonstrates that tumor-derived exosomes may play a key role in systemic immune suppression and tumor progression. In this article, we highlight the role of exosomal immune checkpoint proteins in tumor immunity, with an emphasis on programmed death ligand 1 (PD-L1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), as well as emerging evidence on roles of T cell immunoglobulin-3 (TIM-3), arginase 1 (ARG1), and estrogen receptor binding fragment-associated antigen 9 (EBAG9) expressed by exosomes.

[Clinical Significance of CRLF2 High Expression in Bone Marrow Mononuclear Cells from Children with Acute Lymphoblastic Leukemia].

OBJECTIVE: To detect the expression of CRLF2 in bone marrow mononuclear cells from children with newly diagnosed acute lymphoblastic leukemia(ALL) and to explore its clinical significance in pediatric ALL. METHODS: A total of 218 children with newly diagnosed ALL who achieveal the complete remission and had the complete follow-up information were selected, and the expression level of CRLF2 in bone marrow mononuclear cells of these children was detected by real-time fluorescent quantitative PCR, and the significance of CRLF2 expression level in clinical prognosis of ALL children was analyzed by using statistical method. RESULTS: 28 cases in 218 children with complete data showed high expression of CRLF2. The cumulative recurrence rate in the CRLF2 high expression group was significantly higher than that in the low expression group (53.6% vs 12.6%) (P＜0.01). The predicted 5-year recurrence-free survival rate (RFS) of ALL children with CRLF2 high expression was significantly higher than that of low expression group (P＜0.01). There was no significant difference in the predicted 5-year RFS between ALL children with CRLF2 low and high expression in the standard-risk(SR) group (P＞0.05). The predicted 5-year RFS of ALL children with CRLF2 low expression was higher than that of ALL children with CRLF2 high expression in the intermediate-risk (IR) and high-risk (HR) groups. (P＜0.05). Cox analysis showed that CRLF2 high expression is an independent risk factor for the relapse of children with ALL. CONCLUSION: The recurrence rate of pediatric ALL with CRLF2 high expression is high, and CRLF2 high expression is an important prognostic factor for high risk of relapse in ALL children with IR and HR. It is necessary to use CRLF2 expression as an indicator of risk stratification in pediatric ALL.

Lysophosphatidic acid enhances human umbilical cord mesenchymal stem cell viability without differentiation via LPA receptor mediating manner.

Human umbilical cord mesenchymal stem cells (hUC-MSCs) are potential stromal cells which are regarded as the most feasible stem cell group in cell therapy. The maintenance of cell survival without differentiation is important in cell transplantation and stem cell therapy. However, negative factors exist in cell transplantation. Lysophosphatidic acid (LPA) is a non-antigenic small molecule phospholipid which induced several fundamental cellular responses, such as cell proliferation, apoptosis and migration. In this study we aimed to explore the effects of LPA on the survival and differentiation of MSCs and its availability in cell therapy. We found that LPA stimulated hUC-MSC proliferation and protected hUC-MSCs from lipopolysaccharide (LPS) induced apoptosis. We also observed that CD29, CD44, CD73, CD90 and CD105 were expressed, whereas CD34 and CD45 were not expressed in hUC-MSCs, and these makers have no change in LPA containing medium, which indicated that LPA accelerated the survival of hUC-MSCs in an undifferentiating status. We also demonstrated that higher expressed LPAR1 involved in LPA stimulated cell survival action. LPA stimulated cell proliferation was associated with LPAR1 mediated Gi/o-proteins/ERK1/2 pathway. On the other hand, LPA protected hUC-MSCs from LPS-induced apoptosis through suppressing caspase-3 activation by LPAR1 coupled with a G protein, but not Gi/o or Gq/11 in hUC-MSC. Collectively, this study demonstrated that LPA increased the proliferation and survival of hUC-MSCs without differentiation through LPAR1 mediated manner. Our findings provide that LPA as a anti-apoptotic agent having potential application prospect in cell transplantation and stem cell therapy.

[Effect of Icaritin on Proliferation and Apoptosis of THP-1 Cell and Its Mechanism].

