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.
Objective To explore the effects of heat-inactivated Lactobacillus gasseri TMC0356 on liver lipid metabolism in rats with metabolic syndrome (MS) and its possible mechanism. Methods Sixty male Sprague-Dawley rats were selected. Rats were randomly divided into 5 groups, including control group, MS model group and three TMC0356 test groups (low-, medium- and high-dose groups). The rats in each group were fed with different diets for 7 days, and the liver was dissected and removed after 15 weeks. The mRNA and protein expression levels of peroxisome hyperbioactive receptor-α (PPAR-α), sterol regulatory element binding protein-1c (REBP-1c), fatty acid synthase (FAS) and carnitine lipoacyltransferase-1 (CPT-1) genes in liver were detected. Results There was no significant difference in the mRNA expression of PPAR-α, SREBP-1c or CPT-1 among the five groups (P>0.05). The mRNA expression of FAS in low-dose TMC0356 test group was lower than that in MS model group (P=0.011), medium-dose TMC0356 test group (P=0.042) and high-dose TMC0356 test group (P=0.009). There was no significant difference in the expression of FAS mRNA between other groups (P>0.05). There was no significant difference in the protein expression of PPAR-α, SREBP-1c or FAS among the five groups (P>0.05). The protein expression of CPT-1 in low-dose TMC0356 test group was higher than that in control group (P=0.033) and high-dose TMC0356 test group (P=0.043). There was no significant difference in the protein expression of CPT-1 between the other groups (P>0.05). Conclusion Heat-inactivated Lactobacillus gasseri TMC0356 may improve the symptoms of metabolic disorder in rats by suppressing appetite, improving insulin resistance, and downregulating the expression of key fat metabolism genes such as FAS and SREBP-1c.
Objective To explore the possible anti-inflammatory mechanism of peroxisome proliferators-activated receptor（PPAR） gamma-agonists by investigating the effects of Rosiglitazone on the expression of phosphorylation of signal transducer and activator of transcription 6（p-STAT6） and the secretion of interleukin（IL）-4 in T-lymphocytes from patients with acute asthma.Methods Peripheral blood T-lymphocytes from 10 healthy volunteers（group A） and 10 patients with acute asthma were isolated，purificated and cultured.T-lymphocytes from the asthma patients were divided into a control group（group B） and a Rosiglitazone treated group（group C）.Rosiglitazone was added with a single dose of 10-4 mol/L at 0 hour of cultrue.After cultured for 48 hours，the concentration of IL-4 in supernatant of each groups were detected by ELISA.The express of p-STAT6 in the T-lymphocytes were determined by Western blot and immunohistochemical techniques.Results The levels of IL-4 were increased markedly in group B than those in group A and group C[（170.34±9.05）pg/mL vs（76.82±7.06）pg/mL and（123.59±8.70）pg/mL，both Plt;0.01]，and which in group C was significantly lower than group A（Plt;0.01）.The levels of p-STAT6 in T lymphocytes were increased markedly in group B than in group A and C[Western blot：（6.28±0.19 vs 3.07±0.18 and 4.12±0.16；immunohistochemistry：（36.58%±7.41）% vs（11.39±4.02）% and（23.92±5.8）%，all Plt;0.01），and which in group C were significantly higher than that in group B（both Plt;0.01）.There was a positive correlation between the level of p-STAT6 and IL-4（Plt;0.01）.Conclusion The levels of p-STAT6 and IL-4 in T-lymphocytes of patients with acute asthma were suppressed by Rosiglitazone in vitro.
As the COVID-19 pandemic is intensifying globally, more and more people are pinning their hopes on the development of vaccines. At present, there are many research teams who have adopted different vaccine technology routes to develop 2019-nCoV vaccines. This article reviews and analyzes the current development and research status of 2019-nCoV vaccines in different routes, and explores their possible development in the future.
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 summarize the current advancement of peroxisome proliferator activated receptors (PPARs) participating in formation of abdominal aortic aneurysm (AAA) and to find out the potential treatment strategy of AAA.
MethodsRelevant literatures about PPARs and formation of AAA were reviewed.
ResultsAAA involved inflammation of all the layers of aorta, and the formation of AAA needed many kinds of inflammatory cells and cytokines. Many researches in vitro or in vivo had shown that PPARs could reduce the expression of inflammatory cytokines, to reduce formation of AAA. However, PPARγ was also confirmed to participate in the formation of AAA and the mechanism might be the transformation of macrophage from type 1 macrophage (M1) to type 2 macrophage (M2). According to the existing studies, the assumption could be that PPARγ can suppress the inflammatory function of M1 to reduce formation of AAA at the initiating stage, and promote formation of AAA by inducing the transform of macrophage to M2 at the late stage.
ConclusionPPARs may be a potential targeting point for the prevention of AAA. More studies are needed to show the feasibility and to decide the application timing.
ObjectiveTo investigate the effect of pharmacologic delay with pioglitazone, a peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, on extended perforator flap survival in a rat model.
