Effects and molecular mechanism of exogenous L-carnitine on excessive endoplasmic reticulum stress-mediated hepatic pyroptosis in severely scald rats / 中华烧伤杂志

Objective: To investigate the effects and molecular mechanism of exogenous L-carnitine on hepatic pyroptosis mediated by excessive endoplasmic reticulum stress in severely scald rats. Methods: The experimental research method was adopted. According to the random number table (the same group method below), fifteen female Sprague Dawley rats aged 6-8 weeks were divided into sham-injury group, scald alone group, and scald+carnitine group (with 5 rats in each group), and full-thickness scald of 30% total body surface area were made on the back of rats in scald alone group and scald+carnitine group, and rats in scald+carnitine group were additionally given intraperitoneal injection of L-carnitine. At post injury hour (PIH) 72, The levels of aspartate aminotransferase (AST) and alanine dehydrogenase (ALT) of biochemical indicators of liver injury were detected by automatic biochemical analyzer with the sample number of 5. At PIH 72, liver tissue damage was detected by hematoxylin-eosin staining. At PIH 72, The mRNA levels of nucleotide-binding oligomerization domain-containing protein-like receptor family pyrin domain containing 3 (NLRP3), cysteine aspartic acid specific protease 1 (caspase-1), gasderminD (GSDMD), and interleukin 1β(IL-1β) in liver tissue as pyroptosis-related markers and glucose regulatory protein 78 (GRP78) and CCAAT/enhancer binding protein homologous protein (CHOP) in liver tissue as endoplasmic reticulum stress-related markers were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-qPCR). Protein expression levels of GRP78, CHOP, NLRP3, caspase-1, caspase-1/p20, GSDMD-N, and cleaved IL-1β in liver tissue were detected by Western blotting, and the sample numbers were all 5. HepG2 cells as human liver cancer cells were divided into dimethyl sulfoxide (DMSO) group, 0.1 μmol/L tunicamycin (TM) group, 0.2 μmol/L TM group, 0.4 μmol/L TM group, and 0.8 μmol/L TM group and were treated accordingly. After 24 h of culture, cell viability was detected by cell counting kit 8, and the intervention concentration of TM was screened, and the sample number was 5. HepG2 cells were divided into DMSO group, TM alone group, and TM+carnitine group, and treated accordingly. After 24 h of culture, the protein expression levels of GRP78, CHOP, NLRP3, caspase-1, caspase-1/p20, GSDMD-N, and cleaved IL-1β in cells were detected by Western blotting, and the sample numbers were all 3. Data were statistically analyzed with one-way analysis of variance and least significant difference-t test. Results: At PIH 72, the AST and ALT levels of serum in scald alone group were (640±22) and (157±8) U/L, which were significantly higher than (106±13) and (42±6) U/L in sham-injury group, respectively, with t values of -46.78 and -25.98, respectively, P<0.01. The AST and ALT levels of serum in scald+carnitine group were (519±50) and (121±10) U/L, which were significantly lower than those in scald alone group, respectively, with t values of 4.93 and 6.06, respectively, P<0.01. At PIH 72, the morphology of liver tissue of rats in sham-injury group were basically normal with no obvious inflammatory cell infiltration; compared with those in sham-injury group, the liver tissue of rats in scald alone group showed a large number of inflammatory cell infiltration and disturbed cell arrangement; compared with that in scald alone group, the liver tissue of rats in scald+carnitine group showed a small amount of inflammatory cell infiltration. At PIH 72, the mRNA expression on levels of NLRP3, caspase-1, GSDMD, and IL-1β in liver tissue of rats in scald alone group were significantly higher than those in sham-injury group (with t values of 34.42, 41.93, 30.17, and 15.68, respectively, P<0.01); the mRNA levels of NLRP3, caspase-1, GSDMD, and IL-1β in liver tissue of rats in scald+carnitine group were significantly lower than those in scald alone group (with t values of 34.40, 37.20, 19.95, and 7.88, respectively, P<0.01). At PIH 72, the protein expression levels of NLRP3, caspase-1, caspase-1/p20, GSDMD-N, and cleaved IL-1β in liver tissue of rats in scald alone group were significantly higher than those in sham-injury group (with t values of 12.28, 26.92, 5.20, 10.02, and 24.78, respectively, P<0.01); compared with those in scald alone group, the protein expression levels of NLRP3, caspase-1, caspase-1/p20, GSDMD-N, and cleaved IL-1β in liver tissue of rats in scald+carnitine group were significantly decreased (with t values of 10.99, 27.96, 12.69, 8.96, and 12.27, respectively, P<0.01). At PIH 72, the mRNA levels of GRP78 and CHOP in liver tissue of rats in scald alone group were significantly higher than those in sham-injury group (with t values of 21.00 and 16.52, respectively, P<0.01), and the mRNA levels of GRP78 and CHOP in liver tissue of rats in scald+carnitine group were significantly lower than those in scald alone group (with t values of 8.92 and 8.21, respectively, P<0.01); the protein expression levels of GRP78 and CHOP in liver tissue of rats in scald alone group were significantly higher than those in sham-injury group (with t values of 22.50 and 14.29, respectively, P<0.01), and the protein expression levels of GRP78 and CHOP in liver tissue of rats in scald+carnitine group were significantly lower than those in scald alone group (with t values of 14.29 and 5.33 respectively, P<0.01). After 24 h of culture, the cell survival rates of 0.1 μmol/L TM group, 0.2 μmol/L TM group, 0.4 μmol/L TM group, and 0.8 μmol/L TM group were significantly decreased than that in DMSO group (with t values of 4.90, 9.35, 18.64, and 25.09, respectively, P<0.01). Then 0.8 μmol/L was selected as the intervention concentration of TM. After 24 h of culture, compared with that in DMSO group, the protein expression levels of GRP78 and CHOP in cells in TM alone group were significantly increased (with t values of 10.48 and 17.67, respectively, P<0.01), and the protein expression levels of GRP78 and CHOP in TM+carnitine group were significantly lower than those in TM alone group (with t values of 8.08 and 13.23, respectively, P<0.05 or P<0.01). After 24 h of culture, compared with those in DMSO group, the protein expression levels of NLRP3 and GSDMD-N in cells in TM alone group were significantly increased (with t values of 13.44 and 27.51, respectively, P<0.01), but the protein expression levels of caspase-1, caspase-1/p20, and cleaved IL-1β in cells were not significantly changed (P>0.05); compared with that in TM alone group, the protein expression levels of NLRP3 and GSDMD-N in cells in TM+carnitine group were significantly decreased (with t values of 20.49 and 21.95, respectively, P<0.01), but the protein expression levels of caspase-1, caspase-1/p20, and cleaved IL-1β in cells were not significantly changed (P>0.05). Conclusions: In severely scald rats, exogenous L-carnitine may play a protective role against liver injury by inhibiting the pathways related to excessive endoplasmic reticulum stress-mediated pyroptosis.

