Effect and mechanism of oxycodone hydrochloride on inflammation and neuronal apoptosis in epileptic rats / 中华老年心脑血管病杂志

Objective To explore the effect of oxycodone hydrochloride on inflammation and neuro-nal apoptosis in epileptic rats through c-Jun amino terminal kinase(JNK)/p38 mitogen activated protein kinase(p38 MAPK)signaling pathway.Methods After epileptic rat model was success-fully constructed,72 epileptic rats were randomly divided into model group,low-,medium-and high-dose oxycodone hydrochloride groups(0.125,0.25 and 0.5 mg/kg),anisomycin(JNK activa-tor 5 mg/kg)and combined group(0.5 mg/kg oxycodone hydrochloride+5 mg/kg anisomycin),with 12 rats in each group.Another 12 healthy rats were selected as control group.In 24 h after the end of administration,the frequency and duration of seizures were recorded for all rats.ELISA was used to detect the serum levels of TNF-α and IL-6,HE staining was employed to observe the his-topathological changes in hippocampal CA1 region,and TUNEL staining was applied to detect the apoptosis of CA1 region neurons.The expression of JNK,p-JNK,p38 MAPK,p-p38 MAPK and Caspase-3 in hippocampal CA1 region was detected by Western blotting.Results Compared with the rats from the control group,those of the model group showed higher frequency and longer du-ration of seizures,higher serum TNF-α and IL-6 levels,increased apoptotic rate of hippocampal CA1 neurons,and elevated p-JNK/JNK ratio,p-p38 MAPK/p38 MAPK ratio and Caspase-3 expression(P＜0.05).While low-,medium-and high-dose oxycodone hydrochloride treatment re-versed above changes in frequency and duration of seizures,serum TNF-α and IL-6 levels,neuro-nal apoptosis,p-JNK/JNK ratio,p-p38 MAPK/p38 MAPK ratio and Caspase-3 expression(P＜0.05).In the anisomycin group,higher frequency and longer duration of seizures,elevated serum TNF-α and IL-6 levels,increased neuronal apoptotic rate in hippocampal CA1 region,and en-hanced p-JNK/JNK ratio,p-p38 MAPK/p38 MAPK ratio and Caspase-3 expression(P＜0.05).Lower frequency and shorter duration of seizures,decreased serum TNF-α and IL-6 levels,and re-duced neuronal apoptotic rate in hippocampal CA1 region were observed in the combined group than the anisomycin group(P＜0.05).The combined group obtained statistically lower p-JNK/JNK ratio,p-p38 MAPK/p38 MAPK ratio and Caspase-3 expression in hippocampal CA1 region than the high-dose group,and opposite results than the anisomycin group(0.89±0.12 vs 0.25± 0.05 vs 1.08±0.16,0.81±0.08 vs 0.21±0.04 vs 0.94±0.12,0.79±0.12 vs 0.26±0.04 vs 0.89± 0.14,P＜0.05).Conclusion Oxycodone hydrochloride can reduce inflammatory response,im-prove epileptic symptoms and pathological damages,and protect neurons in epileptic rats,which is related to the inhibition of JNK/p38 MAPK signaling pathway.

Role of autophagy in morphine preconditioning-induced reduction of OGD/R injury in primary cortical neurons of mice and the relationship with JNK / 中华麻醉学杂志

Objective:To evaluate the role of autophagy in morphine preconditioning-induced reduction of oxygen-glucose deprivation and restoration (OGD/R) injury in primary cortical neurons of mice and the relationship with c-Jun N-terminal kinase (JNK).Methods:Primary cortical neurons extracted from C57BL/6 neonatal mice within 24 h after birth were divided into 9 groups ( n=24 each) using a random number table method: control group (C group), OGD/R group, morphine preconditioning group (M group), autophagy inhibitor 3-methyladenine (3-MA) group (3-MA group), 3-MA+ morphine preconditioning group (3-MA+ M group), autophagy inhibitor chloroquine group (Ch group), chloroquine + morphine preconditioning group (Ch+ M group), JNK inhibitor SP600125 group (SP group) and SP600125 + morphine preconditioning group (SP+ M group). Morphine preconditioning: morphine was added at a final concentration of 3 μmol/L before OGD/R, and the cells were incubated for 2 h in OGD/R group. In 3-MA, Ch and SP groups, 3-MA 5 mmol/L, chloroquine 50 μmol/L and SP600125 25 μmol/L were added, respectively, and the cells were incubated for 150 min. In 3-MA+ M, Ch+ M and SP+ M groups, 3-MA 5 mmol/L, chloroquine 50 μmol/L and SP600125 25 μmol/L were added, respectively, at 30 min before morphine preconditioning. Then the cells were subjected to oxygen-glucose deprivation for 1 h followed by restoration of oxygen-glucose supply for 24 h. CCK-8 assay was used to detect the neuronal viability. The expression of JNK, phosphorylated JNK (p-JNK), microtubule-associated protein 1 light chain 3 (LC3), p62, Beclin1, caspase-3, and cleaved-caspase-3 was determined by Western blot. The autophagosomes and autolysosomes were counted using LC3-double fluorescent adenovirus transfection, and the neuronal apoptosis rate was determined by TUNEL staining. Results:Compared with C group, the neuronal viability was significantly decreased, the expression of Beclin1 was up-regulated, the expression of p62 was down-regulated, and the LC3Ⅱ/LC3Ⅰ ratio, p-JNK/JNK ratio, the number of autophagosomes and autolysosomes, cleaved-caspase-3/caspase-3 ratio and neuronal apoptosis rate were increased in OGD/R group ( P<0.001). Compared with OGD/R group, the neuronal viability, p-JNK/JNK ratio, LC3Ⅱ/LC3Ⅰ ratio and the number of autophagosomes and autolysosomes were significantly increased, the expression of Beclin1 was up-regulated, and the expression of p62 was down-regulated in M group, the LC3Ⅱ/LC3Ⅰ ratio was significantly decreased, and the expression of p62 was down-regulated in 3-MA group, the LC3Ⅱ/LC3Ⅰ ratio was significantly increased, and the expression of p62 was up-regulated in Ch group ( P<0.001), and no significant change was found in the parameters mentioned above in SP600125 group ( P>0.05). Compared with M group, the neuronal viability was significantly decreased, the LC3Ⅱ/LC3Ⅰ ratio was decreased, and the expression of p62 was up-regulated in M+ 3-MA group, the neuronal viability was significantly decreased, the LC3Ⅱ/LC3Ⅰ ratio was increased, and the expression of p62 was up-regulated in M+ Ch group, and the neuronal viability, LC3Ⅱ/LC3Ⅰ ratio and p-JNK/JNK ratio were significantly decreased, the expression of p62 was up-regulated, the number of autophagosomes and autolysosomes was decreased, the expression of Beclin1 was down-regulated, and the cleaved-caspase-3/caspase-3 ratio and neuronal apoptosis rate were increased in M+ SP group ( P<0.001). Conclusions:Morphine preconditioning can attenuate OGD/R injury by activating JNK, enhancing autophagy and inhibiting apoptosis in primary cortical neurons of mice.

