L-limonene reduces aortic artery atherosclerosis by inhibiting oxidative stress/inflammatory responses in diabetic rats fed high-fat diet.

Atherosclerosis, a leading cause of mortality worldwide, is driven by multiple risk factors such as diabetes. Oxidative stress and inflammation assist interrelated roles in diabetes-accelerated atherosclerosis. Thereby, treatment of diabetic atherosclerosis from an oxidative stress/inflammatory perspective seems to be a more effective modality to prevent and delay plaque formation and progression. This study aimed to evaluate the effects of l-limonene (LMN) on oxidative stress/inflammatory responses in the aortic artery of diabetic atherosclerosis-modeled rats. Male Wistar rats (n = 30, 250-280 g, 12 weeks old) were used to establish a diabetic atherosclerosis model (8 weeks) using high-fat diet/low-dose streptozotocin. LMN (200 mg/kg/day) was administered orally, starting on day 30th before tissue sampling. Plasma lipid profiles, aortic histopathological changes, atherogenic index, aortic artery levels of oxidative stress markers (manganese superoxide dismutase, glutathione, and 8-isoprostane), inflammatory markers (tumor necrosis factor-alpha, interleukin (IL)-6, and IL-10), and expression of phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK)/AMPK, Sirtuin 1 (SIRT1), and p-p65/p65 proteins were evaluated. The administration of LMN to diabetic rats improved lipid profiles, aortic histopathological morphology, and atherogenic index (P < 0.05 to P < 0.001). It also increased enzymatic antioxidant activities, decreased 8-isoprostane level, suppressed inflammatory response, upregulated p-AMPK and SIRT1 proteins, and downregulated p-p65 protein (P < 0.05 to P < 0.01). Inhibiting the AMPK through the administration of compound C significantly abolished or reversed the positive effects of LMN in diabetic rats (P < 0.05 to P < 0.01). LMN treatment had dual anti-oxidative and anti-inflammatory actions against atherosclerosis in the aortic artery of diabetic rats. Atheroprotection by LMN was mediated partly through modulation of AMPK/SIRT1/p65 nuclear factor kappa B signaling pathway. LMN appears to be a promising anti-atherosclerotic modality to improve the quality of life in diabetic patients.

Vagal-mAChR4 signaling promotes Friend virus complex (FV)-induced acute erythroleukemia.

Erythroleukemia belongs to acute myeloid leukemia (AML) type 6 (M6), and treatment remains difficult due to the poor prognosis of the disease. Friend virus (FV) is a complex of two viruses: Friend murine leukemia virus (F-MuLV) strain along with a defective spleen focus-forming virus (SFFV), which can induce acute erythroleukemia in mice. We have previously reported that activation of vagal α7 nicotinic acetylcholine receptor (nAChR) signaling promotes HIV-1 transcription. Whether vagal muscarinic signaling mediates FV-induced erythroleukemia and the underlying mechanisms remain unclear. In this study, sham and vagotomized mice were intraperitoneally injected with FV. FV infection caused anemia in sham mice, and vagotomy reversed this change. FV infection increased erythroblasts ProE, EryA, and EryB cells in the spleen, and these changes were blocked by vagotomy. In bone marrow, FV infection reduced EryC cells in sham mice, an effect that was counteracted by vagotomy. FV infection increased choline acetyltransferase (ChAT) expression in splenic CD4+ and CD8+ T cells, and this change was reversed by vagotomy. Furthermore, the increase of EryA and EryB cells in spleen of FV-infected wild-type mice was reversed after deletion of ChAT in CD4+ T cells. In bone marrow, FV infection reduced EryB and EryC cells in sham mice, whereas lack of ChAT in CD4+ T cells did not affect this change. Activation of muscarinic acetylcholine receptor 4 (mAChR4) by clozapine N-oxide (CNO) significantly increased EryB in the spleen but decreased the EryC cell population in the bone marrow of FV-infected mice. Thus, vagal-mAChR4 signaling in the spleen and bone marrow synergistically promotes the pathogenesis of acute erythroleukemia. We uncover an unrecognized mechanism of neuromodulation in erythroleukemia.

Activation of α7 nicotinic acetylcholine receptor promotes HIV-1 transcription.

