• BMB Reports
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• 제48권7호
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• pp.367-368
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• 2015

It has long been thought that glucocorticoid receptor (GR) functions as a DNA-binding transcription factor in response to its ligand (a glucocorticoid) and thus regulates various cellular and physiological processes. It is also known that GR can bind not only to DNA but also to mRNA; this observation points to the possible role of GR in mRNA metabolism. Recent data revealed a molecular mechanism by which binding of GR to target mRNA elicits rapid mRNA degradation. GR binds to specific RNA sequences regardless of the presence of a ligand. In the presence of a ligand, however, the mRNA-associated GR can recruit PNRC2 and UPF1, both of which are specific factors involved in nonsense-mediated mRNA decay (NMD). PNRC2 then recruits the decapping complex, consequently promoting mRNA degradation. This mode of mRNA decay is termed "GR-mediated mRNA decay" (GMD). Further research demonstrated that GMD plays a critical role in chemotaxis of immune cells by targeting CCL2 mRNA. All these observations provide molecular insights into a previously unappreciated function of GR in posttranscriptional regulation of gene expression. [BMB Reports 2015; 48(7): 367-368]

• Molecules and Cells
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• 제39권2호
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• pp.156-162
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• 2016

Estrogen receptor ${\alpha}$ (ER-${\alpha}$), which is involved in bone metabolism and breast cancer, has been shown to have transcriptional targets. Dlx3 is essential for the skeletal development and plays an important role in osteoblast differentiation. Various osteogenic stimulators and transcription factors can induce the protein expression of Dlx3. However, the regulatory function of ER-${\alpha}$ in the Dlx3 mediated osteogenic process remains unknown. Therefore, we investigated the regulation of Dlx3 and found that ER-${\alpha}$ is a positive regulator of Dlx3 transcription in BMP2-induced osteoblast differentiation. We also found that ER-${\alpha}$ interacts with Dlx3 and increases its transcriptional activity and DNA binding affinity. Furthermore, we demonstrated that the regulation of Dlx3 activity by ER-${\alpha}$ is independent of the ligand (estradiol) binding domain. These results indicate that Dlx3 is a novel target of ER-${\alpha}$, and that ER-${\alpha}$ regulates the osteoblast differentiation through modulation of Dlx3 expression and/or interaction with Dlx3.

• 한국수정란이식학회지
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• 제25권4호
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• pp.273-279
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• 2010

Follicular cystic follicles (FCFs) show delayed regression with persistent follicle growth. However, the mechanism by which follicles are persistently grown remains unclear. Glutathione S-transferases (GSTs) are drug-metabolizing and detoxification enzymes that are involved in the intracellular transport and metabolism of steroid hormones. In this study, a proteomic analysis was performed to identify whether GST expression is changed in bovine FCFs and to predict the interactions between GST and other proteins. Normal follicles and FCFs were classified based on their sizes (5 to 10 mm and 25 mm). In bovine follicles, GST mu 1 (GSTM1) was detected as a differentially expressed protein (DEP) and significantly up-regulated in FCFs compared to normal follicles (p<0.05). Consistent with the proteomic results, semi-quantitative PCR data and western blot analysis revealed an up-regulation of GSTM1 in FCFs. Expression levels of aromatase and dehydrogenase proteins were changed in FCFs. These results show that the up-regulation of GSTM1 that is observed in bovine FCFs is likely to be responsible for the persistent follicle growth in FCFs as the activity of aromatase and the dehydrogenases.

• Molecules and Cells
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• 제37권6호
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• pp.441-448
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• 2014