Yomogin, Isolated from Artemisia iwayomogi, Inhibits Neuroinflammation Stimulated by Lipopolysaccharide via Regulating MAPK Pathway.

Neuroinflammation causes various neurological disorders, including depression and neurodegenerative diseases. Therefore, regulation of neuroinflammation is a promising therapeutic strategy for inflammation-related neurological disorders. This study aimed to investigate whether yomogin, isolated from Artemisia iwayomogi, has anti-neuroinflammatory effects. First, we evaluated the effects of yomogin by assessing pro-inflammatory mediators and cytokines in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. The results showed that yomogin inhibited the increase in neuroinflammatory factors, including nitric oxide, inducible nitric oxide synthase, cyclooxygenase-2, interleukin-6, and tumor necrosis factor-α, and suppressed phosphorylation of c-Jun N-terminal kinase, extracellular signal-regulated kinase and p38, which participate in the mitogen-activated protein kinase (MAPK) pathway. To confirm these effects in vivo, we measured the activation of astrocyte and microglia in LPS-injected mouse brains. Results showed that yomogin treatment decreased astrocyte and microglia activations. Collectively, these results suggest that yomogin suppresses neuroinflammation by regulating the MAPK pathway and it could be a potential candidate for inflammation-mediated neurological diseases.

Sec-O-glucosylhamaudol mitigates inflammatory processes and autophagy via p38/JNK MAPK signaling in a rat neuropathic pain model.

BACKGROUND: This study investigated the effect of intrathecal Sec-O-glucosylhamaudol (SOG) on the p38/c-Jun N-terminal kinase (JNK) signaling pathways, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-related inflammatory responses, and autophagy in a spinal nerve ligation (SNL)-induced neuropathic pain model. METHODS: The continuous administration of intrathecal SOG via an osmotic pump was performed on male Sprague-Dawley rats (n = 50) with SNL-induced neuropathic pain. Rats were randomized into four groups after the 7th day following SNL and treated for 2 weeks as follows (each n = 10): Group S, sham-operated; Group D, 70% dimethylsulfoxide; Group SOG96, SOG at 96 µg/day; and Group SOG192, SOG at 192 µg/day. The paw withdrawal threshold (PWT) test was performed to assess neuropathic pain. Western blotting of the spinal cord (L5) was performed to measure changes in the expression of signaling pathway components, cytokines, and autophagy. Additional studies with naloxone challenge (n = 10) and cells were carried out to evaluate the potential mechanisms underlying the effects of SOG. RESULTS: Continuous intrathecal SOG administration increased the PWT with p38/JNK mitogen-activated protein kinase (MAPK) pathway and NF-κB signaling pathway inhibition, which induced a reduction in proinflammatory cytokines with the concomitant downregulation of autophagy. CONCLUSIONS: SOG alleviates mechanical allodynia, and its mechanism is thought to be related to the regulation of p38/JNK MAPK and NF-κB signaling pathways, associated with autophagy during neuroinflammatory processes after SNL.

Role of IL-1β/JNK pathway in sevoflurane-induced necroptosis of rat hippocampal neurons in vitro / 中华麻醉学杂志

