• The Plant Pathology Journal
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• v.30 no.2
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• pp.136-150
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• 2014

Although multiple transcription factors (TFs) have been characterized via mutagenesis to understand their roles in controlling pathogenicity and infection-related development in Magnaporthe oryzae, the causal agent of rice blast, if and how forkhead-box (FOX) TFs contribute to these processes remain to be characterized. Four putative FOX TF genes were identified in the genome of M. oryzae, and phylogenetic analysis suggested that two of them (MoFKH1 and MoHCM1) correspond to Ascomycota-specific members of the FOX TF family while the others (MoFOX1 and MoFOX2) are Pezizomycotina-specific members. Deletion of MoFKH1 (${\Delta}Mofkh1$) resulted in reduced mycelial growth and conidial germination, abnormal septation and stress response, and reduced virulence. Similarly, ${\Delta}Mohcm1$ exhibited reduced mycelial growth and conidial germination. Conidia of ${\Delta}Mofkh1$ and ${\Delta}Mohcm1$ were more sensitive to one or both of the cell cycle inhibitors hydroxyurea and benomyl, suggesting their role in cell cycle control. On the other hand, loss of MoFOX1 (${\Delta}Mofox1$) did not show any noticeable changes in development, pathogenicity, and stress response. Deletion of MoFOX2 was not successful even after repeated attempts. Taken together, these results suggested that MoFKH1 and MoHCM1 are important in fungal development and that MoFKH1 is further implicated in pathogenicity and stress response in M. oryzae.

• BMB Reports
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• v.41 no.10
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• pp.728-732
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• 2008

FoxO3a is a member of the forkhead box class O (FoxO) transcription factor family and an important regulator of apoptosis. This work aimed to elucidate the involvement of FoxO3a in transforming growth factor-${\beta}1$(TGF-${\beta}1$)-induced apoptosis in FaO rat hepatoma cells. TGF-${\beta}1$ caused a time-dependent activation of FoxO3a and a subsequent increase in FoxO response-element-containing luciferase reporter activity, which was Akt-sensitive. The FaO cells stably transfected with a wild type FoxO3a were more susceptible to the formation of apoptotic bodies, populations of sub-G1 apoptotic cells, and collapse of the mitochondrial-membrane potential triggered by TGF-${\beta}1$. In contrast, transfection with small-interfering RNA (siRNA) oligonucleotide specific for FoxO3a significantly inhibited caspase activation in FaO cells treated with TGF-${\beta}1$. It thus appears that FoxO3a plays a crucial mediatory role in the TGF-${\beta}1$ signaling pathway leading to apoptosis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1589-1595
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• 2014

Objective: Forkhead box C2 (FOXC2) is a member of the winged helix/forkhead box (Fox) family of transcription factors. It has been suggested to regulate tumor vasculature, growth, invasion and metastasis, although it has not been studied in cervical cancer. Here, we analyzed FOXC2 expression in cervical tissues corresponding to different stages of cervical cancer development and examined its correlation with clinicopathological characteristics. In addition, we examined the effects of targeting FOXC2 on the biological behavior of human cervical cancer cells. Methods: The expression of FOXC2 in normal human cervix, CIN I-III and cervical cancer was examined by immunohistochemistry and compared among the three groups and between cervical cancers with different pathological subtypes. Endogenous expression of FOXC2 was transiently knocked down in human Hela and SiHa cervical cells by siRNA, and cell viability and migration were examined by scratch and CCK8 assays, respectively. Results: In normal cervical tissue the frequency of positive staining was 25% (10/40 cases), with a staining intensity (PI) of $0.297{\pm}0.520$, in CIN was 65% (26/40cases), with a PI of $3.00{\pm}3.29$, and in cancer was 91.8% (68/74 cases), with a PI of $5.568 {\pm}3.449$. The frequency was 100% in adenocarcinoma (5/5 cases) and 91.3% in SCCs (63/69 cases). The FOXC2 positive expression rate was 88.5% in patients with cervical SCC stage I and 100% in stage II, showing significant differences compared with normal cervix and CIN. With age, pathologic differentiation degree and tumor size, FOXC2 expression showed no significant variation. On transient transfection of Hela and SiHa cells, FOXC2-siRNA inhibition rates were 76.2% and 75.7%; CCK8 results showed reduced proliferation and relative migration (in Hela cells from $64.5{\pm}3.16$ to $49.5{\pm}9.24$ and in SiHa cells from $60.1{\pm}3.05$ to $44.3{\pm}3.98$) (P < 0.05). Conclusion: FOXC2 gene expression increases with malignancy, especially with blood vessel hyperplasia and invasion degree. Targeted silencing was associated with reduced cell proliferation as well as invasion potential.

