ObjectiveTo investigate the effect of erigeron breviscapus (EBHM) on ocular hypertension and the protective effect of retinal ganglion cells (RGCs) in rats by regulating mitogen activated protein kinase (MAPK) signaling pathway.MethodsSixty male Sprague-Dawley rats were divided into control group, model group, low-dose EBHM group (group A), medium-dose EBHM group (group B), and high-dose EBHM group (group C) by random number table method. There were 12 rats in the group, the left eye was used as the experimental eye. The rats of model group, group A, group B, and group C were infused with normal saline through the anterior chamber to construct an acute ocular hypertension model; the control group was given general anesthesia only. Then, 2-30 days after modeling, rats in the control group and model group were given 3 ml of normal saline once a day; rats in group A, group B, and group C were given 0.30, 0.45, and 0.60 g/100 g EBHM by intragastric administration, respectively, 1 time/d. The rat intraocular pressure was measured before modeling and 1, 14, and 30 days after modeling, and the proportion of high intraocular pressure model was measured. Thirty days after modeling, hematoxylin-eosin (HE) staining was used to observe the pathological changes of retinal tissue; immunofluorescence staining was used to detect the changes in the number of RGCs; real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was used to detect p38 in the retinas of rats in each group. The relative expression of MAPK and Caspase-3 mRNA; western blot was used to detect p38MAPK and phosphorylation in the retina of rats in each group relative expression of phosphorylate-p38MAPK (p-p38MAPK) and Caspase-3 protein. One-way analysis of variance was used for multi-sample comparison, and SNK-q test was used for comparison between two samples.ResultsOne day after modeling, none of the rats in the control group developed acute ocular hypertension, and the other groups were successfully modeled. Compared with the model group, the rates of acute ocular hypertension at 14 days after modeling in groups B and C were lower (χ2=98.701, P＜0.05), and the rates of acute ocular hypertension at 30 days after modeling in groups A, B, and C were 0. There was no statistically significant difference in the rates of acute ocular hypertension between 14 and 30 days after modeling in the A, B, and C groups (P＞0.05). The results of HE staining showed that the structure of the retina in the control group was complete, and the layers were clearly visible; the RGCs count was not abnormal, and the morphology was plump and round. The retina of rats in the model group became thinner; the number of RGCs was greatly reduced, the morphology was vacuolated, and the arrangement was sparse. The retina of rats in groups A, B, and C became thicker, and the number of RGCs increased, and the retina structure in group C was better restored. The results of immunofluorescence staining showed that the RGCs counts of rats in groups A, B, and C were higher than those in the model group, and the difference was statistically significant (F=297.514, P＜0.05); pairwise comparison between groups, group A was lower than that of group B and C Group (q=2.842, 5.263), group B was lower than group C (q=2.457), the difference was statistically significant (P＜0.05). The results of RT-qPCR and Western blot showed that compared with the model group, the relative expression of Caspase-3 mRNA (F=267.912) and protein (F=692.279) and the relative expression of p-p38MAPK protein in the retina of rats in groups A, B and C. The expression level (F=150.061) all decreased, and the difference was statistically significant (P＜0.05); pairwise comparisons between groups showed that Caspase-3 mRNA (q=6.977, 15.642) and protein (q=6.997, 15.642) relative expression levels and p-p38MAPK protein (q=12.443, 24.358) relative expression levels are lower than groups A and B, group B was lower than group A (q=11.678, 12.471, 10.204), the difference was statistical academic significance (P＜0.05).ConclusionsEBHM can significantly reduce intraocular pressure in rats with acute ocular hypertension, increase RGCs counts, and reduce retinal damage. Its regulatory mechanism may be related to the MAPK pathway.
ObjectiveTo evaluate the inhibitory effect of small interfering RNA (siRNA) targeting peroxisome-proliferator-activated receptor-γcoactivator-1α(PGC-1α) on retinal neovascularization in the mouse.
