The synergistic effects of heat shock protein 70 and ginsenoside Rg1 against tert-butyl hydroperoxide damage model in vitro

Neural stem cells (NSCs) transplanted is one of the hottest research to treat Alzheimer's disease (AD), but cholinergic neurons from stem cells were also susceptible to cell death which Heat shock protein 70 (HSP70) was affirmed to reverse. Related to cognitive impairment, cholinergic nervous cells should be investigated and ginsenoside Rg1 (G-Rg1) was considered to increase them. We chose tert-butyl hydroperoxide (t-BHP) damage model to study in vitro. Functional properties of our recombination plasmid pEGFP-C2-HSP70 were affirmed by SH-SY5Y cells. To opposite the transitory appearance of HSP70, NSCs used as the vectors of HSP70 gene overexpressed HSP70 for at least 7 days in vitro. After transfection for 3 days, G-Rg1 pretreatment for 4 hours, and coculture for 3 days, the expression of acetylcholinesterase (ChAT), synaptophysin, and the ratio of NeuN and GFAP were assessed by western blot; Morphological properties were detected by 3D reconstruction and immunofluorescence. ChAT was markedly improved in the groups contained G-Rg1. In coculture system, the ratio of neurons/astrocytes and the filaments of neurons were increased; apoptosis cells were decreased, compared to monotherapy (P < 0.05). In conclusion, we demonstrated that, as a safe cotreatment affirmed in vitro, overexpression of HSP70 in NSCs plus G-Rg1 promoted nervous cells regeneration from chronic oxidative damage.

Oligomeric proanthocyanidin protects retinal ganglion cells against oxidative stress-induced apoptosis

The death of retinal ganglion cells is a hallmark of many optic neurodegenerative diseases such as glaucoma and retinopathy. Oxidative stress is one of the major reasons to cause the cell death. Oligomeric proanthocyanidin has many health beneficial effects including antioxidative and neuroprotective actions. Here we tested whether oligomeric proanthocyanidin may protect retinal ganglion cells against oxidative stress induced-apoptosis in vitro. Retinal ganglion cells were treated with hydrogen peroxide with or without oligomeric proanthocyanidin. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that treating retinal ganglion cell line RGC-5 cells with 20 μmol/L oligomeric proanthocyanidin significantly decreased the hydrogen peroxide (H2O2) induced death. Results of flow cytometry and Hoechst staining demonstrated that the death of RGC-5 cells was mainly caused by cell apoptosis. We further found that expression of pro-apoptotic Bax and caspase-3 were significantly decreased while anti-apoptotic Bcl-2 was greatly increased in H2O2 damaged RGC-5 cells with oligomeric proanthocyanidin by western blot assay. Furthermore, in retinal explant culture, the number of surviving retinal ganglion cells in H2O2-damaged retinal ganglion cells with oligomeric proanthocyanidin was significantly increased. Our studies thus demonstrate that oligomeric proanthocyanidin can protect oxidative stress-injured retinal ganglion cells by inhibiting apoptotic process.

Daucosterol promotes the proliferation of neural stem cells

Neural stem cells (NSCs) are self-regenerating cells, but their regenerative capacity is limited. The present study was conducted to investigate the effect of daucosterol (a sterolin) on the promotion of NSC proliferation and determine the corresponding molecular mechanism. Results of cell counting kit-8 (CCK-8) assay showed that daucosterol significantly increased the quantity of viable cells and the effectiveness of daucosterol was similar to that of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). Flow cytometry detection of CFSE-labeled (CFSE, carboxyfluorescein diacetate succinimidyl ester) NSCs showed that Div Index (or the average number of cell divisions) and % Divided (or the percentage of cells that divided at least once) of the cells were increased, indicating that daucosterol increased the percentage of NSCs re-entering the cell cycle. mRNA microarray analysis showed that 333 genes that are mostly involved in the mitotic cell cycle were up-regulated. By contrast, 627 genes that are mostly involved in differentiation were down-regulated. In particular, insulin-like growth factor I (IGF1) was considered as an important regulatory gene that functionally promoted NSC proliferation, and the increased expression of IGF1 protein was validated by ELISA. In addition, the phosphorylation of AKT was increased, indicating that the proliferation-enhancing activity of daucosterol may be involved in IGF1-AKT pathway. Our study provided information about daucosterol as an efficient and inexpensive growth factor alternative that could be used in clinical medicine and research applications.