Objective:To evaluate the role of interleukin 1β (IL-1β)/c-Jun N-terminal kinase (JNK) pathway in sevoflurane-induced necroptosis of rat hippocampal neurons in vitro. Methods:Primarily cultured hippocampal neurons of Sprague-Dawley rat fetuses were inoculated into 96-well plates (cell density: 1×10 4 cells/ml, 200 μl/hole) and 6-well plates (cell density: 1×10 6 cells/ml, 2 ml/hole). The cells were divided into 3 groups ( n=20 each) using a random number table method after being cultured for 7 days: control group (group C), sevoflurane group (group S) and IL-1 receptor antagonist group (group I). Group C received routine culture, IL-1 receptor antagonist IL-1ra 1 μg/μl was added, and the cells were incubated for 30 min in group I, and in addition the cells were placed in the incubator containing 2% sevoflurane and cultured for 5 h at 37 ℃ in S and I groups.The cells were collected for microscopic examination of the morphology of neurons (with an inverted microscope) and for determination of the cell necroptosis rate (by flow cytometry), cell viability (by MTT method), and expression of IL-1β, interleukin-1 receptor type I (IL-1RI), interleukin-1 receptor accessory protein (IL-1RAcP), phosphorylated JNK (p-JNK) ), receptor-interacting protein 1 (RIP1), RIP3 and phosphorylated mixed lineage kinase-like (p-MLKL) (by Western blot ). Results:Compared with group C, the cell viability was significantly decreased, the necroptosis rate was increased, and the expression of IL-1β, IL-1RI, IL-1RAcP, p-JNK, RIP1, RIP3 and p-MLKL was up-regulated in group S ( P<0.05). Compared with group S, the cell viability was significantly increased, the necroptosis rate was decreased, and the expression of IL-1β, IL-1RI, IL-1RAcP, p-JNK, RIP1, RIP3 and p-MLKL was down-regulated in group I ( P<0.05). There was no obvious abnormality in the morphology of neurons in group C. The cell body of neurons was shrunk, the processes were broken, and the network between processes was sparse in group S. The cell body was round, and the morphology was close to normal in group I. Conclusion:The mechanism by which sevoflurane induces necroptosis of rat hippocampal neurons in vitro is related to activation of IL-1β/JNK pathway.

Inhibition of yes-associated protein dephosphorylation prevents aggravated periodontitis with occlusal trauma.

BACKGROUND: Occlusal trauma can aggravate periodontitis, but the mechanism remains unclear. Yes-associated protein (YAP), a mechanical stressor protein, may play an important role in this process. METHODS: Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were applied to detect the expression of YAP and inflammatory factors in patients with periodontitis accompanied with or without occlusal trauma. Through local administration of Porphyromonas gingivalis and composite resin bonding on maxillary molars in mice, we established periodontitis and occlusal trauma models. Treatment with or without XAV939, to inhibit YAP activation, was performed in these models. Micro-computed tomography, immunofluorescence (IF), and qRT-PCR were used to explore the YAP pathway in periodontitis with occlusal trauma. Cyclic stress and lipopolysaccharide (LPS) stimuli were applied to the L929 mouse fibroblast cell line with or without XAV939. Western blot, IF, and qRT-PCR were used to verify the in vivo results. RESULTS: Activated dephosphorylated YAP and increased expression of inflammatory factors were observed in patients with periodontitis accompanied with occlusal trauma. In the mouse model of periodontitis with occlusal trauma, YAP transferred into the nucleus, resulting in Jun N-terminal kinases (JNK) related pro-inflammatory pathway up-regulation. L929 cell cyclic stress and LPS stimulation results confirmed the in vivo results. Application of XAV939 inhibited YAP protein dephosphorylation and reduced JNK pro-inflammatory pathway factor expression in vivo and in vitro. CONCLUSIONS: Occlusal trauma can activate YAP nuclear transfer, resulting in the up-regulation of the JNK pro-inflammatory pathway. This can be inhibited by the XAV939 YAP inhibitor.

JNK2, a Newly-Identified SERCA2 Enhancer, Augments an Arrhythmic [Ca2+]SR Leak-Load Relationship.

RATIONALE: We recently discovered pivotal contributions of stress kinase JNK2 (c-Jun N-terminal kinase isoform 2) in increased risk of atrial fibrillation through enhanced diastolic sarcoplasmic reticulum (SR) calcium (Ca2+) leak via RyR2 (ryanodine receptor isoform 2). However, the role of JNK2 in the function of the SERCA2 (SR Ca2+-ATPase), essential in maintaining SR Ca2+ content cycling during each heartbeat, is completely unknown. OBJECTIVE: To test the hypothesis that JNK2 increases SERCA2 activity SR Ca2+ content and exacerbates an arrhythmic SR Ca2+ content leak-load relationship. METHODS AND RESULTS: We used confocal Ca2+ imaging in myocytes and HEK-RyR2 (ryanodine receptor isoform 2-expressing human embryonic kidney 293 cells) cells, biochemistry, dual Ca2+/voltage optical mapping in intact hearts from alcohol-exposed or aged mice (where JNK2 is activated). We found that JNK2, but not JNK1 (c-Jun N-terminal kinase isoform 1), increased SERCA2 uptake and consequently elevated SR Ca2+ content load. JNK2 also associates with and phosphorylates SERCA2 proteins. JNK2 causally enhances SERCA2-ATPase activity via increased maximal rate, without altering Ca2+ affinity. Unlike the CaMKII (Ca2+/calmodulin-dependent kinase II)-dependent JNK2 action in SR Ca2+ leak, JNK2-driven SERCA2 function was CaMKII independent (not prevented by CaMKII inhibition). With CaMKII blocked, the JNK2-driven SR Ca2+ loading alone did not significantly raise leak. However, with JNK2-CaMKII-driven SR Ca2+ leak present, the JNK2-enhanced SR Ca2+ uptake limited leak-induced reduction in SR Ca2+, normalizing Ca2+ transient amplitude, but at a higher arrhythmogenic SR Ca2+ leak. JNK2-specific inhibition completely normalized SR Ca2+ handling, attenuated arrhythmic Ca2+ activities, and alleviated atrial fibrillation susceptibility in aged and alcohol-exposed myocytes and intact hearts. CONCLUSIONS: We have identified a novel JNK2-induced activation of SERCA2. The dual action of JNK2 in CaMKII-dependent arrhythmic SR Ca2+ leak and a CaMKII-independent uptake exacerbates atrial arrhythmogenicity, while helping to maintain normal levels of Ca2+ transients and heart function. JNK2 modulation may be a novel therapeutic target for atrial fibrillation prevention and treatment.

