Neuroprotective effect and mechanism of cPLA2 inhibitor increases autophagic flux on spinal cord injury / 中国骨伤

OBJECTIVE@#To investigate the mechanism of cytosolic phospholipase A2(cPLA2) inhibitor to improve neurological function after spinal cord injury (SCI).@*METHODS@#Thirty-six 3 months old female SD rats, with body mass (280±20) g, were divided into three groups (n=12):sham group, SCI group, and SCI+ arachidonyl trifluoromethyl ketone(AACOCF3) group. Balloon compression SCI model was established in all three groups. In the sham model group, the spinal cord compression model was created after the balloon was placed without pressure treatment, and the remaining two groups were pressurized with the balloon for 48 h. After successful modeling, rats in the SCI+AACOCF3 group were injected intraperitoneally with AACOCF3, a specific inhibitor of cPLA2. The remaining two groups of rats were injected intraperitoneally with saline. The animals were sacrificed in batches on 7 and 14 days after modeling, respectively. And the damaged spinal cord tissues were sampled for pathomorphological observation, to detect the expression of cPLA2 and various autophagic fluxPrelated molecules and test the recovery of motor function.@*RESULTS@#Spinal cord histomorphometry examination showed that the spinal cord tissue in the sham group was structurally intact, with normal numbers and morphology of neurons and glial cells. In the SCI group, spinal cord tissue fractures with large and prominent spinal cord cavities were seen. In the SCI+AACOCF3 group, the spinal cord tissue was more intact than in the SCI group, with more fused spinal cord cavities, more surviving neurons, and less glial cell hyperplasia. Western blot showed that the sham group had the lowest protein expression of LC3-Ⅱ, Beclin 1, p62, and cPLA2 compared with the SCI and SCI+AACOCF3 groups (P<0.05) and the highest protein expression of LC3-Ⅰ (P<0.05). P62 and cPLA2 expression in the SCI group were higher than in the SCI+AACOCF3 group (P<0.05). Behavioral observations showed that the time corresponding to BBB exercise scores was significantly lower in both the SCI and SCI+AACOCF3 groups than in the sham group (P<0.05). Scores at 3, 7, and 14 days after pressurization were higher in the SCI+AACOCF3 group than in the SCI group (P<0.05).@*CONCLUSION@#cPLA2 inhibitors can reduce neuronal damage secondary to SCI, promote neurological recovery and improve motor function by improving lysosomal membrane permeability and regulating autophagic flux.

Leptin promotes the neurorehabilitation of seizure-induced brain damage / 中华物理医学与康复杂志

Objective To explore the effect of leptin on neurorehabilitation and on the expression of dopamine receptor D2 (Drd2) and cytosolic phospholipase A2 (cPLA2) in the cerebral cortex after convulsive brain injury.Methods Five-day-old Sprague-Dawley rats were randomly assigned to a control group (CONT),a leptin injection control group (Leptin),a seizure group (RS),or a seizure with leptin injection group (RS+Leptin).The rats in the RS group and the RS+Leptin group were injected intraperitoneally with lithium chloride (5 mEq/kg) and pilocarpine (320 mg/kg) on day 6,and then scopolamine methyl chloride (1 mg/kg) 30 minutes later to block the peripheral effect of pilocarpine.The animals in the Leptin and RS+Leptin groups were then given leptin (4 mg/kg,i.p.) injections daily from days 8 to 14.The animals' plane righting reflex and negative geotaxis reaction reflex were observed on day 23.The open field test was performed on D30.Real-time reverse-transcription polymerase chain reactions (RT-PCRs) were used to detect the expression of Drd2 and cPLA2 mRNA in the rats' cerebral cortexes on day 34.Results There were significant differences in the plane righting times and negative geotaxis reflexes among the four groups,with those in the RS and RS+Leptin groups significantly longer than among the controls.Both reflexes were significantly quicker in the RS + Leptin group than in the RS group.There were also significant differences in the locomotor scores in the open field test among the four groups,with the average scores in the RS and RS+Leptin groups significantly higher than in the other two groups.The RS+Leptin group's average was significantly higher than that of the RS group.The expression of Drd2 was significantly higher in the leptin,RS and leptin +RS groups than in the control group,and that of the RS and leptin+RS groups was significantly higher than that of the Leptin control group.The expression of cPLA2 in the Leptin and RS groups was significantly higher than in the CONT group,while that of the RS + Leptin group was significantly lower than in the Leptin and RS groups.Conclusions Leptin has a neurorehabilitation effect on the behavioral impairment caused by seizures,at least in neonatal rats.Its neuroprotective mechanism may be related to the regulation of Drd2-mediated cPLA2 expression in the cerebral cortex.

