• The Korean Journal of Physiology and Pharmacology
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• 제27권2호
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• pp.167-176
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• 2023

This study aims to explore the impact of Rehmannioside D (RD) on ovarian functions of rats with diminished ovarian reserve (DOR) and its underlying mechanisms of action. A single injection of cyclophosphamide was performed to establish a DOR rat model, and fourteen days after the injection, the rats were intragastrically administrated with RD for two weeks. Rat estrus cycles were tested using vaginal smears. Ovarian tissues were histologically evaluated, the number of primordial, mature, and atretic follicles was calculated, and the apoptotic rate of granulosa cells. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂) levels were determined by ELISA assays. Protein levels of Forkhead Box O1 (FOXO1), KLOTHO, Bcl-2, and Bax were investigated in ovarian tissues of DOR rats. The binding between FOXO1 and KLOTHO was verified by ChIP assay. High-dose administration of RD into DOR rats improved their estrus cycles, increased ovarian index, enhanced the number of primordial and mature follicles, reduced the number of atretic follicle number, and ovarian granulosa cell apoptosis in addition to inhibiting FSH and LH levels and upregulating E₂ expression. FOXO1 and KLOTHO were significantly suppressed in DOR rats. FOXO1 knockdown partially suppressed the protective effects of RD on DOR rats, and KLOTHO overexpression could restore RD-induced blockade of DOR development despite knocking down FOXO1. FOXO1 antibody enriched KLOTHO promoter, and the binding between them was reduced in DOR group compared to that in sham group. RD improved ovarian functions in DOR rats and diminished granulosa cell apoptosis via the FOXO1/KLOTHO axis.

• Journal of Oral Medicine and Pain
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• 제48권2호
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• pp.39-44
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• 2023

Primary Sjögren's syndrome (pSS) is an autoimmune progressive disease characterized by dysfunction and inflammation of the salivary glands. The underlying mechanisms of salivary gland involvement in pSS remain unclear, and researchers have primarily focused on immunological phenomena, making it difficult to distinguish between the cause and effect of the disease. Consequently, our research aims to directly investigate changes in homeostasis occurring in acinar cells, specifically in the context of muscarinic signaling, mucins, aquaporins, and forkhead box protein O1, to elucidate the initial step of pSS. We compare the disease-related phenomena observed in salivary gland acinar cells in pSS with the overall process of salivary secretion.

• 대한의생명과학회지
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• 제24권1호
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• pp.15-22
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• 2018

Pristimerin is a triterpene compound isolated from plant extracts that reportedly possesses antitumor, antioxidant, and anti-inflammatory activities. The current study was designed to evaluate the antitumor effects of pristimerin on human colon cancer cells. Treatment of the human colon cancer cells, HCT116 and SW480, with pristimerin led to a dose-dependent decrease in cell proliferation. Flow cytometry experiments showed that pristimerin increased cell apoptotic rate and decreased the mitochondrial membrane potential in HCT116 and SW480 cells. Western blot assay showed that pristimerin induced increased cleavage of caspase-3, -7, -8, and poly ADP ribose polymerase. Treatment with pristimerin also caused a marked decrease in the expression of Bcl-2 and Bcl-xL. Additionally, the levels of phosphorylated AKT and forkhead box O3a (FOXO3a) were decreased in pristimerin-treated colon cancer cells. Taken together, our study illustrated that pristimerin promoted apoptosis via the AKT/FOXO3a signaling pathway in colon cancer cells, elucidating that it might be considered as a potential agent for colon cancer therapy.

