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Objective:To evaluate the role of secreted protein acidic and rich in cysteine like protein 1 (SPARCL1) in spinal dorsal horns in the development of remifentanil-induced hyperalgesia in mice with incisional pain.Methods:Forty-eight healthy male C57BL/6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 6 groups ( n=8 each) using a random number table method: control group (group C), incisional pain group (group I), remifentanil group (group R), incisional pain plus remifentanil group (group I+ R), incisional pain plus remifentanil plus negative control group (group I+ R+ N), and incisional pain plus remifentanil plus SPARCL1-siRNA group (group I+ R+ S). In I+ R+ N and I+ R+ S groups, 1×10 8 IFU/ml negative control siRNA and SPARCL1-siRNA 10 μl were intrathecally injected, respectively, once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected once a day for 3 consecutive days in C, I, R and I+ R groups.After transfection was stable, normal saline 0.1 ml was intravenously injected through the tail vein for 4 consecutive times at 15 min interval in C and I groups, and remifentanil 10 μg/kg (diluted to 0.1 ml in normal saline) was intravenously injected via the tail vein for 4 consecutive times at 15 min interval in R, I+ R, I+ R+ N and I+ R+ S groups.The incisional pain model was established after the first administration via the tail vein in R, I+ R, I+ R+ N and I+ R+ S groups.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 24 h before infusing normal saline or remifentanil (T 0) and 3, 6, 24 and 48 h after stopping infusion (T 1-4). Animals were sacrificed after measuring pain threshold at T 4, and L 4-6 segments of the spinal cord were removed for determination of the expression of SPARCL1 protein and mRNA by Western blot and quantitative real-time polymerase chain reaction, respectively. Results:Compared with group C, MWT was significantly decreased and TWL was shortened at T 1-4 in I+ R and I+ R+ N groups and at T 2-4 in I, R and I+ R+ S groups, and the expression of SPARCL1 protein and mRNA was significantly up-regulated in R, I+ R and I+ R+ C groups ( P<0.05 or 0.01). Compared with group I and group R, MWT was significantly decreased, TWL was shortened, and the expression of SPARCL1 protein and mRNA was up-regulated in group I+ R ( P<0.01). Compared with group I+ R, MWT was significantly increased and TWL was prolonged at T 1-4, and the expression of SPARCL1 protein and mRNA was down-regulated in group I+ R+ S ( P<0.05 or 0.01). Conclusion:Enhanced activity of SPARCL1 in the spinal dorsal horns is involved in the development of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective@#To evaluate the role of neuroligin 1 (NL-1) in trafficking of GluR1-containing AMPA receptor to cell membrane in spinal cord dorsal horns during remifentanil-induced hyperalgesia in mice with incisional pain.@*Methods@#Forty SPF healthy male C57BL/6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 5 groups (n=8 each) using a random number table method: control group (group C), NL1-shRNA plasmid group (group NL), incisional pain plus remifentanil group (group I+ R), incisional pain plus remifentanil plus blank vector group (group I+ R+ B), and incisional pain plus remifentanil plus NL-1-shRNA plasmid group (group I+ R+ NL). Negative lentivirus was intrathecally injected in group I+ R+ B.In NL and I+ R+ NL groups, 10 μl NL-1-shRNA lentivirus at 1×108 IFU/ml was intrathecally injected once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected at the same time point in C and I+ R groups.After transfection was stable, normal saline 0.1 ml was injected via the caudal vein for 4 consecutive times at 15 min intervals in C and NL groups.In I+ R, I+ R+ B and I+ R+ NL groups, 0.1 ml remifentanil 10 μg/kg was injected via the caudal vein for 4 consecutive times at 15 min intervals, and the model of incisional pain was established after the first administration.The mechanical paw withdrawal threshold (MWT) and tail-flick latency (TFL) were measured at 24 h before normal saline or remifentanil administration (T0) and at 3, 6, 24 and 48 h after the end of administration (T1-4). The animals were sacrificed after measurement of pain threshold at T4, and L4-6 segments of the spinal dorsal horn were then collected for determination of the expression of NL-1 protein and mRNA and AMPA receptors, and the ratio of AMPA receptor expression in the membrane protein to that in the total protein (m/t ratio) was calculated.@*Results@#Compared with group C, the MWT was significantly decreased, and TFL was shortened at T1-4, the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was up-regulated, and m/t ratio was increased in I+ R and I+ R+ B groups (P<0.05). Compared with I+ R and I+ R+ B groups, the MWT was significantly increased and TFL was prolonged at T1-4, the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was down-regulated, and m/t ratio was decreased in group I+ R+ NL (P<0.05).@*Conclusion@#NL-1 in spinal cord dorsal horns can promote the trafficking of GluR1-containing AMPA receptors to cell membrane, which is involved in the development and maintenance of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective@#To evaluate the role of spinal COX-1 and COX-2 in remifentanil-induced hyperalgesia in mice with incisional pain.@*Methods@#Thirty-two male C57BL/6J mice, aged 8-10 weeks, weighing 20-25 g, were divided into 4 groups (n=8 each) using a random number table method: control group (group C), incisional pain plus remifentanil group (group IR), incisional pain plus remifentanil plus selective COX-1 inhibitor group (group IR+ SC560), and incisional pain plus remifentanil plus selective COX-2 inhibitor group (group IR+ SC236). In IR, IR+ SC560 and IR+ SC236 groups, normal saline 10 μl, SC560 25 μg and SC236 25 μg were intrathecally injected, respectively, 15 min later remifentanil 10 μg/kg was injected via the tail vein for 4 times at 15 min intervals.An incisional pain model was established after the first injection of remifentanil.The mechanical paw withdrawal threshold (MWT) was measured at 24 h before normal saline or remifentanil injection and 3, 6, 24 and 48 h after the last injection (T0-T4). The mice were sacrificed after the last measurement of pain threshold, and the L4-6 segments of the spinal cord were removed for determination of the expression of COX-1 and COX-2 (by Western blot) and expression of COX-1 and COX-2 mRNA (by quantitative real-time polymerase chain reaction).