Mannosylerythritol lipids ameliorate ultraviolet A-induced aquaporin-3 downregulation by suppressing c-Jun N-terminal kinase phosphorylation in cultured human keratinocytes.

Mannosylerythritol lipids (MELs) are glycolipids and have several pharmacological efficacies. MELs also show skin-moisturizing efficacy through a yet-unknown underlying mechanism. Aquaporin-3 (AQP3) is a membrane protein that contributes to the water homeostasis of the epidermis, and decreased AQP3 expression following ultraviolet (UV)-irradiation of the skin is associated with reduced skin moisture. No previous study has examined whether the skin-moisturizing effect of MELs might act through the modulation of AQP3 expression. Here, we report for the first time that MELs ameliorate the UVA-induced downregulation of AQP3 in cultured human epidermal keratinocytes (HaCaT keratinocytes). Our results revealed that UVA irradiation decreases AQP3 expression at the protein and messenger RNA (mRNA) levels, but that MEL treatment significantly ameliorated these effects. Our mitogen-activated protein kinase inhibitor analysis revealed that phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase or p38, mediates UVA-induced AQP3 downregulation, and that MEL treatment significantly suppressed the UVA-induced phosphorylation of JNK. To explore a possible mechanism, we tested whether MELs could regulate the expression of peroxidase proliferator-activated receptor gamma (PPAR-γ), which acts as a potent transcription factor for AQP3 expression. Interestingly, UVA irradiation significantly inhibited the mRNA expression of PPAR-γ in HaCaT keratinocytes, whereas a JNK inhibitor and MELs significantly rescued this effect. Taken together, these findings suggest that MELs ameliorate UVA-induced AQP3 downregulation in HaCaT keratinocytes by suppressing JNK activation to block the decrease of PPAR-γ. Collectively, our findings suggest that MELs can be used as a potential ingredient that modulates AQP3 expression to improve skin moisturization following UVA irradiation-induced damage.

Constant hypoxia inhibits osteoclast differentiation and bone resorption by regulating phosphorylation of JNK and IκBα.

BACKGROUND: Osteoclasts are responsible for the bone loss in rheumatoid arthritis (RA). Hypoxia has been suggested to play key roles in pathological bone loss. However, the current understanding of the effects of hypoxia on osteoclastogenesis is controversial. Effects of hypoxia on both the formation and function of osteoclasts requires examination. In the current study, we aimed to explore the effect of hypoxia on osteoclast differentiation and the underlying mechanisms. METHODS: RAW264.7 cells and murine bone-marrow-derived monocytes were used to induce osteoclastogenesis in the presence of macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa B ligand (RANKL). Hypoxic conditions were maintained in a hypoxic chamber at 5% CO2 and 1% O2, balanced with N2. Osteoclasts were detected by tartrate-resistant acid phosphatase (TRAP) staining. A bone resorption assay was carried out in vitro using bone slices. RT-PCR was conducted to detect osteoclast markers and transcription factors. The phosphorylation of nuclear factor-κBα (IκBα), c-Jun N-terminal kinase (JNK), extracellular regulated protein kinase (ERK), and p38 was detected by western blotting. Mann-Whitney U test or Student's t test was used to compare differences between the two groups. RESULTS: TRAP staining and the bone resorption assay revealed that hypoxia-restrained osteoclast differentiation and bone resorption. Expression of osteoclast markers including cathepsin K, RANK, and TRAP decreased during osteoclast differentiation under hypoxic conditions (all P < 0.05). Hypoxia at 1% O2 did not affect cell viability, whereas it dramatically abated RANKL-dependent phosphorylation of the JNK-mitogen-activated protein kinases (MAPK) and IκBα pathways. Moreover, the expression of nuclear factor of activated T-cell cytoplasmic 1 (NFATc1) was inhibited under hypoxic conditions (all P < 0.05). CONCLUSIONS: These results suggest that constant hypoxia at 1% O2 significantly restrains osteoclast formation and resorbing function without affecting cell viability. Constant hypoxia might inhibit RANKL-induced osteoclastogenesis by regulating NFATc1 expression via interfering the phosphorylation of JNK and IκBα.

Anti-inflammatory effects of Ang-(1-7) via TLR4-mediated inhibition of the JNK/FoxO1 pathway in lipopolysaccharide-stimulated RAW264.7 cells.

Targeting inflammation is considered a challenging pharmacological strategy to prevent or delay the development of inflammatory diseases, such as severe asthma, Crohn's disease, and rheumatoid arthritis. The angiotensin-(1-7) -Mas axis ((Ang-(1-7)-Mas axis) was confirmed to antagonize the effects of the Angiotensin II-AT1 receptor axis and the latter is reported to regulate cardiovascular and renal function, as well as contribute to the inflammatory process. In this paper, we aim to explore the crucial effect of Ang-(1-7) in inflammation and disclose the mechanisms in lipopolysaccharide (LPS)-induced murine macrophages RAW264.7. We found that Ang-(1-7) inhibited the production and secretion of tumor necrosis factor-α and interleukin-6 in a concentration-dependent manner in LPS-induced macrophages. The overexpression of TLR4, phospho-JNK, and FoxO1 induced by LPS were also inhibited by incubation with Ang-(1-7). These inhibitory effects were reversed by A-779. Moreover, we also used a selective JNK inhibitor Sp600125 to further corroborate the involvement of TLR4, JNK, and FoxO1 in the anti-inflammatory action of Ang-(1-7). Our research reveals a new mechanism that Ang-(1-7) may drive anti-inflammatory effects via the Mas receptor through inhibition of the TLR4-mediated JNK/FoxO1 signaling pathway in LPS-induced macrophages. Our findings open new perspectives of Ang-(1-7)-Mas axis in local inflammation.

