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1.
Int J Biol Sci ; 20(9): 3530-3543, 2024.
Article in English | MEDLINE | ID: mdl-38993551

ABSTRACT

During muscle regeneration, interferon-gamma (IFN-γ) coordinates inflammatory responses critical for activation of quiescent muscle stem cells upon injury via the Janus kinase (JAK) - signal transducer and activator of transcription 1 (STAT1) pathway. Dysregulation of JAK-STAT1 signaling results in impaired muscle regeneration, leading to muscle dysfunction or muscle atrophy. Until now, the underlying molecular mechanism of how JAK-STAT1 signaling resolves during muscle regeneration remains largely elusive. Here, we demonstrate that epithelial-stromal interaction 1 (Epsti1), an interferon response gene, has a crucial role in regulating the IFN-γ-JAK-STAT1 signaling at early stage of muscle regeneration. Epsti1-deficient mice exhibit impaired muscle regeneration with elevated inflammation response. In addition, Epsti1-deficient myoblasts display aberrant interferon responses. Epsti1 interacts with valosin-containing protein (VCP) and mediates the proteasomal degradation of IFN-γ-activated STAT1, likely contributing to dampening STAT1-mediated inflammation. In line with the notion, mice lacking Epsti1 exhibit exacerbated muscle atrophy accompanied by increased inflammatory response in cancer cachexia model. Our study suggests a crucial function of Epsti1 in the resolution of IFN-γ-JAK-STAT1 signaling through interaction with VCP which provides insights into the unexplored mechanism of crosstalk between inflammatory response and muscle regeneration.


Subject(s)
Interferon-gamma , Regeneration , STAT1 Transcription Factor , STAT1 Transcription Factor/metabolism , Animals , Mice , Regeneration/physiology , Interferon-gamma/metabolism , Signal Transduction , Inflammation/metabolism , Muscle, Skeletal/metabolism , Cell Cycle Proteins/metabolism , Cell Cycle Proteins/genetics , Mice, Inbred C57BL , Mice, Knockout
2.
Redox Biol ; 73: 103212, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38838552

ABSTRACT

The dynamic regulation of mitochondria through fission and fusion is essential for maintaining cellular homeostasis. In this study, we discovered a role of coactivator-associated arginine methyltransferase 1 (CARM1) in mitochondrial dynamics. CARM1 methylates specific residues (R403 and R634) on dynamin-related protein 1 (DRP1). Methylated DRP1 interacts with mitochondrial fission factor (Mff) and forms self-assembly on the outer mitochondrial membrane, thereby triggering fission, reducing oxygen consumption, and increasing reactive oxygen species (ROS) production. This sets in motion a feedback loop that facilitates the translocation of CARM1 from the nucleus to the cytoplasm, enhancing DRP1 methylation and ROS production through mitochondrial fragmentation. Consequently, ROS reinforces the CARM1-DRP1-ROS axis, resulting in cellular senescence. Depletion of CARM1 or DRP1 impedes cellular senescence by reducing ROS accumulation. The uncovering of the above-described mechanism fills a missing piece in the vicious cycle of ROS-induced senescence and contributes to a better understanding of the aging process.


Subject(s)
Cellular Senescence , Cytoplasm , Dynamins , Mitochondrial Dynamics , Protein-Arginine N-Methyltransferases , Reactive Oxygen Species , Dynamins/metabolism , Dynamins/genetics , Protein-Arginine N-Methyltransferases/metabolism , Protein-Arginine N-Methyltransferases/genetics , Humans , Reactive Oxygen Species/metabolism , Methylation , Cytoplasm/metabolism , Mitochondria/metabolism , Mitochondria/genetics , Mitochondrial Proteins/metabolism , Mitochondrial Proteins/genetics , Membrane Proteins
3.
Free Radic Biol Med ; 208: 73-87, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37536458

ABSTRACT

Since sirtuins (SIRTs) are closely associated with reactive oxygen species (ROS) and antioxidant system, the development of their selective inhibitors is drawing attention for understanding of cellular redox homeostasis. Here, we describe the pharmacological properties of SPC-180002, which incorporates a methyl methacrylate group as a key pharmacophore, along with its comprehensive molecular mechanism as a novel dual inhibitor of SIRT1/3. The dual inhibition of SIRT1/3 by SPC-180002 disturbs redox homeostasis via ROS generation, which leads to an increase in both p21 protein stability and mitochondrial dysfunction. Increased p21 interacts with and inhibits CDK, thereby interfering with cell cycle progression. SPC-180002 leads to mitochondrial dysfunction by inhibiting mitophagy, which is accompanied by a reduction in oxygen consumption rate. Consequently, SPC-180002 strongly suppresses the proliferation of cancer cells and exerts anticancer effect in vivo. Taken together, the novel SIRT1/3 dual inhibitor, SPC-180002, impairs mitochondrial function and redox homeostasis, thereby strongly inhibiting cell cycle progression and cancer cell growth.