Luteolin inhibits SH-SY5Y cell apoptosis through suppression of the nuclear transcription factor-κB, mitogen-activated protein kinase and protein kinase B pathways in lipopolysaccharide-stimulated cocultured BV2 cells

Microglial activation is one of the causative factors for neuroinflammation, which is associated with the pathophysiology of neurodegenerative diseases. Our previous study showed that the flavonoid luteolin inhibited several pro-inflammatory enzymes and pro-inflammatory cytokines that are induced by activated microglia; however, its effect on signaling pathways is currently unknown. The present study examined the effects of luteolin on signaling pathways stimulated by lipopolysaccharide (LPS), including Toll-like receptor-4 (TLR-4), nuclear transcription factor-κB (NF-κB), mitogen-activated protein kinase (MAPK) family and protein kinase B (Akt) pathways in murine microglial BV2 cells. In addition, BV2 microglia and SH-SY5Y neuroblastoma cells were cocultured to observe the indirect neuroprotective effects of luteolin. Luteolin inhibited the LPS-stimulated expression of TLR-4. In addition, luteolin blocked LPS-induced NF-κB, p38, JNK and Akt activation, but had no effect on ERK. When SH-SY5Y cells were cocultured with LPS-stimulated BV2 microglia, pretreatment with luteolin increased neuronal viability and reduced the number of apoptotic cells. These data suggest that luteolin has a beneficial effect on neuroinflammatory events in neurodegenerative diseases via suppression of the NF-κB, MAPK and Akt pathways in activated microglial cells.

α₁ adrenoceptor activation by norepinephrine inhibits LPS-induced cardiomyocyte TNF-α production via modulating ERK1/2 and NF-κB pathway

Cardiomyocyte tumour necrosis factor α (TNF-α) production contributes to myocardial depression during sepsis. This study was designed to observe the effect of norepinephrine (NE) on lipopolysaccharide (LPS)-induced cardiomyocyte TNF-α expression and to further investigate the underlying mechanisms in neonatal rat cardiomyocytes and endotoxaemic mice. In cultured neonatal rat cardiomyocytes, NE inhibited LPS-induced TNF-α production in a dose-dependent manner. α₁- adrenoceptor (AR) antagonist (prazosin), but neither β₁- nor β₂-AR antagonist, abrogated the inhibitory effect of NE on LPS-stimulated TNF-α production. Furthermore, phenylephrine (PE), an α₁-AR agonist, also suppressed LPS-induced TNF-α production. NE inhibited p38 phosphorylation and NF-κB activation, but enhanced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and c-Fos expression in LPS-treated cardiomyocytes, all of which were reversed by prazosin pre-treatment. To determine whether ERK1/2 regulates c-Fos expression, p38 phosphorylation, NF-κB activation and TNF-α production, cardiomyocytes were also treated with U0126, a selective ERK1/2 inhibitor. Treatment with U0126 reversed the effects of NE on c-Fos expression, p38 mitogen-activated protein kinase (MAPK) phosphorylation and TNF-α production, but not NF-κB activation in LPS-challenged cardiomyocytes. In addition, pre-treatment with SB202190, a p38 MAPK inhibitor, partly inhibited LPS-induced TNF-α production in cardiomyocytes. In endotoxaemic mice, PE promoted myocardial ERK1/2 phosphorylation and c-Fos expression, inhibited p38 phosphorylation and IκBα degradation, reduced myocardial TNF-α production and prevented LPS-provoked cardiac dysfunction. Altogether, these findings indicate that activation of α₁-AR by NE suppresses LPS-induced cardiomyocyte TNF-α expression and improves cardiac dysfunction during endotoxaemia via promoting myocardial ERK phosphorylation and suppressing NF-κB activation.

[Effects of antagonist and agonist of nicotinic acetylcholine receptors on injury of rat neurons induced by amyloid β-protein]

OBJECTIVE

To explore the chronic effects of nicotinic antagonist and agonist on rat neurons injury induced by β-amyloid protein.

METHODS

The rat model of neuron injury was established by the exposure to Aβ25-35 and the intervention agent was either methyllycaconitine (MLA) or nicotine (Nic). And the experimental groups were control (distilled water), Aβ25-35, MLA (MLA and Aβ25-35) and Nic (Nic and Aβ25-35). Cellular viability was detected by methyl thiazolyl tetrazolium (MTT) chromatometry while apoptosis and necrosis were detected by flow cytometer.

RESULTS

Compared with control, cellular viability decreased while the apoptotic and necrotic rates increased in Aβ25-35 group(P = 0.00). The values of cellular viability at (0.75 ± 0.02) and (0.75 ± 0.09) in Aβ25-35 and MLA groups respectively were significantly lower than that of Nic group (0.81 ± 0.02, P = 0.01) at Day 3 and 7. No significant differences existed in cellular viability between Aβ25-35 and MLA groups. At Day 14, the differences of cellular viability were not obvious in all groups. At Day 21, cell viability of MLA group (0.64 ± 0.10) was significantly higher than those of Aβ25-35 (0.57 ± 0.04, P = 0.019) and Nic groups (0.56 ± 0.04, P = 0.008). The apoptotic rate was lower than that of Aβ25-35 group (3.70% ± 0.20% vs 4.70% ± 0.46%, P = 0.008) while the necrotic rate lower than that of Aβ25-35 group (7.73% ± 0.86% vs 16.30% ± 1.05%, P = 0.00) and Nic group (16.03% ± 1.53%, P = 0.00). However, no significant differences existed in cellular viability or apoptotic and necrotic rate between Aβ25-35 and Nic groups.

CONCLUSION

With chronic treatment, the protective effect of α7 nicotinic antagonist methyllycaconitine increases whereas that of nicotinic agonist nicotine decreases.

