Objective To study the effect of knockdown of signal transducer and activator of transcription 3 (STAT3) expression by short hairpin RNA (shRNA) on proliferation, apoptosis and invasion of human gastric cancer cell line MKN-45 in vitro . Methods Specific shRNA plasmids to STAT3 were constructed, and then transfected into MKN-45 cells by lipofectamine methods. Cells were divided into three groups: control group, psiRNA-H1 transfected group as negative group and psiRNA-H1/STAT3 transfected group. Semi-quantitative RT-PCR and Western blotting were used to detect the expression of STAT3 mRNA and protein, respectively. Proliferation and apoptosis of the transfected cells were observed by methyl thiazolyl tetrazolium (MTT) method and flow cytometry (FCM), respectively. The invasion of the transfected MKN-45 cells was measured by Boyden chamber. Results Compared with the negative control cells, semi-quantitative RT-PCR and Western blotting showed that the expressions of STAT3 mRNA and protein were down-regulated in the psiRNA-H1/STAT3 transfected group ( P ＜ 0.05) . The subcloned recombinant plasmid expressing shRNA effectively inhibited MKN-45 cell growth and proliferation while empty plasmid had no such specific effect. Cell apoptosis rate increased significantly in psiRNA-H1/STAT3 transfected group （ P ＜ 0.01）, and the invasion of MKN-45 cells was efficiently inhabited in psiRNA-H1/STAT3 transfected group as compared with control group and psiRNA-H1 transfected group( P ＜ 0.01).Conclusion Recombinant plasmid psiRNA-H1/STAT3 shRNA significantly inhibits the proliferation and invasion of MKN-45 cells and promotes their apoptosis.
Objective To investigate changes of TLR2 mRNA expression in lung of a mouse model of Chlamydia Pneumoniae pneumonitis, and to explore the possible mechanism of signal transduction. Methods Ninety-six male C3H/HeJ mice were randomly divided into four groups as follows: a control group, a model group, a SB203580 intervened group, and a pyrrolidine dithiocarbamate( PDTC) intervened group. Chlamydia Pneumoniae pneumonitis was induced by intranasally inoculated with 4. 0 ×106 IFU/mL of C. Pneumoniae per mouse in the model group and two intervened groups. Then the intervened groups were intraperitoneally injected with the p38MAPK inhibitor SB203580 and nuclear factor kappa B ( NF-κB)inhibitor PDTC, respectively. Six mice in each group were randomly killed in 1st, 4th, 7th and 14th day. The expressional changes of TLR2 mRNA in the mice lung tissue were measured by semi-quantitative RT-PCR. The concentrations of TNF-α in the lung homogenate were measured by ELISA. Results TLR2 mRNA expression in the lung tissue significantly increased after C. Pneumoniae infection, peaking at 4th and 7th days, then decreased after 14th day. Tumor necrosis factor-α( TNF-α) was also elevated in the lung tissue after C. Pneumoniae challenging. Both SB203580 and PDTC treatment effectively inhibited TNF-αand TLR2 mRNA expressions in lung. The inhibitory effect was more obvious by SB203580 treatment. Conclusion C. Pneumoniae can upregulate the expressions of TLR2 and TNF-α in lung, and TLR2/MAPK and TLR2 /NF-κB signal pathways may be involved in Chlamydia Pneumoniae pneumonitis.
Objective To analyze the clinical presentations and radiological characteristics of acute exacerbation of idiopathic pulmonary fibrosis ( IPF) . Methods Clinical and radiological data of 2 patients with acute exacerbation of IPF from April 2006 to July 2008 were retrospectively analyzed and literatures were reviewed. Results Both patients were senior male patients over 60 years old. Dyspnea, cough and inspiratory crackles were the major symptoms and signs. Two patients were experiencing an exacerbation of dyspnea for one week and half of month, respectively. PaO2 /FiO2 of both patients was less than225 mm Hg. In both patients, high-resolution computed tomography ( HRCT) scans at the exacerbation showed typical signs of IPF including peripheral predominant, basal predominant reticular abnormality, with honeycombing and traction bronchiectasis and bronchiolectasis, and newly developing alveolar opacity. HRCT scan showed peripheral area of ground-glass attenuation adjacent to subpleural honeycombing in one patient, and diffusely distributed ground-glass opacity in another patient. Two patients had received corticosteroid treatment. For one patient, the symptoms improved, and ground-glass attenuation adjacent to subpleural honeycombing had almostly resolved. The other patient died of respiratory failure. Conclusions Some acute exacerbation in idiopatic pulmonary fibrosis can be idiopathic. The clinical presentations mainly include the worsening of dyspnea within short time. HRCT generally demonstrates new bilateral ground-glass abnormality with or without areas of consolidation, superimposed on typical changes of IPF.