Effect of the activation of P2X7 receptor on D-serine release in ventrolateral periaqueductal gray in rats with bone cancer pain / 医学研究生学报

Objective　The activation of P2X7 receptor in ventrolateral periaqueductal gray (vlPAG) is involved in the formation and maintenance of bone cancer pain (BCP). This study will establish a rat model of BCP and observe the effect of the activation of P2X7 receptor in vlPAG on D-serine level through brain microdialysis combined with ELISA.　Methods　Forty-two female SD rats were divided into four groups by random number table: normal control group (n=12), sham group (n=12), BCP group (n=12) and P2X7 receptor antagonist group (n= 6). The model of metastatic BCP in the tibias of the rats was established in the BCP group, and 20μL of RPMI-1640 medium cell suspension containing SHZ-88 breast cancer cells was injected (1×107 cancer cells/0.5 mL). The sham group was injected with treated cancer cells of the same volume (SHZ-88 breast cancer cells were kept in boiling water at 90 ℃ for 20 min), and the rest of the operation was the same as the BCP group. The normal control group received no treatment. The P2X7 receptor antagonist group was treated the same as the BCP group, except that the P2X7 receptor-specific antagonist A-438079 was added to the perfusion solution. The thermal pain threshold and mechanical pain threshold were detected at the same time in the normal control group, the sham group and the BCP group. The positive expression of P2X7 receptor in vlPAG of rats was detected by immunohistochemistry in each group in 21 days. The changes of D-serine in vlPAG dialysate were detected by ELISA in each group.　Results　The mechanical pain threshold and thermal pain threshold of the rats in BCP group on Day 5, 7, 10, 14, 18 and 21 were lower than those of the normal control group and sham group (P<0.01). The positive expression of P2X7 was scattered in vlPAG in normal control group and sham group. The number of P2X7 receptor positive cells in the BCP group was significantly higher than that in the control group and sham group (P<0.01). The content of D-serine in vlPAG of the rats in BCP group [(220.28±63.38)ng/mL] was significantly higher than that in the control group [(148.09±46.89)ng/mL] and the sham group [(147.32±51.44)ng/mL] (P<0.05). The content of D-serine in vlPAG [(134.20±41.77)ng/mL] in P2X7 receptor antagonist group was significantly lower than that in BCP group (P<0.05).　Conclusion　The activation of the P2X7 receptor in ventrolateral periaqueductal gray promotes D-serine release and participates in the mechanisms of BCP in rats .