Yohimbine promotes cardiac NE release and prevents LPS-induced cardiac dysfunction via blockade of presynaptic α2A-adrenergic receptor

Myocardial depression is an important contributor to mortality in sepsis. We have recently demonstrated that α2-adrenoceptor (AR) antagonist, yohimbine (YHB), attenuates lipopolysaccharide (LPS)-induced myocardial depression. However, the mechanisms for this action of YHB are unclear. Here, we demonstrated that YHB decreased nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α) levels in the myocardium and plasma, attenuated cardiac and hepatic dysfunction, but not kidney and lung injuries in endotoxemic mice. Immunohistochemical analysis revealed that cardiac α2A-AR was mostly located in sympathetic nerve presynaptic membrane; YHB decreased cardiac α2A-AR level and promoted cardiac norepinephrine (NE) release in endotoxemic mice. Reserpine that exhausted cardiac NE without markedly decreasing plasma NE level abrogated the inhibitory effects of YHB on cardiac TNF-α and iNOS expression as well as cardiac dysfunction, but not the suppressive effects of YHB on plasma TNF-α and NO elevation in LPS-challenged mice. Furthermore, both reserpine and YHB significantly inhibited LPS-induced myocardial apoptosis. α1-AR, β2-AR, but not β1-AR antagonists reversed the inhibitory effect of YHB on LPS-stimulated myocardial apoptosis. However, β1-AR antagonist attenuated LPS-caused cardiomyocyte apoptosis, partly abolished the protective effect of YHB on the left ventricular ejection fraction in endotoxemic mice. Altogether, these findings indicate that YHB attenuates LPS-induced cardiac dysfunction, at least in part, through blocking presynaptic α2A-AR and thus increasing cardiac NE release. YHB-elevated cardiac NE improves cardiac function via suppressing cardiac iNOS and TNF-α expression, activating β1-AR and inhibiting cardiomyocyte apoptosis through α1- and β2-AR in endotoxemic mice. However, cardiac β1-AR activation promotes LPS-induced cardiomyocyte apoptosis.

Rhynchophylline prevents cardiac dysfunction and improves survival in lipopolysaccharide-challenged mice via suppressing macrophage I-κBα phosphorylation

Myocardial dysfunction is a common complication during sepsis and significantly contributes to the mortality of patients with septic shock. However, none of the available therapeutic strategies proven to be effective in patients with severe sepsis are designed specifically to target myocardial dysfunction. The purpose of the present study is to investigate the effect of rhynchophylline (Rhy) on LPS-induced myocardial dysfunction in mice. We found that pretreatment with Rhy significantly improved cardiac systolic dysfunction, increased stroke volume and cardiac output in mice challenged with LPS. LPS induced cardiac inhibitor-κBα (I-κBα) phosphorylation, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) mRNA expression, and in turn increased cardiac TNF-α and IL-1β protein production, all of which were attenuated by pretreatment with Rhy. Immunohistochemistry revealed that TNF-α was found in infiltrated macrophages (F4/80(+)) and myocardium, and Rhy reduced TNF-α immunostaining in cardiac infiltrated macrophages in LPS-challenged mice. Furthermore, Rhy inhibited LPS-induced I-κBα phosphorylation and TNF-α production in cultured mouse peritoneal macrophages, but not in neonatal mouse cardiomyocytes. Pretreatment with Rhy significantly decreased the mortality of LPS-challenged mice. These results indicate that Rhy reduces cardiac dysfunction and improves survival via suppression of macrophage I-κBα phosphorylation in LPS-challenged mice, and suggest that Rhy may be a potential agent for the treatment of septic cardiac dysfunction.

Chlorogenic acid inhibits LPS-induced microglial activation and improves survival of dopaminergic neurons

Pro-inflammatory factors released by activated microglia may contribute to the progression of neurodegenerative diseases. As a natural phenolic acid, chlorogenic acid (CGA) has been shown to have anti-inflammatory properties. However, it is unclear whether CGA has the ability to mediate microglial activation. The present study investigated the role of CGA in lipopolysaccharide (LPS)-stimulated microglia. Our data demonstrated that CGA significantly suppressed NO production and TNF-α release in LPS-stimulated primary microglia. In addition, CGA decreased LPS-stimulated phosphorylation and degradation of inhibitory kappa B-alpha (IκBα), and prevented translocation of nuclear factor-kappaB (NF-κB). Furthermore, CGA prevented neurotoxicity caused by microglial activation and ultimately improved survival of dopaminergic (DA) neuron. Finally, in vivo data showed that CGA pretreatment attenuated LPS-induced IL-1β and TNF-α release in substantia nigra (SN). Our results suggested that the pretreatment of CGA significantly inhibits the microglial activation, and CGA may be neuroprotective for pro-inflammatory factor-mediated neurodegenerative disorders.