Objective To review the progress of the mechanisms of Wnt/β-catenin and nuclear factor-kappa B (NF-кB) pathways in the process of the intervertebral disc degeneration. Methods The related literature about the mechanisms of Wnt/β-catenin and NF-кB pathways in the process of the intervertebral disc degeneration was reviewed, analyzed, and summarized. Results Wnt/β-catenin and NF-кB pathways are both activated in the process of the intervertebral disc degeneration, and exist interaction. However, the specific mechanisms and interactive mediums of Wnt/β-catenin and NF-кB pathways in the process of the intervertebral disc degeneration are still unclear. Conclusion The mechanisms of Wnt/β-catenin and NF-кB pathways in the process of the intervertebral disc degeneration have to be studied deeply.
【Abstract】 Objective To summarize the recent progress in related research on transforming growth factor β1 （TGF-β1）/Smad3 signal transduction pathway and post-traumatic scar formation. Methods Recent related literature at home and abroad on TGF-β1/Smad3 signal transduction pathway and post-traumatic scar formation was reviewed and summarized. Results TGF-β1 is an important influence factor of fibrotic diseases, and it plays biological effects by TGF-β1/Smad3 signal transduction pathway. The pathway is regulated by many factors and has crosstalk with other signal pathways at cellular and molecular levels. The pathway is involved in the early post-traumatic inflammatory response, wound healing, and late pathological scar formation. Intervening the transduction pathway at the molecular level can influence the process of fibrosis and extracellular matrix deposition. Conclusion TGF-β1/Smad3 signal transduction pathway is an important way to affect post-traumatic scar formation and extracellular matrix deposition. The further study on the pathway will provide a theoretical basis for promotion of wound healing, as well as prevention and treatment of pathological scar formation.
Objective To observe the protein expression of c-Jun amino-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in normal skin and keloid and to explore their influences on the formation of kloid. Methods Keloid tissues and normal skin tissues were collected from 16 keloid resection patients (experimental group) and 10 voluntary plastic surgery patients (control group). In the experimental group, the keloid formation time ranged from 8 months to 10 years; the keloid tissues were collected from the chest in 6 cases, the ear lobe in 4 cases, the perineum in 2 cases, the shoulder in 3 cases, and the abdomen in 1 case; and all keloid tissues were confirmed by pathological examination. In the control group, normal skin tissues were collected from the abdomen in 4 cases, the thighs in 3 cases, the shoulder in 2 cases, and the back in 1 case. Two-step l ine of Envision immunohistochemical staining was performed to observe the expressions of nonphosphorylated and phosphorylated JNK and ERK; Image Pro Plus 4.5 image analysis system was used to measure the integrated absorbance (IA) and to observe the positive staining strength. Results The immunohistochemical staining showed that no obvious expressions of phosphorylated and non-phosphorylated ERK, JNK were observed in the fibroblasts of the control group, and the expressions of phosphorylated JNK and ERK proteins were significantly higher in the experimental group than in the control group (P lt; 0.05). There was no significant difference in the expressions of non-phosphorylated JNK and ERK proteins between 2 groups (P gt; 0.05). Conclusion Activation of ERK and JNK pathways might be involved in formation of keloid.
