Protein Expression Of p-JNK Research Articles

Apelin-12 exerts neuroprotective effect against ischemia-reperfusion injury by inhibiting JNK and P38MAPK signaling pathway in mouse.

Cerebral ischemia is a common neurological disease, and its pathological process remains elusive. This study focused on the protective mechanism of Apelin-12 protein on the nervous system of mice during cerebral ischemia-reperfusion injury through JNK and P38MAPK signaling pathway. The mouse model with an ischemia-reperfusion injury in middle cerebral artery was prepared by the modified thread-occlusion method and divided into 4 groups randomly. Before implantation of the mice, we assessed the neurological function and evaluated the cerebral edema by the wet-dry weight method. Lactate dehydrogenase (LDH) kit was used to assess the degree of cell injury. Malondialdehyde (MDA) kit was used to measure the level of neuron MDA. Immunohistochemistry was performed to evaluate the neuronal cell in the ischemic brain. Protein expressions of JNK and P38MAPK and apoptosis-related molecules, including Bax, Bcl-2, caspase-3, and cleaved caspase-3, were measured by Western blot assay. After focal cerebral ischemia-reperfusion, a significant decrease in neurobehavioral score, brain edema and neuron injury in mice occurred. Apelin-12 significantly improved the neurobehavioral score of the mice with ischemia-reperfusion injury, alleviated brain edema and the damage to neurons. In addition, Apelin-12 inhibited the morphological changes and apoptosis of neuronal cells in the ischemic penumbra of mice. Apelin-12 could downregulate the expression of Bax and caspase-3, inhibit the activity of caspase-3 and upregulate the expression of Bcl-2, an anti-apoptotic protein. A significant reduction in the protein expression of p-JNK and p-p38 was observed in the Apelin-12 group compared with that in the I/R or Vehicle group (p<0.05). When an ischemia-reperfusion injury occurred, Apelin-12 can inhibit the JNK and P38MAPK signaling pathway of the apoptosis-related MAPKs family, thus offering protection to neurons.

CD137-CD137L signaling influences the autophagy via JNK pathway in mouse vascular smooth muscle cells

Objective: To investigate whether CD137-CD137L signaling can affect the autophagy of mouse vascular smooth muscle cells(VSMCs) through JNK signal pathway. Methods: Primary culture of C57BL/6J mouse thoracic aorta VSMCs was performed by tissue block adherence method. VSMCs between the third to fifth passages were isolated and cultured. VSMCs were divided into 4 groups: control group, CD137 agonist group, JNK inhibition group, and DMSO group. VSMCs in CD137 agonist group were treated with recombinant protein of CD137L (10 μg/ml), VSMCs in JNK inhibition group were treated with JNK inhibitor SP600125 (10 μmol/L) for 30 minutes followed by recombinant protein of CD137L (10 μg/ml) and DMSO group was treated with the same amount of DMSO in JNK inhibition group for 30 minutes, then added recombinant protein of CD137L (10 μg/ml). Western blot was used to detect the protein expression of p-JNK, LCⅡ and p62 in each group. Fluorescence microscopy was used to track the changes of autophagy in cells which was infected with adenovirus expressing tandem mRFP-GFP-LC3. Transmission electron microscope (TEM) was used to observe intracellular autophagosomes and autolysosomes. Results: (1) Compared with the control group, stimulating CD137-CD137L axis by recombinant protein of CD137L significantly upregulated the expression of p-JNK, LCⅡ and p62 (1.15±0.19 vs. 0.72±0.21, P<0.05;1.03±0.13 vs. 0.59±0.15, P<0.05, and 1.10±0.19 vs. 0.76±0.15, P<0.05). These effects could be reduced by JNK inhibitor (0.61±0.21 vs. 1.15±0.19, P<0.05;0.74±0.11 vs. 1.03±0.13, P<0.05, and 0.21±0.12 vs. 1.10±0.19, P<0.05). The expression of these proteins in DMSO group remained unchanged compared with CD137 agonist group (P>0.05). (2) Changes of autophagy in cells of various group: the number of total fluorescent spots and yellow fluorescent spots in CD137 agonist group was significantly increased compared to control group (total fluorescent spots:(93.00±14.11)/cell vs. (52.33±9.61)/cell, P<0.05, and (64.33±6.81)/cell vs. (25.67±3.51)/cell, P<0.05), moreover, the number of yellow fluorescent spots was higher than the red fluorescent spots fluorescent spots in CD137 agonist group. Compared with CD137 agonist group, pretreatment with JNK inhibitor significantly reduced the number of total fluorescent spots and yellow fluorescent spots ((53.00±3.17)/cell vs. (93.00±14.11)/cell, P<0.05,and (15.33±4.51)/cell vs. (64.33±6.81)/cell, P<0.05). The red fluorescent spots were higher than the yellow fluorescent spots in JNK inhibition group. The number of total fluorescent spots and yellow fluorescent spots in CD137 agonist group was not affected by pretreatment with DMSO (P>0.05). (3) The number of intracellular autophagosomes and autolysosomes was significantly higher in CD137 agonist group than in control group((17.67±6.03)/cell vs. (5.67±2.52)/cell, P<0.05), and the number of autophagosomes was higher than that of autolysosomes in CD137 agonist group((14.00±4.00)/cell vs. (3.67±2.08)/cell, P<0.05). The number of intracellular autophagosomes and autolysosomes was significantly lower in JNK inhibition group compared to CD137 agonist group((5.67±4.04)/cell vs. (17.67±6.03)/cell, P<0.05) and the number of autophagosomes was lower than that of autolysosomes in JNK inhibition group((1.33±1.53)/cell vs. (4.33±2.52)/cell, P<0.05). The number of intracellular autophagosomes and autolysosomes was similar between DMSO group and CD137 agonist group (P>0.05). Conclusion: CD137-CD137L signal may influence autophagy of mouse VSMCs via JNK pathway.