Functional characterization of the p53 binding site in the human PYNOD promoter

Many members of the NOD-like receptor (NLR) family play important roles in pathogen recognition and inflammation. However, human PYNOD, an NLR-like protein consisting of a pyrin domain and a nucleotidebinding and oligomerization domain (NOD), has been reported to inhibit inflammatory signals. Using bioinformatics, we found a completely preserved canonical p53 binding site in the PYNOD core promoter (-228 to -237 bp) both in humans and in chimpanzees. In this study, we investigated the characterization and biologic function of this binding site in vitro. The results show that either deletion of the p53 binding elements within the PYNOD promoter or treatment with p53 inhibitor (PFT-α) could significantly reduce PYNOD promoter activity and PYNOD expression as detected by the enhanced green fluorescent protein (EGFP) reporter system, reverse transcription-polymerase chain reaction, and Western blot respectively. Furthermore, the chromatin immunoprecipitation (ChIP) method confirmed that p53 could bind to the PYNOD promoter. Our findings suggest that the p53 binding site plays a positive role in regulating PYNOD gene expression, which may maintain an efficient balance between defense and self-inflicted injury in respond to pathogen invasion.

Berberine inhibits doxorubicin-triggered cardiomyocyte apoptosis via attenuating mitochondrial dysfunction and increasing Bcl-2 expression

Cardiomyocyte apoptosis is an important event in doxorubicin (DOX)-induced cardiac injury. The aim of the present study was to investigate the protection of berberine (Ber) against DOX- triggered cardiomyocyte apoptosis in neonatal rat cardiomyocytes and rats. In neonatal rat cardiomyocytes, Ber attenuated DOX-induced cellular injury and apoptosis in a dose-dependent manner. However, Ber has no significant effect on viability of MCF-7 breast cancer cells treated with DOX. Ber reduced caspase-3 and caspase-9, but not caspase-8 activity in DOX-treated cardiomyocytes. Furthermore, Ber decreased adenosine monophosphate-activated protein kinase α (AMPKα) and p53 phosphorylation at 2 h, cytosolic cytochrome c and mitochondrial Bax levels and increased Bcl-2 level at 6 h in DOX-stimulated cardiomyocytes. Pretreatment with compound C, an AMPK inhibitor, also suppressed p53 phosphorylation and apoptosis in DOX-treated cardiomyocytes. DOX stimulation for 30 min led to a loss of mitochondrial membrane potential and a rise in the AMP/ATP ratio. Ber markedly reduced DOX-induced mitochondrial membrane potential loss and an increase in the AMP/ATP ratio at 1 h and 2 h post DOX exposure. In in vivo experiments, Ber significantly improved survival, increased stroke volume and attenuated myocardial injury in DOX-challenged rats. TUNEL and Western blot assays showed that Ber not only decreased myocardial apoptosis, caspase-3 activation, AMPKα and p53 phosphorylation, but also increased Bcl-2 expression in myocardium of rats exposed to DOX for 84 h. These findings indicate that Ber attenuates DOX-induced cardiomyocyte apoptosis via protecting mitochondria, inhibiting an increase in the AMP/ATP ratio and AMPKα phosphorylation as well as elevating Bcl-2 expression, which offer a novel mechanism responsible for protection of Ber against DOX-induced cardiomyopathy.

Yohimbine enhances protection of berberine against LPS-induced mouse lethality through multiple mechanisms

Sepsis remains a major cause of mortality in intensive care units, better therapies are urgently needed. Gram-negative bacterial lipopolysaccharide (LPS) is an important trigger of sepsis. We have demonstrated that berberine (Ber) protects against lethality induced by LPS, which is enhanced by yohimbine (Y) pretreatment, and Ber combined with Y also improves survival in septic mice. However, the precise mechanisms by which Y enhances protection of Ber against LPS-induced lethality remain unclear. The present study confirmed that simultaneously administered Y also enhanced protection of Ber against LPS-induced lethality. Ber or/and Y attenuated liver injury, but not renal injury in LPS-challenged mice. Ber or/and Y all inhibited LPS-stimulated IκBα, JNK and ERK phosphorylation, NF-κB activation as well as TNF-α production. Ber also increased IL-10 production in LPS-challenged mice, which was enhanced by Y. Furthermore, Ber or/and Y all suppressed LPS-induced IRF3, TyK2 and STAT1 phosphorylation, as well as IFN-β and IP-10 mRNA expression in spleen of mice at 1 h after LPS challenge. Especially, Y enhanced the inhibitory effect of Ber on LPS-induced IP-10 mRNA expression. In vitro experiments further demonstrated that Y significantly enhanced the inhibitory effect of Ber on TNF-α production in LPS-treated peritoneal macrophages, Ber combined with Y promoted LPS-induced IL-10 production and LPS-stimulated IκBα, JNK, ERK and IRF3 phosphorylation and NF-κB activation were also suppressed by Ber or/and Y pretreatment in peritoneal macrophages. Taken together, these results demonstrate that Y enhances the protection of Ber against LPS-induced lethality in mice via attenuating liver injury, upregulating IL-10 production and suppressing IκBα, JNK, ERK and IRF3 phosphorylation. Ber combined with Y may be an effective immunomodulator agent for the prevention of sepsis.

