ABSTRACT
In the original article, Figs. 2, 3b, and 4b were published incorrectly.
ABSTRACT
Adenosine triphosphate (ATP) participates in signal transmission by acting on P2X receptors, and the P2X7 receptor is involved in the pathophysiological changes of ischemic injury. The PC12 cell line is a popular model system to study sympathetic neuronal function. Long noncoding RNAs (lncRNAs) are highly expressed in the nervous system and serve as regulatory RNAs. In this study, the effects of NONRATT021972 lncRNA siRNA on P2X7-mediated PC12 neuronal injury after exposure to oxygen-glucose deprivation (OGD) were investigated. Our results showed that the viability of PC12 cells cultured with OGD or the P2X7 agonist BzATP was significantly decreased. Treatment with NONRATT021972 siRNA reversed the decreased viability of PC12 cells under OGD conditions. The upregulated P2X7 mRNA and protein levels in PC12 cells under OGD conditions or BzATP treatment were significantly decreased when pretreated with NONRATT021972 siRNA. Moreover, NONRATT021972 siRNA treatment effectively suppressed the increase in [Ca(2+)]i induced by OGD or P2X7 agonists (ATP or BzATP) in PC12 cells. Therefore, treatment with NONRATT021972 siRNA may decrease sympathetic neuronal injury induced by ischemia.
Subject(s)
Ischemia/metabolism , RNA, Long Noncoding/metabolism , Receptors, Purinergic P2X7/metabolism , Animals , Blotting, Western , Cell Hypoxia , Cell Survival/drug effects , Disease Models, Animal , Gene Knockdown Techniques , Glucose/deficiency , Oxygen , PC12 Cells , Polymerase Chain Reaction , RNA, Long Noncoding/pharmacokinetics , RatsABSTRACT
BACKGROUND: Long non-protein-coding RNAs (lncRNAs) are involved in the pathological processes of nervous system diseases. NONRATT021972 is an lncRNA. This study explores the effects of lncRNA NONRATT021972 small interference RNA (siRNA) on diabetic neuropathic pain (DNP) mediated by the P2X7 receptor in the rat dorsal root ganglia (DRG). RESULTS: Our results show that NONRATT021972 expression was significantly higher in the DRG of diabetes mellitus (DM) group compared with control group. NONRATT021972 expression in the DRG was reduced when DM rats were treated with NONRATT021972 siRNA. NONRATT021972 siRNA treatment in type 2 DM rats increased the mechanical withdrawal threshold (MWT), the thermal withdrawal latency (TWL) and the sensory nerve conduction velocity (SNCV) of rat tail nerves. After intravenous injection with NONRATT021972 siRNA in DM rats, the P2X7, GFAP and TNF-É expression levels in DRG were decreased. An interaction between the RNA (NONRATT021972) and protein (P2X7) was predicted by the application of bioinformatics technology. The BzATP-activated currents in DRG non-neurons (satellite glial cells) of DM rats were significantly increased compared to control rats. NONRATT021972 siRNA treatment inhibited the ATP-activated currents in HEK293 cells transfected with pEGFP-P2X7. CONCLUSIONS: NONRATT021972 siRNA treatment can decrease the expression levels of P2X7 mRNA and protein and inhibit the activation of satellite glial cells (SGCs) in the DRG of type 2 DM rats. Moreover, NONRATT021972 siRNA treatment reduced the release of inflammatory factors (TNF-α), thereby inhibiting the excitability of DRG neurons and reducing mechanical and thermal hyperalgesia in type 2 DM rats.
Subject(s)
Diabetes Mellitus, Type 2/genetics , Ganglia, Spinal/metabolism , Neuralgia/genetics , RNA, Long Noncoding/metabolism , RNA, Small Interfering/metabolism , Receptors, Purinergic P2X7/metabolism , Adenosine Triphosphate/analogs & derivatives , Adenosine Triphosphate/pharmacology , Animals , Behavior, Animal , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/physiopathology , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/physiopathology , Fluorescent Antibody Technique , Ganglia, Spinal/drug effects , Gene Expression Regulation/drug effects , Glial Fibrillary Acidic Protein/metabolism , HEK293 Cells , Humans , Hyperalgesia/complications , Hyperalgesia/genetics , Hyperalgesia/physiopathology , Ion Channel Gating/drug effects , Neural Conduction/drug effects , Neuralgia/complications , Neuralgia/physiopathology , Protein Binding/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Purinergic P2X7/genetics , Sensory Receptor Cells/drug effects , Sensory Receptor Cells/pathology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Adenosine triphosphate (ATP) acts on P2X receptors to initiate signal transmission. P2X7 receptors play a role in the pathophysiological process of myocardial ischemic injury. Long noncoding RNAs (lncRNAs) participate in numerous biological functions independent of protein translation. LncRNAs are implicated in nervous system diseases. This study investigated the effects of NONRATT021972 small interference RNA (siRNA) on the pathophysiologic processes mediated by P2X7 receptors in stellate ganglia (SG) after myocardial ischemic injury. Our results demonstrated that the expression of NONRATT021972 in SG was significantly higher in the myocardial ischemic (MI) group than in the control group. Treatment of MI rats with NONRATT021972 siRNA, the P2X7 antagonist brilliant blue G (BBG), or P2X7 siRNA improved the histology of injured ischemic cardiac tissues and decreased the elevated concentrations of serum myocardial enzymes, creatine kinase (CK), CK isoform MB (CK-MB), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) compared to the MI rats. NONRATT021972 siRNA, BBG, or P2X7 siRNA treatment in MI rats decreased the expression levels of P2X7 immunoreactivity, P2X7 messenger RNA (mRNA), and P2X7 protein, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) in the SG compared to MI rats. NONRATT021972 siRNA treatment prevented the pathophysiologic processes mediated by P2X7 receptors in the SG after myocardial ischemic injury.