Mannosylerythritol lipids ameliorate ultraviolet A-induced aquaporin-3 downregulation by suppressing c-Jun N-terminal kinase phosphorylation in cultured human keratinocytes

Mannosylerythritol lipids (MELs) are glycolipids and have several pharmacological efficacies. MELs also show skin-moisturizing efficacy through a yet-unknown underlying mechanism. Aquaporin-3 (AQP3) is a membrane protein that contributes to the water homeostasis of the epidermis, and decreased AQP3 expression following ultraviolet (UV)-irradiation of the skin is associated with reduced skin moisture. No previous study has examined whether the skin-moisturizing effect of MELs might act through the modulation of AQP3 expression. Here, we report for the first time that MELs ameliorate the UVA-induced downregulation of AQP3 in cultured human epidermal keratinocytes (HaCaT keratinocytes). Our results revealed that UVA irradiation decreases AQP3 expression at the protein and messenger RNA (mRNA) levels, but that MEL treatment significantly ameliorated these effects. Our mitogen-activated protein kinase inhibitor analysis revealed that phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase or p38, mediates UVA-induced AQP3 downregulation, and that MEL treatment significantly suppressed the UVA-induced phosphorylation of JNK. To explore a possible mechanism, we tested whether MELs could regulate the expression of peroxidase proliferator-activated receptor gamma (PPAR-γ), which acts as a potent transcription factor for AQP3 expression. Interestingly, UVA irradiation significantly inhibited the mRNA expression of PPAR-γ in HaCaT keratinocytes, whereas a JNK inhibitor and MELs significantly rescued this effect. Taken together, these findings suggest that MELs ameliorate UVA-induced AQP3 downregulation in HaCaT keratinocytes by suppressing JNK activation to block the decrease of PPAR-γ. Collectively, our findings suggest that MELs can be used as a potential ingredient that modulates AQP3 expression to improve skin moisturization following UVA irradiation-induced damage.

Characterization of Behavioral, Signaling and Cytokine Alterations in a Rat Neurodevelopmental Model for Schizophrenia, and Their Reversal by the 5-HT6 Receptor Antagonist SB-399885.

Post-weaning social isolation of rats produces neuroanatomical, neurochemical and behavioral alterations resembling some core features of schizophrenia. This study examined the ability of the 5-HT6 receptor antagonist SB-399885 to reverse isolation-induced cognitive deficits, then investigated alterations in hippocampal cell proliferation and hippocampal and frontal cortical expression of selected intracellular signaling molecules and cytokines. Male Lister hooded rats (weaned on post-natal days 21-24 and housed individually or in groups of 3-4) received six i.p. injections of vehicle (1% Tween 80, 1 mL/kg) or SB-399885 (5 or 10 mg/kg) over a 2-week period starting 40 days post-weaning, on the days that locomotor activity, novel object discrimination (NOD), pre-pulse inhibition of acoustic startle and acquisition, retention and extinction of a conditioned freezing response (CFR) were assessed. Tissue was collected 24 h after the final injection for immunohistochemistry, reverse-phase protein microarray and western blotting. Isolation rearing impaired NOD and cue-mediated CFR, decreased cell proliferation within the dentate gyrus, and elevated hippocampal TNFα levels and Cdc42 expression. SB-399885 reversed the NOD deficit and partially normalized CFR and cell proliferation. These effects were accompanied by altered expression of several members of the c-Jun N-terminal Kinase (JNK) and p38 MAPK signaling pathways (including TAK1, MKK4 and STAT3). Although JNK and p38 themselves were unaltered at this time point hippocampal TAK1 expression and phosphorylation correlated with visual recognition memory in the NOD task. Continued use of this neurodevelopmental model could further elucidate the neurobiology of schizophrenia and aid assessment of novel therapies for drug-resistant cognitive symptoms.

Effect of intratracheal injection of JNK siRNA on ischemia-reperfusion injury in a rat model of lung transplantation / 中华麻醉学杂志

