ABSTRACT
Neuropathic pain is a type of chronic pain caused by nervous system damage and dysfunction. The pathogenesis of chronic pain is complicated, and there are no effective therapies for neuropathic pain. Studies show that the P2X4 receptor expressed in the satellite glial cells (SGCs) of dorsal root ganglia (DRG) is related to neuropathic pain. Artemisinin is a monomeric component extracted from traditional Chinese medicine and has a variety of important pharmacological effects and potential applications. This study observed the effect of artemisinin on neuropathic pain and delineated its possible mechanism. The chronic constriction injury (CCI) rat model was used in this study. The results demonstrated that artemisinin relieved pain behaviors in the CCI rats, inhibited the expression of P2X4 receptor in the DRG, and decreased the ATP-activated currents in HEK293 cells transfected with P2X4 plasmid. Dual-labeling immunofluorescence showed that the coexpression of P2X4 receptor and glial fibrillary acidic protein (GFAP) in the DRG of CCI rats was increased compared to control rats. After CCI rats were treated with artemisinin, the coexpression of P2X4 receptor and GFAP in the DRG was significantly decreased compared to the CCI group. This finding suggested that artemisinin could inhibit the nociceptive transmission mediated by P2X4 receptor in the DRG SGCs and thus relieve pain behaviors in the CCI rats.
Subject(s)
Artemisinins/therapeutic use , Ganglia, Spinal/metabolism , Neuralgia/drug therapy , Neuralgia/metabolism , Pain Measurement/methods , Receptors, Purinergic P2X4/physiology , Animals , Artemisinins/pharmacology , Dose-Response Relationship, Drug , Ganglia, Spinal/drug effects , HEK293 Cells , Humans , Male , Pain Measurement/drug effects , Purinergic P2X Receptor Antagonists/pharmacology , Purinergic P2X Receptor Antagonists/therapeutic use , Rats , Rats, Sprague-Dawley , Treatment OutcomeABSTRACT
Diabetic cardiac autonomic neuropathy (DCAN) is a serious and common complication in diabetes mellitus (DM). Long noncoding RNAs (lncRNAs), an important class of regulatory molecules in diverse biological processes, have attracted considerable interest in DCAN. Our previous study has indicated a lncRNA, NONRATT021972 (NONCODE ID), was enhanced in sympathetic neuronal-like PC12 cells in the setting of high glucose (HG) and high FFAs (HF); its silence was found to significantly alleviate HGHF-induced tumor necrosis factor-α (TNF-α) release in PC12 cells. Here we further explore the effects of NONRATT021972 small interference RNA (siRNA) on heart rate variability (HRV) mediated by superior cervical ganglia (SCG) in diabetic rats and the possible mechanism underlying. We found an increment of NONRATT021972 in SCG of DM rats. Treatment of NONRATT021972 siRNA in DM rats decreased the elevated expression of TNF-α, blocked serine phosphorylation of insulin receptor substrate (IRS) 1 and increased the down-regulated expression of IRS1 in SCG. Meanwhile, NONRATT021972 siRNA rescued decreased HRV in DM rats. Therefore, inhibition of NONRATT021972 may serve as a novel therapeutic strategy for preventing the development of DCAN.
Subject(s)
Arrhythmias, Cardiac/therapy , Diabetes Mellitus, Experimental/therapy , Diabetic Cardiomyopathies/therapy , Ganglia, Spinal/metabolism , RNA, Long Noncoding/metabolism , RNAi Therapeutics , Animals , Arrhythmias, Cardiac/metabolism , Arrhythmias, Cardiac/pathology , Cervical Vertebrae , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Diabetic Cardiomyopathies/metabolism , Diabetic Cardiomyopathies/pathology , Ganglia, Spinal/pathology , Heart Rate/physiology , Insulin Receptor Substrate Proteins/metabolism , Male , RNA, Long Noncoding/genetics , RNA, Small Interfering/administration & dosage , Random Allocation , Rats , Rats, Sprague-Dawley , Tumor Necrosis Factor-alpha/metabolismABSTRACT
OBJECTIVE: To investigate the effect of di-(2-ethylhexyl) phthalate (DEHP) exposure on the growth and development of placenta, uterine natural killer (uNK) cell number and angiogenesis at the maternal-fetal interface in pregnant mice. METHODS: From day 1 of pregnancy, pregnant mice were exposed daily to DEHP by oral gavage at 125, 250, or 500 mg/kg for 13 consecutive days. The uterine and placental tissues were then harvested for HE staining and immunohistochemistry to examine the effect of DEHP exposure on the growth and development of the placenta and angiogenesis and uNK cell number at the maternal-fetal interface. RESULTS: Compared with the control group, the mice exposed to 500 mg/kg DEHP, but not those exposed to 125 and 250 mg/kg, showed significantly reduced number of embryo implantation (P<0.05). DEHP exposure significantly increased the rate of abortion. DEHP exposure at 125, 250, and 500 mg/kg significantly and dose-dependently lowered the placental weight compared with that in the control group (0.0637±0.0133, 0.0587±0.0176, 0.0524±0.0183 g vs 0.0786±0.0143 g, respectively; P<0.01), and significantly reduced the total area of the placenta and area of spongiotrophoblasts. DEHP exposure resulted in a significant reduction in the number of fetal vascular branches, and collapse and atresia of blood vessels. The mice exposed to DEHP at 125, 250, and 500 mg/kg had significantly lowered numbers of uNK cells (83.2±10.3, 60.7±12.4, and 50.4±14.5/HP, respectively) as compared with the control group (105.1±14.2/HP) at the maternal-fetal interface (P<0.01). CONCLUSION: DEHP exposure significantly affects the growth and development of the placenta in mice possibly by suppressing angiogenesis and reducing uNK cell number at the maternal-fetal interface during pregnancy.
