Analysis of histone modification of MtSERK1 during in vitro regeneration in Medicago truncatula / 生物工程学报

Epigenetic modification, especially histone modification, plays an important role in maintaining plant genome stability, regulating gene expression and promoting regeneration in vitro. MtSERK1 is an important marker gene involved in establishing of embryogenic callus during in vitro regeneration of Medicago truncatula. In order to understand the regulation Epigenetic modification, especially histone modification, plays an important role in maintaining plant genome stability, regulating gene expression and promoting regeneration in vitro. MtSERK1 is an important marker gene involved in establishing of embryogenic callus during in vitro regeneration of Medicago truncatula. In order to understand the regulation relationship between dynamic histone modification and MtSERK1s expression during the processes of in vitro organogenesis, the expression of MtSERK1 was analyzed by qRT-PCR, and the modification status of H3K9me2, H3K4me3 and H3K9ac in the promoter region and different regions included in the gene body was analyzed by chromatin immunoprecipitation (ChIP). We found expression activation of MtSERK1 was related to the dynamic changes of histone H3K4me3 and H3K9ac in the 5' and 3' regions. This study will provide important theoretical guidance for understanding of the regulatory mechanism of MtSERK1 and also for establishing efficient genetic transformation system of Medicago truncatula.

Clinical study of dexmedetomidine in elderly patients undergoing laparoscopic cholecystectomy under gen-eral anesthesia / 临床麻醉学杂志

Objective Replacement of dexmedetomidine with propofol for maintaining the anes-thesia in elderly patients undergoing laparoscopic cholecystectomy.Methods Ninety patients,over 70 years old,undergoing laparoscopic cholecystectomy were randomly divided into 2 groups,propofol combined with remifentanil (group A),dexmedetomidine combined with remifentanil (group B),45 patients in each group.Group A was not treated with any preoperative medication,while group B was treated with loading dose of 0.5 μg/kg dexmedetomidine intravenously completed within 10 minutes. Induction methods were same in both groups,3 # or 4 # laryngeal mask were inserted after induction in both groups.Maintenance of anesthesia in group A treated with propofol 2.0-3.0 μg/ml + 4.5-5.5 ng/ml TCI;Maintenance of anesthesia in group B treated with dexmedetomidine 0.25 μg·kg-1·h-1 +remifentanil 4.5-5.5 ng/ml (TCI).HR,SBP,DBP,BIS were recorded at inserting the LMA (T1 ), beginning of the surgery (T2 ),dissociate the cholecyst (T3 ),withdrawal of the laparoscope (T4 ), extubate the LMA (T5 ).Postoperative recovery time,Steward awakening score and modified OAA/S score at extubation time were recorded.Results No significant difference was found between BIS val-ue of two groups at different time point.Compared with group A,HR at T1-T5 in group B were sig-nificantly lower,SBP,DBP were significantly decreased (P <0.05).There was no significant differ-ence between Steward awakening score and modified OAA/S score at recovery and extubation time in two groups.Conclusion Dexmedetomidine replacing propofol can be safely used in laparoscopic chole-cystectomy with less hemodynamic changes during maintenance of anesthesia in elderly patients.

Effects of CX3CR1 on expression of μ-receptor and TRPV1 in spinal dorsal horn of morphine-tolerent rats with bone cancer pain / 中华麻醉学杂志