@*Results@#Compared with group C, the MWT was significantly decreased, and the expression of COX-2 protein and mRNA was up-regulated in IR, IR+ SC560 and IR+ SC236 groups (P<0.05). Compared with group IR, the MWT was significantly increased in IR+ SC560 and IR+ SC236 groups (P<0.05). There was no significant difference in the MWT at each time point between IR+ SC560 and IR+ SC236 (P>0.05) .There was no significant difference in the expression of COX-2 protein and mRNA among group IR, group IR+ SC560 and group IR+ SC236 (P>0.05). There was no significant difference in the expression of COX-1 protein and mRNA among the four groups (P>0.05).@*Conclusion@#Compared with COX-1, spinal COX-2 plays a major role in the pathophysiological mechanism of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective To evaluate the role of spinal COX-1 and COX-2 in remifentanil-induced hyperalgesia in mice with incisional pain.Methods Thirty-two male C57BL/6J mice,aged 8-10 weeks,weighing 20-25 g,were divided into 4 groups (n =8 each) using a random number table method:control group (group C),incisional pain plus remifentanil group (group IR),incisional pain plus remifentanil plus selective COX-1 inhibitor group (group IR+SC560),and incisional pain plus remifentanil plus selective COX-2 inhibitor group (group IR+SC236).In IR,IR+SC560 and IR+SC236 groups,normal saline 10 μl,SC560 25 μg and SC236 25 μg were intrathecally injected,respectively,15 min later remifentanil 10 μg/kg was injected via the tail vein for 4 times at 15 min intervals.An incisional pain model was established after the first injection of remifentanil.The mechanical paw withdrawal threshold (MWT) was measured at 24 h before normal saline or remifentanil injection and 3,6,24 and 48 h after the last injection (T0-T4).The mice were sacrificed after the last measurement of pain threshold,and the L4-6 segments of the spinal cord were removed for determination of the expression of COX-1 and COX-2 (by Western blot)and expression of COX-1 and COX-2 mRNA (by quantitative real-time polymerase chain reaction).Results Compared with group C,the MWT was significantly decreased,and the expression of COX-2 protein and mRNA was up-regulated in IR,IR+SC560 and IR+SC236 groups (P＜0.05).Compared with group IR,the MWT was significantly increased in IR+SC560 and IR+SC236 groups (P＜0.05).There was no significant difference in the MWT at each time point between IR+SC560 and IR+SC236 (P＞0.05).There was no significant difference in the expression of COX-2 protein and mRNA among group IR,group IR+SC560 and group IR+SC236 (P＞0.05).There was no significant difference in the expression of COX-1 protein and mRNA among the four groups (P＞0.05).Conclusion Compared with COX-1,spinal COX-2 plays a major role in the pathophysiological mechanism of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective To evaluate the role of neuroligin 1 (NL-1) in trafficking of GluR1-containing AMPA receptor to cell membrane in spinal cord dorsal horns during remifentanil-induced hyperalgesia in mice with incisional pain.Methods Forty SPF healthy male C57BL/6J mice,aged 8-10 weeks,weighing 18-22 g,were divided into 5 groups (n=8 each) using a random number table method:control group (group C),NL1-shRNA plasmid group (group NL),incisional pain plus remifentanil group (group I+R),incisional pain plus remifentanil plus blank vector group (group I+R+B),and incisional pain plus remifentanil plus NL-1-shRNA plasmid group (group I+R+NL).Negative lentivirus was intrathecally injected in group I+R+B.In NL and I+R+NL groups,10 μl NL-1-shRNA lentivirus at 1×10s IFU/ml was intrathecally injected once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected at the same time point in C and I+R groups.After transfection was stable,normal saline 0.1 ml was injected via the caudal vein for 4 consecutive times at 15 min intervals in C and NL groups.In I+R,I+R+B and I+R+NL groups,0.1 ml remifentanil 10 μg/kg was injected via the caudal vein for 4 consecutive times at 15 min intervals,and the model of incisional pain was established after the first administration.The mechanical paw withdrawal threshold (MWT) and tail-flick latency (TFL) were measured at 24 h before normal saline or remifentanil administration (T0) and at 3,6,24 and 48 h after the end of administration (T1-4).The animals were sacrificed after measurement of pain threshold at T4,and L4-6 segments of the spinal dorsal horn were then collected for determination of the expression of NL-1 protein and mRNA and AMPA receptors,and the ratio of AMPA receptor expression in the membrane protein to that in the total protein (m/t ratio) was calculated.Results Compared with group C,the MWT was significantly decreased,and TFL was shortened at T1-4,the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was up-regulated,and m/t ratio was increased in I+R and I+R+B groups (P＜0.05).Compared with I+R and I+R+B groups,the MWT was significantly increased and TFL was prolonged at T1-4,the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was down-regulated,and m/t ratio was decreased in group I+R+NL (P＜0.05).Conclusion NL-1 in spinal cord dorsal horns can promote the trafficking of GluR1-containing AMPA receptors to cell membrane,which is involved in the development and maintenance of remifentanil-induced hyperalgesia in mice with incisional pain.