MethodsEighty seven-day-old C57BL/6J mice were divided into normal group, model blank group, model control group and PGC-1αsiRNA group, twenty mice in each group. Mice in the normal group were kept in normal room air. Mice in the model blank group, model control group and PGC-1αsiRNA group were induced for retinal neovascularization by hypoxia. Liposome with PGC-1αsiRNA (1 μl) and liposome with negative control siRNA (1 μl) were injected into the vitreous in the PGC-1αsiRNA group and model control group respectively when mice were moved out to room air from the cabin (Postnatal 12). No injection were performed in the model blank group. At postnatal 17, fluorescein angiography was used to assess the vascular pattern.The proliferative neovascular response was quantified by counting the nuclei of new vessels extending from the retina into the vitreous in cross-sections. PGC-1αand vascular endothelial growth factor (VEGF) level in retina were measured by real-time polymerase chain reaction (real-time PCR) and Western blot. Inhibition efficiency of PGC-1αsiRNA on PGC-1αand VEGF was calculated.
ResultsMice in the normal group showed reticular distribution of retinal blood vessels. Central nonperfused retina, neovascular tufts and fluorescein leakage were seen in the model blank group and model control group. Neovascular tuft and fluorescein leakage were decreased in the PGC-1αsiRNA group compared to the model blank group and model control group. The neovascular nuclei were increased in the model blank group and model control group compared to the normal group (P < 0.05). The neovascular nuclei were decreased in the PGC-1αsiRNA group compared to the model blank group and model control group (P < 0.05). The expression of PGC-1αmRNA and protein in retina was increased significantly in the model blank group and model control group as compared with normal group, while decreased 54% and 53% respectively in the PGC-1αsiRNA group as compared with model blank group and model control group (P < 0.05). The expression of VEGF mRNA and protein in retina was increased significantly in the model blank group and model control group as compared with normal group, while decreased significantly in the PGC-1αsiRNA group (decreased 48% and 40% respectively) as compared with model blank group and model control group (P < 0.05).
ConclusionsIntravitreal injection of PGC-1αsiRNA mediated by liposome can inhibit retinal neovascularization in the mouse effectively.
Epilepsy is a disorder of the brain in which sudden abnormal discharges of neurons cause transient dysfunction and is a common disorder of the nervous system. Although most patients experience remission of symptoms with medication, about 20 ~ 30% of patients still have poor outcomes with medication and progress to refractory epilepsy. The etiology of epilepsy is complex and the exact pathogenesis is not yet clear. Current research has explored the pathophysiological mechanisms underlying epileptogenesis, thus providing a basis for identifying potential therapeutic targets for epilepsy and advancing the precision treatment of epilepsy. p38 Mitogen-activated protein kinase (MAPK) signalling pathway is a conserved class of kinases involved in many physiological/pathological processes by regulating intracellular gene expression levels, cell division, differentiation and apoptosis in response to various extracellular stimuli in order to mediate intracellular signalling cascades. The p38 MAPK signalling pathway is one of the subfamilies of MAPK that mediates inflammatory responses, apoptosis, tissue edema and other biological processes involved in the development of central nervous system diseases. The p38 MAPK signalling pathway is now reviewed for its involvement in the development of epilepsy through unused pathways, in order to identify new potential targets for epilepsy treatment and provide clinical precision.
