Comparison of cleavage activity in vitro between two ribozymes targeted against different sites of PDGF receptor β subunit

Objective: To compare the cleavage activity of ribozymes directed against 2 sites of PDGF receptorP subunit cDNA gene in vitro. Methods: The 608 bp fragment of PDGF receptor β subunit cDNA was clonedinto T-vector under the control of T7 promoter, named pPDGFR-β. Two ribozymes were designed to cleavethe CUU sequence at codon 45 and codon 252 of PDGF receptor β subunit mRNA respectively. These 2 ham-merhead ribozyme genes were cloned into vector PI. 5 between 5' -cis ribozyme and 3' -cis ribozyme to gener-ate the plasmids of pRZ1 and pRZ2. The pPDGFR-β, pRZl and pRZ2 were linearized and then transcribedwith T7 promoter in vitro. Results: The RZ1 showed high cleavage activity in vitro, but the RZ2 showed nocleavage activity under the same condition. Conclusion: The cleavage site selection is an important factor in-fluencing the cleavage activities of ribozymes.

Cognitive dysfunction in schizophrenia patients caused by downregulation of γ-aminobutyric acid receptor subunits

BACKGROUND The expression pattern of gamma aminobutyric acid(GABA)receptor subunits are commonly altered in patients with schizophrenia,which may lead to nerve excitation/inhibition problems,affecting cognition,emotion,and behavior.AIM To explore GABA receptor expression and its relationship with schizophrenia and to provide insights into more effective treatments.METHODS This case-control study enrolled 126 patients with schizophrenia treated at our hospital and 126 healthy volunteers who underwent physical examinations at our hospital during the same period.The expression levels of the GABA receptor subunits were detected using 1H-magnetic resonance spectroscopy.The recognized cognitive battery tool,the MATRICS Consensus Cognitive Battery,was used to evaluate the scores for various dimensions of cognitive function.The correlation between GABA receptor subunit downregulation and schizophrenia was also analyzed.RESULTS Significant differences in GABA receptor subunit levels were found between the case and control groups(P<0.05).A significant difference was also found between the case and control groups in terms of cognitive function measures,including attention/alertness and learning ability(P<0.05).Specifically,as the expression levels of GABRA1(α1 subunit gene),GABRB2(β2 subunit gene),GABRD(δsubunit),and GABRE(εsubunit)decreased,the severity of the patients’condition increased gradually,indicating a positive correlation between the downregulation of these 4 receptor subunits and schizophrenia(P<0.05).However,the expression levels of GABRA5(α5 subunit gene)and GABRA6(α6 subunit gene)showed no significant correlation with schizophrenia(P>0.05).CONCLUSION Downregulation of the GABA receptor subunits is positively correlated with schizophrenia.In other words,when GABA receptor subunits are downregulated in patients,cognitive impairment becomes more severe.

Neuroprotective effects of autophagy inhibition on hippocampal glutamate receptor subunits after hypoxia-ischemia-induced brain damage in newborn rats

Autophagy has been suggested to participate in the pathology of hypoxic-ischemic brain damage（HIBD）.However,its regulatory role in HIBD remains unclear and was thus examined here using a rat model.To induce HIBD,the left common carotid artery was ligated in neonatal rats,and the rats were subjected to hypoxia for 2 hours.Some of these rats were intraperitoneally pretreated with the autophagy inhibitor 3-methyladenine（10 m M in 10 μL） or the autophagy stimulator rapamycin（1 g/kg） 1 hour before artery ligation.Our findings demonstrated that hypoxia-ischemia-induced hippocampal injury in neonatal rats was accompanied by increased expression levels of the autophagy-related proteins light chain 3 and Beclin-1 as well as of the AMPA receptor subunit GluR 1,but by reduced expression of GluR 2.Pretreatment with the autophagy inhibitor 3-methyladenine blocked hypoxia-ischemia-induced hippocampal injury,whereas pretreatment with the autophagy stimulator rapamycin significantly augmented hippocampal injury.Additionally,3-methyladenine pretreatment blocked the hypoxia-ischemia-induced upregulation of Glu R1 and downregulation of GluR2 in the hippocampus.By contrast,rapamycin further elevated hippocampal Glu R1 levels and exacerbated decreased GluR2 expression levels in neonates with HIBD.Our results indicate that autophagy inhibition favors the prevention of HIBD in neonatal rats,at least in part,through normalizing Glu R1 and GluR2 expression.