The effect of activation of P2X7 receptor on Ca2+ level in lateral midbrain periaqueductal gray neuron / 医学研究生学报

Objective The main intracellular signal of P2X7 receptor activation is the increasing of Ca2+, which then presents the diversity of its physiological and pathological functions through multiple intracellular signal transduction. To observe the effect of activation of P2X7 receptor on intracellular calcium（Ca2+）level in lateral midbrain periaqueductal gray (lPAG) neurons of primary cultured rat. Methods The primary cultured lPAG neurons were randomly divided into 4 groups: control group(no drug added), only for control; BzATP group(100 μmol/L); A-740003+ BzATP group(incubate with 100 nmol/L A-740003 for 10 min, then add 10 μmol/L ofBzATP); BzATP control group(add in Ca2+-free solution for 20 min, then add BzATP). The incubation solution of control group, BzATP group and A-740003+ BzATP group are DMEM/F12 medium, and the BzATP control group is Ca2+-free. The laser scanning confocal microscopy (LSCM) was used to detect : the changes of cultured neuron Ca2+ levels by different concentrations of BzATP; the effects of A-740003 and Ca2+-free medium preincubation on BzATP-induced Ca2+ level alterations in cultured neurons. Results BzATP dose-dependently increased the Ca2+ levels in cultured lPAG neurons; A-740003 and Ca2+-free medium inhibited the BzATP-induced increasing of Ca2+ level in cultured lPAG neurons. LSCM showed: The intracellular calcium fluorescence insensity(2.48±1.05) in the BzATP group was significantly higher than that in the blank control group, BzATP control group and A-740003+ BzATP group[(1.12±0.03), (1.09±0.03), (1.14±0.08)](P<0.01). Conclusion The activation of P2X7 receptor can increase the level of lPAG neurons Ca2+ , and is associated with the extracellular Ca2+ influx.

Advances in studies on cancerous pain-related ion channels / 医学研究生学报

With the improvement of tumor diagnosis and treatment, the survival time in cancer patients has been gradually prolonged, but the complications such as severe pain are often found. Due to the unrevealed mechanisms of cancer pain, clinical analgesic treatments are unsatisfied needs , and the cancerous pain seriously affected the life quality of icancer patients. Ion channels are the transmembrane glycoproteins which produce and transmit electrical signals when activated, and involved in the regulation of a variety of physiological and pathological processes. Alterations in the ion channel function may play an important role in the formation and maintenance of cancer pain. In this review, the research developments of several major ion channels in the mechanisms of cancer pain in recent years are summarized, which can provide some useful references for the study of ion channel and related drug development of cancer pain.

Activation of spinal P2X7 receptor and analgesic effect of tramadol on neuropathic pain in rats / 医学研究生学报

