【 Abstract 】 Objective To investigate the effects of 250 ml/m3 carbon monoxide (CO) inhalation or intraperitoneal infusion on lipopolysaccharide (LPS) induced rat intestinal tract injury, and to detect the roles of p38 mitogen-activated protein kinase (MAPK) pathway during CO administration. Methods After received 5 mg/kg LPS or an equal volume of normal saline by intravenous injection, 108 male SD rats were randomly divided into 6 groups: control group, CO inhalation (250 ml/m3) group, CO intraperitoneal infusion (250 ml/m3 at a rate of 2 L/min) group, LPS (5 mg/kg) group, LPS (5 mg/kg)+CO inhalation (250 ml/m3) group and LPS (5 mg/kg)+CO intraperitoneal infusion (250 ml/m3 at a rate of 2 L/min) group. The animals were differently sacrificed at 1, 3 and 6 h for the observation, and the ileum tissues were homogenized for determination the levels of platelet activator factor (PAF), intercellular adhesion molecule-1 (ICAM-1) and interlukin-10 (IL-10) with enzyme-lined immunosorbent assay, the content of maleic dialdehyde (MDA) with thiobarbitric acid, the activity of myeloperoxidase (MPO) with chemical method, the activity of superoxide dismutase (SOD) with hydroxylamine, the activity of phosphorylated p38 MAPK with Western blot, the pathology with light microscope, and the extents of cell apoptosis were showed by the ratio of the apoptotic cells which had less DNA to the total cells of a cell-suspension sample by using the flow cytometry after being stained with propidium iodide. Results Compared with both control, CO inhalation and intraperitoneal infusion group at the same time point, the levels of PAF, ICAM-1, MDA, MPO, cell apoptosis rate and the phosphorylated p38 MAPK protein in LPS group were increased, while IL-10 and SOD were decreased (P ＜ 0.05 or 0.01), and accompanied by severe intestinal tract injury. There were no statistics differences at the different time point in the same group. PAF, ICAM-1, MDA, MPO and cell apoptosis rate in both LPS+CO inhalation group and LPS+CO intraperitoneal infusion group were lower, while IL-10 and SOD were higher than the corresponding value in LPS group at the same time point (all P ＜ 0.05), with ameliorate injury too, but the expression of phosphorylated p38 MAPK was further up-regulated than that of LPS group (all P ＜ 0.05). However, there were no significant differences in these parameters between LPS+CO inhalation group and LPS+CO intraperitoneal infusion group. Conclusion 250 ml/m3 CO inhalation and intraperitoneal infusion exerts the similar protection against LPS induced rat intestinal tract injury via anti-oxidant, anti-inflammation, and anti-apoptosis. This may involve the p38 MAPK pathway.
OBJECTIVE: To observe the protein expression of phosphorylated form of P38 mitogen-activated protein kinase(P38MAPK) and c-Jun in hypertrophic scar skin and to explore their influences on the formation and maturation of hypertrophic scar. METHODS: The expression intensity and distribution of phosphorylated form of P38MAPK and c-Jun were examined with immunohistochemistry and pathological methods in 16 cases of hypertrophic scar skin and 8 cases of normal skin. RESULTS: In normal skin, the positive signals of phosphorylated form of P38MAPK mostly distributed in basal lamina cells of epidermis, while c-Jun was mainly located in epidermal cells and endothelial cells. The positive cellular rates of two proteins were 21.3% +/- 3.6% and 33.4% +/- 3.5% respectively. In proliferative hypertrophic scar skin, the particles of phosphorylated P38MAPK and c-Jun were mainly located in epidermal cells and some fibroblasts. The positive cellular rates of two proteins were significantly elevated to 69.5% +/- 3.3% and 59.6% +/- 4.3% respectively (P lt; 0.01). In mature hypertrophic scar, the expression of these proteins decreased but was still higher than that of normal skin. CONCLUSION: The formation and maturation of hypertrophic scar might be associated with the alteration of phosphorylated P38MAPK and c-Jun protein expression in hypertrophic scar.
