ABSTRACT
Objective:To determine the expression of Brahma-related gene 1 (BRG1) in cutaneous squamous cell carcinoma (cSCC) tissues and cells, and to investigate molecular mechanisms underlying the regulatory effect of its interaction with activating transcription factor 2 (ATF2) on the proliferation, migration and invasion of cSCC cells.Methods:From 2015 to 2021, 66 paraffin-embedded actinic keratosis (AK) tissue samples and 80 paraffin-embedded cSCC (including squamous cell carcinoma in situ) tissue samples were collected from the Department of Dermatology, Affiliated Hospital 2 of Nantong University, and the diagnoses of all the cases were confirmed histopathologically; at the same time, 35 paraffin-embedded normal skin tissue samples obtained by cosmetic surgery served as normal control group. Immunohistochemical staining was performed to determine the BRG1 expression in cSCC, AK, and normal skin tissues, and correlations between BRG1 expression and clinicopathological parameters of cSCC patients were analyzed. Fresh tissue samples were collected from 12 cSCC patients and 12 healthy controls, and cSCC cell lines A431 and Scl-1 and a human immortalized keratinocyte cell line HaCaT were routinely cultured; real-time fluorescence-based quantitative PCR (qRT-PCR) was performed to determine the mRNA expression of BRG1 in tissues and cells, and co-immunoprecipitation assay and cellular immunofluorescence staining were conducted to analyze the interaction between BRG1 and ATF2. The expression of BRG1 (BRG1 siRNA1 - 5 groups) and ATF2 (ATF2-shRNA group) in A431 and Scl-1 cells was knocked down by RNA interference, and cells transfected with negative control siRNA or shNC served as controls (control siRNA group and shNC group, respectively), cell counting kit-8 (CCK8) assay, colony formation assay, cell scratch assay, and Transwell assay were conducted to evaluate effects of knocking down BRG1 and ATF2 on the proliferation, migration, and invasion of cSCC cells. Comparisons of measurement data among multiple groups were conducted using one-way analysis of variance, and multiple comparisons were conducted using Dunnett- t test. Results:Immunohistochemical staining showed that the expression intensity of BRG1 protein was significantly lower in the cSCC and AK tissues than in the normal skin tissues ( χ2 = 44.40, P < 0.001). qRT-PCR showed that the mRNA expression level of BRG1 was significantly lower in the cSCC tissues (1.345 ± 0.956) than in the normal skin tissues (2.499 ± 1.501, t = 2.25, P = 0.035), and also significantly lower in A431 and Scl-1 cells (0.041 ± 0.002, 0.026 ± 0.003, respectively) than in HaCaT cells (0.135 ± 0.033, t = 4.95, 5.73, P = 0.008, 0.005, respectively). The low expression of BRG1 was associated with tumors at sun-exposed sites ( P = 0.041), low tumor differentiation ( P = 0.001), and high Broder′s grade ( P < 0.001) in the cSCC patients. In both A431 cells and Scl-1 cells, the BRG1 siRNA1 group and BRG1 siRNA2 group showed significantly increased numbers of cell colonies, migratory cells and invasive cells, as well as cell migration rates compared with the control siRNA group (all P < 0.05). Co-immunoprecipitation assay showed that BRG1 protein could bind to ATF2 protein in A431 and Scl-1 cells, and immunofluorescence staining showed that the two proteins were co-localized; compared with the control siRNA group, the BRG1 siRNA1 group (both A431 and Scl-1 cells) and BRG1 siRNA2 group (A431 cells) both showed increased phosphorylation and activation of ATF2 (all P < 0.05) ; in both A431 cells and Scl-1 cells, the shATF2 group showed significantly decreased numbers of cell colonies (both P = 0.001), cellular proliferative activity at 24 - 96 hours (all P < 0.001), and numbers of migratory cells and invasive cells compared with the shNC group (all P ≤ 0.001) . Conclusion:BRG1 was lowly expressed in the cSCC and AK tissues, and could inhibit the proliferation, migration, and invasion of cSCC cells; ATF2 could promote the proliferation, migration, and invasion of cSCC cells; BRG1 may exert an anti-tumor effect by interacting with ATF2 protein and inhibiting phosphorylation-dependent activation of ATF2.