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1412-1419
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• 2020

Human noroviruses (HuNoVs) are a leading cause of gastroenteritis outbreaks worldwide. However, the paucity of appropriate cell culture models for HuNoV replication has prevented developing effective anti-HuNoV therapies. In this study, first, the replication of the virus at various temperatures in different cells was compared, which showed that lowering the culture temperature from 37℃ significantly increased virus replication in Madin-Darby canine kidney (MDCK) cells. Second, the expression levels of autophagy-, immune-, and apoptosis-related genes at 30℃ and 37℃ were compared to explore factors affecting HuNoV replication. HuNoV cultured at 37℃ showed significantly increased autophagy-related genes (ATG5 and ATG7) and immune-related genes (IFNA, IFNB, ISG15, and NFKB) compared to mock. However, the virus cultured at 30℃ showed significantly decreased expression of autophagy-related genes (ATG5 and ATG7), but not significantly different major immune-related genes (IFNA, ISG15, and NFKB) compared to mock. Importantly, expression of the transcription factor FOXO1, which controls autophagy- and immune-related gene expression, was significantly lower at 30℃. Moreover, FOXO1 inhibition in temperature-optimized MDCK cells enhanced HuNoV replication, highlighting FOXO1 inhibition as an approach for successful virus replication. In the temperature-optimized cells, various HuNoV genotypes were successfully replicated, with GI.8 showing the highest replication levels followed by GII.1, GII.3, and GII.4. Furthermore, ultrastructural analysis of the infected cells revealed functional HuNoV replication at low temperature, with increased cellular apoptosis and decreased autophagic vacuoles. In conclusion, temperature-optimized MDCK cells can be used as a convenient culture model for HuNoV replication by inhibiting FOXO1 and providing adaptability to different genotypes.

• Journal of Life Science
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• v.25 no.3
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• pp.293-298
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• 2015

Muscle atrophy, known as a sarcopenia, is defined as a loss of muscle mass resulting from a reduction in the muscle fiber area or density due to a decrease in muscle protein synthesis and an increase in protein breakdown. Schisandrae fructus (SF) extract of the fruits of Schisandra chinensis (Turcz) Baillon has been used as a tonic in traditional medicine for thousands of years. Although a great deal of work has been carried out on the therapeutic potential of SF, its pharmacological mechanisms of action in muscle diseases actions remain unclear. In the present study, we investigated the inhibitory effects of SF ethanol extracts on the production of muscle atrophy factors in C2C12 myotubes stimulated with 5-aminoimidazole-4-carboxamide-ribonucleotide (AICAR), an AMP-activated kinase (AMPK) activator, and sought to determine the underlying mechanisms of action. AICAR upregulated atrophy-related ubiquitin ligase muscle RING finger-1 (MuRF-1) and stimulated the levels of the forkhead box O3a (FoxO3a) transcription factor in the C2C12 myotubes. SF supplementation effectively and concentration- dependently counteracted AICAR-induced muscle cell atrophy and reversed the increased expression of MuRF-1 and FoxO3a. Our study demonstrates that SF can reverse the muscle cell atrophy caused by AICAR through regulation of the AMPK and FoxO3a signaling pathways, followed by inhibition of MuRF-1.