Berberine protects against lipopolysaccharide-induced intestinal injury in mice via alpha 2 adrenoceptor-independent mechanisms

AIM

To investigate the mechanisms responsible for the protective action of berberine (Ber) against gut damage in endotoxemic mice.

METHODS

Male BALB/c mice were administered intragastrically with distilled water (0.1 mL/10 g), Ber (50 mg/kg) alone, yohimbine (2 mg/kg) alone, or Ber (50 mg/kg) in combination with yohimbine (2 mg/kg) for 3 d. On the third day, lipopolysaccharide (LPS, 18 mg/kg) or normal saline was intraperitoneally injected one hour after the intragastric administration. Following the treatment, intestinal injury in the ileum was histopathologically accessed; enterocyte apoptosis was examined using TUNEL method; Toll-like receptor 4 (TLR4) mRNA expression was measured using RT-PCR assay; inhibitor protein-κBα (I-κBα) phosphorylation and myeloperoxidase content were examined using Western blloting. The macrophage inflammatory protein-2 (MIP-2) production was measured using ELISA assay.

RESULTS

Mice challenged with LPS caused extensive ileum injury, including a significantly increased injury score, decreased intestinal villus height, reduced gut mucosal weight and increased intestinal permeability. Furthermore, LPS significantly induced enterocyte apoptosis, increased TLR4 mRNA expression, I-κBα phosphorylation, MIP-2 production and myeloperoxidase content in the ileum. Pretreatment with Ber significantly alleviated all the alterations in the ileum in the endotoxemic mice. Pretreatment with the α2-adrenoceptor antagonist yohimbine did not block the protective action of Ber against LPS-induced intestinal injury. In addition, treatment with yohimbine alone did not prevent LPS-induced intestinal injury.

CONCLUSION

Pretreatment with Ber provides significant protection against LPS-induced intestinal injury in mice, via reducing enterocyte apoptosis, inhibiting the TLR4-nuclear factor κB-MIP-2 pathway and decreasing neutrophil infiltration that are independent of α2-adrenoceptors.

Luteolin inhibits microglial inflammation and improves neuron survival against inflammation

Microglia activation is one of the causative factors for neuroinflammation, which results in brain damage during neurodegenerative disease. Accumulating evidence has shown that the flavonoid luteolin (Lut) possesses potent anti-inflammatory properties; however, its effect on microglia inhibition is currently unknown. Moreover, it is not clear whether Lut also has indirect neuroprotective effects by reducing inflammatory mediators and suppressing microglia activation. In this study, we examined the effects of Lut on lipopolysaccharide (LPS)-induced proinflammatory mediator production and signaling pathways in murine BV2 microglia. In addition, we cocultured microglia and neurons to observe the indirect neuroprotective effects of Lut. Lut inhibited the LPS-stimulated expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β) as well as the production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)). Moreover, Lut blocked LPS-induced nuclear factor kappa B (NF-κB) activation. Preincubation of microglia with Lut diminished the neurotoxic effects, owing to the direct anti-inflammatory effects of the compound. Taken together, our findings suggest that Lut may have a potential therapeutic application in the treatment of neuroinflammatory disorders.

Pretreatment with berberine and yohimbine protects against LPS-induced myocardial dysfunction via inhibition of cardiac I-[kappa]B[alpha] phosphorylation and apoptosis in mice

Myocardial dysfunction is a common complication in sepsis and significantly contributes to the mortality of patients with septic shock. Our previous study demonstrated that pretreatment with berberine (Ber) protected against the lethality induced by LPS, which was enhanced by yohimbine, an [alpha]2-adrenergic receptor antagonist, and Ber combined with yohimbine also improved survival in mice subjected to cecal ligation and puncture. However, no studies have examined whether Ber and yohimbine reduce LPS-induced myocardial dysfunction. Here, we report that pretreatment with Ber, Ber combined with yohimbine, or yohimbine significantly reduced LPS-induced cardiac dysfunction in mice. LPS-provoked cardiac apoptosis, I-[kappa]B[alpha] phosphorylation, IL-1[beta], TNF-[alpha], and NO production were attenuated by pretreatment with Ber and/or yohimbine, whereas cardiac Toll-like receptor 4 mRNA expression, malondialdehyde content, and superoxide dismutase activity were not affected. These data demonstrate for the first time that pretreatment with Ber and/or yohimbine prevents LPS-induced myocardial dysfunction in mice through inhibiting myocardial apoptosis, cardiac I-[kappa]B[alpha] phosphorylation, and TNF-[alpha], IL-1[beta], and NO production, suggesting that activation of [alpha]2-adrenergic receptor in vivo may be responsible at least in part for LPS-induced cardiac dysfunction, and Ber in combination with yohimbine may be a potential agent for preventing cardiac dysfunction during sepsis.

Effect of siRNAs on HSV-1 plaque formation and relative expression levels of RR mRNA

RNA interference (RNAi) is a process by which introduced small interfering RNA (siRNA) can cause the specific degradation of mRNA with identical sequences. The human herpes simplex virus type 1 (HSV-1) RR is composed of two distinct homodimeric subunits encoded by UL39 and UL40, respectively. In this study, we applied siRNAs targeting the UL39 and UL40 genes of HSV-1. We showed that synthetic siRNA silenced effectively and specifically UL39 and UL40 mRNA expression and inhibited HSV-1 replication. Our work offers new possibilities for RNAi as a genetic tool for inhibition of HSV-1 replication.