N-methyl-D-aspartate receptor subunit 1 regulates neurogenesis in the hippocampal dentate gyrus of schizophrenia-like mice

N-methyl-D-aspartate receptor hypofunction is the basis of pathophysiology in schizophrenia. Blocking the N-methyl-D-aspartate receptor impairs learning and memory abilities and induces pathological changes in the brain. Previous studies have paid little attention to the role of the N-methyl-D-aspartate receptor subunit 1 (NR1) in neurogenesis in the hippocampus of schizophrenia. A mouse model of schizophrenia was established by intraperitoneal injection of 0.6 mg/kg MK-801, once a day, for 14 days. In N-methyl-D-aspartate-treated mice, N-methyl-D-aspartate was administered by intracerebroventricular injection in schizophrenia mice on day 15. The number of NR1-, Ki67- or BrdU-immunoreactive cells in the dentate gyrus was measured by immunofluorescence staining. Our data showed the number of NR1-immunoreactive cells increased along with the decreasing numbers of BrdU- and Ki67-immunoreactive cells in the schizophrenia groups compared with the control group. N-methyl-D-aspartate could reverse the above changes. These results indicated that NR1 can regulate neurogenesis in the hippocampal dentate gyrus of schizophrenia mice, supporting NR1 as a promising therapeutic target in the treatment of schizophrenia. This study was approved by the Experimental Animal Ethics Committee of the Ningxia Medical University, China (approval No. 2014-014) on March 6, 2014.

Propofol effectively inhibits lithium-pilocarpine-induced status epilepticus in rats via downregulation of N-methyl-D-aspartate receptor 2B subunit expression

Status epilepticus was induced via intraperitoneal injection of lithium-pilocarpine.The inhibitory effects of propofol on status epilepticus in rats were judged based on observation of behavior,electroencephalography and 24-hour survival rate.Propofol（12.5-100 mg/kg） improved status epilepticus in a dose-dependent manner,and significantly reduced the number of deaths within 24 hours of lithium-pilocarpine injection.Western blot results showed that,24 hours after induction of status epilepticus,the levels of N-methyl-D-aspartate receptor 2A and 2B subunits were significantly increased in rat cerebral cortex and hippocampus.Propofol at 50 mg/kg significantly suppressed the increase in N-methyl-D-aspartate receptor 2B subunit levels,but not the increase in N-methyl-D-aspartate receptor 2A subunit levels.The results suggest that propofol can effectively inhibit status epilepticus induced by lithium-pilocarpine.This effect may be associated with downregulation of N-methyl-D-aspartate receptor 2B subunit expression after seizures.

Subcellular distribution of N-methyl-D-aspartic acid receptor subunit 1 in neural stem cells within subventricular zone of adult rats

The subcellular localization of N-methyI-D-aspartic acid receptor subunit 1 in neural stem cells of the subventricular zone of adult rats was detected using electron microscopy, following immunohistochemistry and immunogold-silver double staining. Results confirmed the presence of neural stem cells in the subventricular zone, which is a key neurogenic region in the central nervous system of adult mammals. The expression of N-methyI-D-aspartic acid receptor subunit 1 was higher than that of nestin and mainly distributed in the cell membrane, cytoplasm, rough endoplasmic reticulum and Golgi complex of neural stem cells.

Serotonin type 3 receptor subunit gene polymorphisms associated with psychosomatic symptoms in irritable bowel syndrome:A multicenter retrospective study