Objective To investigate the effect of intratracheal injection of c-Jun N-terminal kinase ( JNK) siRNA plasmid on ischemia-reperfusion ( I∕R) injury in a rat model of lung transplantation. Meth-ods ExperimentⅠ Thirty-two male Wistar rats, weighing 250-280 g, were divided into 2 groups ( n=16 each) using a random number table method: control group ( group C) and JNK siRNA group. JNK siR-NA plasmid 2 mg∕kg ( diluted to 0. 2 ml in sterile phosphate buffer solution) was intratracheally injected in JNK siRNA group. Scrambled siRNA plasmid 2 mg∕kg ( diluted to 0. 2 ml in sterile phosphate buffer solu-tion) was intratracheally injected in group C. Six rats in each group were sacrificed at 48 h of administra-tion, and left lung tissues were removed for determination of the expression of JNK and JNK mRNA ( by Western blot and real-time polymerase chain reaction, respectively) . The other 10 rats left in each group were used for left lung transplantation. Experiment Ⅱ Thirty male Wistar rats, weighing 250-280 g, were divided into 3 groups ( n=10 each ) using a random number table method: sham operation group ( group S) , transplanted lung I∕R group ( group I∕R) and transplanted lung I∕R+JNK siRNA group ( group I∕R+JNK siRNA) . In group I∕R and group I∕R+JNK siRNA, the left lung transplantation was performed, and the donor lungs were obtained from the living donors in group C and group JNK siRNA, respectively. At 15 min of mechanical ventilation and 30, 60, 90 and 120 min of reperfusion, arterial blood samples were obtained for blood gas analysis, PaO2 was recorded, and the oxygenation index ( PaO2 ÷ FiO2 ) was calculated. Arterial blood samples were obtained at 120 min of reperfusion in transplanted lungs for determi-nation of concentrations of interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-α) and interferon-γ( IFN-γ) in serum ( using enzyme-linked immunosorbent assay) , and the rats were sacrificed and left lung tissues were removed for microscopic examination of the pathological changes which were scored and for de-termination of wet∕dry lung weight ratio ( W∕D ratio) , and nuclear factor kappa B ( NF-κB) and activator protein-1 ( AP-1) activities ( using enzyme-linked immunosorbent assay) . Results ExperimentⅠ Com-pared with group C, the expression of JNK and JNK mRNA was significantly down-regulated in group JNK siRNA (P<0. 05). ExperimentⅡ Compared with group S, the oxygenation index was significantly de-creased, and the concentrations of serum IL-8, TNF-α and IFN-γ, W∕D ratio, lung injury score and ac-tivities of NF-κB and AP-1 were increased in I∕R and I∕R+JNK siRNA groups ( P<0. 05) . Compared with group I∕R, the oxygenation index of receptors were significantly increased, and the concentrations of serum IL-8, TNF-α and IFN-γ, W∕D ratio, lung injury score and activities of NF-κB and AP-1 were decreased in group I∕R+JNK siRNA ( P<0. 05) . Conclusion Intratracheal injection of JNK siRNA can reduce trans-planted lung I∕R injury, and the mechanism may be related to inhibiting inflammatory responses of rats.

A Sialidase-Deficient Porphyromonas gingivalis Mutant Strain Induces Less Interleukin-1ß and Tumor Necrosis Factor-α in Epi4 Cells Than W83 Strain Through Regulation of c-Jun N-Terminal Kinase Pathway.

BACKGROUND: Porphyromonas gingivalis is one of the major periodontal pathogens. In a previous study, a mouse abscess model showed that sialidase deficiency of P. gingivalis weakened its virulence, but the mechanism behind this observation remains unknown. METHODS: A sialidase-deficient mutant strain (△PG0352) and a complemented strain (com△PG0352) were constructed. Epi4 cells were stimulated by wild-type strain P. gingivalis W83, △PG0352, or com△PG0352. Real-time polymerase chain reaction was carried out to detect expression of virulent genes in P. gingivalis and interleukin (IL)-1ß, IL-6, IL-8, and tumor necrosis factor (TNF)-α in epi4 cells. Activities of sialidase, gingipains, and lipopolysaccharide (LPS) were compared among the different P. gingivalis strains. Levels of IL-1ß and TNF-α in the epi4 cells supernatant were detected by enzyme-linked immunosorbent assay and levels of p38, extracellular signal-regulated kinase, c-Jun N-terminal kinase (JNK), and phospho-c-Jun were detected by western blotting. RESULTS: Compared with P. gingivalis W83 and com△PG0352, activities of Kgp and Rgp gingipains and amount of LPS decreased in △PG0352, whereas there were no differences in LPS activity among these three strains. Level of phospho-JNK was lower in epi4 cells stimulated by △PG0352. △pG0352 induced less IL-1ß and TNF-α and more IL-8 in epi4 cells; differences in IL-1ß and TNF-α could not be detected after JNK blocking. CONCLUSION: A sialidase-deficient P. gingivalis mutant strain induces less IL-1ß and TNF-α in epi4 cells than W83 strain through regulation of JNK pathway.

The influence of actin depolymerization induced by Cytochalasin D and mechanical stretch on interleukin-8 expression and JNK phosphorylation levels in human retinal pigment epithelial cells.