F235. DIFFERENTIAL EFFECTS OF ANTIPSYCHOTICS ON NEUROINFLAMMATION AND ENERGY SENSING IN A HYPOTHALAMIC CELL LINE

BackgroundAntipsychotics (AP)s are the cornerstone of treatment for schizophrenia but cause serious metabolic side-effects. The hypothalamus is the primary brain region responsible for whole body energy regulation and disruptions in energy sensing (e.g. insulin signaling) and inflammation in this brain region have been implicated in the development of peripheral insulin resistance and obesity. Thus, it is possible that hypothalamic inflammation and disturbed energy sensing could be involved in AP-induced metabolic disturbances. Data in relation to AP-associated changes in inflammatory markers in schizophrenia has been inconsistent, owing in part to confounds of illness-related factors (e.g. diet, smoking) and secondary effects of weight gain. To our knowledge, direct effects of APs on hypothalamic cells in relation to insulin signaling and inflammation have not been examined.MethodsTo examine direct, molecular effects of APs in the hypothalamus, an immortalized rat hypothalamic cell line, rHypoE-19, was treated with olanzapine (dose range between 0.25–100 uM), clozapine (2.5–100 uM) or aripiprazole (5–20 uM). Western blotting was used to detect changes in the energy sensing protein AMPK, components of the insulin signaling pathway (AKT, GSK3B), and components of the mitogen activated-protein kinase (MAPK) pathway (ERK1/2, JNK, p38), the latter which are linked to inflammation. Quantitative real-time PCR was performed to determine changes in the mRNA expression of interleukin (IL)-6, IL-10 and brain derived neurotrophic factor (BDNF).ResultsBoth olanzapine (100 uM) and clozapine (100 uM) significantly increased pERK1/2 and pJNK protein expression, while aripiprazole (20 uM) only increased pJNK. Clozapine (100 uM) and aripiprazole (5 and 20 uM) significantly increased AMPK phosphorylation and inhibited insulin-induced phosphorylation of AKT. Olanzapine (100 uM) treatment caused a significant increase in IL-6 while aripiprazole (20 uM) significantly decreased IL-10. Olanzapine (100 uM) and aripiprazole (20 uM) increased BDNF expression.DiscussionAll the APs studied upregulated pJNK, along with olanzapine-associated increases in IL-6, and aripiprazole-associated decreases in IL-10, together suggesting AP-mediated upregulation of pro-inflammatory pathways in rHypoE-19 neurons. Aripiprazole and clozapine (but not olanzapine) inhibited insulin-stimulated AKT, suggesting impaired hypothalamic insulin action by some, but not all, APs. Clozapine additionally increased AMPK phosphorylation (activation), an orexigenic energy sensor, which would also be expected to disrupt energy homeostasis. Conversely, olanzapine and aripiprazole increased BDNF, a factor linked to the underlying etiology of schizophrenia, suggesting BDNF upregulation may be a mechanism of therapeutic action. Taken together, our findings suggest differential and pleotropic effects of APs on neuroinflammation and energy sensing in the hypothalamus, which do not necessarily align consistently with known metabolic liability of these agents (i.e. clozapine = olanzapine > aripiprazole). Our data warrants further exploration into the mechanism of these effects, including replication of these effects in an in vivo model.

Aβ1-42 regulates astrocytes through JNK/AP-1 pathway.

In Alzheimer's disease (AD), astrocytes are generally found in the surrounding of senile plaques participating in the production of phagocytosis and the removal of toxic compounds such as Aβ. This study aimed at investigating the effect of Aβ1-42 on astrocytes. Cellular viability of primary cultured astrocytes was analyzed using CCK-8 assay. Quantitative Real-time PCR was used to assess the mRNA expression of JNK and AP-1. The proteins of JNK/AP-1 pathway were investigated using Western blot. Our findings showed that Aβ1-42 inhibited cell viability and promoted apoptosis in astrocytes in primary culture. Additionally, Aβ1-42 increased the mRNA expression level of AP-1, but had no effect on the expression of JNK. Furthermore, Aβ1-42 increased the protein expression of p-JNK, p-c-jun and Fra-1 and the ratio of p-c-jun/c-jun and p-JNK/JNK. We showed that Aβ1-42 promoted cell apoptosis in astrocytes in primary culture. Furthermore, Aβ1-42 activated JNK/AP-1 pathway through promoting the phosphorylation of JNK, c-jun and Fra-1 expression, then inducing cell apoptosis.

The effects of transient receptor potential channel (TRPC) on airway smooth muscle cell isolated from asthma model mice.