OBJECTIVE: To investigate the effect of icaritin on the proliferation and apoptosis of THP-1 cells and its mechanism. METHODS: After treated with various concentrations of icaritin, cell proliferation was detected by MTS method, and apoptosis was measured with flow cytometry and Hoechst 33258 staining. Expression of BCL-2, BAX and Caspase-3 protein in THP-1 cell was detected by Western blot. RESULTS: After treatment with various concentrations (4-32 µmol/L) of icaritin for 24, 48, 72 h, the inhibition rate of cell growth significantly increased (P<0.05) in time-dose dependent manner(r=0.946); and the apoptotic rate of cells significantly increased (P<0.05) in time-dose dependent manner(r= 0.924). The expression of BCL-2 protein at 48 h decreased significantly in icaritin-treated group, compared with that in control group (P<0.05), while the expression of BAX and Caspase3 protein at 48 h increased significantly in icaritin-treated group, compared with that in control group (P<0.05). CONCLUSION: Icaritin can inhibit proliferation and induce apoptosis of THP-1 in vitro, Icaritin may induce apoptosis in THP-1 cells through the mitochondrial pathway.

Four New Kaurane Diterpenoids from the Chinese Liverwort Jungermannia comata Nees.

In our continuing program to find new bioactive compounds from the Chinese liverworts, four new kaurane-type diterpenoids, (6ß)-kaur-16-ene-6,9-diol (1), (6ß,12ß)-kaur-16-ene-6,9,12-triol (2), (6ß)-kaur-16-ene-5,6,9-triol (3), and kaur-16-ene-9,19-diol (4), have been isolated from the Chinese liverwort Jungermannia comata Nees. Five known kaurane-type diterpenoids (5 - 9) and four known trachylobane-type diterpenoids (10 - 13) were also obtained. The structures of the new compounds were established unequivocally on the basis of spectroscopic data. The absolute configuration of compound 1 was established by comparing experimental and calculated electronic circular dichroism spectra.

Pharmacological mechanism underlying anti-inflammatory properties of two structurally divergent coumarins through the inhibition of pro-inflammatory enzymes and cytokines.

BACKGROUND: The aim of the present study is to investigate the effects of two structurally divergent coumarins, calipteryxin (1) and (3'S,4'S)-3',4'-disenecioyloxy-3',4'-dihydroseselin (2) from Seseli recinosum, in lipopolysaccharide (LPS)-stimulated murine macrophages. METHODS: The nitrite production was evaluated using Griess reagent. The protein and mRNA expression levels were investigated through Western blot and quantitative real time-PCR analyses. The NF-κB and AP-1 DNA-binding activities were assessed using an electrophoretic mobility shift assay. The docking studies were performed with Glide XP in Schrödinger suite (version 2013). RESULTS: The results of the present study revealed that calipteryxin (1) and (3'S,4'S)-3',4'-disenecioyloxy-3',4'-dihydroseselin (2) treatment showed potent inhibitory effects on pro-inflammatory enzymes and cytokines associated with molecular signaling pathways. Treatment with calipteryxin and (3'S,4'S)-3',4'-disenecioyloxy-3',4'-dihydroseselin also decreased the production of nitric oxide (NO), tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß) in a dose-dependent manner. Additionally, both coumarins inhibited the LPS-induced protein and mRNA expression levels of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in RAW264.7 cells. To explore the potential mechanisms underlying the inhibitory activity of coumarin derivatives, the protein signaling pathways for NF-κB, mitogen-activated protein kinase (MAPK) and Akt were examined. Calipteryxin and (3'S,4'S)-3',4'-disenecioyloxy-3',4'-dihydroseselin markedly reduced the LPS-stimulated phosphorylation of IKKα/ß, p-IκBα and IκBα degradation as well as the nuclear translocation of the p65 subunit of pro-inflammatory transcription factor NF-κB. In addition, calipteryxin and (3'S,4'S)-3',4'-disenecioyloxy-3',4'-dihydroseselin) considerably inhibited the LPS-induced expression of ERK, c-Jun N-terminal kinase (JNK), p38 and Akt proteins. Furthermore, both coumarins significantly inhibited c-Jun expression in the nucleus. CONCLUSIONS: Taken together, these results support the therapeutic potential and molecular mechanism of calipteryxin and (3'S,4'S)-3',4'-disenecioyloxy-3',4'-dihydroseselin associated with inflammatory diseases.

MicroRNA-148b is down-regulated in non-small cell lung cancer and associated with poor survival.