BACKGROUND Single-nucleotide polymorphisms(SNPs)of the serotonin type 3 receptor subunit(HTR3)genes have been associated with psychosomatic symptoms,but it is not clear whether these associations exist in irritable bowel syndrome(IBS).AIM To assess the association of HTR3 polymorphisms with depressive,anxiety,and somatization symptoms in individuals with IBS.METHODS In this retrospective study,623 participants with IBS were recruited from five specialty centers in Germany,Sweden,the United States,the United Kingdom,and Ireland.Depressive,anxiety,and somatization symptoms and sociodemographic characteristics were collected.Four functional SNPs—HTR3A c.-42C>T,HTR3B c.386A>C,HTR3C c.489C>A,and HTR3E c.*76G>A—were genotyped and analyzed using the dominant and recessive models.We also performed separate analyses for sex and IBS subtypes.SNP scores were calculated as the number of minor alleles of the SNPs above.The impact of HTR3C c.489C>A was tested by radioligand-binding and calcium influx assays.RESULTS Depressive and anxiety symptoms significantly worsened with increasing numbers of minor HTR3C c.489C>A alleles in the dominant model(F_(depressive)=7.475,P_(depressive)=0.006;F_(anxiety)=6.535,P_(anxiety)=0.011).A higher SNP score(range 0-6)was linked to a worsened depressive symptoms score(F=7.710,P-linear trend=0.006)in IBS.The potential relevance of the HTR3C SNP was corroborated,showing changes in the expression level of 5-HT3AC variant receptors.CONCLUSION We have provided the first evidence that HTR3C c.489C>A is involved in depressive and anxiety symptoms in individuals with IBS.The SNP score indicated that an increasing number of minor alleles is linked to the worsening of depressive symptoms in IBS.

Expression of gamma-aminobutyric acid type A receptor α_2 subunit in the dorsal root ganglion of rats with sciatic nerve injury

The γ-aminobutyric acid neurotransmitter in the spinal cord dorsal horn plays an important role in pain modulation through primary afferent-mediated presynaptic inhibition. The weakening of γ-aminobutyric acid-mediated presynaptic inhibition may be an important cause of neuropathic pain. γ-aminobutyric acid-mediated presynaptic inhibition is related to the current strength of γ-aminobutyric acid A receptor activation. In view of this, the whole-cell patch-clamp technique was used here to record the change in muscimol activated current of dorsal root ganglion neurons in a chronic constriction injury model. Results found that damage in rat dorsal root ganglion neurons following application of muscimol caused concentration-dependent activation of current, and compared with the sham group, its current strength and γ-aminobutyric acid A receptor protein expression decreased. Immunofluorescence revealed that γ-aminobutyric acid type A receptor α2 subunit protein expression decreased and was most obvious at 12 and 15 days after modeling. Our experimental findings confirmed that the y-aminobutyric acid type A receptor α2 subunit in the chronic constriction injury model rat dorsal root ganglion was downregulated, which may be one of the reasons for the reduction of injury in dorsal root ganglion neurons following muscimol-activated currents.

Gamma-aminobutyric acid promotes human hepatocellular carcinoma growth through overexpressed gamma-aminobutyric acid A receptor α3 subunit

AIM:To investigate the expression pattern of gamma-aminobutyric acid A(GABAA) receptors in hepatocellular carcinoma(HCC) and indicate the relationship among gamma-aminobutyric acid(GABA),gamma-aminobutyric acid A receptor α3 subunit(GABRA3) and HCC.METHODS:HCC cell line Chang,HepG2,normal liver cell line L-02 and 8 samples of HCC tissues and paired non-cancerous tissues were analyzed with semiquantitative polymerase chain reaction(PCR) for the expression of GABAA receptors.HepG2 cells were treated with gamma-aminobutyric acid(GABA) at serial concentrations(0,1,10,20,40 and 60 μmol/L),and their proliferating abilities were analyzed with the 3-(4,5-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay,cell doubling time test,colon formation assay,cell cycle analysis and tumor planted in nude mice.Small interfering RNA was used for knocking down the endogenous GABRA3 in HepG2.Proliferating abilities of these cells treated with or without GABA were analyzed.RESULTS:We identified the overexpression of GABRA3 in HCC cells.Knockdown of endogenous GABRA3 expression in HepG2 attenuated HCC cell growth,suggesting its role in HCC cell viability.We determined the in vitro and in vivo effect of GABA in the proliferation of GABRA3-positive cell lines,and found that GABA increased HCC growth in a dose-dependent manner.Notably,the addition of GABA into the cell culture medium promoted the proliferation of GABRA3-expressing HepG2 cells,but not GABRA3-knockdown HepG2 cells.This means that GABA stimulates HepG2 cell growth through GABRA3.CONCLUSION:GABA and GABRA3 play important roles in HCC development and progression and can be a promising molecular target for the development of new diagnostic and therapeutic strategies for HCC.