This study aimed to validate whether transient receptor potential channel1 (TRPC1) and TRPC3 participate in the regulation the proliferation of airway smooth muscle cells (ASMCs) through modulating calcium ion (Ca2+ ) influx in vitro. Chronic model of murine asthma was induced and ASMCs isolated from asthmatic mice were used in this whole study. TRPC1 and TRPC3 were upregulated in asthmatic mouse ASMCs and selected for further investigation. Ca2+ concentration and the cell viability of asthmatic mouse ASMCs were significantly higher than that from non- asthma mice, however, TRPC channels blocker SKF96365 alleviated these effects. Furthermore, TRPC1 or TRPC3 overexpression markedly increased Ca2+ concentration and significantly induced the viability of ASMCs; whereas TRPC1 or TRPC3 knockdown exerted the completely conversed effects. Moreover, knockdown of TRPC1 and TRPC3 also exerted different effects on the protein expression of growth-related proteins p-p38, p-JNK, cleaved caspase-3 and Bcl-2, as well as on cell cycle. Finally, we found Ca2+ chelator EGTA or BAPTA-AM significantly diminished the effects of si-TRPC1 and si-TRPC3 on the cell viability, cell cycle, and the protein expression of p-p38, p-JNK, cleaved caspase-3, and Bcl-2 in asthmatic mouse ASMCs. Our findings demonstrated that the effects of TRPC1 and TRPC3 on the cell viability and cell cycle of ASMCs were, at least partially, through regulating Ca2+ influx.

Protective role and mechanism of snakegourd peel against myocardial infarction in rats

BackgroundInjection of snakegourd peel (SP), an herb used in traditional Chinese medicine, is used to treat coronary artery disease and stable angina in China. However, its therapeutic role and mechanism of action for the treatment of myocardial infarction (MI) is not fully understood. PurposeThe present study was designed to investigate the effect of SP on MI-induced cardiac injury and elucidate its underlying molecular mechanisms. MethodsTo create an in vivo model of MI, we ligated the left coronary artery of Wistar rats. For our in vitro model of MI, we treated primary neonatal rat ventricular myocytes with hypoxia. Myocardial infarct size was measured by triphenyltetrazolium chloride (TTC) staining. Intracellular calcium concentration (Ca2+) was measured by confocal microscopy, and cardiomyocyte apoptosis was assessed by TUNEL assay. Western blot was applied to determine protein levels. ResultsThree days post-MI, SP significantly improved MI-induced impairment of cardiac function, as indicated by increased left ventricular systolic pressure (LVSP), maximum rate of left ventricular pressure rise and fall (± dp/dt max), and decreased left ventricular end-diastolic pressure (LVEDP). In addition, SP treatment markedly reduced the infarct size and serum lactate dehydrogenase (LDH) activity; inhibited cardiomyocyte apoptosis and Caspase-3 activation both in vivo and in vitro; and decreased intracellular calcium overload, Cav1.2, phosphorylated JNK (p-JNK), and p38 MAPK (p-p38 MAPK) levels in ischemic myocardium. ConclusionSP alleviated cardiac ischemic injury and inhibited cardiomyocyte apoptosis by attenuating intracellular calcium overload, suppressing Caspase-3 activation, and downregulating protein expression of p-JNK and p-p38MAPK. These results suggest that SP may serve as a potential novel therapeutic drug for MI.

Inhibition of plasma kallikrein–kinin system to alleviate renal injury and arthritis symptoms in rats with adjuvant-induced arthritis

Background: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. Impairment of kidney functions in RA was observed. However, the mechanism of kidney injury of RA has not been clear. Plasma kallikrein–kinin system (KKS) was involved in inflammatory processes in kidney disease.Aim: This study aimed to explore the role of plasma KKS in immune reactions and kidney injury of RA.Results: The paw of AA rats appeared to be swelling and redness, the arthritis index was significantly increased on the 18, 21 and 24 d after injection and secondary inflammation in multi-sites was observed. Kidney dysfunction accompanied with inflammatory cell infiltration, tubular epithelial cell mitochondrial swelling and vacuolar degeneration, renal glomerular foot process fusions and glomerular basement membrane thickening were observed in AA rats. The expressions of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (Kim-1) in kidney of AA rats were increased. In addition, expressions of BK, PK, B1R and B2R in the renal tissue of AA rats were up-regulated. Pro-inflammatory cytokines IL-2, IFN-γ and TNF-α were increased and anti-inflammatory cytokines IL-4 and IL-10 were low in kidney. Plasma kallikrein (PK) inhibitor PKSI-527 attenuated arthritis signs and renal damage, and inhibited BK, PK, B1R and B2R expressions. The protein expressions of P38, p-P38 and p-JNK and IFN-γ and TNF-α were inhibited by PKSI-527.Conclusions: These findings demonstrate that plasma KKS activation contributed to the renal injury of AA rats through MAPK signaling pathway. Plasma KKS might be a potential target for RA therapy.

