Objective To evaluate the inhibiting effect of adenosine on rat retinal ganglion cells (RGC) death induced by P2X7 and N-methyl-D-aspartate (NMDA) receptor. Methods (1) Long-Evan neonatal rats were back labeled with aminostilbamidine to identify RGC. The viability of RGC affected by P2X7 excitomotor BzATP (50 mu;mol/L), glutamate receptor excitomotor NMDA (100 mu;mol/L) and adenosine (300 mu;mol/L) was detected. (2) RGC from the retinae of unlabeled neonatal rats were cultured in vitro. After labeled with Fura-2 methyl acetate, an intracellular calcium indicator, the effect of BzATP, NMDA and adenosine on intracellular Ca2+ level was detected byCa2+ imaging system. Results Both BzATP (50 mu;mol/L) and NMDA(100 mu;mol/L) could kill about 30% of the RGC. Cell death was prevented by adenosine (300 mu;mol/L) with the cell viability increased from (68.9plusmn;2.3)% and (69.9plusmn;3.2)% to (91.2plusmn;3.5)% (P＜0.001) and (102.1plusmn;3.9)% (P＜0.001), respectively. BzATP (50 mu;mol/L) led to a large, sustained increase of intracellular Ca2+ concentration to (1183plusmn;109) nmol/L. After the adenosine intervened, Ca2+ concentration increased slightly to (314plusmn;64) nmol/L (P＜0.001). Conclusion Adenosine may prevent RGC death and increase of intracellular Ca2+ concentration from P2X7and NMDA receptor stimulation. (Chin J Ocul Fundus Dis, 2007, 23: 133-136)
Objective To explore the effects of drugs on functions of mitochondria in retinal nerve cells, and to lay a foundation of the investigation of drug protection for retinal nerve cells. Methods Cultivation of the retinal nerve cells of 8 eyes of neonatal calves was performed. The changes of fluorescent density of the mitochondria of cultured cells labeled by dye rhodamine 123 (Rh123) before and after the activation of the medicines, including ferulic acid (FA), arginine, glycine,taurine, vitamine E and brain derived neurotrophic factor( BDNF) respectively, were detected by laser-scanning confocal microscopy. Results FA with the concentration of 500 μg/ml led the diphasic variation of the fluorescent intensity of mitochondria. After scanning for 60.772 seconds when treated with FA firstly, the fluorescent intensity decreased rapidly (from 45.425±4.153 to 22.135±5.293); while after 112.774 seconds when treated secondly, the in tensity increased obviously (from 19.655±4.383 to 28.247±4.764), and after 168.773 seconds when treated thirdly the intensity still increased. After scanning for 56.457 seconds when treated with vitamin E (12.5 mg/ml), the fluorescent in tensity increased obviously (from 88.255±5.039 to 111.273±4.529), which suggested that vitamin E with the concentration of 12.5 mg/ml strengthen the fluorescent intensity. After scanning for 58.147 and 134.148 seconds when treated with BDNF(50 ng/ml) respectively, the fluorescent intensity increased obviously (from 69.115±5.038 to 77.225±5.131) which suggested that BDNF with the concent ration of 50 ng/ml led the increase of the fluorescent intensity. Glycine (2.5 mg/ml) and arginine(30 mg/ml) didn’t affect the fluorescent intensity of mitochondria, and taurine (6.25 mg/ml) caused the appreciable decrease of the fluorescent intensity . Conclusion FA, BDNF and vitamin E may promote the metabolism of retinal nerve cells via the path of mitochondria, while amino acids may adjust the activation of retinal nerve cells through other ways. (Chin J Ocul Fundus Dis，2004，20：229-232)
PURPOSE: To probe the effect of taurine on lipid peroxidation,surperoxide dismutase(SOD) and glutathione peroxidase(GSH-Px)in retina in vitro. METHODS: The animal eye cups were put into media(divided into four groups:control,model,taurine and beta;-carotene) respectively,and incubated at 37deg;C in a humidified atmosphere of 5% CO2/95% air. After 24h or 48h ,the retinas were taken out from the media and the SOD,GSH-Px ,protein and malondialdehyde(MDA) were examined. RESULTS:Taurine could inhibite lipid peroxidation in retina ,decrease MDA level ,could not protect GSH-Px activity in retina. The effect of taurine on SOD activity in retina was also uncertain. CONCLUSION:Taurine can inhibit lipid peroxidation in retina in vitro,but the mechanism of that has nothing to do with the effect of taurine on SOD activity and GSH-Px activity. （Chin J Ocul Fundus Dis,1996,12: 183-185 ）