Objective To investgate the expression of p38 mitogen-activated protein kinase （p38MAPK） in lung tissue of rats with severe acute pancreatitis （SAP）， and to explore the relationship between p38MAPK and pulmonary capillary barrier injury. Methods Forty male and healthy Sprague-Dawley （SD） rats were randomly （random number method） divided into sham operation （SO） group and SAP group， then rats of SAP group were sub-divided into 3， 6， 12， and 24 h group， each group enrolled 8 rats， respectively. SAP model rats were established by injecting 5% sodium taurocholate solution retrograde into the biliopancreatic duct. ELISA method was used to test the serum tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β）， and pathological changes in lung and pancreas tissues were observed by HE staining. Immunohischemistry method was used to detect phosphorylated p38 （p-p38） protein and aquaporin 1 （AQP1） protein of lung tissues. The expression level of AQP1 mRNA was measured by quantitative real-time PCR. Results Hyperemia， edema， and inflammatory cell infiltration were observed in lung tissues， abundance of necrosis， part gland structure fuzzy or even disappear were observed in pancreas tissues of all 4 time point groups. Compared with SO group， levels of serum TNF-α and IL-1β were significantly higher in 4 time point groups （P＜0.05）. Lower expression level of p-p38 protein was detected in lung tissues of SO group， while in the early stage of SAP （SAP 3 h group）， the expression level of p-p38 protein significantly increased， which peaked in 6 h group and was still higher than SO group in 24 h group （P＜0.05）. Compared with SO group， the expression levels of AQP1 mRNA and protein were significantly lower in all 4 time point groups （P＜0.05）， which had negative correlation with the levels of serum TNF-α，IL-1β， and the expression level of p-p38 protein （r=-0.87， P＜0.05；r=-0.88， P＜0.05；r=-0.78， P＜0.05）. Conclusion The decrease of AQP1 protein in lung tissue is one of the vital causes for pulmonary capillary barrier injury in SAP， which probably works by the activation of p38MAPK and the excessive release of inflammatory cytokines.
ObjectiveTo detect FoxM1 expression in thyroid papillary carcinoma TPC-1 cells,and explore influence of FoxM1 expression on important genes (RAS gene and CDK1 gene) of mitogen activated protein kinase (MAPK) signal pathway. MethodsThe hFoxM1-RNA interference was used to deal with the thyroid papillary carcinoma TPC-1 cells (experiment group),another untreated TPC-1 cell was as control group.Then the real-time quantitative PCR was used to detect the FoxM1,Ras,and CDK1 gene expressions in all the TPC-1 cells. ResultCompared with the control group,the FoxM1 gene expression was significantly decreased (0.452 9 versus 1.005 0,t=24.692 9,P<0.01),the Ras gene expression was significantly elevated (1.319 0 versus 1.001 2,t=14.218 5,P<0.01),and the CDK1 gene expression was significantly decreased (0.767 5 versus 1.008 1，t=10.763 4,P<0.01) in the experiment group. ConclusionFoxM1 gene expression level in thyroid papillary carcinoma TPC-1 cells could influence Ras and CDK1 expression,which suggests that its role in thyroid papillary carcinoma might be associated with MAPK signal pathway.
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.
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.
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.
Myocardial remodeling is one of the important pathological basis when myocardial infarction or pressure overload occurs, whereas mangiferin which is a naturally occurring xanthone has a broad range of therapeutic effect on postinfarction myocardial remodeling. Mangiferin attenuates myocardial infarction by preventing the accumulation of myocardial collagen and the development of intercellular fibrosis. Mangiferin's inhibition to p38 mitogen activated protein kinases plays an important role in the cardioprotective effect. Inhibition of p38 mitogen activated protein kinases significantly decreases TNF-α and then brings the cardioprotective effect. Similarly, p38 mitogen activated protein kinases in pressure overload disease also play a very important role. Understanding of these has direct implications for clinical therapy.
Objective To investigate the effects and mechanisms of lactic acid bacteria on MAPK signaling in immune response of dust mite sensitized mice. Methods Forty C57BL/6 mice in Group M, P and L, were sensitized and challenged with mite extract while then the animals in Group N were treated with saline as control. The mice in Group L and P were fed with Lactococcus lactis or Lactobacillus respectively.Three days after the last challenge, all mice were sacrificed for lung pathological examination. IL-10 level in culture supernatant of splenocytes stimulated with mite extract was detected by ELISA. The expression of IL-4/ IFN-γon CD3 +CD4 + cells was detected by flow cytometry. Western blot were performed for detection of MAPK signaling ( P38, ERK, and JNK) from mice’s spleen cells stimulated with mite extract. Results The mice fed with Lactococcus lactis ( Group L) had lower rate of eosinophilic airway inflammation and higher level of IL-10 in the culture supernatant of splenocytes than Group P. Meanwhile, the number of CD4 + T cell with IL-4 expression was decreased revealed by the analysis of flow cytometry. P38 signaling inspleen cells was activated in the mice of Group M, similarly in the mice of Group P, but not of Group L.Conclusion Oral treatment of Lactococcus lactis can induce an immune tolerance in response to mite by up-regulating the level of Tr cells secreting IL-10, thus inhibiting activation of P38 signaling.