The type I cGMP-dependent protein kinase (PKG I) is recognized as a tumor suppressor, but its role in EGFR regulated epithelial ovarian cancer (EOC) progression remains unclear. We evaluated the in vivo and in vitro effects of activated PKG I in EGF-induced EOC cell proliferation, migration, and invasion. The expressions of EGFR and PKG I were elevated, but the activated PKG I was decreased in EOC tissues of patients and cells lines. The addition of 8-Br-cGMP, a specific PKG I activator, attenuated the EGF-induced EOC cell proliferation, migration, and invasion in vitro. Similarly, activated PKG I also attenuated EOC progression in vivo using an EOC xenograft nude mouse model. The activated PKG I interacted with EGFR, causing increased threonine (693) phosphorylation and decreased tyrosine (1068) phosphorylation of EGFR, which resulted in disrupted EGFR-SOS1-Grb2 combination. Subsequently, the cytoplasmic phosphorylation of downstream proteins (c-Raf, MEK1/2, and ERK1/2) were declined, impeding the phosphorylated ERK1/2’s nucleus translocation, and this reduction of phosphorylated tyrosine (1068) EGFR and ERK1/2 were also abolished by Rp-8-Br-cGMPS. Our results suggest that the activation of PKG I attenuates EGF-induced EOC progression, and the 8-Br-cGMP-PKG I-EGFR/MEK/ERK axis might be a potential target for EOC therapy.
Febrile seizures (FS) are the most common type of convulsive events in infants and young children, but the precise underlying genetic mechanism remains to be explored. To investigate the underlying pathogenic factors in FS and subsequent epilepsy, alterations in gene expression between the two new strains of rats (hyperthermia-prone [HP] vs hyperthermia-resistant [HR]), were investigated by using the Whole Rat Genome Oligo Microarray. This process identified 1,140 differentially expressed genes (DEGs; 602 upregulated and 538 downregulated), which were analyzed to determine significant Gene Ontology (GO) categories, signaling pathways and gene networks. Based on the GO analyses, the modified genes are closely related to various FS pathogenesis factors, including immune and inflammatory responses and ion transport. Certain DEGs identified have not been previously examined in relation to FS pathogenesis. Among these genes is dipeptidyl peptidase 4 (DPP4), a gene closely linked to interleukin 6 (IL-6), which played a key role in the gene network analysis. Furthermore, sitagliptin, a DPP4 inhibitor significantly decreased epileptic discharge in rats, observed via electroencephalogram, suggesting an important role for DPP4 in FS. The effectiveness of sitagliptin in reducing seizure activity may occur through a mechanism that stabilizes cellular Ca2+ homeostasis. In addition, DPP4 expression may be regulated by DNA methylation. The hippocampal gene expression profiles in novel rat models of FS provides a large database of candidate genes and pathways, which will be useful for researchers interested in disorders of neuronal excitability.
2 September 2021 in Journal of Physiology and Biochemistry
Background: Ovarian cancer (OC) is the second most common gynecological malignancy and has a high mortality rate. The current chemotherapeutic drugs have the disadvantages of drug resistance and side effects. Myricetin, a kind of natural compound, has the advantages of easy extraction, low price, and fewer side effects. Multiple studies have demonstrated the anti-cancer properties of myricetin. However, its impact on OC is still unknown and needs further investigation. Therefore, this study aimed to elucidate the mechanism by which myricetin suppresses transforming growth factor-β (TGF-β) -induced epithelial-to-mesenchymal transition (EMT) in OC through in vivo and in vitro experiments.Methods:In vitro experiments were conducted to evaluate the effects of myricetin on cell proliferation and apoptosis using CCK8 assay, plate clonal formation assay, and flow cytometry. Western blot was employed to evaluate the expression levels of caspase-3, PARP, and the MAPK/ERK and PI3K/AKT signaling pathways. Wound healing, transwell, western blot and immunofluorescence assay were used to detect TGF-β-induced cell migration, invasion, EMT and the levels of Smad3, MAPK/ERK, PI3K/AKT signaling pathways. Additionally, a mouse xenograft model was established to verify the effects of myricetin on OC in vivo.Results: Myricetin inhibited OC proliferation through MAPK/ERK and PI3K/AKT signaling pathways. Flow cytometry and western blot analyses demonstrated that myricetin promoted apoptosis by increasing the expression of cleaved-PARP and cleaved-caspase-3 and the ratio of Bax/Bcl-2 in OC. Furthermore, myricetin suppressed the TGF-β-induced migration and invasion by transwell and wound healing assays. Mechanistically, western blot indicated that myricetin reversed TGF-β-induced metastasis through Smad3, MAPK/ERK and PI3K/AKT signaling pathway. In vivo, myricetin significantly repressed OC progression and liver and lung metastasis.Conclusion: Myricetin exhibited inhibitory effects on OC progression and metastasis both in vivo and in vitro. And it also reversed TGF-β-induced EMT through the classical and non-classical Smad signaling pathways.