Imperatorin Suppresses Degranulation and Eicosanoid Generation in Activated Bone Marrow-Derived Mast Cells

Imperatorin has been known to exert many biological functions including anti-inflammatory activity. In this study, we investigated the inhibitory effects of imperatorin on the production of inflammatory mediators in mouse bone marrow-derived mast cells (BMMC). Imperatorin inhibited degranulation and the generation of eicosanoids (leukotriene C4 (LTC4) and prostaglandin D2 (PGD2)) in IgE/antigen (Ag)-stimulated BMMC. To elucidate the molecular mechanism involved in this process, we investigated the effect of imperatorin on intracellular signaling in BMMC. Biochemical analyses of the IgE/Ag-mediated signaling pathway demonstrated that imperatorin dramatically attenuated degranulation and the production of 5-lipoxygenase-dependent LTC4 and cyclooxygenase-2-dependent PGD2 through the inhibition of intracellular calcium influx/phospholipase Cgamma1, cytosolic phospholipase A2/mitogen-activated protein kinases and/or nuclear factor-kappaB pathways in BMMC. These results suggest that the effects of imperatorin on inhibition of degranulation and eicosanoid generation through the suppression of multiple steps of IgE/Ag-mediated signaling pathways would be beneficial for the prevention of allergic inflammation.

Epidural Dexamethasone Decreased Inflammatory Hyperalgesia and Spinal cPLA2 Expression in a Rat Formalin Test

PURPOSE: The aim of this study was to investigate the effect of epidural dexamethasone on analgesia and cytosolic phospholipase A2 (cPLA2) expression in the spinal cord in a rat formalin test. MATERIALS AND METHODS: Epidural dexamethasone injection was performed to Sprague-Dawley rats with a 25 gauge needle under fluoroscopy. Following the epidural injection, a formalin induced pain behavior test was performed. Next, the spinal cords corresponding to L4 dorsal root ganglion was extracted to observe the cPLA2 expression. RESULTS: There were no differences in pain response during phase I among the groups. The phase II pain response in 300 microg of epidural dexamethasone group decreased as compared to control, 30 microg of epidural dexamethasone, 100 microg of epidural dexamethasone, and 300 microg of systemic dexamethasone groups. The expression of cPLA2 decreased in Rexed laminae I-II in 300 microg of the epidural dexamethasone group compared with the ones in the control group. CONCLUSION: Taken together, these results suggest that 300 microg of epidural dexamethasone has an attenuating effect on the peripheral inflammatory tissue injury induced hyperalgesia and this effect is mediated through the inhibition of intraspinal cPLA2 expression and the primary site of action is the laminae I-II of the spinal cord.

Anti-proliferative efficacy comparison of conjugated linoleic acid on human cancer cell lines / 동물의과학연구지

The anti-proliferative efficacy of t,t-conjugated linoleic acid (t,t-CLA), c9,t11-CLA, and t10,c12-CLA was compared in several human cancer cell lines. Gastric NCI-N87, liver Hep3B, pancreas Capan-2, and lung NCI-H522 cancer cells were incubated with 50 microM CLA isomers over a period of 6 days. The t,t-CLA inhibited the growth of all cancer cell lines to different extents, but c9,t11-CLA and t10,c12-CLA inhibited or stimulated the growth of the cancer cell lines. NCI-N87 cells were the most sensitive to growth inhibition and apoptosis from all CLA isomers tested. In NCI-N87 cells, CLA isomers reduced the release of arachidonic acid (AA) via the inhibition of cytosolic phospholipase A2 (cPLA2) activity, consequently reducing the production of PGE2 through the inhibition of cyclooxygenase-2 (COX-2). The efficacies of CLA isomers were in the following order (from most to least effective): t,t-CLA, t10,c12-CLA and c9,t11-CLA. Overall, these results imply that the anti-proliferative efficacy of t,t-CLA on cancer cells, especially NCI-N87 cells, was greater than other CLA isomers due to its induction of apoptosis through the inhibition of cPLA2 and COX-2 activities.