N-methyl-D-aspartate receptor subunit 1 protein expression in the hippocampus and temporal cortex of kainic acid-induced epilepsy rats

BACKGROUND： The N-methyl-D-aspartate receptor subunit 1 （NMDAR1） contributes to the incidence of epilepsy. However, the relationship between epilepsy-induced brain injury and NMDAR1 remains poorly understood. OBJECTIVE： To investigate changes in NMDAR1 protein expression in the hippocampus and temporal cortex of kainic acid-induced epilepsy rats. DESIGN, TIME AND SETFING： A randomized, controlled, animal experiment was performed at the Department of Physiology and Department of Pathology, Basic Medical College of Jilin University from March 2002 to March 2003. MATERIALS： Rabbit anti-NMDAR1 antibody was purchased from Wuhan Boster Biological Technology, China. METHODS： A total of 80 healthy, male, Wistar rats, aged 22 weeks, were randomly assigned to sham-surgery （n = 10） and model （n = 70） groups. Epilepsy models were established by injecting kainic acid （1μL） into the right amygdala, and rats were sacrificed at 2, 6, 24, 72 hours, and 7, 15, 30 days after surgery, with 10 animals at each time point. The rats in the sham-surgery group were injected with 1μL phosphate buffered saline into the right amygdala. MAIN OUTCOME MEASURES： NMDAR1 protein expression in the hippocampus and temporal cortex at 2, 6, 24, 72 hours and 7, 15, 30 days after epilepsy was detected using immunohistochemistry and flow cytometry analysis. RESULTS： In the sham-surgery group, a few NMDARl-positive cells were distributed in the hippocampus and temporal cortex. In the model group, NMDARl-positive cells were increased in the hippocampus and temporal cortex at 2 hours following kainic acid-induced epilepsy. They were significantly increased at 6 hours, and slightly decreased at 7 days （CA3 region and temporal cortex）, but remained greater than the sham-surgery group. This continued until day 30 （P 〈 0.01 ）. In addition, there were more NMDAR1 positive cells in the hippocampal CA3 and dentate gyrus than the temporal cortex （P 〈 0.01）. CONCLUSION： In epilepsy model rats, NMDAR1 protein expression was upregulated in the hippocampus and temporal cortex, and in particular in the hippocampal CA3 and dentate gyrus. NMDAR1 may participate in epilepsy and the excitation process of the epileptic brain.

Gamma-aminobutyric acid A receptor gamma 2 subunit following Mg-free-induced seizures in cultured developing neurons

BACKGROUND： Studies have demonstrated that in vitro cultured cortical neurons from embryonic rats can produce spontaneous recurrent epileptiform discharges following transient Mg^2＋-free extracellular solution culture. OBJECTIVE： To explore gammaminobutyric acid A receptor （GABAAR）γ 2 subunit expression following Mg^2＋-free-induced seizures in cultured developing neurons. DESIGN, TIME AND SETTING： Cellular and molecular biology. The in vitro experiment was performed at the Department of Pediatrics, Second Xiangya Hospital of Central Southern University between January 2007 and February 2008. MATERIALS： Cortical neurons of Wistar rats on gestational days 16-17 were used. Normal extracellular solution （pH 7.3） consisted of NaCl 145 mmol/L, KCl 2.5 mmol/L, HEPES l0 mmol/L, MgC12 1 mmol/L, CaC12 2 mmol/L, glucose 10 mmol/L, and glycine 0.01 mmol/L. In addition, there was no MgCl2 in the Mg^2＋-free extracellular solution. METHODS： Cortical neurons cultured for 6 days were exposed to normal extracellular solution （control group） and Mg^2＋-free media （Mg^2＋-free group） respectively for 3 hours, followed by continuous culture in DMEM solution. MAIN OUTCOME MEASURES： On days 1, 7 and 12 after Mg^2＋-free treatment, real-time RT-PCR, immunochemistry, and flow cytometry were used to detect GABAAR 3/2 subunit expression. RESULTS： Compared with the control group, GABAAR γ-positive cells decreased significantly on days 1 and 7 after Mg^2＋-free treatment （P 〈 0.01）, but significantly increased on day 12 （P 〈 0.01 ）. GABAAR γ2 subunit mRNA expression decreased significantly at 7 days Mg^2＋-free treatment when measured by real-time RT-PCR compared with the control group （P 〈 0.05）. CONCLUSION： GABAAR γ2 subunit expression is modified following Mg-free-induced seizures in cultured developing neurons. This indicates the possibility that abnormal GABAA receptor expression might play an important role in development of neuronal injury.