Review Hepatoprotektor Rosela (Hibiscus sabdariffa): Aktivitas, Mekanisme Aksi dan Toksisitas

Liver cirrhosis has become the international health problem that causes significant mortality. Handling using herbs from various countries has been done, one of them by consuming roselle (Hibiscus sabdariffa) calyx extract. H. sabdariffa contains anthocyanins, flavonoids, tannins, and ascorbic acid that function as hepatoprotector. H. sabdariffacalyx extract may inhibit the increasing of various clinical parameters, such as ALT, AST, ALP, and LDH in various inducer types, ie acetaminophen, CCl4, CdCl2, DNPH, and TAA. The mechanism of action of H. sabdariffacalyx extract are as an antioxidant, inhibition of cytochrome enzyme, induction of phase II metabolism enzymes, increase cell viability percentage, increase CAT, GSH and decrease protein expression of pJNK, tBid and Bax. However, the consumption of H. sabdariffacalyx extract may also cause acute, subchronic, and chronic toxicity depending on the given dose.

MiRNA-21 Expression in the Serum of Elderly Patients with Acute Myocardial Infarction.

BackgroundThe aims of this study were to examine the expression of miRNA-21 in the serum of elderly patients (>65 years) with acute myocardial infarction (AMI) and to investigate the potential role of serum miRNA-21 as a marker of early cardiac myocyte damage.Material/MethodsThirty-eight elderly patients with recent AMI, 27 elderly patients with unstable angina pectoris, and 25 healthy elderly individuals were included in the study. Serum miRNA-21 expression was determined following total RNA extraction and reverse-transcribed into cDNA, followed by reverse transcription-polymerase chain reaction (RT-PCR). Serum creatine kinase MB isoenzyme (CK-MB) and cardiac troponin I (cTnI) levels were analyzed by electrochemiluminescence. Apoptosis of human cardiac myocytes (HCM) was analyzed using fluorescence-activated cell sorting (FACS), and protein expression of caspase-3 was detected using Western blot.ResultsExpression levels of miRNA-21 in the serum of elderly patients with AMI were positively correlated with serum levels of CK-MB (r=0.3683, P=0.0229) and cTnI (r=0.5128, P=0.009). Following tumor necrosis factor (TNF)-α induction, the apoptosis rates of HCM transfected with the miRNA-21 mimic short hairpin RNA (shRNA) were downregulated by 39.1% compared with control HCM cells, and protein expression of c-Jun N-terminal kinases (JNK) and p38 were unchanged (P>0.05); protein expression of p-JNK, p-p38 and caspase-3 were downregulated by 37.1%, 35.8%, and 36.0%, respectively.ConclusionsExpression of miRNA-21 was upregulated in the serum of elderly patients with AMI, which inhibited TNF-α induced apoptosis in HCM by activating the JNK/p38/caspase-3 signaling pathway.

JNK inhibitor alleviates apoptosis of fetal neural stem cells induced by emulsified isoflurane.

Isoflurane can provide both neuroprotection and neurotoxicity in various culture models and in rodent developing brains. Emulsified Isoflurane (EI) is an emulsion formulation of isoflurane, while its underlying molecular mechanism of developemental nerve toxicity largely remains unclear. We hypothesized that EI induced fetal neural stem cells (FNSCs) apoptosis, endoplasmic reticulum (ER) stress and c-Jun N-terminal kinase (JNK) activation.FNSCs were isolated from the cortex of SD rats during 14 days of gestation. The cell viability, cell apoptotic rates and the expression of apoptosis-related protein Caspase3, inositol requiring enzyme 1 (IRE1), poly (adenosine diphosphate-ribose) polymerase (PARP), Bax, Bcl-2, JNK, p-JNK and XBP1 were determined. Specific inhibition was performed by siRNA-targeting of JNK in FNSCs. EI could increase the p-JNK, JNK and caspase3 protein expression, the JNK pathway was activated by EI, and EI-induced apoptosis was blocked by inhibiting JNK pathway with SP600125 or JNK-small interfering RNA (siRNA), EI enhanced the level of IRE1, PARP, Bax/Bcl-2 and XBP1, which led FNSCs to apoptosis and ER stress. Meanwhile, dilatation of the ER lumens in FNSCs treated by EI for 24 h was significant. Green fluorescent protein (GFP) positive cell ratios were significantly decreased by FNSCs transfecting with JNK gene silencing. JNK was efficiently silenced in siRNA-JNK1 group.The results provided in-vitro evidence which supports that the underlying mechanisms of EI-induced apoptosis are the induction of ER stress and sequent JNK activation. Together, these data suggest that JNK inhibiting might be applied for improving therapeutic outcomes in anesthestics-induced neurotoxicity.Highlights:1. Prolonged treatment with high-dose EI decreased the survival level of FNSCs by inducing apoptosis and inhibiting proliferation via the JNK signaling pathway.2. EI induced ER stress and sequent JNK activation.3. JNK inhibiting might be applied for improving therapeutic outcomes in anesthestics-induced neurotoxicity

Fusaric Acid immunotoxicity and MAPK activation in normal peripheral blood mononuclear cells and Thp-1 cells