Objective To explore the regulation of peroxisome proliferator-activated receptor γ coactivator 1α( PGC-1α) and NF-E2-related factor 2( Nrf2) on expression of γ-glutamylcysteine synthetase ( γ-GCS) , and their roles in chronic obstructive pulmonary disease( COPD) . Methods Twenty-four SD rats were randomly divided into a COPD group and a normal control group. COPD model was established by intratracheal instillation of lipopolysaccharide ( LPS) and daily exposure to cigarette smog in the COPD group. The lung function was measured and the pathological changes were observed. The protein and mRNA expressions of PGC-1α, Nrf2, and γ-GCS in lung tissue were measured by immunohistochemistry, Western blot, in site hybridization ( ISH) , and reverse transcription-polymerase chain reaction ( RT-PCR ) ,respectively. Results In the COPD group, the pulmonary function ( FEV0. 3, FEV0. 3 /FVC, PEF) damage and lung pathological changes were conformed as morphological characteristics of COPD. The mRNA of PGC-1α and Nrf2 expressed in lung tissues of two group rats in the region consistent with γ-GCS mRNA. The protein and mRNA expressions of PGC-1αand γ-GCS were markedly increased in the COPD group( all P lt;0. 05) ,and the protein expression of Nrf2 was obviously up-regulated ( P lt; 0. 01) , while Nrf2 mRNA had no significant difference between the two groups( P gt;0. 05 ) . Linear correlation analysis showed that the level ofPGC-1αprotein was positively correlated with the levels of Nrf2 protein and mRNA ( r = 0. 775, 0. 515, all P lt; 0. 01) , and the levels of PGC-1αand Nrf2 protein were positively correlated with the levels of γ-GCS protein ( r = 0. 531, 0. 575, all P lt; 0. 01) and mRNA ( r = 0. 616, 0. 634, all P lt; 0. 01) . Conclusions PGC-1α, which may serve as a co-activator of Nrf2, can up-regulate the expression of γ-GCS gene cooperatively with Nrf2 through a common pathway, which might involve in the oxidative and antioxidative mechanism in the pathogenesis of COPD.
Objective To investigate the mechanism of p38 mitogen activated protein kinase (MAPK) signaling pathway in regulating the hyperplasia and hypertrophy of human lumbar ligamentum flavum via transforming growth factor β1 (TGF-β1)/connective tissue growth factor (CTGF). Methods The lumbar ligamentum flavum tissue taken from patient with lumbar intervertebral disc herniation was isolated by collagenase-predigested explant cultures. The ligamentum flavum cells were treated with the extracellular regulated protein kinase pathway blocker PD98059, c-Jun N-terminal kinase pathway blocker SP600125, and p38 pathway blocker SB203580, and then the mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ were detected by real-time fluorescence quantitative PCR (qRT-PCR). The ligamentum flavum cells were divided into 4 groups, and transfected with small interfering RNA (siRNA), p38 siRNA, siRNA+3 ng/mL TGF-β1, and p38 siRNA+3 ng/mL TGF-β1 in groups A, B, C, and D, respectively. After 24 hours of transfection, immunofluorescence staining was performed to observe the expressions of p38 and phosphorylation p38 (p-p38); the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ in each group were detected by qRT-PCR; the protein expression of CTGF in each group was detected by Western blot. Results p38 pathway blocker SB203580 could significantly reduce the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ (P<0.05). After 24 hours of transfection, immunofluorescence staining showed positive staining with p38 and p-p38 expressions in groups A, C, and D and negative staining in group B. Compared with group A, the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ and relative protein expression of CTGF in group B decreased significantly (P<0.05), while those in groups C and D increased significantly (P<0.05); and those indicators significantly increased in group C than in group D (P<0.05). Conclusion TGF-β1/CTGF based on the p38 MAPK signaling pathway play an important role in the occurance and development of hypertrophy of human lumbar ligamentum flavum.
Objective
To investigate the effects of docosahexenoic acid (DHA) on large conductance Ca2+-activated K+ (BK) channels in normal retinal artery smooth muscle cells (RASMCs).
Methods
Cultured human RASMCs (6 th-8 th generations) were used to patch clamp experiment. The open probabihties (NP0) in BK channels with different concentrations (0.0, 1.0, 3.0, 5.0, 7.5, 10.0 μmol/L) of DHA were recorded by patch clamp technique in single channel configuration. RASMCs were intervened by different concentrations (0.0, 1.0, 5.0 μmol/L) of DHA as control group, low and high doses of DHA groups, respectively. The protein expressions of β subunit of BK channels in RASMCs from three groups were measured by Western blot.
