ABSTRACT
Objective:To evaluate the effect of intrathecal insulin-like growth factor-1 (IGF-1) on chemotherapy-induced neuropathic pain (NP) in mice.Methods:Forty clean-grade healthy male C57 mice, aged 7-9 weeks, weighing 22-24 g, were divided into 4 groups ( n=10 each) using a random number table method: control group (group C), chemotherapy-induced NP group (group CIPN), low-dose IGF-1 group (group I1) and high-dose IGF-1 group (group I2). In CIPN, I1 and I2 groups, oxaliplatin 5 mg/kg was intraperitoneally injected for 5 consecutive days to establish chemotherapy-induced NP model.Normal saline 0.2 ml was given in group C. After measurement of the pain threshold at 10 days after establishment of the model, IGF-1 0.5 and 1.0 μg were intrathecally injected in group I1 and group I2, respectively.Normal saline 5 μl was intrathecally injected in C and CINP groups.Mechanical withdrawal threshold (MWT) was measured at 3, 5, 8, 10, 11, 13 and 15 days after establishment of the model.After measurement of the pain threshold at 15 days after establishment of the model, the expression of spinal IGF-1, IGF-1receptor (IGF-1R), interleukin (IL)-17A, IL-1β and tumor necrosis factor (TNF)-α was detected, and IGF-1 positive cells were counted using immunofluorescence. Results:Compared with group C, MWT was significantly decreased, the expression of spinal IGF-1 was down-regulated, the count of IGF-1 positive cells was decreased, and expression of IL-17A, IL-1β and TNF-α was up-regulated at 3-25 days after establishment of the model in CINP, I1 and I2 groups ( P<0.05). Compared with group CIPN, MWT was significantly increased at 15 days after establishment of the model in group I1, and MWT was increased, the expression of spinal IGF-1 was up-regulated, the count of IGF-1 positive cells was increased, and expression of IL-17A, IL-1β and TNF-α was down-regulated at 13 and 15 days after establishment of the model in group I2 ( P<0.05). Compared with group I1, the count of IGF-1 positive cells in spinal dorsal horn was increased in group I2 ( P<0.05). There was no significant difference in the expression of spinal IGF-1R among the 4 groups ( P>0.05). Conclusion:Intrathecal IGF-1 can alleviate chemotherapy-induced NP, and the mechanism may be related to inhibiting the inflammatory responses in spinal cord of mice.
ABSTRACT
Objective To evaluate the effect of intrathecal cardamonin on diabetic neuropathic pain (DNP) in rats.Methods Healthy adult male Sprague-Dawley rats,aged 2 months,weighing 180-220 g,were included in the study.Diabetes mellitus was produced by intraperitoneal injection of streptozotocin 60 mg/kg after intrathecal catheterization.When decrease in pain threshold＞50％ of the baseline at 21 days after diabetes mellitus was produced,the induction of DNP was considered successful.Twenty-four rats with DNP were divided into 4 groups (n=6 each) using a random number table:group DNP,rapamycin group (group R),cardamonin 50 μg group (group D50) and cardamonin 100 μg group (group D100).Another 6 healthy age-matched rats were used as normal control (group C).In DNP,R,D50 and D100 groups,dimethyl sulfoxide 10 μl,rapamycin 5 μg and cardamonin 50 μg and 100 μg were intrathecally injected,respectively,once a day for 7 consecutive days starting from 21 days after successful estabiishment of the model.Mechanical paw withdrawal threshold (MWT) was measured before establishment of the model,on 7,14 and 21 days after establishment of the model,and on 1,4 and 7 days after intrathecal injection.The rats were sacrificed after the last MWT measurement,and their L3-5 segments of the spinal cord were removed for determination of the expression of S6K,p-S6K and synapsin Ⅱ by Western blot.Results Compared with group C,MWT was significantly decreased,and the expression of spinal S6K,p-S6K and synapsin Ⅱ was up-regulated in group DNP (P＜0.05 or 0.01).Compared with group DNP,MWT was significantly increased,and the expression of spinal S6K,p-S6K and synapsin Ⅱ was down-regulated in R,D50 and D100 groups (P＜0.05 or 0.01).Compared with group D50,MWT was significantly increased,and the expression of spinal S6K,p-S6K and synapsin Ⅱ was down-regulated in group D100 (P＜0.05).Conclusion Intrathecal cardamonin can relieve DNP in rats,and the mechanism is related to inhibiting spinal mammalian target of rapamycin activity and down-regulating the expression of synapsin Ⅱ.
ABSTRACT
Objective To investigate the effect of propofol on human renal tubule epithelial cell (HK-2 cells) fibrosis induced by ATP depletion/recovery and the role of transforming growth factor β activated kinase 1 (TAK1) in it.Methods HK-2 cells were seeded in 96-well plates,and randomly divided into 4 groups (n =36 each) using a random number table:control group (group C),ATP depletion/recovery group (group D/R),propofol group (group P),and TAK1 over-expression group (group T).HK-2 cells were exposed to antimycin A for 1 h and then returned to normal culture medium to establish the model of ATP depletion/recovery-induced injury.At 1 h before ATP depletion,the cells were incubated for 1 h in the DMEM liquid culture medium containing propofol with the final concentration of 20 μmol/L in group P,and the cells were incubated for 1 h in the DMEM liquid culture medium containing propofol with the final concentration of 20 μmol/L and TAK1 with the titer of 2× 107 TU/ml in group T,and the other treatments were similar to those previously described in group D/R.At 12 h after ATP recovery,the cell viability was evaluated by methyl thiazolyl tetrazolium assay,and cell apoptosis was detected using TUNEL and scored.The expression of TAK1 was detected using Western blot at 12,24 and 48 h after ATP recovery.The expression of α-smooth muscle actin (αSMA),fibronectin (FN),and collagen protein 1 (COL1) was measured at 48 h after ATP recovery.Results Compared with group C,the cell viability was significantly decreased,the apoptosis score was increased,and the expression of TAK1,COL1,αSMA and FN was up-regulated after ATP recovery in D/R,P and T groups (P＜0.05).Compared with group D/R,the cell viability was significantly increased,the apoptosis score was decreased,and the expression of TAK1,COL1,αSMA and FN was down-regulated after ATP recovery in P and T groups (P＜0.05).Compared with group P,the cell viability was significantly decreased,the apoptosis score was increased,and the expression of TAK1,COL1,αSMA and FN was up-regulated after ATP recovery in group T (P＜ 0.05).Conclusion Propofol can reduce HK-2 cell fibrosis induced by ATP depletion/recovery,and the mechanism may be related to down-regulation of TAK1 expression.