Fusaric acid (FA), a food-borne mycotoxin, is a potent divalent metal chelator. The human immune system is complex and susceptible to environmental insult however, the immunotoxity of FA remains unknown. We investigated the immunotoxicity of FA on human peripheral blood mononuclear cells (PBMCs) and Thp-1 cells. FA was cytotoxic to PBMCs (IC50-240.8 μg/ml) and Thp-1 (IC50-107.7 μg/ml) cells at 24 h. FA induced early apoptosis but significantly decreased caspase activity in PBMCs, a characteristic of paraptosis. In Thp-1 cells, FA induced apoptosis and increased caspase −9 and −3/7 activities. In PBMCs, FA maintained mitochondrial membrane potential and decreased protein expression of Bax whilst increasing expression of p-Bcl-2; FA induced oxidative stress and depleted ATP levels in both cell types. In Thp-1 cells, FA increased mitochondrial membrane depolarization and decreased p-Bcl-2 expression. In PBMCs, FA significantly up-regulated the MAPK protein expression of p-ERK and p-JNK but down-regulated p-p38 expression. In Thp-1 cells, FA up-regulated MAPK protein expression of p-ERK whilst p-JNK and p-p38 expression were down-regulated. In conclusion FA induced programmed cell death and altered MAPK signaling in healthy PBMCs and Thp-1 cells strongly suggesting a possible mechanism of FA induced immunotoxicity in vitro.

Effects of MAPKs inhibitors on GSH metabolic enzymes in rat hepatocytes

To investigate the effects of mitogen-activated protein kinases (MAPKs) inhibitors on glutathione (GSH) metabolism, and to explore the pathway related to GSH metabolism. BRL rat hepatocytes were treated by c-Jun NH2-terminal kinase (JNK),p38, and extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitors:SP600125, SB203580 and PD98659, respectively, for 24 h. MTT method was used to measure hepatocytes viability. The content of GSH was determined by high performance liquid chromatography. The protein expressions of JNK and phosphorylated JNK (p-JNK) was tested by Luminex method. Activities of GSH metabolic enzymes were detected by commercial kits. Hepatocytes vitality was inhibited when the concentrations of SP600125, SB203580 and PD98659 were higher than 10 μmol/L, 20 μmol/L, and 40 μmol/L, respectively; SP600125 decreased the content of GSH in hepatocytes, while SB203580 and PD98659 had no effect. SP600125 reduced p-JNK protein expression, and enhanced GSH-Px activity significantly. JNK MAPK pathway takes part in the GSH metabolism in hepatocytes.

Effect of mitogen-activated protein kinase signaling pathway on apoptosis induced by chloroacetic acid in human normal bronchial epithelial 16HBE cells

Objective: The aim of this study was to investigate the effect of mitogen-activated protein kinase (MAPK) signaling pathway on apoptosis induced by chloroacetic acid in human normal bronchial epithelial 16HBE cells. Methods: 16HBE cells were exposed to 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 mmol/L chloroacetic acid for 24 h in vitro. The cytotoxicity induced by chloroacetic acid was assessed by CCK-8 and LDH assays. Cell apoptosis was detected by Annexin V-FITC and PI staining. The protein expression levels of phosphorylation of p38, ERK1/2 and JNK were determined by western blotting. 16HBE cells were pretreated with MAPK signaling pathway specific inhibitors including SB203580, U0126 and SP600125 for 1 h, and these cells were subsequently treated with 2.5 mmol/L chloroacetic acid for 24 h. The expressions of p-p38, p-ERK1/2 and p-JNK as well as the changes of cell viability and apoptosis were measured after pretreated with inhibitors for 1 h. Results: The cell viability by CCK-8 and LDH methods gradually reduced in a dose-dependent manner when chloroacetic acid concentrations elevated (P<0.05) , and their correlation coefficients were -0.902 and -0.825, respectively. The detection efficiency of CCK-8 assay significantly increased compared with LDH assay (P<0.05) . The cell apoptosis rates, which were (17.2±4.0) %, (24.6± 4.2) %, (39.3 ± 5.7) % in 1.5, 2.0, 2.5 mmol/L chloroacetic acid-treated groups, were higher than that of the control group[ (5.6 ± 3.0) %] (P<0.05) . There was a time-or dose-dependent change in the protein expressions of p-p38, p-ERK1/2 and p-JNK. Compared with the control, the levels of p-p38 had 2.1 and 2.6-fold increases in 16 and 24 h treated groups (P<0.01) , while the levels of p-ERK1/2 distinctly decreased by 37% and 52% (P<0.01) . In comparison with the control group, the expressions of p-p38 had 1.9 and 2.6-fold increases in 1.5 and 2.5 mmol/L treatment groups (P<0.01) , whereas the expressions of p-ERK1/2 significantly decreased by 40% and 50% (P<0.01) . No significant change was observed in p-JNK protein expression between the chloroacetic acid-treated and control groups. In comparison with the vehicle control and the exposed group, p-p38, p-ERK1/2, p-JNK protein expressions significantly declined in the inhibitor controls and inhibitor groups. Compared with the controls, the cell survival rates had significant reductions of 28%, 18%, 36% and 26% respectively in chloroacetic acid treated group, SB203580 group, U0126 group and SP600125 group, and the apoptosis rates in the abovementioned groups were 7, 4, 8 and 7 times. Compared with chloroacetic acid-treated group, the cell viability increased by 14% in SB203580 group and decreased by 11% in U0126 group, and the cell apoptosis rates decreased by 36% in SB203580 group and increased by 18% in U0126 group (P<0.05) . But no significant changes were observed in cell viability and apoptosis between SP600125 and chloroacetic acid-treated group. Conclusion: Chloroacetic acid might activate p38 MAPK signaling pathway and inhibit ERK1/2 MAPK signaling pathway. The signaling pathways of p38 and ERK1/2 MAPK are involved in 16HBE cell apoptosis induced by chloroacetic acid, but JNK is not involved in chloroacetic acid-induced 16HBE cell apoptosis.