Objective The mechanisms underlying neuropathic pain are complicated and the clinical effect of analgesia therap on this condition is not quite satisfactory.In this study, we observed the analgesic effects of the different doses of tramadol (T ) on neuropathic pain in rats and explored its action mechanisms . Mehtods The model of chronic sciatic nerve constriction injury (CC)I was established in male SD rats.The rats were randomly divided into five groups , sham operation ,CCI model control, low-dose T, mediumdose T, and high-dose T ,those in the latter three groups injected intraperitoneally with T at 5 , 15,and 25mg /kg qd ,respectively ,from the 7th to the 14th day after modeling.The mechanical and thermal pain thresholds of the nerve -injured hindleg were measured pre-operatively and at1 ,5 , 7, 10, 12and 14 days post-operatively.At 14 days after modeling, the expression of the P2X7receptor in the spinal dorsal horn was detected by immunohistochemistry and Western blot . Results At 5, 7,10 , 12 and 14 days after modeling,the mechanical pain threshold values were significantly decreased in the rats of the CCI model control group ([34.97±3.86 ],[34.06 ±3.79], [ 33.27±3.65], [29.03±3 . 54], and [17.90±2.34] g) and high-dose Tgroup([ 34.87±3.85], [33.47±3.66],[34 .50±3. 78 ], [29.43±3.64], and [18.63±2.42] g) as compared with the animals of the sham operation group ([39.73±5.55],[39.50±5.51], [40.97±5. 58], [41.87±5.60], and [42.97±6.75] g) (all P<0.01), and so were the thermal pain threshold valuesin the CCI model control group ([35 .21±3.94], [35.16±3.80], [29.74±2. 76], [ 20. 47±2.16], and[12.08±1.48] s) and high -dose T group ([35.76±3.76], [33.27±3.52], [31.22±3.05], [19.41±2.08], and [10.35±1.34] s) in comparison with the shamoperation group ([39.69±4.86], [39.21±4.82], [39.42±5.08], [41.17±4.88], and [42.53±5.12] s) (all P<0. 01 ).The number of the P2X7receptor positive cells and the ROD value of the P 2X7 receptor protein in the spinal dorsal horn were remarkably higher in the CCI model control than in the sham operation , low-dose T and medium-dose T groups (all P<0.01). Conclusion Intraperitoneal injection of low-dose tramadol has an analgesic effect on neuropathic pain in rats , which may be related to its decreasing effect on theexpression of the P2X7 receptor in the spinal dorsal horn.

Influence of different endothelial cells conditioned medium on the function of mitochondria of cortical neurons and the protective effect of Tongluo Jiunao Injection / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the influence of conditioned medium of rat brain microvascular endothelial cells on mitochondrial function of cortical neurons and the protective effect of Tongluo Jiunao Injection (TJI) on it.</p><p><b>METHODS</b>Four kinds of conditioned endothelial cell (EC) cultured medium were prepared, i.e. the N-CM medium prepared by EC cultured in the normal conditioned medium without any treatment; the NT-CM prepared by EC cultured in N-CM and treated with TJI 1 microl/ml for 10 h; the I-CM prepared by EC cultured in the non-glucose kreb medium under hypoxia condition; and the IT-CM by EC pre-treatce with TJI 1 microl/ml for 4 h and cultured as that of I-CM. The levels of neuronic mitochondrial activity, membrane potential (MMP) and cytochrome C (Cyt C) were determined before and after the glucose-oxygen deprived model neurons of brain cortex being cultured with different kinds of conditioned EC cultured medium for assessing the effects of these media on mitochondria of injured neuron.</p><p><b>RESULTS</b>As compared with those of the normal neuron, the mitochondrial activity and MMP of all injured neurons decreased and Cyt C level increased significantly. But comparison of these indexes among neurons cultured with different conditioned EC culture media showed that the greatest extent abnormality revealed in the N-CM cultured neurons, which even greater than that in the model neuron; while that was less in the N-CM cutured neuron than in model neuron; as for those cultured in the NT-CM and IT-CM, i.e. the TJI treated cuture medium, the abnormal changes were reduced significantly when compared with those cultured in medium untreated with TJI (N-CM and I-CM), respectively (all P < 0.05).</p><p><b>CONCLUSION</b>The paracrine secretion of the brain microvascular endothelial cells has evident regulatory effect on survival of the injured neurons, which might possibly be related to its protective effect on neuron mitochondrial function, and TJI could enhance the protective effect.</p>

