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Protein kinase Cε (PKCε) is a transforming oncogene and plays an important role in many cellular processing. In the present paper, we review the development of experimental researches on the acute-chronic pain transformation. Results indicated that prostaglandin E2 (PGE2) / EP1 receptor-Gq-PKCε is an important signaling pathway to modulate chronic pain in peripheral dorsal root ganglion (DRG) neurons, and also plays a role in the later stage of hyperalgesia during transformation from acute to chronic pain. PKCε in DRG neurons induces mechanical and thermal hypersensitivity respectively by over expression of transient receptor potential vanilloid 1 (TRPV1) and TRP ankyrin-1 (TRPA1), further mediating the transformation from acute to chronic pain. Whereas, PGE2-evoked activation of EP1-Gq-PKCε signaling may be the key link in initiating the pain translation process through regulating downstream TRPA1 and TRPV1. Electroacupuncture (EA) has been used to effectively relieving various types of acute and chronic pain for decades, and can significantly inhibit the expression of PKCε and its upstream and downstream molecules. Therefore, it can be inferred that there exists a possibility of EA interventions in interfering the transformation from acute to chronic pain by regulating peripheral PKCε signaling pathway.
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Objective To investigate the effects of remote ischemic preconditioning(RIPC)on the expression of brain-derived neurotrophic factor(BDNF),Serine/threonine protein kinase Cε(PKCε)in spinal cord tissues and change in mRNA content after spinal cord ischemic reperfusion injury(SCIRI). Methods A total of 36 cases of Japanese white rabbits were randomly divided into sham(group S),is-chemic reperfusion injury(group IR)and group IR+ RIPC(12 rabbits in each group).Each group was further divided into two sub-groups according to time points after reperfusion(2 and 5 days),six rabbits of each group were sacrificed at each time point.In group S,abdominal aorta were only separated and ex-posed and were not camped.In group IR and group IR+RIPC,the abdominal aorta were camped for 30 min,and the SCIRI models were established.In group IR+RIPC,RIPC was performed 1 h before aortic calmping.Hind-limb neurological function of each group was evaluated using Tarlov Scale at 2,5 d after surgery,then rabbits were sacrificed,and L4-L6 spinal cord segments were taken.Pathological change in spinal cord tissues were observed,the protein and mRNA expression of BDNF and PKCε were detected by Western blotting analysis and PT-PCR.Results In comparison with group IR,hind-limb neurologic func-tion scores at the same time point were significantly higher(P<0.05),and the protein and mRNA expres-sion of BDNF and PKCε were significant increased in group IR+RIPC(P<0.05).Conclusion RIPC has an important role in prevention and treatment of SCIRI in rabbits.The mechanisms may be that RIPC activates the PKCε/PKC signaling pathway and up-regulates the expression of BDNF and PKCε in spinal cord tissues after spinal cord injury.
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OBJECTIVE: To observe the effect of electroacupuncture (EA)on mechanical pain transition and content of protein kinase C epsilon(PKCε)in dorsal root ganglia (DRG) in inflammatory articular pain rats，so as to explore its peripheral mechanism underlying relieving transition from acute to chronic pain. METHODS: 1)In the first part of the present study，male SD rats were equally randomized into blank control，sham hyperalgesic priming(HP), and real HP groups(n＝6 in each). The HP model was established by subcutaneous injection of 1% carrageenan (100 µL) into the left hind paw (the first injection)，followed by injection of PGE 2 (100 ng/25 µL, the second injection) into the dorsum pedis of the same hind paw 7 days after the first injection. The mechanical withdrawal threshold (MWT) of the ipsilateral paw was detected before and 4, 24, 48, 72 h, and 7 d after the first injection，and 1, 4, 24 and 48 h after the second injection. 2) In the second part，SD rats were randomly divided into sham-HP，real HP，sham-EA and EA groups(n＝6 in each). The sham-HP and HP models were made in the same way as those in the first part. Bilateral "Zusanli"(ST 36)and "Kunlun"(BL 60)were punctured with filiform needles and also stimulated with electrical current：2 Hz/100 Hz，0.5－1.5 mA(0.5 mA increase per 10 min)for 30 min，1 time/d from the 1st carrageenan injection on till the end of the experiments. PKCε protein expression in the L 4－L 6 DRGs was assayed by Western blot 48 h after the second injection. RESULTS: 1)In the first part of the study，compared with the sham-HP group，the MWT at 4, 24、48 h after carrageenan injection and 4, 24 and 48 h after PGE 2 injection were significantly decreased in the HP model group(P<0.01). 2)In the second part，compared with the HP group，the MWT at 24、48 and 72 h after carrageenan injection, and 24 and 48 h after PGE 2 injection were significantly up-regulated in the EA group(P<0.05，P<0.01). 3)The relative content of PKCε in the DRGs(L 4－L 6)was significantly higher in the HP group than in the sham-HP group(P<0.01)，but considerably lower in the EA group than in the HP group (P<0.01)．. CONCLUSION: EA has a good effect on pain conversion in inflammatory joint pain rats，which may be related to its effect in down-regulating the PKCε level in the ipsilateral lumbar DRGs.