Effects of vitamin D and resveratrol on metabolic associated markers in liver and adipose tissue from SAMP8 mice

SAMP8 mice exhibit multiple metabolic characteristics associated with age, and it is a suitable candidate for researching aging associated metabolic dysfunction. ObjectivesWe aimed to 1) explore how key metabolic markers will be altered in both liver and adipose tissue with aging in SAMP8 mice; and 2) how the combination of vitamin D (VD) with resveratrol (RSV) will affect aging associated metabolic impairment in liver and adipose tissue from SAMP8 mice. MethodsSAMP8 mice and their control SAMR1 mice were divided into 5 groups, i.e. SAMR1, SAMP8, SAMP8 mice supplemented with VD, RSV and VD combined with RSV group, respectively. At the end of the intervention, glucose and insulin tolerance, p-AMP-activated protein kinase (AMPK) and amyloid precursor protein (APP), and endoplasmic reticulum (ER) stress markers in liver and adipose tissue, adiponectin secretion, p-NF-κBp65 and TNF-α protein expression in adipose tissue were determined. ResultsCompared to SAMR1 control, SAMP8 mice demonstrate impaired glucose tolerance and reduction in circulating adiponectin level; in the liver, SAMP8 mice have reduction in p-Aktser473, elevation in PTP1B and APP, p-eIF2α, GRP78 and p-JNK protein expression. In epididymal (EPI) fat, SAMP8 mice also have elevated p-Aktser473 and PTP1B compared to SAMR1 mice. In both epididymal (EPI) and subcutaneous (SC) fat, there were elevated ER stress markers, reduced p-AMPK and elevated APP, as well as elevated p-NF-κBp65 and TNF-α protein expression from SAMP8 compared to SAMR1 mice. In liver, the combined intervention significantly restored p-Aktser473, p-eIF2α and p-JNK protein expression. In both EPI and SC fat, the combined intervention is effective for reducing p-NF-κB p65 and TNF-α in both fat depot, while only partially reduced ER stress markers in SC fat. As for adiponectin, their combination is unable to reverse reduction in adiponectin level. Adiponectin secretion in SC fat from VD, RSV and VDRSV group were also significantly reduced compared to SAMR1. ConclusionThe combined intervention might exert greater beneficial effects for reversing aging associated metabolic dysfunction in liver and adipose tissue from SAMP8 mice.

O-GlcNAc transferase promotes fatty liver-associated liver cancer through inducing palmitic acid and activating endoplasmic reticulum stress

O-GlcNAc transferase (OGT) is a unique glycosyltransferase involved in metabolic reprogramming. We investigated the functional role of OGT in non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). The biological function of OGT in NAFLD-HCC was determined by gain- or loss- of OGT functional assays in vitro and in nude mice. OGT target factors and pathways were identified by liquid chromatography-tandem mass spectrometry (LC-MS), promoter luciferase assay, DNA binding activity assay and Western blot. OGT was upregulated in 12 out of 18 (66.7%) NAFLD-HCC tumor tissues by transcriptome sequencing, which was confirmed in additional NAFLD-HCC tumor tissues and cell lines. Biofunctional investigation demonstrated that OGT significantly increased cell growth (p<0.001), clonogenicity (p<0.01), migration and invasion (p<0.05) ability in vitro, and promoted xenograft tumor growth as well as lung metastasis in nude mice. The oncogenic effect of OGT was investigated, we found that OGT significantly induced palmitic acid production identified by LC-MS, which enhanced the protein expression of endoplasmic reticulum (ER) stress masters of glucose-regulated protein 78 and inositol-requiring enzyme 1α. Consequently, OGT significantly activated JNK/c-jun/AP-1 cascade by increasing protein expression of p-JNK, p-c-Jun and activation of AP-1; and induced NF-κB pathway through enhancing the protein levels of p-IKKα/ p-IKKβ, p-p65, p-p50 and the NF-κB DNA binding activity. Notably, OGT inhibition by its antagonist (ST045849) suppressed cell proliferation in vitro (p<0.001) and in xenograft mice models (p<0.05). OGT plays an oncogenic role in NAFLD-associated HCC through regulating palmitic acid and inducing ER stress, consequently activating oncogenic JNK/c-jun/AP-1 and NF-κB cascades. OGT, a unique glycosyltransferase enzyme, was identified to be upregulated in non-alcoholic fatty liver disease-associated hepatocellular carcinoma tissues by transcriptome sequencing. Here, we found that OGT plays a role in cancer by promoting tumor growth and metastasis in both cell models and animal models. This effect is mediated by the induction of palmitic acid.