Paeoniflorin improves survival in LPS-challenged mice through the suppression of TNF-α and IL-1β release and augmentation of IL-10 production

Lipopolysaccharide (LPS) plays an important role in Gram-negative bacteria-induced sepsis and multiple organ dysfunction syndrome, which are still the leading cause of high mortality in intensive care units. Although paeoniflorin (Pae) has reportedly exhibited anti-inflammatory effect and protection against immunological liver injury in mice, it is not known whether Pae improve survival in endotoxemic mice. The purpose of this study was to determine the effect of Pae on the mortality, multiple organ dysfunction and cytokine production in lipopolysaccharide (LPS)-treated mice. We found that pretreatment with Pae decreased mortality, reduced lung and kidney injury, decreased serum creatinine level and improve systolic function of heart in mice challenged with LPS. Further experiments showed that Pae inhibited LPS-stimulated tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) release and promoted LPS-induced interleukin-10 (IL-10) production. Our results indicate that Pae protects mice against lethal LPS challenge, at least in part, through inhibiting TNF-α and IL-1β production and accelerating IL-10 expression.

Functional characterization of the NF-kappaB binding site in the human NOD2 promoter

Nucleotide-binding and oligomerization domain 2 (NOD2), a member of the NOD protein family, plays an important role in innate immunity. In response to pathogen attack, NOD2 stimulates cytokine and defensin production by activating nuclear factor (NF)-kappaB, a key transcription factor responsible for mediating downstream reactions. However, the mechanism linking NOD2 regulation and NF-kappaB activation is poorly understood. Using bioinformatics, we found a completely preserved canonical NF-kappaB binding site in the NOD2 core promoter (-16 to -25 bp) in both humans and chimpanzees. The functional role of this NF-kappaB binding site was investigated using the enhanced green fluorescent protein (EGFP) reporter system, site-directed mutagenesis, the NF-kappaB activation inhibitor (JSH-23) and the chromatin immunoprecipitation (ChIP) assay. The results show that the NF-kappaB binding site is critical for regulation of the NOD2 gene. Either deletion of the NF-kappaB binding elements within the NOD2 promoter or treatment with an NF-kappaB activation inhibitor could lead to a significant loss of NOD2 promoter activity as detected by reporter gene assay. The canonical NF-kappaB binding site was bound by NF-kappaB as determined by the ChIP method. Based on these results, we suggest a positive feedback regulation between NF-kappaB and NOD2, which may represent an efficient mechanism in response to pathogen invasion.

Effect of Kangshuai Yizhi Formula I on learning and memory dysfunction induced by scopolamine in mice

OBJECTIVE

To evaluate the improvement of Kangshuai Yizhi Formula I ( I, KYF I) on: the learning and memory dysfunction in mice, and on the mechanism of the hippocampal cholinergic system and the nervous system of monoamine which are closely related to learning and memory function.

METHODS

Mice: in the low-, middle-, and high-dose KYF I groups were given low-, middle-, and high-dose KYF, respectively, by gastrogavage for 35 successive days. Animals in the control group and the model group were treated with distilled water. The acute learning and memory dysfunction model was established by injection of scopolamine from day 31, and Morris water maze was used to assess the behavior performance of scopolamine-induced model mice for five days. The activities of acetylcholinesterase (AChE), choline acetyl transferase (ChaT) and the content of monoamine neurotransmitters in hippocampus were measured. The activity of monoamine oxidase (MAO) in hippocampus and serum was also detected.

RESULTS

(1) Compared with the control group, the: mean escape latency was shortened, and the frequency across the platform and the staying time at the platform area on the 5th day were decreased in the model group by Morris water maze test. The activities of AChE and MAO were increased, and the ChaT activity and monoamine neurotransmitter content were decreased as well. (2) The escape latency for 4 days in the low-, middle-, and high-dose KYF I groups was significantly shortened than that in the model group, with the shortest latency in the high-dose KYF I group (P<0.05, P<0.01). The frequency across the platform was significantly increased and the staying time at the platform was significantly prolonged in the middle- and high-dose KYF I groups (P<0.05, P<0.01). (3) As compared with the model group, the activity of ChaT and the content of monoamine neurotransmitters in the hippocampus were significantly increased, and the activities of AchE and MAO were significantly decreased in the hippocampus in the high-dose KYF I group (P<0.01).

CONCLUSIONS

High-dose KYF I can significantly improve the learning and memory dysfunction: induced by scopolamine in mice. Its mechanism may be related to improving the central cholinergic system and regulating the hippocampal monoamine neurotransmitters.