Expression of mRNA-encoding subunits of N-methyl-D-aspartate receptor in the hypothalamus in sustained monaural block of auditory air-conduction model rats

A sustained monaural block of auditory air-conduction model was established in rats through subcutaneous suture in the right ear canal.The gene expression levels of hypothalamic N-methyl-D-aspartate receptor NR1,NR2A,NR2B and NR2C mRNA in the auditory central nervous system of Sprague-Dawley rats at postnatal 9,23,37 days were determined after an environmental change.Reverse transcription-PCR assay showed that the critical period for the development of NR1,NR2A,and NR2B subunits in the left hypothalamus and NR1-and NR2B-dependent auditory neurons in the right hypothalamus terminated 23 days after the suture in the right ear.The critical period for the development of NR2A subunit-dependent auditory neurons in the right hypothalamus was terminated by postnatal day 37.The results confirmed that N-methyl-D-aspartate receptor subunits in the hypothalamus may be regulated by the auditory environment.

Silencing gamma-aminobutyric acid A receptor alpha 1 subunit expression and outward potassium current in developing cortical neurons

We used RNA interference （RNAi） to disrupt synthesis of the cortical neuronal y-aminobutyric acid A receptor （GABAAR） al in rats during development, and measured outward K＋ currents during neuronal electrical activity using whole-cell patch-clamp techniques. Three pairs of small interfering RNA （siRNA） for GABAAR al subunit were designed using OligoEngine RNAi software. This siRNA was found to effectively inhibited GABAAR al mRNA expression in cortical neuronal culture in vitro, but did not significantly affect neuronal survival. Outward K^currents were decreased, indicating that GABAAR al subunits in developing neurons participate in neuronal function by regulating outward K＋ current.

Effects of physical exercise on the developmental expression of hippocampal zinc transporter 1 and glutamate receptor subunit 2, and on cognitive function in a rat model of recurrent neonatal seizure

BACKGROUND： Developmental seizures are pathologically characterized by regenerative sprouting of hippocampal mossy fibers rich in Zn^2＋. Zn^2＋ metabolism in the mossy fiber pathway, and Zn^2＋ accumulation in presynaptic membrane vesicles, are dependent on zinc transporter 1 （ZnT1） and glutamate receptor subunit 2 （GluR2）. OBJECTIVE： To investigate the effects of long-term recurrent neonatal seizure, in the presence and absence of physical exercise, on the developmental expression of hippocampal zinc transporter 1 （ZnT1） and GluR2, and on cognitive function in rats. DESIGN, TIME AND SETTING： Based on behavioral examination and molecular biological research, a randomized, controlled animal experiment was performed at the Department of Neurobiology, Medical College of Soochow University, between January 2007 and April 2008. MATERIALS： Twenty-one 6-day-old Sprague Dawley rats of either gender were employed in this study. ZnT1 mRNA in situ hybridization kit was provided by Tianjin Haoyang Biological Manufacture Co.,Ltd., China. Rabbit anti-GluR2 was purchased from Santa Cruz Biotech, Inc, USA. METHODS： Rats were randomly divided into a recurrent seizure group （n = 11） and a control group （n = 10）. In the recurrent seizure group, 30-minute seizure was induced by flurothyl gas inhalation for a total of 6 consecutive days. Rats from the control group underwent experimental procedures similar to the recurrent seizure group, with the exception of flurothyl gas inhalation. Thirty minutes of treadmill exercise was performed daily by all rats at postnatal days 51–56. MAIN OUTCOME MEASURES： At postnatal day 82, rat hippocampal tissue was harvested for analysis of hippocampal ZnT1 and GluR2 expression by in situ hybridization and immunohistochemistry, respectively. Rat learning and memory capabilities were examined using the Y-maze test. RESULTS： In the recurrent seizure group, the gray scale value of ZnT1 in situ hybridization positive neurons in the hippocampal CA3 region was significantly greater （P 〈 0.05）, while the gray scale value of GluR2 immunoreactive neurons in the hippocampal hilus and dentate gyrus was significantly lower （P 〈 0.05）, than in the control group. At postnatal days 29–35, numbers of trials to criteria for successful learning were greater in the recurrent seizure group than in the control group （P 〈 0.05）; at postnatal days 61–67, the numbers of trials to criteria for successful learning were similar between the two groups （P 〉 0.05）. At postnatal days 29–35 and 61–67, there was no significant difference in memory capability between the recurrent seizure and control groups （P 〉 0.05）. CONCLUSION： Physical exercise likely improves the learning deficits caused by recurrent neonatal seizure in rats during brain development by modulating ZnT1 and GluR2 expression.