Alpha7 nicotinic acetylcholine receptor (α7 nAChR), a hub of the cholinergic anti-inflammatory pathway (CAP), is required for the treatment of inflammatory diseases. HIV-1 infection can upregulate the expression of α7 nAChR in T lymphocytes and affect the role of CAP. However, whether α7 nAChR regulates HIV-1 infection in CD4+ T cells is unclear. In this study, we first found that activation of α7 nAChR by GTS-21 (an α7 nAChR agonist) can promote the transcription of HIV-1 proviral DNA. Then, through transcriptome sequencing analysis, we found that p38 MAPK signaling was enriched in GTS-21 treated HIV-latent T cells. Mechanistically, activation of α7 nAChR could increase reactive oxygen species (ROS), reduce DUSP1 and DUSP6, and consequently enhance the phosphorylation of p38 MAPK. By co-immunoprecipitation and liquid chromatography tandem mass spectrometry, we found that p-p38 MAPK interacted with Lamin B1 (LMNB1). Activation of α7 nAChR increased the binding between p-p38 MAPK and LMNB1. We confirmed that knockdown of MAPK14 significantly downregulated NFATC4, a key activator of HIV-1 transcription. Taken together, activation of the α7 nAChR could trigger ROS/p-p38 MAPK/LMNB1/NFATC4 signaling pathway enhancing HIV-1 transcription. We have revealed an unrecognized mechanism of α7 nAChR-mediated neuroimmune regulation of HIV infection.

Smad4 deficiency substitutes Cdkn2b but not Cdkn2a downregulation in pancreatic cancer following induction of genetic events in adult mice.

BACKGROUND: Minor progress in pancreatic cancer treatment and prognosis implies that more reliable animal models are urgently needed to decipher its molecular mechanisms and preclinical research. We recently reported a genetically engineered adult mouse model where Cdkn2b downregulation was required together with Cdkn2a downregulation to inactivate the Rb pathway. Besides, the role of Smad4, which is mutated more frequently than Cdkn2b in human pancreatic cancer, was determined critical on the development of the pancreas tumor by some reports. However, the impact of Smad4 deficiency in combination with PDAC-relevant mutations, such as Cdkn2a when induced in adult pancreas has not been completely elucidated in mice. METHODS: Lentiviral delivered oncogene/tumor suppressors in adult pancreas. The development of pancreatic cancer was monitored. Hematoxylin and eosin staining and immunofluorescence were performed for pathological identification of the pancreatic cancer. Real-time polymerase chain reaction, immunofluorescence and western blot were used to test gene expression. RESULTS: Loss of Smad4 could cooperate with alterations of KRAS, Trp53, and Cdkn2a to induce pancreatic cancer in adult mice. The role of Smad4 was mainly in downregulating the expression of Cdkn2b and further inducing phosphorylation of the Rb1 protein. CONCLUSIONS: These findings show an essential role of Smad4 deficiency in pancreatic ductal adenocarcinoma (PDAC) formation. This model better recapitulates the adult onset, clonal origin, and genetic alterations in human PDAC and can be simply generated on a large-scale.

Effect of miR-195-5p on cardiomyocyte apoptosis in rats with heart failure by regulating TGF-ß1/Smad3 signaling pathway.

PURPOSE: The present study set out to investigate the effect of miR-195-5p on cardiomyocyte apoptosis in rats with heart failure (HF) and its mechanism. METHODS: HF rat model and hypoxia/reoxygenation (H/R) cardiomyocyte model were established. miR-195-5p expression and transforming growth factor-ß1 (TGF-ß1)/signal transduction protein (Smad)3 signaling pathway in HF rats and H/R cardiomyocytes were interfered. miR-195-5p expression was tested by Rt-PCR, TGF-ß1/Smad3 signaling pathway related proteins were detected by Western Blot, apoptosis of HF rat cardiomyocytes was tested by TUNEL, and apoptosis of cardiomyocytes induced by H/R was checked by flow cytometry. RESULTS: miR-195-5p was lowly expressed in myocardium of HF rats, while TGF-ß1 and Smad3 proteins were high-expressed. Up-regulating miR-195-5p expression could obviously inhibit cardiomyocyte apoptosis of HF rats, improve their cardiac function, and inhibit activation of TGF-ß1/Smad3 signaling pathway. Up-regulation of miR-195-5p expression or inhibition of TGF-ß1/Smad3 signaling pathway could obviously inhibit H/R-induced cardiomyocyte apoptosis. Dual-luciferase reporter enzyme verified the targeted relationship between miR-195-5p and Smad3. CONCLUSION: miR-195-5p can inhibit cardiomyocyte apoptosis and improve cardiac function in HF rats by regulating TGF-ß1/Smad3 signaling pathway, which may be a potential target for HF therapy.