【Abstract】Objective To investigate whether SUMO-1 enhances the apoptosis induced by wild-type p53 plasmid transfection in HepG2 cells. Methods The HepG2 cells were transfected respectively or simultaneouly with the following expressional plasmids as pcDNA3-wtp53（pwtp53，including human wild-type p53 gene），pCMV-HDM1B（pMDM2，including HDM2 gene， homologous gene as murine double minute gene 2），pcDNA3-His6-SUMO-1（pSUMO-1 ，including small ubiquitin-like modifier1 gene）and plasmid pcDNA3.The proteins expressed in cells were detected by means of Western blotting and the apoptosis rates of cells were measured by flow cytometry. Results The protein bands of p53 and MDM2 could be seen in cells transfected with pwtp53 and pMDM2. Meanwhile，the relative larger molecular weight bands were also seen in cells transfected with pSUMO-1 which represented the p53 and MDM2 protein modification by SUMO-1. Merely the trace of p53 protein was detected in cells not transfected with any plasmid or only transfected with empty plasmid and pSUMO-1. In cells transfected with pwtp53 and pwtp53+pSUMO-1，the apoptosis rates were (16.79±1.62)%and (18.15±1.36)%. When transfected with pwtp53+pMDM2，the rate decreased to (5.17±1.23)%. The apoptosis rate would come up again to (14.06±1.84)% after transfected with pwtp53+pMDM2+pSUMO-1 and the difference of rates were significant compared to the cells transfected with pwtp53+pMDM2 (PH＜0.01）. The apoptosis rates in other cells were less than 2% and had no significant difference. Conclusion SUMO-1 could increase the apoptosis induced by wild-type p53 plasmid transfection in HepG2 cells through combining to p53 protein or its post-translational modification and inhibiting p53 degradation by MDM2.
Retinal neuronal cells are crucial in the formation of vision. Injury or death of these cells may lead to irreversible damage to visual function due to their low regenerative capacity. The P2X7 receptor is a trimeric adenosine triphosphate (ATP)-gated cation channel. Recent studies have shown that P2X7 receptor plays a role in retinal neuronal death. In a series of animal models, when exposed to conditions of hypoxia or ischemia, elevated ocular pressure, trauma and exogenous agonists, P2X7 receptor activated by extracellular ATP can cause death of retinal neuronal cells such as retinal ganglion cells and photoreceptor cells through direct or indirect pathways. Blocking the expression and function of P2X7 receptor by its specific antagonist and gene knocking-out, the loss of retinal neuronal cells is significantly attenuated. P2X7 receptor may become a potential novel neuroprotective target for diseases related to the loss of retinal neurons.
Objective To observe the effects of taurine on ventricular remodeling of rats with acute myocardial infarction (AMI) though the establishment of rat AMI model by ligating the left anterior descending coronary branch. Methods Sixty 8-week-old male Wistar rats were randomly divided into four groups: sham group, AMI group, small-dose and high-dose taurine group, with 15 rats in each. Rats in the AMI group and taurine groups received ligation of the anterior descending coronary branch to establish an animal model of AMI. Meanwhile, rats in the sham group were subjected to sham coronary ligature. From the next day of the operation, rats in the taurine groups were dosed orally per day with taurine 300 mg/kg or 400 mg/kg for 8 weeks, respectively. Echocardiographic images were acquired before and 8 weeks after the operation, to get the indexes such as left ventricular end systolic diameter (LVIDs), left ventricular end diastolic diameter (LVIDd), left ventricular posterior wall end diastolic thickness (LVPWd), left ventricular ejection fraction (LVEF), fractional shortening (FS), mitral inflow velocity E (E), mitral inflow velocity A (A), and E/A ratio, and all the measurements above were expressed as the average of 6 consecutive cardiac cycles. After the animals were executed, cardiac mass and left ventricular mass were measured, and cardiac mass index (CMI) and left ventricular mass index (LVMI) were calculated. Brain natriuretic peptide (BNP) in all groups were measured by enzyme-linked immunosorbent assay before and 8 weeks after the operation. Results In comparison with the AMI group, CMI, LVMI, LVIDd and LVIDs of the small-dose and high-dose taurine groups were lower, and LVPWd, LVEF, FS and E/A were higher (P<0.05). Plasma BNP level in the AMI group and two taurine-treated groups were higher than that in the sham group, and it was the highest in the AMI group (P<0.05). Conclusion Taurine has a protective effect on ventricular remodeling in rats with AMI, and the protective effect is dose-dependent.