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AIM: In this study, CD147 antibody was used to carry out targeted modification of nanoparticles for protein kinase Cε (PKCε)-siRNA gene therapy to target lung cancer cells.The inhibitory effects of the nanoparticles on the proliferation and invasion of the lung cancer cells were observed.METHODS: The magnetic nanoparticles targeting CD147 protein were assembled as gene vector.The expression of CD147 in the lung cancer cells was observed under laser scanning confocal microscope.The cells were divided into CP group, CN group and LP group as the experimental groups. Targeted nanoparticles were used as CA group.Non-transfected cells were used as control group.The cell transfection was carried out with 250 ng plasmids/well in 6-well plate.The effect of nanocontrast agent on the cell endocytosis was observed under laser scanning confocal microscope.The mRNA expression of PKCε was detected by RT-qPCR.The protein expres-sion of Ki67, MMP3, PKCε, Wnt1 and GAPDH was determined by Western blot.The cell proliferation ability was detec-ted with colony formation assay.The cell invasion ability was detected by Transwell method.RESULTS: The expression of CD147 protein in the human lung cancer A549 cells was confirmed by immunofluorescence staining.The endocytosis of siRNA into the A549 cells in CP group was observed with the highest efficiency as compared with CN group and LP group. The relative mRNA expression of PKCε in the A549 cells of CP group, CN group, LP group and CA group were (9.76 ± 0.18)%, (98.51 ±0.32)%, (99.17 ±0.16)% and (99.68 ±0.11)%, respectively.The difference between CP group and control group was statistically significant (P <0.05).No significant difference among CN group, LP group and control group was observed.The protein expression of PKCε, Ki-67, MMP3 and Wnt1 in CP group was significantly reduced, and the protein expression levels among CN group, LP group and control group had no significant difference.The colony number in CP group was significantly smaller than that in control group (P <0.05).The effective colony numbers in CN group, LP group and CA group had no significant difference as compared with control group.The number of the invading cells in CP group was significantly less than that in control group (P <0.05).The numbers of the invading cells in CN group, LP group and CA group had no significant difference as compared with control group.CONCLUSION: Nanogene vector targe-ting CD147 can carry PKCε-siRNA to conduct gene therapy efficiently on the lung cancer cells to achieve effective inhibito-ry effects on the proliferation and invasion of the lung cancer cells.
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AIM:To observe the therapeutic effect of glucagon-like peptide 1 (GLP-1) analog on nonalcoholic fatty liver disease of rats and to investigate the underlying mechanism.METHODS:SD rats (n=21) were used to estab-lish a nonalcoholic fatty liver disease model by feeding a high fat diet for 12 weeks, and other 11 rats were fed with a normal diet for 16 weeks.The model rats were randomly divided into 2 equal groups:one group was treated with glucagon-like pep-tide 1 analog (0.6 mg· kg-1 · d-1 ) by intraperitoneal injection for 4 weeks, the other group using saline as a control.Af-ter treatment, fasting blood glucose, serum insulin, blood lipids, liver function and the pathological changes of the hepatic tissues were evaluated and the expression of PKCεat mRNA and protein levels in the liver tissues was detected by real-time PCR and Western blot, respectively.RESULTS:Compared with model group, the intervention of GLP-1 significantly re-duced insulin resistance index (HOMA-IR), improved the liver function (P<0.05), decreased the liver index and blood lipids (P<0.05).HE staining showed obvious pathological changes of the hepatic tissues in model group, and the inter-vention of GLP-1 significantly reduced lipid droplets in the hepatocytes and improved the structural damage of the liver.The expression of hepatic protein kinase Cε( PKCε) at mRNA and protein levels significantly decreased which were reversed by treating with GLP-1.CONCLUSION:GLP-1 shows good therapeutic effect on nonalcoholic fatty liver disease of rats, pos-sibly by controlling lipid metabolism and reducing insulin resistance, which may be related to PKCεexpression.
