Transmembrane member 16 A(TMEM16 A) is involved in many physiological functions, such as epithelial secretion, sensory conduction, nociception, control of neuronal excitability, and regulation of smooth muscle contrac...Transmembrane member 16 A(TMEM16 A) is involved in many physiological functions, such as epithelial secretion, sensory conduction, nociception, control of neuronal excitability, and regulation of smooth muscle contraction, and may be important in peripheral pain transmission. To explore the role of TMEM16 A in the persistent hyperalgesia that results from chronic constriction injury-induced neuropathic pain, a rat model of the condition was established by ligating the left sciatic nerve. A TMEM16 A selective antagonist(10 μg T16 Ainh-A01) was intrathecally injected at L5–6. For measurement of thermal hyperalgesia, the drug was administered once at 14 days and thermal withdrawal latency was recorded with an analgesia meter. For measurement of other indexes, the drug was administered at 12 days,once every 6 hours, totally five times. The measurements were performed at 14 days. Western blot assay was conducted to analyze TMEM16 A expression in the L4–6 dorsal root ganglion. Immunofluorescence staining was used to detect the immunoreactivity of TMEM16 A in the L4–6 dorsal root ganglion on the injured side. Patch clamp was used to detect electrophysiological changes in the neurons in the L4–6 dorsal root ganglion. Our results demonstrated that thermal withdrawal latency was shortened in the model rats compared with control rats.Additionally, TMEM16 A expression and the number of TMEM16 A positive cells in the L4–6 dorsal root ganglion were higher in the model rats, which induced excitation of the neurons in the L4–6 dorsal root ganglion. These findings were inhibited by T16 Ainh-A01 and confirm that TMEM16 A plays a key role in persistent chronic constriction injury-induced hyperalgesia. Thus, inhibiting TMEM16 A might be a novel pharmacological intervention for neuropathic pain. All experimental protocols were approved by the Animal Ethics Committee at the First Affiliated Hospital of Shihezi University School of Medicine, China(approval No. A2017-170-01) on February 27, 2017.展开更多
目的:探讨大鼠背根神经节持续受压(chronic compression of the dorsal root ganglion,CCD)后,脊髓背角星型胶质细胞的激活情况,以及PKCε是否可以通过调节星型胶质细胞的活性而参与CCD后神经病理性疼痛。方法:将大鼠随机分为6组,每组大...目的:探讨大鼠背根神经节持续受压(chronic compression of the dorsal root ganglion,CCD)后,脊髓背角星型胶质细胞的激活情况,以及PKCε是否可以通过调节星型胶质细胞的活性而参与CCD后神经病理性疼痛。方法:将大鼠随机分为6组,每组大鼠8只:假手术组、CCD7天组、CCD14天组、CCD7天+BIM I组、CCD+DMSO组、CCD+PDBu组,分别通过鞘内注射不同药物,或对正常大鼠鞘注DMSO/PDBu后,测量大鼠机械刺激缩爪阈值(paw withdrawal mechanical threshold,PWMT)的变化,利用Western Blot技术检测脊髓背角PKCε和GFAP蛋白表达的变化,利用免疫荧光技术检测脊髓背角星型胶质细胞激活情况。结果:CCD术后第4天,鞘内注射PKCε的激动剂PDBu 1—4h,明显降低CCD大鼠PWMT(P<0.05),而给予BIM I 1—4h,可升高CCD大鼠PWMT(P<0.05)。从CCD术后第4天起,连续3天鞘注BIM I,可明显缓解大鼠的机械痛敏(4天,P<0.05),但从停止注射后镇痛作用消失(P>0.05)。与假手术组比较,CCD后7天和14天,手术侧背角PKCε和GFAP表达升高,差异有显著性意义(P<0.05),星型胶质细胞激活增加,而注射BIM I可明显抑制PKCε和GFAP表达(P<0.05)和星型胶质细胞激活。PDBu可导致正常大鼠PWMT明显降低(P<0.05),GFAP蛋白质表达量增加(P<0.05),促进星型胶质细胞激活。结论:大鼠背根神经节持续受压后,机械痛阈下降的同时,手术侧脊髓背角内PKCε和GFAP蛋白表达上调,星型胶质细胞激活增加。PKCε可能通过调节星型胶质细胞激活参与CCD后病理性神经痛的中枢敏化机制。展开更多
基金supported by the National Natural Science Foundation of China,No.30160026(to JQS)the High Level Talent Research Project of Shihezi University of China,No.RCSX201705(to YW)
文摘Transmembrane member 16 A(TMEM16 A) is involved in many physiological functions, such as epithelial secretion, sensory conduction, nociception, control of neuronal excitability, and regulation of smooth muscle contraction, and may be important in peripheral pain transmission. To explore the role of TMEM16 A in the persistent hyperalgesia that results from chronic constriction injury-induced neuropathic pain, a rat model of the condition was established by ligating the left sciatic nerve. A TMEM16 A selective antagonist(10 μg T16 Ainh-A01) was intrathecally injected at L5–6. For measurement of thermal hyperalgesia, the drug was administered once at 14 days and thermal withdrawal latency was recorded with an analgesia meter. For measurement of other indexes, the drug was administered at 12 days,once every 6 hours, totally five times. The measurements were performed at 14 days. Western blot assay was conducted to analyze TMEM16 A expression in the L4–6 dorsal root ganglion. Immunofluorescence staining was used to detect the immunoreactivity of TMEM16 A in the L4–6 dorsal root ganglion on the injured side. Patch clamp was used to detect electrophysiological changes in the neurons in the L4–6 dorsal root ganglion. Our results demonstrated that thermal withdrawal latency was shortened in the model rats compared with control rats.Additionally, TMEM16 A expression and the number of TMEM16 A positive cells in the L4–6 dorsal root ganglion were higher in the model rats, which induced excitation of the neurons in the L4–6 dorsal root ganglion. These findings were inhibited by T16 Ainh-A01 and confirm that TMEM16 A plays a key role in persistent chronic constriction injury-induced hyperalgesia. Thus, inhibiting TMEM16 A might be a novel pharmacological intervention for neuropathic pain. All experimental protocols were approved by the Animal Ethics Committee at the First Affiliated Hospital of Shihezi University School of Medicine, China(approval No. A2017-170-01) on February 27, 2017.