Changes in N-methyl-D-aspartate receptor 2A subunit expression caused by binocular form deprivation and chondroitin sulfate proteoglycan degradation

Light deprivation is known to induce a significant decrease in the percentage of N-methyi-D- aspartate receptor 2A subunit （NR2A）-expressing neurons during development. The purpose of this study was to investigate the effects of binocular form deprivation （BFD） and chondroitin sulfate proteoglycan （CSPG） degradation on NR2A expression via an immunohistochemical study, around the end of a critical developmental period. The results show that the positive staining of NR2A in the normal rat visual cortex increases gradually from postnatal 3-5 weeks （P 〈 0.05）, but the changes from 5 weeks to 7 weeks were not significant. The positive staining of NR2A following BFD in the rat visual cortex slightly increased from postnatal 3-7 weeks （P 〉 0.05）. The positive staining of NR2A in the CSPG-treated group was insignificant compared with the BFD group at the same time point from 4 weeks to 7 weeks （P 〉 0.05）. Thus, the effect of BFD on NR2A expression in the rat visual cortex was similar to that of CSPG degradation around the end of the critical developmental period.

Role of α3 nicotinic acetylcholine receptor subunit in the inflammatory responses of atherosclerosis

Aim The expression of α3 subunit of nicotinic acetylcholine receptor （α3-nAChR） has been demonstra- ted in aorta, adipocyte and macrophage. The objective of the present study was to verify the regulatory roles of α3- nAChR in the inflammatory responses of atherosclerosis. Methods The inflammatory indicators were detected in mouse macrophage, adipocytes and mouse aortic endothelial cells （MAECs） after the α3-nAChR was antagonized or after the α3-nAChR gene was silenced. Meanwhile, atherogenesis was induced in the apolipoprotein E knock-out （ ApoE^ -/- ） mice after fed with an atherogenic high-fat diet for 7 weeks. Results In MAECs, the lipopolysaccha- ride （LPS）-stimulated secretions of the adhesion molecules and inflammatory cytokines were significantly enhanced （30%± 80% ） after pretreatment with α-Conotoxin MII （an antagonist for α3-nAChR） or after knock-down with α3-nAChR gene. In adipocytes, the knock-down of α3 gene promoted the generations of the proin？ ammatory adi- pokines or cytokines but decreased the production of adiponectin, an anti-inflammatory adipokine, by 29.29 ± 9.43%. In macrophage silenced with α3-nAChR gene, the M1 （classical） activation was predominantly stimula- ted, whereas the M2 （alternative） activation was suppressed. In addition, the amount of the atherosclerotic lesions and the infiltration of the M1 type activated macrophages into the arterial wall were markedly elevated in the α- Conotoxin MII-treated ApoE -/- mice. Conclusion The α3-nAChR may play a pivotal role in regulating the atherogenesis through influencing the inflammatory responses of ECs, macrophages and adipocytes. The mecha- nisms involve the regulations of multiple cell signaling pathways.

Attenuation of nicotine-evoked Ca²⁺influx by antibody to the nicotinic acetylcholine receptor <i>α</i>3 subunits in human embryonic kidney cells

Autoantibody against neuronal nicotinic acetylcholine receptor (nAChR) α3 subunit is implicated in severe autonomic dysfunction in the patients with autoimmune autonomic ganglionopathy (AAG). Although this autoantibody has been revealed to impair fast excitatory synaptic transmission in autonomic ganglia, its precise mechanism remains unknown. Here, we show that antibody-induced reduction of cell-surface α3 subunits result in impairment of nicotine-evoked Ca2+ influx in stably transfected human embryonic kidney cells. These effects of the antibody were remarkably inhibited by interfering with the endocytic machinery at low-temperature. We conclude that reduction of nAChR in autonomic ganglia can be mediated by the endocytosis of α3 subunits, and resulted in autonomic failure in AAG patients.