Objective To explore the effects of human urine-derived stem cells (hUSCs) and hUSCs combined with chondroitinase ABC (chABC) on the expressions of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in the spinal cord injury (SCI) of rats, and to investigate the underlying mechanism. Methods hUSCs were cultured from human urine, and their phenotypes were detected by flow cytometry. The SCI model of rats were made via Allen method. Sixty Sprague Dawley rats were divided into 5 groups (n=12): the sham operation group (group A), SCI group (group B), SCI+hUSCs group (group C), SCI+chABC group (group D), and SCI+hUSCs+chABC group (group E). Basso, Beattie, Bresnahan (BBB) score was used to measure the lower extremity motor function of rats in each group at 10, 20, and 30 days after operation. Real-time fluorescent quantitative PCR was used to detect the relative mRNA expressions of NGF and BDNF at 30 days. Meanwhile, the protein expression of NGF and BDNF were confirmed by immunohistochemistry staining. The relative protein expressions of Bax and Bcl-2 were detected by Western blot. Results The hUSCs were identified to have multipotential differentiation potential. At 10, 20, and 30 days, BBB score was significantly lower in group B than in groups A, C, D, and E, in groups C, D, and E than in group A, in groups C and D than in group E (P<0.05). Real-time fluorescent quantitative PCR and immunohistochemistry staining demonstrated that the expressions of NGF and BDNF were significantly lower in group B than in groups A, C, D, and E, in groups C, D, and E than in group A, in groups C and D than in group E (P<0.05); but there was no significant difference between groups C and D (P>0.05). Western blot results indicated that the protein expression of Bax was significantly higher in group B than in groups A, C, D, and E, in groups C, D, and E than in group A, in groups C and D than in group E (P<0.05). Meanwhile, the protein expression of Bcl-2 was significantly lower in group B than in groups A, C, D, and E, in groups C, D, and E than in group A, in groups C and D than in group E (P<0.05). Conclusion hUSCs can protect SCI and this positive effect can be enhanced by chABC; this neuro-protective effect may depend on promoting the expressions of NGF and BDNF, and suppressing the neuronal apoptosis.
In recent years, the incidence of thyroid cancer has been increasing. Researchers around the world have begun to pay more attention to the exploration of its pathogenesis, disease evolution and prognosis. Among them, research in the field of gene molecules has become a hotspot, which includes the mutations of v-raf murine sarcoma viral oncogene homologue B1 (BRAF) and the telomerase reverse transcriptase (TERT) promoter. However, this field is not mature, and there are many problems and challenges need to be solved. This paper explores the value of BRAF mutation in the treatment, recurrence, mortality and prognosis of papillary thyroid carcinoma. In addition, we also explore the relationship between BRAF mutation and TERT promoter mutations and their influences in thyroid cancer. We hope this paper could help later scholars understand the current situation in this field and find a research direction in the future.
In recent years, with the improvement of the sensitivity of examination equipment and the change of people's living environment and diet, the rate of thyroid cancer has risen rapidly, which has increased nearly five folds in 10 years. The pathogenesis, clinical manifestation, biological behavior, treatment and prognosis of thyroid carcinoma of different pathological types are obviously different. Papillary thyroid carcinoma (PTC) can develop at any age, which accounts for about 90% of thyroid cancer. It progresses slowly and has favourable prognosis, but lymph node metastasis appears easily. Whether PTC is accompanied by lymph node metastasis has an important impact on its prognosis and outcome. The Raf murine sarcoma viral oncogene homolog B(BRAF)gene mutation plays a crucial role in PTC lymph node metastasis. Having an in-depth understanding of the specific role and mechanism of BRAF gene mutation in PTC is expected to provide new ideas for diagnosis and treatment of PTC.
Neuropathic pain has been redefined by NeuPSIG as “pain arising as a direct consequence of a lesion or disease affecting the somatosensory syste”. However, pharmacological management for neuropathic pain is not effective, which is correlated with the uncertainty of pathogenesis. For a long time, neuron had been considered acting a major role in the development of neuropathic pain. In recent years, a majority of studies revealed that glia cell also involved in the occurrence and development of neuropathic pain, and neuron-glia interaction is one of the key mechanism of neuropathic pain, including complex signaling pathways as purinergic signaling. This review focuses on recent advances on the role of purinergic receptors in neuropathic pain.