Application of magnetic resonance DW imaging technique in studying treatment of cerebral ischemia in rats by single or combined use of jasminoidin and cholalic acid / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To estimate the therapeutic effect of single or combined use of jasminoidin and cholalic acid on focal cerebral ischemia rat with magnetic resonance-diffusion-weighted imaging (MR-DWI) technique, ultra-microscopy, and neuro-behavior scoring.</p><p><b>METHODS</b>The model of cerebral ischemia-reperfusion injury was induced by string method. Three hours after reperfusion, MR-DWI was applied with ultra-microscopy and neuro-behavior test to give evaluation on cerebral ischemic rats, and pathologic, ultramicroscopic observation of tissue were taken as adjuvant measures to comprehensively evaluate the pharmacological effect on ischemia-reperfusion rats and delimit the efficacy of the two different components and their combination.</p><p><b>RESULTS</b>Compared with the model group, ADC and DCavg values of the foci in all the treated groups had the incrensing trend. There was significant difference arund the foci in the group of combined use of jasminoidin and cholalic acid (P < 0.05).</p><p><b>CONCLUSION</b>Combined use of jasminoidin and cholalic acid had protective effects on nerve and brain. MR-DWI technique accompanied with ultramicroscopic observation of tissues and neuro-behavior test is an effective method for evaluating the effect of neuro-protective agent.</p>

Pharmacological evaluation of baicalin and jasminoidin and their combination on focal cerebral ischemia-reperfusion injury / 中国中药杂志

<p><b>OBJECTIVE</b>To elucidate the therapeutic effect and the influence on PI3K-Akt-PKB-BAD-CREB-PCREB pathway in focal cerebral ischemia rat responses before and after treatment with baicalin and jasminoidin given alone or in combination.</p><p><b>METHOD</b>Rat model of ischemia reperfusion was established with thread. Generally accepted methods were used, including TTC staining, behavior test, as well as micro and ultra microscopy which can dynamically and accurately monitor pathological and physiological changes after cerebral ischemia on earlier period, to evaluate the brain injury induced by ischemia and the attenuations by the drugs. The difference of PI3K-Akt-PKB-BAD-CREB-PCREB expression was detected by western-blot technology.</p><p><b>RESULT AND CONCLUSION</b>The combination of baicalin and jasminoidin composition can be potential neuroprotective agent. TTC staining technology combined with behavior grade and ultrmicro-structure observation on brain tissue is effective method to evaluate protective agent, which is related to signal transduction PI3K-Akt-PKB-BAD-CREB-PCREB pathway. The results provide benofical basis for revealing the complex of therapeutic mechanism of traditional Chinese medicine Qingkai Ling (QKL).</p>

Protective effect of jasminoidin on cascade of damage of cerebral ischemia in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the protective effect of jasminoidin on cascade of damage of cerebral ischemia.</p><p><b>METHOD</b>The rats were randomly divided into four groups: sham-operated group, ischemic group, the jasminoidin-treatment group and PNS-treatment group. Focal cerebral ischemia was produced by permanent occlusion of left middle cerebral artery (PMCAO) in rats. Radioimmunoassay (RIA) was utilized to identify the content of tumor necrosis factor-alpha (TNF-alpha) and interlukin 1beta (IL-1beta) in brain tissue of rats following ischemia. and that of Neuron-specific enolase (NSE) in rat's serum was observed too. The plasma concentration of vonWillebrand factor (vWF) was identified by enzyme-linked immunoadsordent assay (ELISA).</p><p><b>RESULT</b>After 12 h and 24 h of ischemia, the contents of TNF-alpha and IL-1beta and vWF as well as on NSE showed concomitant increase. Jasminoidin dramatically inhibited the increase of TNF-alpha and IL-1beta after 12 h and 24 h of ischemia, and repressed the increase of vWF after 12 h and 24 h of ischemia too. However, the influence of jasminodin NSE after 12 h and 24 h of ischemia was not significant.</p><p><b>CONCLUSION</b>Jasminoidin had good effect on repressing the expression of TNF-alpha and IL-1beta as well as vWF caused by cerebral ischemia, thus it manifested the effect of relieving the damage to vascular endothelial cell and blocking the progress of cascade damage of cerebral ischemia through inhibiting the process of inflammation.</p>

Screening of traditional Chinese remedies for SARS treatment / 中国中药杂志

The SARS epidemic is breaking out worldwide. To select suitable herbal drugs for clinical uses is important and urgent amongst the controversial treatment proposals. Nine pharmacological experimental models were used to evaluate the comprehensive efficacy of traditional Chinese remedies by cross validation in different institutes. Eight drugs were optimized for controlling different symptoms of SARS.