In vitro anti-viral activity of the total alkaloids from Tripterygium hypoglaucum against herpes simplex virus type 1

Herpes simplex virus type 1 (HSV-1) is a commonly occurring human pathogen worldwide. There is an urgent need to discover and develop new alternative agents for the management of HSV-1 infection. Tripterygium hypoglaucum (level) Hutch (Celastraceae) is a traditional Chinese medicine plant with many pharmacological activities such as anti-inflammation, anti-tumor and antifertility. The usual medicinal part is the roots which contain about a 1% yield of alkaloids. A crude total alkaloids extract was prepared from the roots of T. hypoglaucum amd its antiviral activity against HSV-1 in Vero cells was evaluated by cytopathic effect (CPE) assay, plaque reduction assay and by RT-PCR analysis. The alkaloids extract presented low cytotoxicity (CC(50) = 46.6 μg/mL) and potent CPE inhibition activity, the 50% inhibitory concentration (IC(50)) was 6.5 μg/mL, noticeably lower than that of Acyclovir (15.4 μg /mL). Plaque formation was significantly reduced by the alkaloids extract at concentrations of 6.25 μg/mL to 12.5 μg/mL, the plaque reduction ratio reached 55% to 75 which was 35% higher than that of Acyclovir at the same concentration. RT-PCR analysis showed that, the transcription of two important delayed early genes UL30 and UL39, and a late gene US6 of HSV-1 genome all were suppressed by the alkaloids extract, the expression inhibiting efficacy compared to the control was 74.6% (UL30), 70.9% (UL39) and 62.6% (US6) respectively at the working concentration of 12.5 μg/mL. The above results suggest a potent anti-HSV-1 activity of the alkaloids extract in vitro.

Glycine inhibits the LPS-induced increase in cytosolic Ca2+ concentration and TNFalpha production in cardiomyocytes by activating a glycine receptor

AIM

Previous studies have demonstrated that glycine (GLY) markedly reduces lipopolysaccharide (LPS)-induced myocardial injury.However, the mechanism of this effect is still unclear. The present study investigated the effect of GLY on cytosolic calcium concentration([Ca2+]c) and tumor necrosis factor-alpha (TNFalpha) production in cardiomyocytes exposed to LPS, as well as whether the glycine-gated chloride channel is involved in this process.

METHODS

Neonatal rat cardiomyocytes were isolated, and the [Ca2+]c and TNFalpha levels were determined by using Fura-2 and a Quantikine enzyme-linked immunosorbent assay, respectively. The distribution of the GLY receptor and GLY-induced currents in cardiomyocytes were also investigated using immunocytochemistry and the whole-cell patch-clamp technique, respectively.

RESULTS

LPS at concentrations ranging from 10 ng/mL to 100 microg/mL significantly stimulated TNFalpha production. GLY did not inhibit TNFalpha production induced by LPS at concentrations below 10 ng/mL but did significantly decrease TNFalpha release stimulated by 100 microg/mL LPS and prevented an LPS-induced increase in [Ca2+]c, which was reversed by strychnine, a glycine receptor antagonist. GLY did not block the isoproterenol-induced increase in [Ca2+]c, but did prevent the potassium chloride-induced increase in [Ca2+]c in cardiomyocytes.Strychnine reversed the inhibition of the KCl-stimulated elevation in [Ca2+]c by GLY. In chloride-free buffer, GLY had no effect on the dipotassium hydrogen phosphate-induced increase in [Ca2+]c. Furthermore, GLY receptor alpha1 and beta subunit-immunoreactive spots were observed in cardiomyocytes, and GLY-evoked currents were blocked by strychnine.

CONCLUSION

Cardiomyocytes possess the glycine-gated chloride channel, through which GLY prevents the increase in [Ca2+]c and inhibits the TNFalpha production induced by LPS at high doses in neonatal rat cardiomyocytes.

Curcumin improves spatial memory impairment induced by human immunodeficiency virus type 1 glycoprotein 120 V3 loop peptide in rats

AIMS

Human immunodeficiency virus-1 (HIV-1)-associated dementia (HAD) is a significant consequence of HIV infection. Although highly active antiretroviral therapy (HAART) has dramatically decreased HIV-1 load in acquired immune deficiency syndrome (AIDS) patients, HAART does not completely protect against the development of HAD, therefore novel strategies for the prevention and treatment are urgently needed. In this study, we chose curcumin which has a neuroprotective role and tested the effect against neuron damage induced by HIV-1gp120 V3 loop peptide.

MAIN METHODS

Rats were given 150 ng gp120 V3 peptide by intracerebroventricular (ICV) infusion for 3 days to establish the cognitive dysfunction model. After recovery from the surgery, the rats in treatment groups were given curcumin by intragastric infusion for 2 weeks. Subsequently, we used the Morris water maze test, long-term potentiation (LTP) recording, biochemical measurement of oxidative damage, Nissl staining, and BDNF immunostaining to evaluate the neuropathological changes and the effect of curcumin on rats.

KEY FINDINGS

Our results documented that the gp120 V3 peptide induced impairment of spatial learning and memory, inhibited LTP in the CA1 region of the hippocampus, and mediated oxidative stress and neuronal injury. These impairments were ameliorated by intragastric infusion of curcumin.

SIGNIFICANCE

These results suggested that dietary supplementation of curcumin may be a potential therapeutic strategy for the treatment and/or prevention of HAD.