Objective To investigate the effects of intrathecal(IT)CX3 CR1 neutralizing antibody(antiFKR)on morphine tolerance in rats with bone cancer pain(BCP)and the unlerlying mechanism.Methods Forty-eight adult female SD rats aged 3 months weighing 180-200 g were randomized into 4 groups(n =12 each):group I sham operation(S); group Ⅱ BCP + normal saline(NS); group Ⅲ BCP + IgG(IgG)and group ⅣBCP + anti-FKR.Bone cancer pain(BCP)was induced by injecting Walker 256 cancer cells 10 μl(400 cells/ μl)into the medullary cavity of right tibia in groups Ⅱ,Ⅲ and Ⅳ.Ten days later morphine 20 μg/kg was administered IT twice a day for 7 consecutive days.Starting from the 8th day NS,IgG and anti-KFR 10 μl was administered IT once a day for 3 consecutive days in groups Ⅱ,Ⅲ and ⅣⅣ respectively.Paw withdrawal threshold to yon Frey filament stimulation(MWT)and paw withdrawal duration(MWD)were determined bcfore(To,baseline)and at 3,6,9 day after intra-tibial cancer cell inoculation(T1.2,3),on the 3rd and 7th day of IT morphine(T4.5)and on the 3rd day of IT NS/lgG/anti-KFR(T6).The animals were killed at T6 after last pain behavior assessment.The lumbar segment(L4-6)of the spinal cord was removed for determination of the expression of CX3 CR1 protein(by Western blot),μ-opioid receptor and TRPV1 receptor(by immuno-histochemistry)in the dorsal horn of spinal cord.Results IT morphine significantly eased BCP at T4,but morphine analgesia was significantly reduced on the 7th day of IT morphine in the 3 groups indicating morphine tolerance which was significantly relieved by anti-KFR in group Ⅳ.IT anti-KFR significantly down-regulated CX3CR1 prolein and TRPVI receptor expression and up-regulated μ-opioid receptor in group Ⅳ as compared with IT NS and lgG in groups Ⅱ and Ⅲ.Conctusion IT anti-KFR can relieve morphine tolerance in the rats with bone cancer pain by up-regulating μ-opioid receptor and down-regulating CX3 CR1 protein and TRPVI receptor expression.

Inhibition of glial activation in rostral ventromedial medulla attenuates mechanical allodynia in a rat model of cancer-induced bone pain / 华中科技大学学报（医学）（英德文版）

Descending nociceptive modulation from the supraspinal structures plays an important role in cancer-induced bone pain (CIBP). Rostral ventromedial medulla (RVM) is a critical component of descending nociceptive facilitation circuitry, but so far the mechanisms are poorly known. In this study, we investigated the role of RVM glial activation in the descending nociceptive facilitation circuitry in a CIBP rat model. CIBP rats showed significant activation of microglia and astrocytes, and also up-regulation of phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) and pro-inflammatory mediators released by glial cells (IL-1β, IL-6, TNF-α and brain-derived neurotrophic factor) in the RVM. Stereotaxic microinjection of the glial inhibitors (minocycline and fluorocitrate) into CIBP rats' RVM could reverse the glial activation and significantly attenuate mechanical allodynia in a time-dependent manner. RVM microinjection of p38 MAPK inhibitor (SB203580) abolished the activation of microglia, reversed the associated up-regulation of pro-inflammatory mediators and significantly attenuated mechanical allodynia. Taken together, these results suggest that RVM glial activation is involved in the pathogenesis of CIBP. RVM microglial p38 MAPK signaling pathway is activated and leads to the release of downstream pro-inflammatory mediators, which contribute to the descending facilitation of CIBP.

Change in 5-hydroxytryptamine level in spinal dorsal horn in a rat model of tibial bone cancer pain / 中华麻醉学杂志