Subject(s)
Myocardial Ischemia/genetics , Myocardial Ischemia/metabolism , RNA, Long Noncoding/genetics , Receptors, Purinergic P2X7/genetics , Receptors, Purinergic P2X7/metabolism , Stellate Ganglion/metabolism , Animals , Cytokines/biosynthesis , Immunohistochemistry , Myocardial Ischemia/enzymology , Myocardium/enzymology , Purinergic P2X Receptor Antagonists/pharmacology , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , RNA, Small Interfering , Rats , Rats, Sprague-DawleyABSTRACT
After the myocardial ischemia, injured myocardial tissues released large quantity of ATP, which activated P2X3 receptor in superior cervical ganglia and made the SCG postganglionic neurons excited. Excitatory of sympathetic postganglionic efferent neurons increased the blood pressure and heart rates, which aggravated the myocardial ischemic injury. Baicalin has anti-inflammatory and anti-oxidant properties. Our study showed that baicalin reduced the incremental concentration of serum CK-MB, cTn-T, epinephrine and ATP, decreased the up-regulated expression levels of P2X3 mRNA and protein in SCG after MI, and then inhibited the sympathetic excitatory activity triggered by MI injury. These results indicated that baicalin acted on P2X3 receptor was involved in the transmission of sympathetic excitation after the myocardial ischemic injury. Baicalin might decrease sympathetic activity via inhibiting P2X3 receptor in rat SCG to protect the myocardium.
Subject(s)
Flavonoids/pharmacology , Myocardial Ischemia/drug therapy , Purinergic P2X Receptor Antagonists/pharmacology , Receptors, Purinergic P2X3/metabolism , Superior Cervical Ganglion/drug effects , Adenosine Triphosphate/blood , Animals , Blood Pressure/drug effects , Disease Models, Animal , Epinephrine/blood , Heart/drug effects , Heart/physiopathology , Heart Rate/drug effects , Injections, Intraperitoneal , Male , Myocardial Ischemia/pathology , Myocardial Ischemia/physiopathology , Myocardium/pathology , RNA, Messenger/metabolism , Random Allocation , Rats, Sprague-Dawley , Superior Cervical Ganglion/metabolismABSTRACT
Irritable bowel syndrome (IBS) and inflammatory bowel disease often display visceral hypersensitivity. Visceral nociceptors after inflammatory stimulation generate afferent nerve impulses through dorsal root ganglia (DRG) transmitting to the central nervous system. ATP and its activated-purinergic 2X7 (P2X7) receptor play an important role in the transmission of nociceptive signal. Purinergic signaling is involved in the sensory transmission of visceral pain. Moxibustion is a therapy applying ignited mugwort directly or indirectly at acupuncture points or other specific parts of the body to treat diseases. Heat-sensitive acupoints are the corresponding points extremely sensitive to moxa heat in disease conditions. In this study, we aimed to investigate the relationship between the analgesic effect of moxibustion on a heat-sensitive acupoint "Dachangshu" and the expression levels of P2X7 receptor in rat DRG after chronic inflammatory stimulation of colorectal distension. Heat-sensitive moxibustion at Dachangshu acupoint inhibited the nociceptive signal transmission by decreasing the upregulated expression levels of P2X7 mRNA and protein in DRG induced by visceral pain, and reversed the abnormal expression of glial fibrillary acidic protein (GFAP, a marker of satellite glial cells) in DRG. Consequently, abdominal withdrawal reflex (AWR) score in a visceral pain model was reduced, and the pain threshold was elevated. Therefore, heat-sensitive moxibustion at Dachangshu acupoint can produce a therapeutic effect on IBS via inhibiting the nociceptive transmission mediated by upregulated P2X7 receptor.