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Objective To explore the expression and role of bromodomain-containing protein 4(BRD4) in spinal cord of mice which suffered inflammatory pain induced by formaldelryde solution. Methods Thirty-two ICR mice were randomly divided into normal saline group and formaldehyde injection 5 minutes, 30 minutes and 60 minutes groups, with 8 mice in each group. The expression of BRD4 protein and mRNA in spinal cord of mice in each group were detected by Western blotting (n = 4/group) and Real-time PCR (n = 4/group); 66 mice were randomly divided into formaldelryde injection group, vehicle (DMSO) plus formaldelryde injection group and 6. 25, 12. 5, 25 and 50 mg/kg JQl injection plus formaldelryde solution group, with 11 mice in each group. The effect of BRD4 inhibitor JQl on spontaneous pain in each group was observed (n= 11/group); Immunohistochemistry (n= 3/group), Real-time PCR (n = 4/group) or Western blotting (n= 4/group) were used to detect the effects of 25 mg/kg JQ1 on the expression of c-fos and glutamate receptor 2 (GluR2) in the spinal cord of model mice. Results The result showed that levels of BRD4 protein (P<0. 01) and mRNA in spinal cord increased significantly 30 min and 60 min after formaldehyde solution injection (P<0. 05). The behavioral test showed that both 25 mg/kg and 50 mg/kg JQf administration could reduce the second phase spontaneous pain compared with the solvent (DMSO) group (P < 0 . 05). Furthennore, immunohistochemistry and Real-time PCR result showed that 25 mg/kg JQf injection could significantly reduce positive numbers (P<0. 01) and high mRNA expression of c-fos in mouse spinal cord induced by formaldehyde solution (P < 0 . 05), and the Western blotting result showed that 25 mg/kg JQf administration could significantly reduce the expression of glutamate receptor GluR2 (P < 0. OOf). Conclusion BRD4 may play an important role in the induction of central sensitization of inflammatory pain, and JQf may alleviate inflammatory pain behavior by inhibiting the formation of central sensitization of pain.
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Objective To investigate the effect of voluntary wheel running on negative affective of mice induced by formaldehyde. Methods Thirty male Kunming mice were randomly divided into three groups, including normal saline control group (NS), formaldehyde model group (F), and voluntary wheel running with formaldehyde injection group ( R+ F). The pain model was established by right hindpaw intraplantar formalin injection, the mice of R+F group experienced voluntary wheel running for three weeks before intraplantar formaldehyde injection. The spontaneous pain behavior was determined by the cumulative time of licking paw. The anxiety-like behavior of each group was determined by open field test (OFT) and elevated plus-maze test (EPM) while the depression-like behavior of each group was determined by forced swimming test (FST). The expression of doublecortin ( DCX ) in the hippocampus was determined by immunohistochemistry. Results Compared with the NS group, the typical two-phase pain response was observed in the F group, and compared with the F group, the second phase pain duration was significantly reduced in the R+F group (P<0. 01). In the open field test, the F group showed remarkably reduced time in the inner area(P<0. 001) compared with the NS group, while the R+F group increased time in the inner area (P<0. 05) compared with the F group. In the elevated plus-maze test, the F group showed remarkably reduced time (P< 0. 001) spent in the open arm compared with the NS group, however, compared with the F group, R+F group increased time spent in the open arm (P<0. 05). In the forced swimming test, the immobility time of the F group significant increased (P<0. 01) compared with the NS group, which was decreased in the R+F group (P<0. 05). The Immunohistochemistry showed that the area of DCX positive cells in the hippocampus of the F group was downregulated compared with the NS group, which was upregulated in the R+F group. Conclusion Our findings indicate that voluntary wheel running can improve anxiety and depression-like in mice induced by formaldehyde injection, which may be related to enhanced neurogenesis in the hippocampus.
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Objective To investigate the expression of BRD 4 in the spinal cord and its relationship with acute in-flammation pain induced by formaldehyde in mice.Methods Thirty-six mice were randomly divided into three groups:control group,formaldehyde group and indomethacin+formaldehyde group;25 μL 1%formaldehyde was injected into the right plantar to establish the acute inflammationpain model,while the indomethacin(20 mg/kg) was injected intraperitoneally 1 hour before formaldehyde injection.Then,all the mice were video recored for 1h to observe the spontaneous pain.Then,cell localization of BRD4 in the spinal cord of normal mice was determined by immunofluorescence assasy.The expression of BRD4 in spinal cord was detected by immunohistochemistry and Western blot.Results Immunofluorescence showed that BRD 4 was mainly co-locolized with the neuronal marker NeuN in the spinal cord of normal mice.Formaldehyde injection could induce two-phase spontaneous pain, while indomethacin intervention could only decrease the second phase pain(P<0.05).Furthermore,formaldehyde injec-tion led to significantly enhanced expression of BRD 4 in bilateral spinal cord,which was remarkbly inhibited by in-domethacin(P<0.05).Conclusions Up-regulation of BRD4 in spinal dorsal horn may be involved in the acute in-flammatory pain.
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<p><b>OBJECTIVE</b>To explore the pathogenesis of tumors by blocking the normal differentiation process of stem cells.</p><p><b>METHODS</b>Bone marrow mesenchymal stem cells (BMSCs) from rats were isolated, cultured and purified by whole bone marrow adherence method. The rat BMSCs were induced to differentiate into adipocytes with dexamethasone, insulin and indomethacin. Blockage of the differentiation process was induced by 3-methylcholanthrene (3-MC).</p><p><b>RESULTS</b>The differentiation experiment showed that at 30 days after the induction, oil red O staining-positive cells occurred with increased intracytolasmic lipid droplets, characteristic for adipocytes. The differentiation blockage experiment showed that at 30 days after induction, the deposits of oil red O staining-cytoplasmic lipid droplets was significantly reduced, indicating that the blocked cells were adipocytes, but not fully differentiated. Morphological identification showed that cell contact inhibition disappeared, abnormal cell nuclei, increased number of micronucleus aberration and karyotype abnormalities, indicating that malignant transformation of the stem cells occurred after the differentiation blockage.</p><p><b>CONCLUSIONS</b>The results of this study show a blockage of the differentiation of that stem cells at the intermediate phase, and a tendency of malignant transformation of the stem cells. The results of our study provide new evidence that cancer stem cells may be originated by suppression of stem cell differentiation.</p>