The novel GLP-1/GIP analogue DA5-CH reduces tau phosphorylation and normalizes theta rhythm in the icv. STZ rat model of AD.

INTRODUCTION: Alzheimer's disease (AD) is the most common progressive neurodegenerative disease for which there is no cure. Recent studies have shown a close link between type 2 diabetes and AD, which suggested that drugs for type 2 diabetes may be effective for AD. GLP-1 and GIP are incretin hormones that can ameliorate diabetes. METHODS: In the present study, we tested the novel dual GLP-1/GIP receptor agonist DA5-CH in the icv. streptozotocin (STZ)-induced insulin desensitization model of AD in rats to explore the protective effects of DA5-CH. RESULTS: The results show that DA5-CH could reverse the STZ-induced working memory impairments in a Y-maze tests, and spatial memory impairments in the water maze task, and decrease the levels of phosphorylated tauS396 protein in the hippocampus. In EEG recordings, STZ treatment diminished the power of the theta band frequency. DA5-CH was able to increase the energy of theta band activity in the hippocampal CA1 region. The drug also increased the expression of synapse-related proteins in the hippocampus. After DA5-CH treatment, mitochondrial stress was alleviated as shown by the improved ratio of Bax/Bcl-2 in the hippocampus. Growth factor signaling was also normalized as shown by the increased level of the transcription factor P-CREBS133 . In addition, we were able to show that DA5-CH can cross the blood-brain barrier at an increased rate compared with other dual GLP-1/GIP or single GLP-1 receptor agonists. CONCLUSION: Therefore, our results demonstrate that DA5-CH has neuroprotective effects in the STZ-induced animal model and that DA5-CH has potential to treat neurodegenerative disorders such as AD.

Identification of two mitochondrial-targeting cyclometalated iridium(III) complexes as potent anti-glioma stem cells agents.

Glioma stem cells (GSCs) are thought to be responsible for the recurrence and invasion of glioblastoma multiform (GBM), which have been evaluated and exploited as the therapeutic target for GBM. Cyclometalated iridium(III) complexes have been demonstrated as the potential anticancer agents, however, their antitumor efficacies against GSCs are still unknown. Herein, we investigated the antitumor activity of two cyclometalated iridium(III) complexes [Ir(ppy)2L](PF6) (Ir1) and [Ir(thpy)2L](PF6) (Ir2) (ppy = 2-phenylpyridine, thpy = 2-(2-thienyl)pyridine and L = 4,4'-Bis(hydroxymethyl)-2,2'-bipyridine) against GSCs. The results clearly indicate that Ir1 and Ir2 kill GSCs selectively with IC50 values ranging from 5.26-9.05 µM. Further mechanism research display that Ir1 and Ir2 can suppress the proliferation of GSCs, penetrate into GSCs efficiently, localize to mitochondria, and induce mitochondria-mediated apoptosis, including the loss of mitochondrial membrane (MMP), elevation of intracellular reactive oxygen species (ROS) and caspases activation. Moreover, Ir1 and Ir2 can destroy the GSCs self-renewal and unlimited proliferation capacity by affecting the GSCs colony formation. According our knowledge, this is the first study to investigate the anti-GSCs properties of cyclometalated iridium(III) complexes.

Correlation between vascular endothelial growth factor and long-term prognosis in patients with acute myocardial infarction.

The aim of the present study was to investigate the correlation between plasma the levels of vascular endothelial growth factor (VEGF) and major adverse cardiovascular events (MACE) in patients with acute myocardial infarction (AMI). A total of 124 patients with AMI undergoing emergency percutaneous coronary intervention (PCI) were selected, and plasma VEGF levels were measured 7 days after the onset of AMI using an enzyme-linked immunosorbent assay. The patients were divided into the L (≤190 pg/ml VEGF) and H (>190 pg/ml VEGF) groups, and were followed up every 2 months for an average of 12 months. MACE were recorded during follow-up. On the basis of these results, the patients were further divided into the MACE and non-MACE (N-MACE) groups, and the serum VEGF concentration was compared between the two groups. At the 6-month follow-up, the incidence of MACE in the H group was found to be significantly reduced compared with the L group. The serum VEGF concentration in the N-MACE group was significantly higher compared with the MACE group. Multinomial logistic regression revealed that reduced VEGF levels (ß=1.243; 95% CI, 1.018-1.326; P=0.026) were independent risk factors for MACE. In conclusion, high plasma VEGF levels at 7 days after AMI onset facilitate the long-term prognosis in the same infarct zone in patients with AMI, while low plasma VEGF levels are independent risk factors for MACE.