• Nutrition Research and Practice
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• 제11권5호
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• pp.430-434
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• 2017

BACKGROUND/OBJECTIVE: Chronic hyperglycemia induces oxidative stress via accumulation of reactive oxygen species (ROS) and contributes to diabetic complications. Hyperglycemia induces mitochondrial superoxide anion production through the increased activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. This study aimed to determine whether fisetin and luteolin treatments suppress the oxidative stress by modulating the expression of sirtuins (SIRTs) and forkhead box O3a (FOXO3a) under hyperglycemic conditions in human monocytes. MATERIALS/METHODS: Human monocytic cells (THP-1) were cultured under osmotic control (14.5 mmol/L mannitol), normoglycemic (NG, 5.5 mmol/L glucose), or hyperglycemic (HG, 20 mmol/L glucose) conditions, in the absence or presence of fisetin and luteolin for 48 h. To determine the effect of fisetin and luteolin treatments on high glucose-induced oxidative stress, western blotting and intracellular staining were performed. RESULTS: Hyperglycemic conditions increased the ROS production, as compared to normoglycemic condition. However, fisetin and luteolin treatments inhibited ROS production under hyperglycemia. To obtain further insight into ROS production in hyperglycemic conditions, evaluation of p47phox expression revealed that fisetin and luteolin treatments inhibited p47phox expression under hyperglycemic conditions. Conversely, the expression levels of SIRT1, SIRT3, SIRT6, and FOXO3a were decreased under high glucose conditions compared to normal glucose conditions, but exposure to fisetin and luteolin induced the expression of SIRT1, SIRT3, SIRT6, and FOXO3a. The above findings suggest that fisetin and luteolin inhibited high glucose-induced ROS production in monocytes through the activation of SIRTs and FOXO3a. CONCLUSIONS: The results of our study supports current researches that state fisetin and luteolin as potential agents for the development of novel strategies for diabetes.

• BMB Reports
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• 제41권10호
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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.

• 생명과학회지
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• 제25권3호
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• pp.293-298
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• 2015

근위축은 근육 단백질 합성의 저하와 근육 단백질의 분해 증가에 따른 근섬유의 감소에 의한 근육량이 감소되는 현상이다. 오미자(Schisandrae Fructus, fruits of Schisandra chinensis (Turcz.) Baillon)는 오랫동안 전통의학에서 강장제로서 널리 사용되어 왔다. 비록 다양한 질병 연관 오미자의 생리활성 효능이 폭넓게 연구되어져 왔으나 근육 질환 관련 연구는 매우 제한적으로 이루어져 왔다. 본 연구에서는 오미자 에탄올 추출물(SF)이 AMPK 활성인자 AICAR 처리에 의한 C2C12 근관세포의 근위축 모델계를 이용하여 근위축 억제 효능을 가지는지의 여부와 관련 기전의 해석을 시도하였다. AICAR 처리는 근단백질 분해 연관 ubiquitin ligase muscle RING finger-1 (MuRF-1)의 발현을 전사 수준에서 증가시켰고, MuRF-1 조절 전사인자의 하나인 forkhead box O3a (FoxO3a) 단백질의 인산화를 증가시켰으며, 이러한 변화는 근위축과 연관된 C2C12 근관세포의 형태적 변형과 동반된 현상이었다. 그러나 SF의 전처리에 의하여, AICAR에 의하여 유도된 근위축성 형태변화를 억제하였으며, MuRF-1의 발현과 FoxO3a의 활성화를 억제시켰다. 본 연구의 결과는 SF가 AICAR 처리에 의한 C2C12 근관세포의 근위축을 AMPK 및 FoxO3a 신호전달계 조절을 통하여 억제하였음을 보여주는 것으로 오미자는 근기능 향상을 위한 식의 약 소재로서의 개발 가능성이 매우 높음을 시사하여 준다.