BACKGROUND: The aim of this study was to clarify the clinicopathological significance of miRNA-148b (miR-148b) expression in NSCLC, and to explore the correlation between miR-148b level and the prognosis of patients with NSCLC. METHODS: 151 patients diagnosed with NSCLC between May 2007 and April 2012 were included in the present study. Real-time RT-PCR method was used to assess the expression levels of miR-148b. The differences between two groups were assessed using Student's t -test, and the Kaplan-Meier method was used to estimate overall survival. RESULTS: The expression of miR-148b was decreased in tumor tissues compared to corresponding adjacent normal lung tissues (0.37 ± 0.12 vs. 1.00 ± 0.53, P < 0.05). Low miR-148b expression was significantly associated with TNM stage (P = 0.014), lymph node metastasis (P = 0.031), and distant metastasis (P = 0.008). Kaplan-Meier survival analysis showed that patients with low expression of miR-148b had significantly worse overall survival rates compared with those who had cancers with high miR-148b expression (log-rank test P = 0.039). Furthermore, multivariate Cox proportional hazards model analysis showed that miR-148b expression was independently associated with overall survival of patients with NSCLC (HR = 2.357, 95% CI: 1.612-9.212, P = 0.011). CONCLUSION: our data indicate that decreased expression of miR-148b in NSCLC tissues has prognostic value.

In silico design of human IMPDH inhibitors using pharmacophore mapping and molecular docking approaches.

Inosine 5'-monophosphate dehydrogenase (IMPDH) is one of the crucial enzymes in the de novo biosynthesis of guanosine nucleotides. It has served as an attractive target in immunosuppressive, anticancer, antiviral, and antiparasitic therapeutic strategies. In this study, pharmacophore mapping and molecular docking approaches were employed to discover novel Homo sapiens IMPDH (hIMPDH) inhibitors. The Güner-Henry (GH) scoring method was used to evaluate the quality of generated pharmacophore hypotheses. One of the generated pharmacophore hypotheses was found to possess a GH score of 0.67. Ten potential compounds were selected from the ZINC database using a pharmacophore mapping approach and docked into the IMPDH active site. We find two hits (i.e., ZINC02090792 and ZINC00048033) that match well the optimal pharmacophore features used in this investigation, and it is found that they form interactions with key residues of IMPDH. We propose that these two hits are lead compounds for the development of novel hIMPDH inhibitors.

Alantolactone selectively suppresses STAT3 activation and exhibits potent anticancer activity in MDA-MB-231 cells.

The important goal of cancer drug discovery is to develop therapeutic agents that are effective, safe, and affordable. In the present study, we demonstrated that alantolactone, which is a sesquiterpene lactone, has potential activity against triple-negative breast cancer MDA-MB-231 cells by suppressing the signal transducer and activator of transcription 3 (STAT3) signaling pathway. Alantolactone effectively suppressed both constitutive and inducible STAT3 activation at tyrosine 705. Alantolactone decreased STAT3 translocation to the nucleus, its DNA-binding, and STAT3 target gene expression. Alantolactone significantly inhibits STAT3 activation with a marginal effect on MAPKs and on NF-κB transcription; however, this effect is not mediated by inhibiting STAT3 upstream kinases. Although SHP-1, SHP-2, and PTEN, which are protein tyrosine phosphatases (PTPs), were not affected by alantolactone, the treatment with a PTP inhibitor reversed the alantolactone-induced suppression of STAT3 activation, indicating that PTP plays an important role in the action of alantolactone. Finally, alantolactone treatment resulted in the inhibition of migration, invasion, adhesion, and colony formation. The in vivo administration of alantolactone inhibited the growth of human breast xenograft tumors. These results provide preclinical evidence to continue the development of alantolactone as a STAT3 inhibitor and as a potential therapeutic agent against breast cancer.

Notolutesins A-J, dolabrane-type diterpenoids from the Chinese liverwort Notoscyphus lutescens.

Ten new dolabrane-type diterpenoids, notolutesins A-J (1-10), were isolated from the Chinese liverwort Notoscyphus lutescens, along with four known compounds. The structures of the new compounds were established on the basis of extensive spectroscopic data, and that of 1 was confirmed by single-crystal X-ray crystallography. The absolute configuration of 1 was determined by comparing its experimental and calculated electronic circular dichroism spectra. All of the isolates were evaluated for their cytotoxicity against a small panel of human cancer cell lines, and compound 1 exhibited an IC50 value of 6.2 µM against the PC3 human prostate cancer cell line.