[Therapeutic effect of intravenous high-dose vitamin C on implanted hepatoma in rats]

OBJECTIVE

To study the therapeutic effect of intravenous high-dose vitamin C on implanted hepatoma in rats.

METHODS

The rats bearing implanted Walker-256 hepatoma were treated with high-dose vitamin C at 2.83 and 5.65 g/kg intravenously, and the general condition, liver functions (A/G, ALT, AST, GGT), tumor volume, and tumor growth of the rats were evaluated.

RESULTS

The A/G of the rats treated with 2.83 g/kg vitamin C was significantly higher, but the ALT and GCT were significantly lower than those of the model rats (P<0.05 or 0.01). The ALT level in rats with 5.65 g/kg vitamin C treatment was significantly lower than that of the model rats (P<0.05). The tumor necrosis rate was significantly higher in rats with 2.83 g/kg vitamin C treatment than in the model rats (P<0.05).

CONCLUSION

Intravenous administration of 2.83 g/kg vitamin C can promote the necrosis and apoptosis of hepatoma Walker256 cells in rats and protect the liver function of the tumor-bearing rats.

[Relationship between flash visual evoked potential and severity and prognosis in critically ill patients]

OBJECTIVE

To explore the relationship between flash visual evoked potential (fVEP) and severity and prognosis in critically ill patients in intensive care unit (ICU).

METHODS

Sixty-nine critically ill patients were divided into two groups according to survival (35 cases) or death (34 cases) in 28 days. fVEP, Glasgow coma scale (GCS) score, acute physiology and chronic health evaluation II (APACHE II) score and sepsis-related organ failure assessment (SOFA) score of survivors were compared with those of nonsurvivors. Also, according to primary disease, the patients were divided into a group of patients with primary intracranial disease and patients with mental disturbance but without primary intracranial lesion. Above mentioned indexes were compared, and clinical outcome was predicted with their correlation with fVEP in each patient.

RESULTS

The latent period of fVEP peak appeared later in nonsurvivors than those in survivors [(228.6+/-41.7) ms vs. (190.5+/-49.2) ms, P<0.01]. APACHE II score (25.9+/-6.4 vs. 22.5+/-6.7) and SOFA score (6.7+/-2.0 vs. 5.4+/-2.5) were higher in nonsurvivors than those in survivors (both P<0.05 ), while the changes in GCS score was in contrary (6.3+/-2.4 vs. 7.0+/-3.0, P<0.05). fVEP peak latency showed a negative correlation with GCS score (r=-0.332, P<0.01). The death rate of the group of patients with primary intracranial lesion was similar to that of the total. fVEP peak latency of the group with no primary intracranial lesion but with mental impairment in nonsurvivors was significantly longer than that of survivors [(226.0+/-46.7) ms vs. (168.8+/-54.1) ms, P<0.05], fVEP peak latency was positively correlated with SOFA score (r=0.526, P<0.05). Area under receiver operator characteristic (ROC) curve of fVEP peak latency was 0.800+/-0.104 (P<0.05) for predicting outcome of patients, while that of SOFA score was 0.650+/-0.131 (P>0.05). The former could be used for predicting death.

CONCLUSION

fVEP reflects the prognosis and severity of critically ill patients in ICU. Especially, it maybe used as a tool for predicting death and multiple organ dysfunction syndrome (MODS) in the patients with no primary intracranial lesion but with mental impairment.

[Influence of different treatment patterns on cost-effectiveness in treatment of acute myocardial infarction]

OBJECTIVE

To investigate the influences of different treatment patterns on the cost-effectiveness in treating acute myocardial infarction (AMI).

METHODS

Data about referral of AMI patients who called for help because of chest pain to the nearby hospitals from October 2003 to December 2005 were collected from the Guangzhou 120 Call Center. All these patients were followed up 6 months after discharge to survey the cost during hospitalization, major treatment, prognosis (death, re-infarction, stroke etc. ), and secondary prevention for coronary heart disease. We used SF-36 scale was used to quantify the health status.

RESULTS

101 AMI patients referred to grade 2 A hospitals (Group A) and 137 patients referred to grade 3 A hospitals (Group B) were successfully followed up. The cost during hospitalization of Group B was (33965 +/- 963) yuan RMB, significantly higher than that of Group A (18943 +/- 893) yuan, P = 0.021). 11 patients of Group B died, and 5 patients suffered from stroke with the mortality and stroke rate both significantly lower than those of Group A (18/101 and 12/101, P = 0.022, P = 0.015). There was no significant difference in the re-infarction rate between the 2 groups. The scores in physical function, general health status, vitality, social function, role-emotional, mental health of Group B were all significantly higher than those of Group A (all P < 0.05) , however, there were not significant differences in body pain and role-physical between these 2 groups. The smoking cessation rate, specialist outpatient department follow-up rate, statins use rate of Group B were significantly higher than those of Group A (P = 0.017, P = 0.016, P = 0.038).

CONCLUSION

The 120-grade 3 A hospital CCU pattern is more cost-effective in treatment of AMI.