MethodsSeventy male Sprague Dawley rats, weighing 250-300 g, were randomly divided into control group (n=35) and experimental group (n=35). A three-territory flap was made, including two choke zones. Pioglitazone was dissolved in 1.5 mL saline. Oral doses of pioglitazone[10 mg/(kg·d)] was given by gavaged for 5 days in the experimental group, while the same volume of saline was given in the control group at same time point. After 7 days, the flap survival area was measured and angiographic diagnosis was made. The tissue samples were harvested from choke zone Ⅱ for histological study and vascular endothelial growth factor (VEGF) expression detection by immunohistochemical staining. The content of nitric oxide (NO) in choke zones I and Ⅱ was measured at immediate, 1, 3, 5, and 7 days after operation.
ResultsThe flap general change of 2 groups was similar. Varying degrees of necrosis occurred with the extension of time in 2 groups. At 7 days after operation, the flap survival rate was 87.73%±3.25% in the experimental group and 76.07%±2.92% in the control group, showing a significant difference (t=-10.338, P=0.000). The number of true anastomosis in choke zones I and Ⅱ was 5.40±1.14 and 3.00±0.71 in the experimental group, and was 3.20±0.84 and 0.80±0.84 in the control group respectively, showing significant differences between the 2 groups (t=-3.479, P=0.008;t=-4.491, P=0.002). The microvessel density and the expression of VEGF in choke zone Ⅱ of experimental group were (33.16±7.73)/mm2 and 4 368.80±458.23, respectively, which were significantly higher than those of control group[(23.29±5.91)/mm2 and 2 241.24±554.43] (t=5.073, P=0.000;t=-14.789, P=0.000). The content of NO in the experimental group were significantly higher than those in the control group at other time points (P<0.05) except for at immediate after operation.
ConclusionPharmacologic delay with pioglitazone can improve extended perforator flap viability through increasing ischemia-induced angiogenesis and choke vessels vasodilation in rat models.
ObjectiveTo investigate the expression of extracellular signalregulated kinase (ERK) and p38 mitogenactivated protein kinase （p38 MAPK） in autogenous vein grafts during vascular remodeling.MethodsAn autogenous vein graft model was established by transplanting the right jugular vein to infrarenal abdominal aorta in 80 Wistar rats. Vein graft samples were harvested 6 hours, 24 hours, 3 days, 7 days, 2 weeks, 4 weeks, 6 weeks and 8 weeks after surgery. Gene expression of ERK and p38 MAPK was measured by reverse transcriptionPCR. Western blot was used to detect the expression of protein products and phosphorylation protein products of ERK and p38 MAPK. Apoptosis of vascular smooth muscle cells (VSMCs) was determined by TUNEL. Proliferating cell nuclear antigen(PCNA) of VSMCs also was studied.ResultsThe expression of ERK1 mRNA and p38 MAPK mRNA increased considerably after surgery. ERK1 mRNA reached the peak on the 7th day 〔（33.2±14.2）%, P＜0.01〕, but p38 MAPK mRNA reached the peak on the second week after surgery 〔(58.8±26.2）%, P＜0.01〕. The expression of ERK1/2 detected by western blot reached the peak during 1 to 2 weeks and decreased gradually to normal level 6 weeks after surgery. The expression of p38 MAPK reached the peak during 2 to 4 weeks and decreased to 1/4 to 1/2fold 8 weeks after surgery. There was a positive relationship between ERK1 and PCNA(r=0.759 6，P＜0.01) and a positive relationship between p38 MAPK and apoptosis(r=0.892 2，P＜0.01). ConclusionActivation of MAPK system exists in autogenous vein grafts and it may become a new target for the therapy of stenosis after vein grafts.
【 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 investigate the activation and role of signal transduction pathway of epidermal growth factor (EGF)-epidermal growth factor receptor (EGFR)-mitogen activated protein kinase (MAPK) in proliferation of human retinal pigment epithelial (RPE) cells. Methods Human RPE cells were stimulated with 0.1%，10% foetal calfserum (FCS) and EGF(0.1, 1, 10, 50 and 100 ng/ml)in 0.1% FCS Dulbeco′s modified Eagle′s medium (DMEM) and in 10% FCS DMEM for 3 days, respectively. Immunohistochemical staining and in situ hybridization were used to observe the expressions of EGFR protein and EGFR mRNA，respectively. Activation of MAPK was detected by immunohistochemical method with specific anti-phosphorylated ERK 1/2 antibody. Results The optimal concentrations of EGF were 10 ng/ml in 0.1% FCS DMEM and 1 ng/ml in 10% FCS DMEM. After 3 days of stimulation with EGF, phosphorylated ERK 1/2 staining was detectable in nucleus of RPE cells, whereas cells presented immunostaining for phosphorylated ERK 1/2 in the cytoplasm before stimulation. Conclusions EGF may improve the expression of EGFR protein and EGFR mRNA of RPE cells, and induced MAPK nuclear translocation in a concentration-dependent manner. EGF-EGFR-MAPK signal transduction pathway may play a key role in RPE cells proliferation, and serum exerts an important acceclerating function in the process. (Chin J Ocul Fundus Dis，2004，20：67-132)