Two new cadinane-type sesquiterpenes from the Chinese liverwort Frullania serrata.

Two new cadinane-type sesquiterpenes, frullanic acid (1) and frullanic acid methyl ester (2), together with four known bibenzyls, brittonin B (3), 3,3'-dimethoxy-4,5-methylenedioxybibenzyl (4), 3,4,5,3',4'-penlamethoxybibenzyl (5) and (±)-3-(4'-methoxybenzyl)-5,6-dimethoxyphtbalide (6), were isolated from the Chinese liverwort Frullania serrata. The structures of the new metabolites were elucidated by analysing the spectroscopic data (1D NMR, 2D NMR, HR-ESI-MS and IR). The absolute configurations of compounds 1 and 2 were determined by comparing the experimental and calculated electronic circular dichroism spectra predicted by using time-dependent density functional theory as well as the CD exciton chirality method.

Phytotoxic cis-clerodane diterpenoids from the Chinese liverwort Scapania stephanii.

Five cis-clerodane diterpenoids, stephanialides A-E, along with seven known cis-clerodanes, scaparvins A-C, parvitexins B and C, 3-chloro-4-hydroxy-parvitexin A, and scapanialide B, were isolated from the Chinese liverwort Scapania stephanii. Their structures were established unequivocally on the basis of spectroscopic data. The absolute configuration of stephanialide A was determined by analysis of CD data using the octant rule. Phytotoxic activity evaluation showed that this type of diterpenoids can significantly inhibit root elongation of the seeds of Arabidopsis thaliana, Lepidium sativum and Brassica pekinensis.

Computational insight into p21-activated kinase 4 inhibition: a combined ligand- and structure-based approach.

p21-Activated kinase 4 (PAK4) is a serine/threonine protein kinase that plays important roles in a wide variety of human diseases including cancer. Targeting this kinase with specific inhibitors is of great interest in the treatment of cancer. In this study, PAK4 and its interaction with ATP-competitive inhibitors was investigated by a combined ligand- and structure-based approach. First, a ligand-based pharmacophore model was generated, consisting of five chemical features: a positive ionizable center, two hydrophobic groups, a hydrogen bond donor, and a hydrogen bond acceptor, which is consistent with available SAR information. The characteristics of the active site were then described as a topological region and used in docking of nine selected inhibitors. Combination of the pharmacophore model and results from the docking studies allowed us to weigh the various pharmacophore features and to identify the positive ionizable center as a spacer rather than an essential point. This research led to the proposal of an interaction model inside the PAK4 active site and provided guidance for the design of more potent PAK4 inhibitors.

Cembrane-type diterpenoids from the Chinese liverworts Chandonanthus hirtellus and C. birmensis.

Six new cembrane-type diterpenoids (1-6) were isolated from two species of Chandonanthus: Chandonanones A, B, and D-F (1, 2, and 4-6) were isolated from C. hirtellus, and chandonanones B, C, E, and F (2, 3, 5, and 6) from C. birmensis. Five known diterpenoids, (8E)-4α-acetoxy-12α,13α-epoxycembra-1(15),8-diene (7), isochandonanthone (8), chandonanthone (9), anadensin (10), and 2,10,14-triacetoxy-7,8,18,19-diepoxydolabell-3(E)-ene (11), were also obtained. The structures of the new metabolites were established by analyses of their spectroscopic data (1D NMR, 2D NMR, HRESIMS, and IR). The absolute configurations of compounds 1 and 2 were unequivocally confirmed using single-crystal X-ray diffraction analysis with Cu Kα radiation. Cytotoxicity tests of the isolated diterpenoids against seven cancer cell lines (DU145, PC3, A549, PC12, NCI-H292, NCI-H1299, and A172) revealed that some of the diterpenoids had weak activity.

Total synthesis of plagiochin G and derivatives as potential cancer chemopreventive agents.

A new and efficient total synthesis has been developed to obtain plagiochin G (22), a macrocyclic bisbibenzyl, and four derivatives. The key 16-membered ring containing biphenyl ether and biaryl units was closed via an intramolecular SNAr reaction. All synthesized macrocyclic bisbibenzyls inhibited Epstein-Barr virus early antigen (EBVEA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells and, thus, are potential cancer chemopreventive agents.