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AIM:To investigate the inhibitory effect of small interfering RNA ( siRNA) on the expression of protein kinase Cε( PKCε) in human hepatoma SK-Hep-1 cells, and the biological behaviors of the transduced cells , inclu-ding proliferation and invasion , were investigated.METHODS:The cultured SK-Hep-1 cells were divided into 3 groups, including PKCε-siRNA group , negative control ( NC)-siRNA group and control group .MTT assay was used to analyze the proliferation of the SK-Hep-1 cells in the respective groups , while invasion potency was determined by Transwell assay .The protein levels of functional biomarkers such as Ki 67 and matrix metalloproteinase 9 ( MMP-9 ) were measured by Western blotting .The Luciferase reporter gene assay was used to explore the activity of the NF-κB pathway .RESULTS:PKCεex-pression in SK-Hep-1 cells transfected with PKCε-siRNA was significantly down-regulated at both mRNA and protein levels compared with that in the normal SK-Hep-1 cells (P<0.01), with the decreases in the protein levels of Ki67 and MMP-9. The invasion and proliferation of SK-Hep-1 cells were obviously inhibited in PKCε-siRNA group compared with control group (P<0.01).Furthermore, the transcriptional activity of NF-κB was down-regulated when PKCε was effectively in-hibited by PKCε-siRNA (P<0.01).CONCLUSION:Down-regulation of PKCεinhibits the proliferation and invasion of hepatic carcinoma cells , which might be mediated via the NF-κB signaling pathway .
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ObjectiveTo explore the expression of novel protein kinase C ε (PKCε) in normal prostate (NP) tissue, benign prostate hyperplasia(BPH), peficancerous (PC) tissue and prostate cancer (Pca), and study its correlation with the grade and stage of Pca.MethodsTen NP slides, ten BPH slides, ten PC slides and 43 Pca slides were collected from our hospital. These slides were routinely proceased and analyzed according to the requirement of immunohistochemical staining. Tumors were classified according to the 2002 TNM staging system. The grading system used in the study was based on the Gleason grade.ResultsWe was found that the expression of PKCεs in Pca (27/43) were significantly higher than those in NP(1/10), BPH (0/10) and PC (2/10) tissue, and the difference was statistically significant ( P ＜0.05 ). With regard to grade of prostate cancer, the expression of PKCε in Pca with Gleason score ≥8 group (12/13) was higher than the Gleason score 2 -4 group (4/10) and the Gleason score 5 -7 group (11/20). The difference was statistically significant (P ＜ 0.05 ). Moreover, the T3 and T4 stages had a more positive rate (10/12 & 9/10) than the T1 and T2 stages( 1/6 &7/15). There is statistically significant difference between early and advanced stage of prostate cancer ( P ＜ 0. 05 ). Furthermore, the positive expression of PKCε in prostatic carcinoma samples increased significantly in the metastasis group (9/10)compared to the non-metastasis group ( 18/33 ) ( P ＜ 0. 05 ), but the difference was not statistically significant between the concentration of prostate-specific antigen in blood serum ( P ＞ 0. 05 ).Conclusions PKCε is expressed in prostate cancer, and it correlates with the grade and stage of prostate cancer. PKCε may be related to the origin and the development of Pca, and it may be used as a prognostic factor for Pca.
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Objective Identify novel protein kinase Cε(nPKCε)-interacted proteins in the cortex of hypoxic preconditioned mice.Methods Immunoprecipitation (IP) and two-dimensional electrophoresis (2-DE) combining with ImageMaster 2D Platinum software were applied to analyze the differential expressions of nPKCe-interacted proteins;the target protein spots were identified by matrix-associated laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and Western blot.Results Compared with control group,there were 34 upregulated protein spots and 20 downregulated protein spots in cytosolic fraction,while 27 upregulated prtein spots and 28 downregulated protein spots were determined in particulate fraction of cerebral cortex of HPC mice.The levels of nPKCε-interacted HSP 70 and 14-3-3γ/protein expressions increased significantly in both cytosolic and particulate fractions;but the protein level of nPKCε-interacted HSP60 increased only in particulate fraction of cerebral cortex of HPC mice.Conclusion nPKCε might be involved in the development of cerebral HPC via the regulation of its interacted proteins such as HSP60,HSP70 and 14-3-3γ.