• BMB Reports
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• v.52 no.3
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• pp.208-213
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• 2019

Chemoresistance is the primary obstacle in the treatment of locally advanced and metastatic nasopharyngeal carcinoma (NPC). Recent evidence suggests that the transcription factor forkhead box M1 (FoxM1) is involved in chemoresistance. Our group previously confirmed that FoxM1 is overexpressed in NPC. In this study, we investigated the role of FoxM1 in cisplatin resistance of the cell lines 5-8F and HONE-1 and explored its possible mechanism. Our results showed that FoxM1 and NBS1 were both overexpressed in NPC tissues based on data from the GSE cohort (GSE12452). Then, we measured FoxM1 levels in NPC cells and found FoxM1 was overexpressed in NPC cell lines and could be stimulated by cisplatin. MTT and clonogenic assays, flow cytometry, ${\gamma}H2AX$ immunofluorescence, qRT-PCR, and western blotting revealed that downregulation of FoxM1 sensitized NPC cells to cisplatin and reduced the repair of cisplatin-induced DNA double-strand breaks via inhibition of the MRN (MRE11-RAD50-NBS1)-ATM axis, which might be related to the ability of FoxM1 to regulate NBS1. Subsequently, we demonstrated that enhanced sensitivity of FoxM1 knockdown cells could be reduced by overexpression of NBS1. Taken together, our data demonstrate that downregulation of FoxM1 could improve the sensitivity of NPC cells to cisplatin through inhibition of MRN-ATM-mediated DNA repair, which could be related to FoxM1-dependent regulation of NBS1.

• Animal Bioscience
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• v.34 no.7
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• pp.1210-1220
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• 2021

Objective: Unlike mammals, goose fatty liver shows a strong tolerance to fatty acids without obvious injury. Stearyl-coenzyme A desaturase 1 (SCD1) serves crucial role in desaturation of saturated fatty acids (SAFs), but its role in the SAFs tolerance of goose hepatocytes has not been reported. This study was conducted to explore the role of SCD1 in regulating palmitic acid (PA) tolerance of goose primary hepatocytes. Methods: 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide was examined to reflect the effect of PA on hepatocytes viability, and quantitative polymerase chain reaction was used to detect the mRNA levels of several genes related to endoplasmic reticulum (ER) stress, inflammation, and apoptosis, and the role of SCD1 in PA tolerance of goose hepatocytes was explored using RNA interfere. Results: Our results indicated that goose hepatocytes exhibited a higher tolerant capacity to PA than human hepatic cell line (LO2 cells). In goose primary hepatocytes, the mRNA levels of fatty acid desaturation-related genes (SCD1 and fatty acid desaturase 2) and fatty acid elongate enzyme-related gene (elongase of very long chain fatty acids 6) were significantly upregulated with 0.6 mM PA treatment. However, in LO2 cells, expression of ER stress-related genes (x box-binding protein, binding immunoglobulin protein, and activating transcription factor 6), inflammatory response-related genes (interleukin-6 [IL-6], interleukin-1β [IL-1β], and interferon-γ) and apoptosis-related genes (bcl-2-associated X protein, b-cell lymphoma 2, Caspase-3, and Caspase-9) was significantly enhanced with 0.6 mM PA treatment. Additionally, small interfering RNA (siRNA) mediated downregulation of SCD1 significantly reduced the PA tolerance of goose primary hepatocytes under the treatment of 0.6 mM PA; meanwhile, the mRNA levels of inflammatory-related genes (IL-6 and IL-1β) and several key genes involved in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT), forkhead box O1 (FoxO1), mammalian target of rapamycin and AMPK pathways (AKT1, AKT2, FoxO1, and sirtuin 1), as well as the protein expression of cytochrome C and the apoptosis rate were upregulated. Conclusion: In conclusion, our data suggested that SCD1 was involved in enhancing the PA tolerance of goose primary hepatocytes by regulating inflammation- and apoptosis-related genes expression.

• Biomolecules & Therapeutics
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• v.28 no.6
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• pp.561-568
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• 2020

