Journal of cellular biochemistry
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Comparative Study
Functional comparison of high and low molecular weight basic fibroblast growth factors.
Acid-electrolyzed functional water (FW) is obtained through the electrolysis of sodium chloride solution. Stimulation of the human fibroblastic cell line HeLa by FW led to the augmented secretion of basic fibroblast growth factor (bFGF). Immunoprecipitation followed by Western blot analysis revealed that both high and low molecular weight isoforms of bFGF were secreted in response to FW treatment. ⋯ Stimulation of HeLa cells with these supernatants resulted in the augmented secretion of vascular endothelial growth factor (VEGF). To further confirm the functionality of these isoforms, an in vitro transcription/translation reaction was performed; both of the isoforms induced VEGF secretion from HeLa cells. Taken together, these results indicate that the high molecular weight 34-kDa isoform and low molecular weight 18-kDa mature bFGF isoform have identical roles in VEGF induction.
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Liver ischemia/reperfusion (I/R) injury has high mortality due to the intense inflammatory process occurs in the liver. However, the pathological mechanism underlying I/R injury is still not clear. Recent works showed that circular RNAs play critical roles in many human diseases. ⋯ To further validate bioinformatics data, two up-regulated and three down-regulated circular RNAs were confirmed in I/R models. The circularity of these differentially expressed circular RNAs was validated through gel electrophoresis and RNase R treatment. In summary, this work provides new insights into the mechanism underlying pathogenesis of liver I/R injury, providing new and potentially efficient targets against I/R injury.
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Pulmonary fibrosis (PF), characterized by the destruction of lung tissue architecture and the abnormal deposition of extracellular matrix (ECM) proteins, currently has no satisfactory treatment. The role of microRNA (miR)-21 in PF has been reported; the current study attempted to investigate a novel molecular mechanism by which miR-21 exerted its function. Consistent with previous studies, miR-21 inhibition reduced ECM protein levels in bleomycin (BLM)-induced mouse model of PF. ⋯ Regarding a novel molecular mechanism, TGFβ1 combined with TGFβ1 receptor 1 (TGFβ1RI) to activate SMAD2/3, promote SMAD4 nucleus transformation, and thus regulate miR-21 expression and ECM. SMAD3 and SMADs complex could bind to the promoter region of miR-21 to promote miR-21 expression. In conclusion, miR-21 exerts promotive effects on BLM-induced PF and TGFβ1-induced ECM in IMR-90; TGFβ1 combines with TGFβ1RI to activate SMAD2/3, promote SMAD4 nucleus transformation, promote miR-21 expression, and thus to promote BLM-induced PF and TGFβ1-induced ECM in IMR-90 cells.
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Like other tumors, lung cancer must induce angiogenesis as it grows. Hypoxia-inducible factor 1α (HIF-1α) is the inducible subunit of the HIF-1 transcription factor that regulates genes involved in the response to hypoxia, some of which contributes to angiogenesis. Vascular endothelial growth factor (VEGF) is one of the genes upregulated by HIF-1 and is the primary cytokine in relation to angiogenesis. ⋯ The treatment with anti-HIF-1α siRNA prior to hypoxia exposure was shown to decrease HIF-1α and VEGF-A expressions and reduce hypoxia-induced angiogenesis, suggesting that HIF-1α expression resulted in increased VEGF-A expression and activation of HIF-1α/VEGF pathway was responsible for hypoxia-induced angiogenesis. In conclusion, we identified the relationship between HIF-1α/VEGF pathway and response to radiotherapy and its role in angiogenesis in lung cancer in vitro. HIF-1α/VEGF pathway as a target for antiangiogenic treatment strategies for this tumor requires further investigation.