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Aims To observe the effect of saccharide extracts of Yiqijianpi herb Codonopsis and Glycyrrhizae on polyamine-dependent activation of K+ channels sig-nal pathway during cell migration and to investigate their mechanism of promoting restoration in gastrointes-tinal mucosal injuries. Method The study was based on IEC-6 cell migration model. While in a normal polyamine level or polyamine was inhibited by DFMO, the effect of Codonopsis saccharide extracts and Glycyr-rhizae saccharide extracts on polyamine-dependent acti-vation of K+ channels signal pathway during cell mi-gration was observed. (1) K+ channel protein Kv1. 1 was determined by Western blot. (2)Membrane poten-tial was measured by Flow Cytometer. (3) Laser scan-ning confocal microscope was used for measuring [ Ca2+] cyt. ( 4 ) The expression of RhoA, which is Ca2+ downstream protein, was determined by Western blot. Results During cell migration, Codonopsis and Glycyrrhizae saccharide extracts could: ( 1 ) improve the expression of Kv1 . 1 protein and ameliorate the de-crease of kv1. 1 protein expression by DFMO;(2) in-crease membrane hyperpolarization and reverse mem-brane depolarization resulted by DFMO; ( 3 ) improve intracellular [ Ca2+] cyt, while Codonopsis could re-verse the decrease of [ Ca2+] cyt caused by DFMO;(4) improve the expression of RhoA protein, reversing its decline caused by DFMO. Conclusion Codonop-sis and Glycyrrhizae saccharide extracts can promote cell migration in IEC-6 cell, which is correlated with their effect on polyamine-dependent activation of K+channels signal pathway.
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OBJECTIVE To observe the effect of Codonopsis and Glycyrrhiza glycoconjugates on migration and membrane potential of small intestinal epithelial cells(IEC-6),and to explore the promoting effects of Yiqi jianpi herb Codonopsis and Glycyrrhiza on gastrointestinal mucosal injury repair and the underlying mechanisms. METHODS Under normal conditions or loaded with the inhibitor of potassium channel 4-aminopyridine(4-AP),IEC-6 cells were treated with Codonopsis and Glycyrrhiza glycoconjugates (25-200 mg · L-1) for 24 h,respectively. IEC-6 cell migration was observed by the phase contrast microscope and cell membrane potential was detected by flow cytometry. RESULTS Codonopsis and Glycyrrhiza glycoconjugates (50 and 100 mg · L-1) increased the number of migrated IEC-6 cell compared with normal control group(P<0.01,P<0.05). Compared with normal control group,4-AP reduced the number of migrated IEC-6 cell(P<0.01). Codonopsis and Glycyrrhiza glycoconjugates (50-200 mg · L-1)reversed cell migration inhibited by 4-AP significantly when compared with 4-AP model group(P<0.01). The results of flow cyometry analysis showed that the cell membrane poten?tial was increased after treatment with Codonopsis and Glycyrrhiza glycoconjugates(50 mg · L-1)compared with normal control group and resulted in an increase in cell membrane hyperpolarization(P<0.01). Compared with normal control group,4-AP decreased the cell membrane potential(P<0.01)and resulted in cell membrane depolarization. Also,compared with 4-AP model group,cell membrane depolarization induced by 4-AP was reversed by treatment with Codonopsis and Glycyrrhiza glycoconjugates(100 and 200 mg·L-1). CONCLUSION Codonopsis and Glycyrrhiza glycoconjugates may promote gastrointestinal mucosal injury repair and the mechanisms may involve the activation of signaling pathways by affecting polyamine-dependent intestinal epithelial cell migration voltage-gated K+channels.