Salvia miltiorrhiza polysaccharide activates T Lymphocytes of cancer patients through activation of TLRs mediated -MAPK and -NF-κB signaling pathways

Ethnopharmacological relevanceSalvia miltiorrhiza polysaccharide (SMP) is one of the most important components in the water extract of Salvia miltiorrhiza Bunge, which has been mainly applied for the prevention or treatment of ischemic encephalopathy and cardiac diseases including myocardial infarction and coronary heart diseases in clinical practice. Aim of the studyOur object is to investigate the immune regulation effects of SMP, specifically on the proliferation and cytotoxicity of T lymphocytes through MAPK and NF-κB pathway in peripheral blood of cancer patients. Materials and methodsSMP was prepared through refluxing with ethanol, refluxing with water, Sevage treatment and ethanol precipitation. The lymphocytes were obtained from the peripheral blood of cancer patients. The effect of SMP on T lymphocyte proliferation was investigated by cell counting and flow cytometry. The effect of SMP on the proliferation of cancer cell lines A549, hepG2 and HCT116 was examined by MTT assay. The cytotoxic activity of T lymphocytes treated with SMP was detected by Calcein-acetoxymethyl (Calcein-AM) release. The gene expression of IL-4, IL-6, IFN-γ and toll like receptors (TLRs) was detected by semi-quantitative PCR. The protein expression of mitogen activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathway were detected by western blotting. To further verify whether SMP functions through the indicated pathways,, T lymphocytes were treated with SMP and an extracellular regulated protein kinase (ERK) inhibitor (U0126), a c-Jun N-terminal kinase (JNK) inhibitor (SP600125) or an inhibitor of NF-κB inhibitor-α (IκBα) (BAY11-7082), respectively. After 24 h co-treatment, the expressions of p-JNK, p-ERK, IκBα, inhibitory kappa B kinase α (IKKα) and inhibitory kappa B kinase β (IKKβ) protein were detected by western blotting, meanwhile cell numbers of T lymphocytes after inhibition were calculated again by cell counter. ResultsSMP dose-dependently promoted the proliferation of T lymphocytes of the cancer patients and significantly improved the cytotoxicity of T lymphocytes against cancer cells. However, SMP showed no effect on the proliferation of the tumor cells from the same source. Furthermore, the gene expression of cytokines including IL-4, IL-6 and IFN-γ were also up-regulated. Moreover, SMP enhanced gene expression of TLR1, TLR2 and TLR4; elevated protein expression of p-JNK and p-ERK; increased protein expression of IKKα, and IKKβ and decreased IκBα levels. Meanwhile, knockdown of ERK、JNK or IκBα expression with specific inhibitor significantly depressed the proliferation of T lymphocytes treated with SMP, corroborating the specific regulation effect of SMP on T lymphocytes through MAPK and NF-κB signaling pathways. ConclusionSMP specifically promotes the proliferation and enhances cytotoxicity of T lymphocytes in peripheral blood of cancer patients through activation of TLRs mediated -MAPK and -NF-κB signaling pathways.

Research on the effect of ginseng polysaccharide on apoptosis and cell cycle of human leukemia cell line K562 and its molecular mechanisms.

Ginseng polysaccharide (GPS), a polymer of glucose and the primary constituent extracted from panax ginseng, has been documented to exert various pharmacological properties, including anti-tumor properties. To provide further insights into the anti-tumor functions of GPS, the present study was designed to investigate the effect of GPS on apoptosis and the cell cycle of human leukemia cell line K562 cells, and its underlying mechanisms. The results demonstrated that GPS could inhibit K562 cell proliferation and induce apoptosis in vitro in a concentration- and time-dependent manner. The transcription of P38 and c-Jun NH2-terminal kinase (JNK) mRNA were significantly augmented, while the transcription of extracellular signal-regulated kinase (ERK) mRNA were significantly reduced following treatment with GPS compared with the control group (all P<0.05). In addition, GPS treatment markedly suppressed the expression of phosphorylated (p)-ERK, nuclear factor (NF)-κB p65 and cyclin D1, and increased the synthesis of p-P38 and p-JNK protein expression, as evidenced by immunofluorescence and western blotting analyses. In conclusion, the results indicate that the GPS-mediated MAPK/NF-κB/cyclin D1 signaling pathway serves a crucial role in cell cycle arrest and apoptosis of K562 cells.

Dexmedetomidine-induced cardioprotection in a mouse model of lung ischemia-reperfusion: the relationship with endoplasmic reticulum stress