ABSTRACT
Aim To investigate the effect of Sijunzi Decoction on mRNA and protein expression related to growth and cell cycle in polyamine/HuR signaling pathway during small intestinal epithelial cell (IEC-6) proliferation, and to explore its mechanism on intestinal mucosal injury repair. Methods Sijunzi Decoction-containing serum (SJZD) was prepared from SD rats, the expression of HuR protein in cytoplasm and nucleus was analyzed by immunofluorescence and Western blot, the mRNA level of activating transcription factor-2 (A T F - 2), JunD and cyclin dependent kinase 4 (CDK4) were determined by real-time fluorescent quantitative PCR (RT-PCR), Western blot was used to detect protein level of HuR, ATF-2, JunD and CDK4, and flow cytometry was applied to analyse cell cycle distribution. Results Compared with the control group, the mRNA and protein expression of ATF-2 and JunD decreased, while the expression of Cdk4 mRNA and protein increased in SZJD group, and the proportion of G
ABSTRACT
Peroxisome proliferator-activated receptor (PPAR) is a transcriptional coactivator that binds to a diverse range of transcription factors. PPAR coactivator 1 (PGC-1) coactivators possess an extensive range of biological effects in different tissues, and play a key part in the regulation of the oxidative metabolism, consequently modulating the production of reactive oxygen species, autophagy, and mitochondrial biogenesis. Owing to these findings, a large body of studies, aiming to establish the role of PGC-1 in the neuromuscular system, has shown that PGC-1 could be a promising target for therapies targeting neuromuscular diseases. Among these, some evidence has shown that various signaling pathways linked to PGC-1 are deregulated in muscular dystrophy, leading to a reduced capacity for mitochondrial oxidative phosphorylation and increased reactive oxygen species (ROS) production. In the light of these results, any intervention aimed at activating PGC-1 could contribute towards ameliorating the progression of muscular dystrophies. PGC-1 is influenced by different patho-physiological/pharmacological stimuli. Natural products have been reported to display modulatory effects on PPAR activation with fewer side effects in comparison to synthetic drugs. Taken together, this review summarizes the current knowledge on Duchenne muscular dystrophy, focusing on the potential effects of natural compounds, acting as regulators of PGC-1.
ABSTRACT
@#Objective: To investigate the effect of Notch4 regulatingATF2 (activating transcription factor 2) on the invasion and migration of pancreatic cancer (PC) cells and its possible mechanism. Methods:Atotal of 60 pairs of PC tissues and corresponding para-cancerous tissues that surgically resected at Taizhou University Hospital during February 2015 and July 2019 were collected for this study. The expression of Notch4 was detected by immunohistochemistry. siRNA technology was used to knock down Notch4 gene expression in PC cell lines (MiaPaCa-2 and PANC-1). Transwell assay was used to analyze the effect of Notch4 knockdown on cell invasion and migration. qPCR and Western blotting (WB) were used to detect the effects of Notch4 knockdown on mRNA and protein expressions of Notch4 and ATF2. Results: Compared with para-cancerous tissues, the expression of Notch4 in PC tissues significantly higher (P<0.01). After Notch4 siRNA transfection, the mRNA and protein expressions of Notch4 and ATF2 in MiaPaCa-2 and PANC-1 cells significantly decreased (all P<0.01). Compared with Control siRNA group, the migration and invasion ability of PC cells in Notch4 siRNA groupsignificantlyreduced(allP<0.01).Conclusion:Notch4ishighlyexpressedinPCtissues.Knockdown of Notch4 can down-regulate the expression ofATF2 at the transcriptional level, thereby inhibiting the invasion and migration ability of PC cells.