Prognostic significance of cytosolic phospholipase A2 expression in patients with colorectal cancer / 대한외과학회지

PURPOSE: Cyclooxygenase-2 is believed to be an important enzyme in the pathogenesis of colorectal cancer (CRC). Cytosolic phospholipase A2 (cPLA2), also, have been suggested to be related to the carcinogenesis of CRC. The aim of this study was to investigate cPLA2 expression and its relationship with prognostic significance in CRC. METHODS: Eighty-eight patients with colorectal cancer who underwent curative surgery were enrolled in this study. cPLA2 was examined in 88 primary CRCs by immunohistochemistry and we compared their expression with clinicopathologic findings, recurrence and survival in patients with CRC. RESULTS: The expression of cPLA2 was positive in 54.5% (48/88). The expression of cPLA2 was not correlated with clinicopathologic parameters. However, cPLA2 expression was significantly related with vascular endothelial growth factor expression. Kaplan-Meier analysis didn't show any clinical significance in disease-free survival and overall survival according to cPLA2 expression. CONCLUSION: These results suggest that cPLA2 expression was not associated with the prognosis of CRC. However, further large-scale studies are needed to clarify the prognostic effect of cPLA2 in CRC.

Expression of cytosolic phospholipase A2, 5-lipoxygenase and LTC4 synthetase mRNA in the peripheral polymorphonuclear leukocytes of patients with systemic lupus erythematosus / 中华风湿病学杂志

0.05, both). The mean levels of 5-LO and LTC4-S mRNA expression in active SLE group were significantly higher than those in normal controls respectively (P0.05). Conclusion The levels of 5-LO and LTC4-S mRNA expression in active SLE group increase markedly, which may be involved in the pathogenesis of SLE and provide a valuable scientific basis for the clinical use of specific 5-LO inhibitors and cysteinyl leukotrienes receptor antagonists.

Mechanisms for protection of berberine against LPS-induced acute lung injury in mice / 中国病理生理杂志

AIM: To investigate the mechanisms by which berberine attenuates LPS-induced acute lung injury, and provide a new strategy for the treatment of the lung injury due to LPS. METHODS: BALB/c mice were randomly assigned into three groups (control, LPS group, and berberine treatment group). Mice were administered intragastrically with distilled water (0.1 mL/10 g) or neutral sulfate berberine (50 mg/kg) once a day for 3 days, 1 h after intragastrical treatment on day 3, LPS (20 mg/kg) or normal saline was injected intraperitoneally (ip). All animals were sacrificed 12 h after LPS injection, the left lung tissue sections were prepared for histology analysis and the right lung were used to determine the ratio of wet to dry lung tissue weight (W/D). In another experiment, bronchoalveolar lavage fluid (BALF) was collected, and then the total protein content, and the amounts of white blood cells (WBC) and polymorphonuclear neutrophils (PMN) in BALF were determined. Furthermore, the phosphorylation of cytosolic phospholipase A2 (cPLA2) was detected with immunohistochemical analysis by using phospho-cPLA2(Ser505) antibody, and the contents of thromboxane B2 (TXB2) in BALF, malondialdehyde (MDA) in the lungs, and activity of superoxide dismutase (SOD) in lung tissues were also determined.RESULTS: LPS induced acute lung injury, activated cPLA2, and increased TXB2 content in the BALF and MDA level in the lung tissue. The pretreatment with berberine significantly attenuated lung injury, lung edema and protein leakage induced by intraperitoneal injection of LPS. The expression of phospho-cPLA2 in the lung tissues and TXB2 content in the BALF in the berberine treatment group were lower than those in LPS group (P0.05). CONCLUSION: Pretreatment with berberine remarkably reduces the LPS-induced lung injury, which is, at least in part, through inhibiting phosphorylation of cPLA2 and decreasing lipid peroxidation. These findings provide a new strategy for the prevention and treatment of LPS-induced acute lung injury.