Results
The NP0 of BK channels were 0.044 4±0.001 2, 0.081 2±0.004 2, 0.209 0±0.006 1, 0.310 5±0.005 3, 0.465 0±0.007 8 and 0.497 7±0.014 5 with perfusate of 0.0, 1.0, 3.0, 5.0, 7.5, 10.0 μmol/L DHA. DHA activated BK channels in a dose-dependent manner (F=2.621,P＜0.05). There was no significant difference in the protein expression of control group, low and high doses of DHA groups (F=11.657,P＞0.05).
Conclusion
DHA can directly activate BK channels, no increasing in subunit expression of BK channels.
ObjectiveTo investigate the expression changes and the repair effect of mitogen and stress- activated protein kinase 1 (MSK1) on spinal cord injury (SCI) in rats.MethodsOne hundred and twenty male Sprague Dawley (SD) rats (weighing 220-250 g) were used for the study, 70 of them were randomly divided into sham-operation group and SCI group (n=35), the rats in SCI group were given SCI according to Allen’s method, and the sham-operation group only opened the lamina without injuring the spinal cord; spinal cord tissue was collected at 8 hours, 12 hours, 1 day, 2 days, 3 days, 5 days, and 7 days after invasive treatment, each group of 5 rats was used to detect the expression of MSK1 and proliferating cell nuclear antigen (PCNA) by Western blot assay. Another 20 SD rats were grouped by the same method as above (n=10). In these rats, a negative control lentiviral LV3NC dilution was injected at a depth of approximately 0.8 mm at the spinal cord T10 level. The results of transfection at 1, 3, 5, 7, and 14 days after injection were observed under an inverted fluorescence microscope to determine the optimal transfection time of the virus. The other 30 SD rats were randomly divided into group A with only SCI, group B with a negative control lentiviral LV3NC injected after SCI, and group C with MSK1 small interfering RNA (siRNA) lentivirus injected after SCI, with 10 rats each group. The Basso, Beatlie, Bresnahan (BBB) score of hind limbs was measured at 1, 3, 5, 7, and 14 days after treatment; spinal cord tissue collected at the optimal time point for lentivirus transfection was detected the expression changes of MSK1 and PCNA by Western blot and the localization by immunofluorescence staining of MSK1 and PCNA proteins.ResultsWestern blot assay showed that there was no significant changes in the expression of MSK1 and PCNA at each time points in the sham-operation group. In the SCI group, the expression of MSK1 protein was gradually decreased from 8 hours after injury to the lowest level at 3 days after injury, and then gradually increased; the expression change of PCNA protein was opposite to MSK1. The expression of MSK1 in SCI group was significantly lower than that in the sham-operation group at 1, 2, 3, and 5 days after injury (P<0.05), and the expression of PCNA protein of SCI group was significantly higher than that of the sham-operation group at 8 hours and 1, 2, 3, 5, and 7 days after injury (P<0.05). The fluorescence expression of both the SCI group and the sham-operation group has be found and peaked at 7 days. There was a positive correlation between fluorescence intensity and time in 7 days after transfection. With the prolongation of postoperative time, the BBB scores of groups A, B, and C showed a gradually increasing trend. The BBB score of group C was significantly lower than those of groups A and B at 5, 7, and 14 days after treatment (P<0.05). After transfection for 7 days, Western blot results showed that the relative expression of MSK1 protein in group C was significantly lower than that in groups A and B (P<0.05); and the relative expression of PCNA protein was significantly higher than that in groups A and B (P<0.05). Immunofluorescence staining showed that MSK1 was expressed in the nuclei of the spinal cord and colocalized with green fluorescent protein, neuronal nuclei, and glial fibrillary acidic protein (GFAP). The relative expression area of MSK1 positive cells in group C was significantly higher than that in group B (P<0.05), and the relative expression areas of PCNA and GFAP positive cells were significantly lower than those in group B (P<0.05).ConclusionLentivirus-mediated MSK1 siRNA can effectively silence the expression of MSK1 in rat spinal cord tissue. MSK1 may play a critical role in the repair of SCI in rats by regulating the proliferation of glial cells.