Objective To introduce the basic research and cl inical potential of the hair foll icle stem cells related signal transduction in prol iferation and differentiation. Methods The recent original articles about the hair foll icle stem cells were extensively reviewed. Results Many different signal pathways had been involved in the skin development and self-newals.The hair foll icle stem cells could play an important role in the skin self-renewal and regeneration which were modulated by several different signal pathways, which included bone morphogenetic protein/transforming growth factor β, Wnt, Notch and ectodysplasin A genes. Conclusion The hair foll icle stem cells may be a future approach to repair cutaneous wounds as a cell therapy．
Objective To investigate the mechanism of adenosine-tri phosphate (ATP) activated mammal ian target of rapamycin (mTOR)/signal transducer and activator of transcription 3 (STAT3) signal pathway in the physiology and pathology of spinal cord injury (SCI). Methods Ninety-six adult healthy female Sprague-Dawley rats were randomly divided into 4 groups (groups A, B, C and D, n=24). In groups A, B and C, the rats were made the SCI models at T8-10 levels by using a modified Allen’ s stall, and in group D, rats were given laminectomy without SCI. The rats were subjected to the administration of ATP (40 mg/kg) for 7 days in group A, to the administration of physiological sal ine (equal-volume) for 7 days in group B, to the administration of ATP (40 mg/kg) and rapamycin (3 mg/kg) for 7 days in group C, and to the administration of physiological sal ine (equal-volume) for 7 days in group D. Locomotor activity was evaluated using the Basso-Beattie-Bresnahan rating scale at the postoperative 1st, 2nd, 3rd, and 4th weeks. Then, the expressions of spinal cord cell marker [Nestin, neuron-specific enolase (NSE), gl ial fibrillary acidic protein (GFAP)] and the mTOR/STAT3 pathway factors (mTOR, STAT3) were detected at the postoperative 1st, 2nd, 3rd, and 4th weeks by immunohistochemistry analysis, Western blot assay, and real-time fluorescence PCR analysis. Results The BBB scores in group A showed a steady increase in the postoperative 1st-4th weeks and were significantly higher than those in groups B and C (P lt; 0.01), but were lower than that in group D (P lt; 0.01). Real-time fluorescence PCR results showed that the mRNA expressions of mTOR, STAT3, NSE of group A steadily increased, however, the Nestin mRNA expression gradually decreased in the postoperative 1st-4th weeks, which were all significantly higher than those of groups B, C, and D (P lt; 0.01). The mRNA expression of GFAP showed a steady increase in group A and was significantly less than those of groups B and C, but was higher than that of group D (P lt; 0.01). There were significant differences (Plt; 0.01) in all markers between groups B, C, and group D; there were significant differences in mTOR, P-mTOR, STAT3, and P-STAT3 mRNA between groups B and C at 1st-4th weeks (P lt; 0.05). The similar changes were found by Western blot assay. Conclusion ATP can activate the mTOR/STAT3 pathway to induce endogenic NSCs to prol iferate and differentiate into neurons in rats, it enhances the heal ing of SCI.
To summarize Notch, basic hel ix-loop-hel ix (bHLH) and Wnt gene signal transduction pathways in the process of differentiation and development of neural stem cells. Methods The l iterature on the gene signal transduction pathway in the process of differentiation and development of neural stem cells was searched and then summarized and analyzed. Results The formation of Nervous System resulted from common actions of multi-signal transduction pathways. There may exist a fixed threshold in the compl icated selective system among Notch, bHLH and Wnt gene signal transduction pathways. Conclusion At present, the specific gene signal transduction pathway of multi pl ication and differentiation of neural stem cells is still unclear.
Objective To study the leptin-mediated intracellular signal pathways and their effects on wound healing.Methods The literature was reviewed extensively, concerning the physical and chemical characters of leptin, the mechanism of its receptor action, the receptor-related intracellular signal pathways and their roles on wound healing. Results Leptin was a protein hormone expressed by ob gene with relative molecular mass 16×103, it could activate the main singal pathways such as Janus kinase/signal transducer and activator of transcription, mitogenactivated protein kinases and phosphoinositide-3-kinase pathways through binding with its specific receptor, to participate in the modulation of multiple functions including energy metabolism, weight balance and wound healing. Leptin receptors were widely distributed in various tissues, which suggest the multiple functions of leptin. Local leptin expression was increased after skin injured, and it could stimulate keratinocytes proliferation, epithelialization, fibroblast proliferation and collagen synthesis, resulting in accelarated wound repair. Leptin expression was significantly increased after mucosal injury or bacteria infections, leading to accelarated mucosal repair through modulation of mucosal glandular secretion, improvment of mucosal blood flow, and synergistic action with endothelin-1.Conclusion Leptin can promote wound healing through activating its receptor-related intracellular signal pathways.