Objective To investigate the change in 5-hydroxytryptomine (5-HT) content in spinal dorsal horn in a rat model of tibial bone cancer pain (BCP). Methods Sixty female SD rats weighing 160-180 g were randomly divided into 3 groups ( n = 20 each): control group (group C), sham operation group (group S) and BCP group. BCP was induced by intra-tibial inoculation of 10 μl Walker 256 breast cancer cell suspension in group BCP, while group S received intra-tibial inoculation of 10 μl D-hank solution. Paw withdrawal threshold to mechanical stimulation with yon Frey filaments (MWT) was measured 1 d before (baseline) and at 3, 5, 7, 9, 11,14, 16, 18 and 21 d after breast cancer cell inoculation. At 1 d before and 7, 14 and 21 d after breast cancer cell inoculation, four animals in each group were sacrificed after measurement of MWT. Their lumber segments of the spinal cord were removed for assay of 5-HT content in spinal dorsal horn using HPLC with fluorescence detector.HE staining was used to detect the damage to the tibia. Correlation between the 5-HT content and MWT was analyzed. Results MWT was significantly decreased after breast cancer cell inoculation in group BCP ( P ＜ 0.05).Microscopic examination showed serious bone destruction of tibia at the injection site in group BCP, while no bone destruction was found in groups C and S. 5-HT content in spinal dorsal horn was significantly higher in group BCP than in groups C and S (P ＜ 0.05). There was strong negative linear correlation between 5-HT content in spinal dorsal horn and MWT ( r = - 0.973, P ＜ 0.05 ). Conclusion The 5- HT content in spinal dorsal horn is significantly increased in rats with tibial BCP and is involved in the development of BCP.

Construction of lentivirus vector expressing antigene RNA and ferritin gene / 中华麻醉学杂志

Objective To construct lentivirus vector expressing antigene RNA and ferritin gene.Methods Intermediate plasmid pGC-FU-HF was constructed by transfecting lentivirus vector pGC-FU with heavy chain ferritin subunit gene.The target plasmid pGC-agRNA-HF was subsequently constructed by transfecting the intermediate plasmid with β-arrestin 2 antigene RNA.The NG108-15 cells were transfected with the target plasmid.The titre of lentivirus vector was measured by RT-PCR.The expression of antigene RNA and ferritin gene was determined by Western blot and RT-PCR.Results Lentivirus vector was successfully transfected with antigene RNA and ferritin gene.The titre of lentivirus vector was 2.00 × 109 TU/ml.The expression of β-arrestin2 protein was down-regulated and the expression of ferritin protein up-regulated in the NG108-15 cells after being transfected with the lentivirus vector.Conclusion Lentivirus vector expressing antigene RNA and ferritin gene has been successfully constructed.

Establishment of a rat model of bone cancer pain-chronic morphine tolerance / 中华麻醉学杂志

Objective To establish a rat model of bone cancer pain-chronic morphine tolerance. Methods Thirty-six adult female Sprague-Dawley rats weighing 180-200 g in which intrathecal catheters were successfully placed without complications were randomly divided into 3 groups ( n = 12 each) :group sham operation (group S),group chronic morphine tolerance (group M) and group bone cancer pain + chronic morphine tolerance (group BM). Bone cancer pain was induced by intra-tibia inoculation of Walker256 mammary gland carcinoma cells (4 ×102 cells/μl) in group BM, while in group M heat-inactivated Walker256 mammary gland carcinoma cells were given instead, and then 10 days later, intrathecal morphine 20 μg,/kg was administered twice a day for 9 consecutive days. The mechanical paw withdrawal threshold (MWT) and mechanical paw withdrawal duration (MWD) were measured before inoculation, at day 1, 3, 6 and 9 after inoculation, and at day 1, 3, 5, 7 and 9 of morphine administration. The degree of bone destruction was assessed by radiological analysis at day 9 after inoculation. After the last measurement of pain threshold, the rats were given innoxious touch-stimulus. The rats were sacrificed 3 h after stopping the stimulus, and L4-6 segment of the spinal cord was isolated to determine the expression of Fos protein in the spinal dorsal horn. Results Compared with group S, MWT was significantly decreased, MWD was significantly prolonged and the expression of Fos protein was up-regulated in group M ( P ＜ 0.05 or 0.01 ). MWT was significantly decreased, MWD was significantly prolonged, bone destruction scores were significantly increased,and the expression of Fos protein was up-regulated in group BM compared with group M ( P ＜ 0.05 or 0.01 ). Conclusion A rat model of bone cancer pain-chronic morphine tolerance is successfully established.