ABSTRACT
AIM:To investigate the role of p38 MAPK/ATF-2 pathway in C-relative protein ( CRP)-induced endothelial cell activation.METHODS:Human coronary artery endothelial cells ( HCAEC) were cultured and were used between passages 3 and 7.CRP served as a stimulus for endothelial cell activation.Western blotting was performed to de-termine the expression and phosphorylation of eNOS, p38 and ATF2.ELISA was carried out to detect the levels of ICAM-1, VCAM-1 and MCP-1 released from HCAEC.Pharmacological p38 inhibitors SB203580 and SB202190 were used to de-termine the effect of p38/ATF-2 pathway.RESULTS:CRP reduced the p-eNOS level in a concentration-dependent man-ner and induced the release of ICAM-1, VCAM-1 and MCP-1.The p38/ATF-2 pathway was activated by CRP treatment. SB203580 and SB202190 partially rescued p-eNOS level and suppressed the secretion of ICAM-1, VCAM-1 and MCP-1. CONCLUSION:p38MAPK/ATF-2 pathway participates in CRP-induced endothelial activation.
ABSTRACT
Aim To investigate whether pioglitazone has protective effect against glutamate induced neurotoxicity in cultured cortical neurons and its possible molecular mechanisms underlying pioglitazone's neuroprotective effects.Methods The cortical neurons were taken from newborn rats and used for experiments 7 days after culture.The neurons were randomly divided into control group;glutamate group; glutamate+piogli-tazone group;glutamate+SP600125 group;SP600125 group.Cell viability was determined by MTT.The morphology change of neurons was observed under a fluorescence microscope with fluorescence dye Hoechst 33258.Immunostaining was used to investigate the expression of phospho-ATF2 in neuronal cells.Western blot was performed to investigate the protein level of phospho-JNK1 and total JNK1.Results Pioglitazone markedly reduced the damage of cortical neurons caused by glutamate.Pioglitazone also significantly inhibited glutamate induced up-regulation of phospho-JNK1 protein level and phospho-ATF2 expression.SP600125, an inhibitor of JNK, antagonized the toxicity induced by glutamate.Conclusions Pioglitazone can protect cultured cortical neurons from glutamate induced damage.The protective effect of pioglitazone appears to be associated with inhibiting the c-Jun N-terminal protein kinase signaling pathway.
ABSTRACT
Objective: To study the role of activating transcription factor 2 (ATF-2) in the growth of mandibular condyle cartilage. Methods: Primary chondrocytes of condyle were cultured. Expression plasmid of ATF-2 and plasmid bcl-2 promoter were transfected into chondrocytes. Luciferase assay and Western blot were used. Results: The absence of ATF-2 in mandibular condyle chondrocytes resulted in a decline in bcl-2 promoter activity, reduction in bcl-2 protein level. Conclusion: The results strongly imply that ATF-2 is required for adequate bcl-2 expression, and play a significant role in controlling growth plate chondrocyte progression.
ABSTRACT
Background and purpose:Cyclooxygenase-2 (Cyclooxygenase-2,COX-2) is an important rate-limiting enzyme that is responsible for transformation of arachidonic acid into prostaglandins(PGs).Although Helicobacter pylori(Hp) infection-induced gastric over-expression of COX-2 (COX-2) is an important factor of gastric cancer,the mechanism of COX-2 expression in gastric mucosa cells infected with Hp is still not clear.Our study was to reveal the effect of Hp on expression of COX-2(cyclooxygenase-2),the impact of p38MAPK signaling pathway in human gastric epithelial cancer cells line MKN45,and to investigate the potential mechanisms of expression of COX-2. Methods:The expression of COX-2 mRNA infection by standard Hp NCTC11637 in human gastric epithelial cancer cells line MKN45 was evaluated by real-time fluorogenic quantitative polymerase chain reaction (RFQ-PCR).The effect of infection by Hp on COX-2 expression,activation of p38MAPK and its downstream of the ATF-2 was assayed by Western blot.Results:The expression of COX-2 mRNA in MKN45 cells infected by Hp compared with control group,COX-2 mRNA had 3 fold,7.2 fold,5.1 fold,4.3 fold up-regulation after 3 hrs,6 hrs,9 hrs,12 hrs,respectively. COX-2 mRNA expression in each time group was significantly higher than that in the control group(P