Inflammasomes are specialized signaling platforms critical for the regulation of innate immune and inflammatory responses. Various NLR family members (i.e., NLRP1, NLRP3, and IPAF) as well as the PYHIN family member AIM2 can form inflammasome complexes. These multiprotein complexes activate inflammatory caspases (i.e., caspase-1) which in turn catalyze the maturation of select pro-inflammatory cytokines, including interleukin (IL)-$1{\beta}$ and IL-18. Activation of the NLRP3 inflammasome typically requires two initiating signals. Toll-like receptor (TLR) and NOD-like receptor (NLR) agonists activate the transcription of pro-inflammatory cytokine genes through an NF-${\kappa}B$-dependent priming signal. Following exposure to extracellular ATP, stimulation of the P2X purinoreceptor-7 ($P2X_7R$), which results in $K^+$ efflux, is required as a second signal for NLRP3 inflammasome formation. Alternative models for NLRP3 activation involve lysosomal destabilization and phagocytic NADPH oxidase and /or mitochondria-dependent reactive oxygen species (ROS) production. In this review we examine regulatory mechanisms that activate the NLRP3 inflammasome pathway. Furthermore, we discuss the potential roles of NLRP3 in metabolic and cognitive diseases, including obesity, type 2 diabetes mellitus, Alzheimer's disease, and major depressive disorder. Novel therapeutics involving inflammasome activation may result in possible clinical applications in the near future.

• Journal of Ginseng Research
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• 제44권2호
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• pp.179-193
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• 2020

Ginseng products on the market show high variability in their composition and overall quality. This becomes a challenge for both consumers and health-care professionals who are in search of high-quality, reliable ginseng products that have a proven safety and efficacy profile. The botanical extract standardization is of crucial importance in this context as it determines the reproducibility of the quality of the product that is essential for the evaluation of effectiveness and safety. This review focuses on the well-characterized and standardized ginseng extract, G115, which represents an excellent example of an herbal drug preparation with constant safety and efficacy within the herbal medicinal products. Over the many decades, extensive preclinical and clinical research has been conducted to evaluate the efficacy and safety of G115. In vitro and in vivo studies of G115 have shown pharmacological effects on physical performance, cognitive function, metabolism, and the immune system. Furthermore, a significant number of G115 clinical studies, most of them double-blind placebo-controlled, have reinforced the findings of preclinical evidence and proved the efficacy of this extract on blood glucose and lipid regulation, chronic obstructive pulmonary disease, energy, physical performance, and immune and cognitive functions. Clinical trials and 50 years of presence on the market are proof of a good safety profile of G115.

• Animal cells and systems
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• 제7권1호
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• pp.1-9
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• 2003

Programmed cell death, or apoptosis, is one of the most studied areas of modern biology. Apoptosis is a genetically regulated process, which plays an essential role in the development and homeostasis of higher organisms. Mitochondria, known to play a central role in regulating cellular metabolism, was found to be critical for regulating apoptosis induced under both physiological and pathological conditions. Mitochondria are a major source of reactive oxygen species (ROS) but they can also serve as its target during the apoptosis process. Release of apoptogenic factors from mitochondria, the best known of which is cytochrome c, leads to assembly of a large apoptosis-inducing complex called the apoptosome. Cysteine pretenses (called caspases) are recruited to this complex and, following their activation by proteolytic cleavage, activate other caspases, which in turn target for specific cleavage a large number of cellular proteins. The redox regulation of apoptosis during and after cytochrome c release is an area of intense investigation. This review summarizes what is known about the biological role of ROS and its targets in apoptosis with an emphasis on its intricate connections to mitochondria and the basic components of cell death.

• Molecules and Cells
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• 제46권3호
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• pp.165-175
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• 2023

The transcription factor Nrf2 was originally identified as a master regulator of redox homeostasis, as it governs the expression of a battery of genes involved in mitigating oxidative and electrophilic stress. However, the central role of Nrf2 in dictating multiple facets of the cellular stress response has defined the Nrf2 pathway as a general mediator of cell survival. Recent studies have indicated that Nrf2 regulates the expression of genes controlling ferroptosis, an iron-and lipid peroxidation-dependent form of cell death. While Nrf2 was initially thought to have anti-ferroptotic function primarily through regulation of the antioxidant response, accumulating evidence has indicated that Nrf2 also exerts anti-ferroptotic effects via regulation of key aspects of iron and lipid metabolism. In this review, we will explore the emerging role of Nrf2 in mediating iron homeostasis and lipid peroxidation, where several Nrf2 target genes have been identified that encode critical proteins involved in these pathways. A better understanding of the mechanistic relationship between Nrf2 and ferroptosis, including how genetic and/or pharmacological manipulation of Nrf2 affect the ferroptotic response, should facilitate the development of new therapies that can be used to treat ferroptosis-associated diseases.