Controlling N-methyl-D-aspartate receptor subunit 1 with calcitonin gene related peptide after cerebral ischemic injury

BACKGROUND: Activation of N-methyl-D-aspartate receptor (NMDAR) is a key link of exitotoxicity at the phase of cerebral ischemic injury. Because NMDAR is a main way to mediate internal flow of Ca2+ among glutamic acid receptors, over-excitation can cause neuronal apoptosis. Calcitonin gene related peptide has a strongly biological activity. On one hand, it can protect ischemic neurons through inhibiting the expression of NMDAR1 mRNA; on the other hand, it can play the protective effect through down-regulating the expression of NMDAR1 mRNA by exogenous calcitonin gene related peptide. OBJECTIVE: To observe the expression of NMDAR1 and the regulatory effect of calcitonin gene related peptide on the expression of NMDAR1 mRNA and protein in the cerebral cortex of rats with focal cerebral ischemia/reperfusion (I/R). DESIGN: Randomized controlled animal study. SETTING: China Medical University. MATERIALS: A total of 216 healthy male Wistar rats, general grade, weighing 250-280 g, were selected in this study. Twelve rats were randomly selected to regard as control group; meanwhile, other 204 rats were used to establish middle cerebral artery occlusion/reperfusion (MACO) models. The main reagents were detailed as follows: calcitonin gene related peptide (Sigma Company); calcitonin gene related peptide kit (Boster Company); antibody Ⅰ, Ⅱ and antibody β-actin Ⅰ, Ⅱ of NMDAR1 mRNA and chemiluminescence reagent (Santa Cruz Company, USA). METHODS: The experiment was carried out in the Laboratory of Neurobiology of China Medical University from August 2005 to June 2006. ① Right MCAO models of rats were established to cause focal ischemia and scored based on Zea Longa five-grade scale. If the scores were 1, 2 and 3 after wakefulness, the MACO models were established successfully and involved in the experiment. A total of 120 rats with successful modeling were randomly divided into I/R group and administration group with 60 in each group. All rats in the both groups were observed at five time points, including 6, 12, 24, 48 and 72 hours after reperfusion and after 2-hour ischemia, with 12 experimental animals at each time point. Six rats were prepared for detection of hybridization in situ, and the other 6 were used for Western blotting histochemical detection. Rats in the control group were opened their skin to separate common carotid artery and not treated with line and drugs. In addition, rats in the I/R group were treated with 1 mL saline at 2 hours after focal cerebral ischemia, and then, rats in the administration group were treated with 1 mL (1 g/L) calcitonin gene related peptide at 2 hours after focal cerebral ischemia. ② The expression of NMDAR1 mRNA was detected with hybridization in situ at various time points; moreover, the expression of NMDAR1 protein was measured with Western blotting method at various time points. The results were analyzed with Metamoph imaging analytical system. MAIN OUTCOME MEASURES: The expression of NMDAR1 mRNA and its protein in cortical neurons of rats at various time points. RESULTS: A total of 84 rats were excluded because of non-symptoms, exanimation or death; and then, 132 rats were involved in the final analysis. The expression of NMDAR1 mRNA and its protein in cortical neurons of rats in the control group was 0.205±0.001 and 0.184±0.001, respectively; after I/R, expression of NMDAR1 mRNA and its protein was up-regulated, especially, expression of mRNA at 6, 12, 24, 48 and 72 hours was 0.245±0.003, 0.287±0.004, 0.354±0.008, 0.284±0.002 and 0.217±0.006, respectively; moreover, expression of protein at 6, 12, 24, 48 and 72 hours was 0.222±0.003, 0.261±0.028, 0.311±0.004, 0.259±0.013 and 0.210±0.008, respectively. There was significant difference between the two groups (0.205±0.001, P < 0.01). The expression was up-related in the former 24 hours, reached peak at 24 hours, down-regulated, and decreased to the level of control group at 72 hours. Except 72 hours, the expression of NMDAR1 mRNA and its protein was lower in administration group than that in I/R group at other four time points. In addition, the expression of mRNA at 6, 12, 24, 48 and 72 hours was 0.223±0.005, 0.243±0.001, 0.292±0.002, 0.250±0.003 and 0.213±0.003, respectively; moreover, the expression of protein at 6, 12, 24, 48 and 72 hours was 0.216±0.006, 0.245±0.025, 0.276±0.003, 0.241±0.045 and 0.202±0.013, respectively. There was significant difference at various time points (P < 0.05). CONCLUSION: The expressions of NMDAR1 mRNA and its protein of peripheral cortical neurons are up-related in ischemic area after focal cerebral I/R. Meanwhile, exogenous calcitonin gene related peptide can protect cortical neurons through inhibiting expression of NMDAR1 mRNA and its protein after focal cerebral I/R.