Effects of beta-arrestin 2 antigene RNAs on mu-opioid receptor desensitization in C17.2 neural stem cells from mice / 中国组织工程研究

BACKGROUND: Antigene RNAs (agRNAs) could be a useful tool to downregulate beta arrestin 2 (Arrb2) gene expressions, and realize gene knock-out effect in cell levels. OBJECTIVE: To observe the effects of agRNAs on DAMGO-induced mu-opioid receptor (MOR) desensitization in C17.2 cells by using agRNAs complementary to transcription start sites of beta arrestin 2 (Arrb2) to downregulate the gene expression in mouse C17.2 cells. METHODS: Mouse neural stem cells C17.2 was cultured in Dulbecco's minimal essential medium containing 10% fetal bovine serum, 10 mg/L penicillin and 10 mg/L ampicillin with 5% CO_2 at 37 ℃. The cells were passaged every 5 to 6 days after digestion with 0.25% trypsin when cells were 80% confluent. The expression of MOR on mouse C17.2 cells was detected by RT-PCR and immunocytochemical method. AgRNAs which could silence the expression of Arrb2 was transfected into C17.2 cells with Lipofectamine. The expression of green fluorescent protein gene was observed by fluorescence microscopy 24 hours after transfection. [~(35)S]GTPγS binding was assessed by autoradiography to examine the ability of the MOR to couple to G proteins on stimulation with selective agonist DAMGO.RESULTS AND CONCLUSION: The expression of MOR on C17.2 cells was confirmed by RT-PCR. The receptors were expressed on cell membrane and in plasma determined by immnocytochemistry. The expression of green fluorescent protein gene could be observed in C17.2 cells transfected with plasmid pGPU6/GFP/Arrb9 using fluorescent microsocpe. The results of [~(35)S]GTPγS binding showed that the stimulation ratio in cells with and without DAMGO stimulation or transfected with agRNAs were (113±14)%, (253±17)% and (239±15)% respectively. This indicated that agRNAs could downregulate the expression of beta-arrestin 2 and inhibit the desensitization of MOR.

Analgesic effects of the selective blocking of descending facilitation targeting μ, opioid receptor positive neurons in a rat model of bone cancer pain / 中华麻醉学杂志

Objective To investigate analgesic effects of the selective blocking of descending facilitation targeting μ opioid receptor positive neurons in the rostral ventromedial medulla ( RVM) in a rat model of bone cancer pain. Methods Forty-eight adult female Wistar rats weighing 180-200 g were randomly divided into 6 groups: group Ⅰ control ( n = 3) ;group Ⅱ bone cancer pain induced by intra-tibia inoculation of Walker 256 mammary gland carcinoma cells ( n = 9) ;group Ⅲ-Ⅵ received a single intra-RVM micro-injection of PBS (group Ⅲ), dermorphin (group Ⅳ) , saporin (group Ⅴ) and dermorphin-saporin ( group Ⅵ) respectively at 28 days before intra-tibia inoculation ( n = 9 each) . Starting from 3 to 20 days after intra-tibia inoculation, mechanical allodynia was assessed and recorded. The animals were sacrificed on 7, 14 and 20 days after intra-tibia inoculation, after repetitive non-noxious tactile stimulation of the hindpaw. The total number of Fos-positive neurons in the spinal dorsal horn was measured as a marker indicative of central sensitization. Results The animals developed nociceptive hypersensitivity after intra-tibia cancer cell inoculation in group Ⅱ -Ⅵ . Nociceptive hypersensitivity was significantly decreased during 4-7 days after the onset of nociception in group Ⅵ (dermorphin-saporin). The number of Fos positive neurons in bilateral spinal dorsal horn was significantly increased by intra-tibia inoculation of cancer cells in group Ⅱ-Ⅵ as compared with control group and was significantly lower at day 14 and 20 after inoculation in group Ⅵ (dermorphin-saporin) than in group Ⅱ - Ⅴ.Conclusion Selective blocking of descending facilitation targeting μ opioid receptor positive neurons in RVM can effectively reduce nociceptive hypersensitivity induced by intra-tibia inoculation of Walker56 mammary gland carcinoma cells.