• BMB Reports
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• 제56권9호
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• pp.488-495
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• 2023

Mitochondrial transplantation is a promising therapeutic approach for the treatment of mitochondrial diseases caused by mutations in mitochondrial DNA, as well as several metabolic and neurological disorders. Animal studies have shown that mitochondrial transplantation can improve cellular energy metabolism, restore mitochondrial function, and prevent cell death. However, challenges need to be addressed, such as the delivery of functional mitochondria to the correct cells in the body, and the long-term stability and function of the transplanted mitochondria. Researchers are exploring new methods for mitochondrial transplantation, including the use of nanoparticles or CRISPR gene editing. Mechanisms underlying the integration and function of transplanted mitochondria are complex and not fully understood, but research has revealed some key factors that play a role. While the safety and efficacy of mitochondrial transplantation have been investigated in animal models and human trials, more research is needed to optimize delivery methods and evaluate long-term safety and efficacy. Clinical trials using mitochondrial transplantation have shown mixed results, highlighting the need for further research in this area. In conclusion, although mitochondrial transplantation holds significant potential for the treatment of various diseases, more work is needed to overcome challenges and evaluate its safety and efficacy in human trials.

• IMMUNE NETWORK
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• 제23권5호
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• pp.36.1-36.16
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• 2023

Thymic epithelial cells (TECs) play a critical role in thymic development and thymopoiesis. As individuals age, TECs undergo various changes that impact their functions, leading to a reduction in cell numbers and impaired thymic selection. These age-related alterations have been observed in both mice and humans. However, the precise mechanisms underlying age-related TEC dysfunction remain unclear. Furthermore, there is a lack of a comprehensive study that connects mouse and human biological processes in this area. To address this gap, we conducted an extensive transcriptome analysis of young and old TECs in mice, complemented by further analysis of publicly available human TEC single-cell RNA sequencing data. Our analysis revealed alterations in both known and unknown pathways that potentially contribute to age-related TEC dysfunction. Specifically, we observed downregulation of pathways related to cell proliferation, T cell development, metabolism, and cytokine signaling in old age TECs. Conversely, TGF-β, BMP, and Wnt signaling pathways were upregulated, which have been known to be associated with age-related TEC dysfunctions or newly discovered in this study. Importantly, we found that these age-related changes in mouse TECs were consistently present in human TECs as well. This cross-species validation further strengthens the significance of our findings. In conclusion, our comprehensive analysis provides valuable insight into the biological and immunological characteristics of aged TECs in both mice and humans. These findings contribute to a better understanding of thymic involution and age-induced immune dysfunction.

• Journal of Ginseng Research
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• 제46권2호
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• pp.235-247
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• 2022

Background: Ginsenoside Rg3 is one of the main active ingredients in ginseng. Here, we aimed to confirm its protective effect on the heart function in transverse aortic coarctation (TAC)-induced heart failure mice and explore the potential molecular mechanisms involved. Methods: The effects of ginsenoside Rg3 on heart and mitochondrial function were investigated by treating TAC-induced heart failure in mice. The mechanism of ginsenoside Rg3 for improving heart and mitochondrial function in mice with heart failure was predicted through integrative analysis of the proteome and plasma metabolome. Glucose uptake and myocardial insulin sensitivity were evaluated using micro-positron emission tomography. The effect of ginsenoside Rg3 on myocardial insulin sensitivity was clarified by combining in vivo animal experiments and in vitro cell experiments. Results: Treatment of TAC-induced mouse models with ginsenoside Rg3 significantly improved heart function and protected mitochondrial structure and function. Fusion of metabolomics, proteomics, and targeted metabolomics data showed that Rg3 regulated the glycolysis process, and Rg3 not only regulated glucose uptake but also improve myocardial insulin resistance. The molecular mechanism of ginsenoside Rg3 regulation of glucose metabolism was determined by exploring the interaction pathways of AMPK, insulin resistance, and glucose metabolism. The effect of ginsenoside Rg3 on the promotion of glucose uptake in IR-H9c2 cells by AMPK activation was dependent on the insulin signaling pathway. Conclusions: Ginsenoside Rg3 modulates glucose metabolism and significantly ameliorates insulin resistance through activation of the AMPK pathway.