Autosomal recessive 333 base pair interleukin 10 receptor alpha subunit deletion in very early-onset inflammatory bowel disease

BACKGROUND Interleukin 10 receptor alpha subunit(IL10RA)dysfunction is the main cause of very early-onset inflammatory bowel disease(VEO-IBD)in East Asians.AIM To identify disease-causing gene mutations in four patients with VEO-IBD and verify functional changes related to the disease-causing mutations.METHODS From May 2016 to September 2020,four young patients with clinically diagnosed VEO-IBD were recruited.Before hospitalization,using targeted gene panel sequencing and trio-whole-exome sequencing(WES),three patients were found to harbor a IL10RA mutation(c.301C>T,p.R101W in one patient;c.537G>A,p.T179T in two patients),but WES results of the fourth patient were not conclusive.We performed whole-genome sequencing(WGS)on patients A and B and reanalyzed the data from patients C and D.Peripheral blood mononuclear cells(PBMCs)from patient D were isolated and stimulated with lipopolysaccharide(LPS),interleukin 10(IL-10),and LPS+IL-10.Serum IL-10 levels in four patients and tumor necrosis factor-α(TNF-α)in the cell supernatant were determined by enzyme-linked immunosorbent assay.Phosphorylation of signal transducer and activator of transcription 3(STAT3)at Tyr705 and Ser727 in PBMCs was determined by western blot analysis.RESULTS The four children in our study consisted of two males and two females.The age at disease onset ranged from 18 d to 9 mo.After hospitalization,a novel 333-bp deletion encompassing exon 1 of IL10RA was found in patients A and B using WGS and was found in patients C and D after reanalysis of their WES data.Patient D was homozygous for the 333 bp deletion.All four patients had elevated serum IL-10 levels.In vitro,IL-10-stimulated PBMCs from patient D failed to induce STAT3 phosphorylation at Tyr705 and only minimally suppressed TNF-αproduction induced by LPS.Phosphorylation at Ser727 in PBMCs was not affected by LPS or LPS+IL-10 in both healthy subjects and in patient D.CONCLUSION WGS revealed a novel 333-bp deletion of IL10RA in four patients with VEO-IBD,whereas the WES results were inconclusive.

Effects of Nourishing “Yin”-Removing “Fire” Chinese Herb Mixture on the Differential Expression of GABA_AReceptor <i>α</i>Subunits in Hypothalamus of Precocious Puberty Female Rats

GABAergic input to Gonadotropin-releasing hormone (GnRH) neurons is necessary to initiate the onset of puberty and its action mainly depends on GABAA receptor of which the subunit composition, properties and consequently function varies during this period. Nourishing “Yin”-Removing “Fire” Chinese herb mixture, a Chinese herb-based formulation, has been proved that it may retard the initiation of pubertal development in female precocious puberty rats. Our objective is to investigate the effects of Nourishing “Yin”-Removing “Fire” Chinese herb mixture on the expression of GABAA receptor α subunits in hypothalamus. Female Sprague-Dawley rats were divided into normal (N), precocious puberty model (M) induced by danazol, model exposed to saline (MS) and model exposed to Chinese herb mixture (CHM) groups. All rats were administered by the Chinese herb mixture from P15 on. Coefficients of reproductive organs and serum gonadotropins and estradiol levels in M were significantly enhanced while they were significantly decreased in CHM. The hypothalamic GnRH mRNA was also significantly increased in M and in CHM, as well as ERα mRNA. At the mean time, the hypothalamic GABAA receptor α1 and α3 subunits mRNA were more significantly decreased in M than those of N, while they were more significantly enhanced in CHM than those in M (p 0.01), the protein expression of which in hypothalamus had the same trend as the mRNA expression. The evidence suggests that Nourishing “Yin”-Removing “Fire” Chinese herb mixture could significantly retard the sexual development of the precocious rats, and up-regulate the expressions of hypothalamic GABAA receptor α1 and α3 subunits. Our result indicated that GABAA receptor α1 and α3 subunits might involve in the effective treatment of herb mixture on idiopathic precocious puberty.