ObjectiveTo investigate the role of the p38 MAPK signaling pathway in sTREM-1 expression of RAW264.7 cells induced by lipopolysaccharide (LPS).
MethodsMacrophage cell line RAW264.7 cells were cultured in vitro and induced with the same concentration of LPS at different time. The protein expressions of p38 MAPK and phosphorylation of p38 MAPK(p-p38 MAPK) were detected by Western blot. The mRNA expression of p38 MAPK was detected by RT-PCR. The level of sTREM-1 was detected by enzyme linked immunosorbent assay method.The RAW264.7 cells were treated by SB203580 at different concentration,the changes of above indexes were observed.
ResultsThe p-p38 MAPK and p38 MAPK mRNA could be inducted by LPS in a time-dependent manner. The p-p38 MAPK and p38 MAPK mRNA could be inhibited by SB203580. After SB203580 blocking p38 MAPK signal transduction pathway,the sTREM-1 expression was significantly inhibited in a dose dependent manner.
ConclusionLPS can induce sTREM-1 expression in RAW264.7 cells by activating the p38 MAPK signaling pathway.
Objective To investigate the role of peroxisome proliferator activated receptor α （PPARα） in the pathogenesis of colorectal cancer. Method The literatures about PPARα and the pathogenesis of colorectal cancer were reviewed and analyzed. Result The relationships of PPARα to the proliferation， apoptosis， and differentiation of colorectal cancer cells in the pathogenesis of colorectal cancer were controversial. Conclusions PPARα might be involved in the regulation of proliferation， differentiation， apoptosis of colorectal cancer cells， but the pathogenesis and the up- and down-stream signal pathways are not elucidated. In additional， PPARα might partly be involved in the mechanism of drug resistance of chemotherapy drugs for colorectal cancer， but the role is not very clear yet. So more research works need to be done about the relationship of PPARα to pathogenesis of colorectal cancer.
ObjectiveTo investigate whether treatment of rivaroxaban, an approved oral direct coagulation factor Xa inhibitor, attenuates functional changes in LPS -induced acute lung injury (ALI) mouse.MethodsC57BL/6 mice were randomly divided into PBS group, N-LPS group, L-LPS group, and H-LPS group. In the C57BL/6 mice being fed chow containing 0.2 mg/g or 0.4 mg/g rivaroxaban for 10 days (L-LPS group and H-LPS group), plasma concentration and coagulation indices were measured. Next, the role of rivaroxaban in ALI by using mice fed by rivaroxaban was studied in a murine ALI model induced by direct intratracheal injection lipopolysaccharides (LPS). Lung injury by histopathological scoring, micro computed tomography, pulmonary edema, inflammatory cell recruitment and activity of inflammatory cytokines in lung tissue or bronchoalveolar lavage fluid (BALF) were assessed. Western blot and immunohistochemistry were performed to examine expression of multiple proteins, including myeloperoxidase, protease-activatedreceptor 2 (PAR-2) and nuclear factor kappa B (NF-κB).ResultsThe increased plasma concentration of rivaroxaban and the prolonged prothrombin time were displayed in the mice with rivaroxaban treatment. Rivaroxaban treatment groups showed significant reductions in neutrophil sequestration and preservation of the lung tissue architecture compared to the LPS positive control (P<0.05). Tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) levels, in addition to total protein and Evans blue concentration were all significantly reduced in BALF from the mice treated with the chow containing rivaroxaban. Administration of rivaroxaban ameliorated ALI with concomitant reductions in the expression of PAR-2 and proinflammatory cytokines. LPS-induced PAR-2 increase and NF-κB activation were also suppressed by rivaroxaban in lung tissues. Furthermore, rivaroxaban inhibited the phosphorylation levels of P65 in ALI.ConclusionsThe results demonstrate that rivaroxaban effectively attenuates LPS-induced inflammatory responses by noncoagulative pathway in ALI. The beneficial effects are associated with the decreased phosphorylation of NF-κB pathways and the reduced expression of PAR-2.