We examined the anticancer effects of a novel sirtuin inhibitor, MHY2256, on HCT116 human colorectal cancer cells to investigate its underlying molecular mechanisms. MHY2256 significantly suppressed the activity of sirtuin 1 and expression levels of sirtuin 1/2 and stimulated acetylation of forkhead box O1, which is a target protein of sirtuin 1. Treatment with MHY2256 inhibited the growth of the HCT116 (TP53 wild-type), HT-29 (TP53 mutant), and DLD-1 (TP53 mutant) human colorectal cancer cell lines. In addition, MHY2256 induced G0/G1 phase arrest of the cell cycle progression, which was accompanied by the reduction of cyclin D1 and cyclin E and the decrease of cyclin-dependent kinase 2, cyclin-dependent kinase 4, cyclin-dependent kinase 6, phosphorylated retinoblastoma protein, and E2F transcription factor 1. Apoptosis induction was shown by DNA fragmentation and increase in late apoptosis, which were detected using flow cytometric analysis. MHY2256 downregulated expression levels of procaspase-8, -9, and -3 and led to subsequent poly(ADP-ribose) polymerase cleavage. MHY2256-induced apoptosis was involved in the activation of caspase-8, -9, and -3 and was prevented by pretreatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, the autophagic effects of MHY2256 were observed as cytoplasmic vacuolation, green fluorescent protein-light-chain 3 punctate dots, accumulation of acidic vesicular organelles, and upregulated expression level of light-chain 3-II. Taken together, these results suggest that MHY2256 could be a potential novel sirtuin inhibitor for the chemoprevention or treatment of colorectal cancer or both.

• Journal of Life Science
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• v.28 no.4
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• pp.435-443
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• 2018

AMP-activated protein kinase (AMPK) functions as a metabolic master through regulating and restoring cellular energy balance. In skeletal muscle, AMPK increases myofibril protein degradation through the expression of muscle-specific ubiquitin ligases. Mori Folium, the leaf of Morus alba, is a traditional medicinal herb with various pharmacological functions; however, the effects associated with muscle atrophy have not been fully identified. In this study, we confirmed the effects of AMPK activation by examining the effects of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an activator of AMPK, on the induction of atrophy and expression of atrophy-related genes in C2C12 myotubes. We also investigated the effects of the ethanol extract of Mori Folium (EEMF) on the recovery of AICAR-induced muscle atrophy in C2C12 myotubes. It was found that exposure to AICAR resulted in the stimulation of Forkhead box O3a (FOXO3a); an up-regulation of muscle-specific ubiquitin ligases such as Muscle Atrophy F-box (MAFbx)/atrogin-1 and muscle RING finger-1 (MuRF1), and a down-regulation of muscle-specific transcription factors, such as MyoD and myogenin; with the activation of AMPK. In addition, AICAR without cytotoxicity indicated a decrease in diameter of C2C12 myotubes. However, treatment with EEMF significantly suppressed AICAR-induced muscle atrophy of C2C12 myotubes in a dose-dependent manner as confirmed by a decrease in myotube diameter, which is associated with a reversed stimulation of FOXO3a by the inhibition of AMPK activation. These results indicate that the activation of AMPK by AICAR induces muscle atrophy, and EEMF has preeminent effects on the inhibition of AICAR-induced muscle atrophy through the AMPK signaling pathway.

• Journal of Life Science
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• v.28 no.1
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• pp.17-25
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• 2018

In this study, we examined the efficacy of the immune regulation of ${\beta}$-1,3/1,6-glucan and Lactobacillus plantarum LM1004 on atopic dermatitis models. The oral administration of ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 on mice significantly decreased the amount of scratching, leakage to evans blue, and concentrations of serum immunoglobulin E (IgE) and histamine compared with the atopic dermatitis - induced group. When atopic dermatitis was induced, the transcription factors (GATA-3, retinoic acid-related orphan receptor ${\gamma}$ T [$ROR{\gamma}T$]) and cytokines (interleukin-4 [IL-4], IL-17) of Th2 and Th17 cells were overexpressed at the transcriptional level, and they significantly decreased with oral administration of ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004. In addition, ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 were shown to modulate the immune balance by increasing the expression of Th1 and Treg transcription (T-bet, forkhead box p3 [Foxp3]) and cytokines (interferon-${\gamma}$ [IFN-${\gamma}$], transforming growth factor-${\beta}$ [TGF-${\beta}$]). Galectin-9 and filaggrin were significantly lower in the atopic dermatitis - induced group and significantly higher in the ${\beta}$-1,3/1,6-glucan-treated group. In contrast, thymic stromal lymphopoietin (TSLP) was highest in the atopic dermatitis-induced group, while mice that were orally administered ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 showed similar TSLP levels to the control group. These results indicate that ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 have immunomodulatory effects and atopic dermatitis improvement effects in an animal model of atopic dermatitis. Therefore, it is expected that ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 can be used as natural materials in the treatment of atopic dermatitis.