• Fisheries and Aquatic Sciences
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• 제22권9호
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• pp.19.1-19.10
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• 2019

We investigated the insulin-like growth factor 1 (IGF-1)/AKT signaling pathway involved in muscle formation, growth, and movement in the adductor muscle of triploid Pacific oyster, Crassostrea gigas. Large and small triploid oysters (LTs and STs) cultured under identical conditions were screened, and the signaling pathways of individuals with superior growth were compared and analyzed. mRNA and protein expression levels of actin, troponin, tropomyosin, and myosin, proteins important in muscle formation, were higher in LTs compared with STs. Expression levels of IGF-1, IGF binding protein (IGFBP), and IGFBP complex acid-labile subunit were also higher in LTs compared with STs. Phosphorylation of the IGF receptor as well as that of AKT was high in LTs. In addition, the expression of phosphomammalian target of rapamycin and phospho-glycogen synthase kinase $3{\beta}$ was increased and the expression of Forkhead box O3 was decreased in LTs. Therefore, we suggested that the IGF-1/AKT signaling pathway affects the formation, growth, and movement of the adductor muscle in triploid oysters.

• Clinical and Experimental Reproductive Medicine
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• 제39권1호
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• pp.10-14
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• 2012

The ovarian follicles develop initially from primordial follicles. The majority of ovarian primordial follicles are maintained quiescently as a reserve for the reproductive life span. Only a few of them are activated and develop to an advanced follicular stage. The maintenance of dormancy and activation of primordial follicles are controlled by coordinated actions of a suppressor/activator with close communications with somatic cells and intra-oocyte signaling pathways. Many growth factors and signaling pathways have been identified and the transforming growth factor-beta superfamily plays important roles in early folliculogenesis. However, the mechanism of maintaining the dormancy and survival of primordial follicles has remained unknown for decades. Recently, since the first finding that all primordial follicles are activated prematurely in mice deficient forkhead box O3a, phosphatidylinositol 3 kinase/phosphatase and tensin homolog (PTEN) signaling pathway was reported to be important in the regulation of dormancy and initial follicular activation. With these informations on early folliculogenesis, clinical application can be expected such as in vitro maturation of immature oocytes or in vitro activation of follicles by PTEN inhibitor in cryopreserved ovarian cortical tissues for fertility preservation.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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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 Ginseng Research
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• 제41권3호
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• pp.247-256
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• 2017

Background: KG-135, a standardized formulation enriched with Rk1, Rg3, and Rg5 ginsenosides, has been shown to inhibit various types of cancer cells; however, the underlying mechanisms are not fully understood. In this study, we explored its effects in A549 human lung cancer cells to investigate the induction of Forkhead Class box O3a (FOXO3a) and autophagy. Methods: Cell viability was determined by sulforhodamine B staining. Apoptosis and cell cycle distribution were analyzed using flow cytometry. The changes of protein levels were determined using Western blot analysis. Autophagy induction was monitored by the formation of acidic vesicular organelles stained with acridine orange. Results: KG-135 effectively arrested the cells in G1 phase with limited apoptosis. Accordingly, a decrease of cyclin-dependent kinase-4, cyclin-dependent kinase-6, cyclin D1, and phospho-retinoblastoma protein, and an increase of p27 and p18 proteins were observed. Intriguingly, KG-135 increased the tumor suppressor FOXO3a and induced the accumulation of autophagy hallmark LC3-II and acidic vesicular organelles without an increase of the upstream marker Beclin-1. Unconventionally, the autophagy adaptor protein p62 (sequestosome 1) was increased rather than decreased. Blockade of autophagy by hydroxychloroquine dramatically potentiated KG-135-induced FOXO3a and its downstream (FasL) ligand accompanied by the cleavage of caspase-8. Meanwhile, the decrease of Bcl-2 and survivin, as well as the cleavage of caspase-9, were also drastically enhanced, resulting in massive apoptosis. Conclusion: Besides arresting the cells in G1 phase, KG-135 increased FOXO3a and induced an unconventional autophagy in A549 cells. Both the KG-135-activated extrinsic FOXO3a/FasL/caspase-8 and intrinsic caspase-9 apoptotic pathways were potentiated by blockade of autophagy. Combination of KG-135 and autophagy inhibitor may be a novel strategy as an integrative treatment for cancers.