BACKGROUND: This study explores the role of actin cytoskeleton depolymerization induced by Cytochalasin D and mechanical stretch on the interleukin-8 (IL-8) expression and c-jun N-terminal kinase (JNK) phosphorylation levels in human retinal pigment epithelial (RPE) cells. METHODS: A Flexcell FX-5000 Tension system was used to apply cyclic stretch to cultured human RPE cells (ARPE-19) at 0.33 Hz with 20% elongation for 0 h, 6 h or 24 h. The cells were stretched alone or pre-treated with Cytochalasin D. The redistribution of the actin cytoskeleton was evaluated using phalloidin immunofluorescence staining. The protein expression levels of IL-8 and JNK in the RPE cells were determined via Western blotting. RESULTS: The cells in the control groups displayed abundant and uniform phalloidin staining. After exposure to mechanical stretch for 24 h, phalloidin staining revealed an unclear and irregular actin cytoskeleton. In all Cytochalasin D-treated cells, the shrinkage and disruption of the cytoskeletal structure was observed regardless of mechanical stress. The stimulation of the RPE cells with cyclic stretch alone did not induce a significant increase in IL-8 expression and JNK phosphorylation levels, which were similar to those of the control groups. After pre-treatment with Cytochalasin D alone, IL-8 expression and JNK phosphorylation levels were not significantly different at 6 h but were significantly increased by approximately 1.2-fold (1.18 ± 0.05; P<0.01) and 3.0-fold (3.01 ± 0.02; P<0.01) at 24 h, respectively. After the pre-incubation of the RPE cells with Cytochalasin D followed by exposure to cyclic stretch, IL-8 expression and JNK phosphorylation levels increased by approximately 1.3-fold (1.31 ± 0.02; P<0.01) and 1.3-fold (1.31 ± 0.02; P<0.01) at 6 h, respectively, and by 1.7-fold (1.69 ± 0.06; P<0.01) and 3.2-fold (3.21 ± 0.12; P<0.01) at 24 h, respectively. CONCLUSIONS: This study demonstrates that disruption of actin polymerization by cytochalasin D and mechanical stretch upregulates interleukin-8 expression and JNK phosphorylation levels in human RPE cells, which indicates that the integrity of the actin cytoskeleton may play important roles in the pro-inflammatory processes in RPE cells.

Puerarin protected rats with traumatic brain injury through autophagy regulation via JNK pathway / 中国医师杂志

Objective To explore the impact of puerarin treatment on autophagy in rats with traumatic brain injury (TBⅠ) and the underlying mechanism.Methods Seventy five Sprague-Dawley (SD) rats were randomized into 5 groups:sham group (S group,n =15),traumatic brain injury group (TBⅠ group,n =15),TBⅠ + puerarin treatment group (TBⅠ + Pue group,n =15),TBⅠ + JNK inhibitor group (TBⅠ + SP group,n =15),and TBⅠ + JNK activator + Pue (TBⅠ + An + Pue group,n =15).Feeney method was applied to make rats with TBⅠ model.Mter that,head water content and neurological deficit score (NDS) were measured and recorded at day 1,3 and 7 in each group.Western blot was used to measure the JNK activity and autophagic marker proteins,including LC3B and Beclin1.Results Compared to S group,the head water content and NDS were decreased significantly among the others (P ＜ 0.05).The head water content and NDS in TBⅠ + Pue and TBⅠ + SP groups was decreased remarkably compared with TBⅠ group.Combined with puerarin and animycin treatments failed to reduce head water content and NDS compared to the TBⅠ + Pue group.Activated autophagy could be observed in TBⅠ group compared to S group.Compared to group S,LC3Ⅱ,Beclin1 and P-JNK1 were increased significantly.Pue and SP could reduce their expressions,respectively.Combined with puerarin and animycin treatments failed to reduce LC3Ⅱ,Beclin1 and P-JNK1 compared to TBⅠ + Pue group.Conclusions Puerarin could protect rats with TBⅠ via inhibiting autophagy,JNK signal pathway could involve the process of puerarin regulating autophagy.

Effects of asymmetric dimethylarginine on apoptosis and expression of c-Jun N-terminal kinase in endothelial outgrowth cells / 天津医药

Objective To investigate the effects of asymmetric dimethylarginine (ADMA) on apoptosis and phosphorylation of c-jun N-terminal kinase (JNK) in endothelial outgrowth cells (EOCs). Methods The mononuclear cells were harvested from umbilical cord blood by ficoll density gradient centrifugation, and induced into EOCs and then expanded in vitro. The identified EOCs were treated with different concentrations of ADMA (0, 1, 5, 10, 20 μmol/L) for 48 h. The adherent cells were treated with 10 μmol/L ADMA,then different concentrations of JNK specific inhibitor SP600125 (0, 5,10,20 and 40 μmol/L) were added and incubated for 48 hours. Caspase-3 activity was measured by microplate reader. Apoptotic incidences of EOCs were quantitatively determined by flow cytometry. The expression of Caspase- 3 and phosphorylase-JNK (p-JNK) were detected by Western blot assay. Results The treatment of ADMA (1-20 μmol/L) significantly induced apoptosis in EOCs by enhancing Caspase-3 express and also induced phosphorylation of JNK (P<0.05). Meantime, the JNK specific inhibitor SP600125 could attenuate the apoptosis induced by ADMA during this process (F=6.733,P<0.05) and inhibit the expression of Caspase-3 and p-JNK. Conclusion ADMA can induce apoptosis in EOC, which may be achieved by activating JNK signal transduction pathway.

Role of c-Jun N-terminal kinase in activation of astrocytes in midbrain periaqueductal gray of rats with neuropathic pain / 中华麻醉学杂志