Objective To evaluate dexmedetomidine-induced cardioprotection in a mouse model of lung ischemia-reperfusion(I/R)and the relationship with endoplasmic reticulum stress. Methods Forty healthy SPF male C57BL/6J mice, weighing 20-24 g, aged 8-10 weeks, were divided into 4 groups(n=10 each)using a random number table: sham operation group(Sham group), lung I/R group(I/R group), dexmedetomidine group(Dex group)and dexmedetomidine plus atipamezole(specific α2-adrenergic receptor antagonist)group(DA group). The model of lung I/R injury was established by clamping the left hilum of lung for 30 min followed by 180 min of reperfusion.In group Sham, only sternotomy was performed, the hilum of lung was not clamped, and the mice were mechanically ventilated for 210 min.In Dex and DA groups, dexmedetomidine 20 μg/kg and dexmedetomidine 20 μg/kg plus atipamezole 250 μg/kg were injected intraperitoneally, respectively, at 30 min before establishment of the model.At 180 min of reperfusion, blood samples were collected from the orbit for determination of creatine kinase-MB(CK-MB)and lactic dehydrogenase(LDH)activities in serum.The animals were then sacrificed, and hearts were removed for determination of apoptosis in cardiomyocytes(by TUNEL)and expression of phosphorylated c-Jun N-terminal kinase(p-JNK), caspase-12, CCAAT/enhancer-binding protein homologous protein(CHOP)and glucose-regulated protein 78(GRP78)in myocardial tissues(by Western blot), and expression of JNK, caspase-12, CHOP, GRP78 mRNA in myocardial tissues(by real-time polymerase chain reaction). Apoptosis index was calculated. Results Compared with Sham group, the serum CK-MB and LDH activities and apoptosis index were significantly increased, the expression of p-JNK, JNK mRNA, and caspase-12, CHOP and GRP78 protein and mRNA was up-regulated in I/R, Dex and DA groups(P 0.05). Compared with DEX group, the serum CK-MB and LDH activities and apoptosis index were significantly increased, the expression of p-JNK, JNK mRNA, and caspase-12 and CHOP protein and mRNA was up-regulated(P 0.05). Conclusion Dexmedetomidine can reduce myocardial injury induced by lung I/R, and the mechanism may be related to activation of α2-adrenergic receptors and inhibition of endoplasmic reticulum stress in myocardial cells of mice. Key words: Dexmedetomidine; Lung; Reperfusion injury; Myocardium; Endoplasmic reticulum; Stress

NLRP3 gene knockout blocks NF-κB and MAPK signaling pathway in CUMS-induced depression mouse model

BackgroundAbundant researches indicate that neuroinflammation has important roles in the pathophysiology of depression. Our previous study found that the NLRP3 inflammasome mediated stress-induced depression-like behavior in mice via regulating neuroinflammation. However, it still remains unclear that how the NLRP3 inflammasome influences related inflammatory signaling pathway to contribute to neuroinflammation in depression. MethodsWe used wild-type mice and NLRP3 gene knockout mice to explore the role of NLRP3 inflammasome and related inflammatory signaling pathways in chronic unpredictable mild stress (CUMS) induced depression mouse model. ResultsBoth wild-type and NLRP3 knockout stress group mice gained less weight than control group mice after 4 weeks CUMS exposure. The wild-type mice subjected to 4 weeks CUMS displayed depression-like behaviors, including decreased sucrose preference and increased immobility time in the tail suspension test. The NLRP3 knockout stress group mice didn’t demonstrate depression-like behaviors. The levels of interleukin-1β protein in serum and hippocampi of CUMS exposed wild-type mice were significantly higher, while the NLRP3 knockout stress group mice didn’t show an elevation of interleukin-1β levels. Similarly to early researches, we found that CUMS led to promoted NLRP3 expression in hippocampi. In addition, the hippocampi in CUMS exposed wild-type mice had higher p-JNK and p-p38 protein expression, which indicated activation of the mitogen-activated protein kinases (MAPK) pathway. The knockout of NLRP3 gene inhibited CUMS-induced activation of the MAPK pathway. The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) protein complex was activated in the hippocampi of wild-type mice after CUMS exposure, while knockout of NLRP3 gene hindered its activation. ConclusionsThese data further proved that the NLRP3 inflammasome mediated CUMS-induced depression-like behavior. The NLRP3 inflammasome regulated CUMS-induced MAPK pathway and NF-κB protein complex activation in depression mouse model. Further researches targeting the NLRP3 inflammasome-signaling pathway might be under a promising future in the prevention and treatment of depression.

N-Acetylcysteine Influence on Oxidative Stress and Cardiac Remodeling in Rats During Transition from Compensated Left Ventricular Hypertrophy to Heart Failure

Background/Aims: To evaluate the effects of the antioxidant N-acetylcysteine (NAC) on cardiac structure and function in rats with long-term ascending aortic stenosis (AS). Methods: Four months after inducing AS, Wistar rats were assigned into the groups Sham, AS, and AS treated with NAC (AS-NAC) and followed for eight weeks. Cardiac structure and function were evaluated by echocardiogram. Myocardial antioxidant enzymes activity was measured by spectrophotometry and malondialdehyde serum concentration by HPLC. Gene expression of NADPH oxidase subunits NOX2, NOX4, p22 phox, and p47 phox was assessed by real time RT-PCR and protein expression of MAPK proteins by Western blot. Statistical analyzes were performed with Goodman and ANOVA or Mann-Whitney Results: NAC restored myocardial total glutathione (Sham 20.8±3.00; AS 12.6±2.92; AS-NAC 17.6±2.45 nmol/g tissue; p<0.05 AS vs Sham and AS-NAC). Malondialdehyde serum concentration was lower in AS-NAC and myocardial lipid hydroperoxide was higher in AS (Sham 199±48.1; AS 301±36.0; AS-NAC 181±41.3 nmol/g tissue). Glutathione peroxidase activity was lower in AS than Sham. Echocardiogram showed LV concentric hypertrophy with systolic and diastolic dysfunction before and after treatment; no differences were observed between AS-NAC and AS groups. NAC reduced p-ERK and p-JNK protein expression, attenuated myocardial fibrosis, and decreased the frequency of right ventricular hypertrophy. Conclusion: N-acetylcysteine restores myocardial total glutathione, reduces systemic and myocardial oxidative stress, improves MAPK signaling, and attenuates myocardial fibrosis in aortic stenosis rats.