Objective To evaluate the role of c-Jun N-terminal kinase (JNK) in activation of astrocytes in midbrain periaqueductal gray (PAG) of rats with neuropathic pain.Methods A total of 72 pathogen-free male Sprague-Dawley rats,aged 9 weeks,weighing 160-200 g,were divided into 4 groups using a random number table:control group (group C,n =8),neuropathic pain group (group NP,n =40),dimethyl sulfoxide control group (group DS,n =12) and JNK inhibitor SP600125 group (group SP,n=12).Neuropathic pain was produced by chronic constriction injury (CCI).At 14 days after CCI,10 nmol JNK inhibitor SP600125 0.5 μl was intraperitoneally injected into the PAG in group SP,and 10％ dimethyl sulfoxide 0.5 μl was given instead in group DS.Eight rats were selected in group C,before CCI and at 3,7,14 and 21 days after CCI in group NP,and in DS and SP groups,and the mechanical pain threshold was measured before CCI,before administration on 14 days after CCI and at 30,45,60,75 and 90 min after administration.The rats in group C were sacrificed after the end of measurement of the mechanical pain threshold,and brains were removed for determination of phosphorylated JNK (p-JNK) and glial fibrillary acidic protein expression (by Western blot) in PAG region.The rats in group NP were sacrificed after the end of measurement of the mechanical pain threshold at each time point,and brains were removed for detection of p-JNK expression in PAG region.Four rats in DS and SP groups were sacrificed after the last measurement of the mechanical pain threshold at 45 min after administration,and brains were removed for determination of glial fibrillary acidic protein expression in PAG region.Results Compared with group C,the mechanical pain threshold was significantly decreased at each time point after CCI,and the expression of p-JNK was up-regulated at 7-21 days after CCI in group NP (P＜0.01).Compared with group DS,the mechanical pain threshold was significantly increased at 30 min after administration,and GFAP expression was down-regulated at 45 min after administration in group SP (P＜ 0.01).The mechanical pain threshold was significantly higher at 30-75 min after administration than before administration in group SP (P＜0.01).Conclusion The mechanism underlying activation of astrocytes in PAG is related to activating JNK in the rats with neuropathic pain.

Intrathecal injection of oxycodone hydrochloride reduces neuropathic pain in rat model of chronic constriction injury via inhibition of microglial c-JNK/CXCL1 signal / 中国医师杂志

Objective To observe the effect of intrathecal injection (IT) of oxycodone hydrochloride on neuropathic pain and spinal cord level of microglial c-Jun N-terminal kinase/chemokine (C-X-C motif) ligand 1 (c-JNK/CXCL) 1signal in rat model of chronic constriction injury (CCI).Methods Male Sprague-Dawley rats were randomly divided into five groups (n =40 per group):sham group (intrathecal normal saline,IT NS),CCI group (CCI + IT NS),oxy group (CCI + IT 5 μg/30 μl oxy),mino group (CCI + IT 5 μg/30 μl Minocycline),and c-JNK inhibitor group (SP group,CCI + IT 5 μg/30 μl SP600125).The lumbar intrathecal catheters were implanted in L5-6 of rats and CCI models were established as previously described.The thermal and mechanical nociceptive thresholds were assessed by paw withdrawal latency (PWL) to radiant heat and von Frey filaments.The oxycodone,minocycline and SP600125 were administered intrathecally for 3 days before surgery.The spinal cord expression of Ⅰ ba-1,p-c-JNK and CXCL1 proteins assessed by Western blot.Immunofluorescence staining was performed to examine microglia morphology and the number of Ⅰ ba-1 positives cells in dorsal horn of injured spinal cord at 7 days post-IR.Results Compared to sham group,rats in CCI group had significantly lower mechanical and thermal pain thresholds,but higher spinal proteins expression of Ⅰ ba-1,and p-c-JNK and CXCL1 (P ＜0.05).Rats in oxy group,mino group and SP group had significantly higher mechanical and thermal pain thresholds and significantly lower proteins expression of Ⅰ ba-1,p-c-JNK and CXCL1 compared to those in CCI group (at any observed time-point after ligation,but most significantly at 7days,P ＜ 0.05).At the 7days after surgery,microglial cells in CCI group transformed from the ramified shape to amoeboid macrophage-like shape by immunofluorescence staining with the increases of Ⅰ ba-1 positive cells;while the other three groups exhibited hypertrophic morphology with less number Ⅰ ba-1 positive cells (P ＜ 0.05).There were no significant differences between these three groups at any observed time (P ＞ 0.05).Conclusions Intrathecal injection of oxycodone hydrochloride can relieve CCI-induced neuropathic pain by down-regulation microglial c-JNK/CXCL1 signal in spinal cords.Provide new therapeutic targets for clinical treatment of neuropathic pain.

Role of JNK signaling pathway in hyperoxia-induced expression of connective tissue growth factor in A549 cells / 中华麻醉学杂志

Objective To investigate the role of c-Jun N-terminal kinase (JNK) signaling pathway in hyperoxia-induced expression of connective tissue growth factor (CTGF) in A549 cells.Methods The cultured A549 cells were seeded in 6-well culture plates at a density of 1 × 105 cells/ml (0.5 ml/well,24 wells in total) and were randomly divided into 4 groups (n =6 each) using a random number table:control group (group C);95％ oxygen group (group 95％ O2);room air plus SP600125 (JNK inhibitor) group (group C+SP);95％ oxygen plus SP600125 group (group 95％ O2+SP).SP600125 5 μmol/L was added to each well in C+SP and 95％ O2+SP groups.The A549 cells were incubated for 48 h in an incubator filled with room air (C and C+SP groups) or 95％ oxygen (95％ O2 and 95％ O2+SP groups).The expression of phosphorylated JNK (p-JNK) and CTGF mRNA was determined using Western blot and realtime reverse transcriptase polymerase chain reaction,respectively.Results Compared with group C,no significant change was found in the expression of p-JNK and CTGF mRNA in group C+SP (P＞0.05),and the expression of p-JNK and CTGF mRNA was significantly up-regulated in group 95％ O2 (P＜ 0.05).Compared with group 95％ O2,the expression of p-JNK and CTGF mRNA was significantly down-regulated in group 95％ O2+SP (P＜0.05).Conclusion JNK signaling pathway activation is involved in up-regulation of hyperoxia-induced CTGF mRNA expression in A549 cells.