Subject(s)
Mitochondria , Sirtuin 1 , Sirtuin 1/genetics , Sirtuin 1/metabolism , Reactive Oxygen Species/metabolism , Mitochondria/metabolism , Oxidation-Reduction , Homeostasis
4.
Int J Mol Sci ; 24(11)2023 May 31.
Article in English | MEDLINE | ID: mdl-37298484

ABSTRACT

We investigated the role of TONSL, a mediator of homologous recombination repair (HRR), in stalled replication fork double-strand breaks (DSBs) in cancer. Publicly available clinical data (tumors from the ovary, breast, stomach and lung) were analyzed through KM Plotter, cBioPortal and Qomics. Cancer stem cell (CSC)-enriched cultures and bulk/general mixed cell cultures (BCCs) with RNAi were employed to determine the effect of TONSL loss in cancer cell lines from the ovary, breast, stomach, lung, colon and brain. Limited dilution assays and ALDH assays were used to quantify the loss of CSCs. Western blotting and cell-based homologous recombination assays were used to identify DNA damage derived from TONSL loss. TONSL was expressed at higher levels in cancer tissues than in normal tissues, and higher expression was an unfavorable prognostic marker for lung, stomach, breast and ovarian cancers. Higher expression of TONSL is partly associated with the coamplification of TONSL and MYC, suggesting its oncogenic role. The suppression of TONSL using RNAi revealed that it is required in the survival of CSCs in cancer cells, while BCCs could frequently survive without TONSL. TONSL dependency occurs through accumulated DNA damage-induced senescence and apoptosis in TONSL-suppressed CSCs. The expression of several other major mediators of HRR was also associated with worse prognosis, whereas the expression of error-prone nonhomologous end joining molecules was associated with better survival in lung adenocarcinoma. Collectively, these results suggest that TONSL-mediated HRR at the replication fork is critical for CSC survival; targeting TONSL may lead to the effective eradication of CSCs.


Subject(s)
Neoplasms , Recombinational DNA Repair , Female , Humans , DNA Damage , DNA Repair/genetics , DNA Replication/genetics , Homologous Recombination , Neoplastic Stem Cells
5.
Int J Mol Sci ; 23(20)2022 Oct 14.
Article in English | MEDLINE | ID: mdl-36293180

ABSTRACT

Protein arginine methyltransferase 7 (PRMT7) regulates various cellular responses, including gene expression, cell migration, stress responses, and stemness. In this study, we investigated the biological role of PRMT7 in cell cycle progression and DNA damage response (DDR) by inhibiting PRMT7 activity with either SGC8158 treatment or its specific siRNA transfection. Suppression of PRMT7 caused cell cycle arrest at the G1 phase, resulting from the stabilization and subsequent accumulation of p21 protein. In addition, PRMT7 activity is closely associated with DNA repair pathways, including both homologous recombination and non-homologous end-joining. Interestingly, SGC8158, in combination with doxorubicin, led to a synergistic increase in both DNA damage and cytotoxicity in MCF7 cells. Taken together, our data demonstrate that PRMT7 is a critical modulator of cell growth and DDR, indicating that it is a promising target for cancer treatment.


Subject(s)
DNA Damage , Protein-Arginine N-Methyltransferases , Protein-Arginine N-Methyltransferases/genetics , Protein-Arginine N-Methyltransferases/metabolism , RNA, Small Interfering/genetics , Cell Movement , Doxorubicin/pharmacology
6.
Int J Mol Sci ; 23(17)2022 Sep 05.
Article in English | MEDLINE | ID: mdl-36077570

ABSTRACT

The activation and degranulation of immune cells play a pivotal role in allergic inflammation, a pathological condition that includes anaphylaxis, pruritus, and allergic march-related diseases. In this study, trifuhalol A, a phlorotannin isolated from Agarum cribrosum, inhibited the degranulation of immune cells and the biosynthesis of IL-33 and IgE in differentiated B cells and keratinocytes, respectively. Additionally, trifuhalol A suppressed the IL-33 and IgE-mediated activation of RBL-2H3 cells through the regulation of the TAK1 and MK2 pathways. Hence, the effect of trifuhalol A on allergic inflammation was evaluated using a Compound 48/80-induced systemic anaphylaxis mouse model and a house dust mite (HDM)-induced atopic dermatitis (AD) mouse model. Trifuhalol A alleviated anaphylactic death and pruritus, which appeared as an early-phase reaction to allergic inflammation in the Compound 48/80-induced systemic anaphylaxis model. In addition, trifuhalol A improved symptoms such as itching, edema, erythema, and hyperkeratinization in HDM-induced AD mice as a late-phase reaction. Moreover, the expression of IL-33 and thymic stromal lymphopoietin, inflammatory cytokines secreted from activated keratinocytes, was significantly reduced by trifuhalol A administration, resulting in the reduced infiltration of immune cells into the skin and a reduction in the blood levels of IgE and IL-4. In summarizing the above results, these results confirm that trifuhalol A is a potential therapeutic candidate for the regulation of allergic inflammation.


Subject(s)
Anaphylaxis , Dermatitis, Atopic , Anaphylaxis/drug therapy , Animals , Cytokines/metabolism , Dermatitis, Atopic/chemically induced , Dermatitis, Atopic/drug therapy , Immunoglobulin E , Inflammation/pathology , Interleukin-33/metabolism , Mast Cells/metabolism , Mice , Pruritus/metabolism , Pyroglyphidae , p-Methoxy-N-methylphenethylamine/pharmacology
7.
Int J Mol Sci ; 23(15)2022 Aug 04.
Article in English | MEDLINE | ID: mdl-35955819

ABSTRACT

The skin acts as a mechanical barrier that protects the body from the exterior environment, and skin barrier function is attributed to the stratum corneum (SC), which is composed of keratinocytes and skin lipids. Skin barrier homeostasis is maintained by a delicate balance between the differentiation and exfoliation of keratinocytes, and keratinocyte desquamation is regulated by members of the serine protease kalikrein (KLK) family and their endogenous inhibitor SPINK5/LEKTI (serine protease inhibitor Kazal type 5/lympho-epithelial Kazal-type-related inhibitor). Furthermore, SPINK5/LEKTI deficiency is involved in impaired skin barrier function caused by KLK over-activation. We sought to determine whether increased SPINK5/LEKTI expression ameliorates atopic dermatitis (AD) by strengthening skin barrier function using the ethanol extract of Lobelia chinensis (LCE) and its active compound, diosmetin, by treating human keratinocytes with UVB and using a DNCB-induced murine model of atopic dermatitis. LCE or diosmetin dose-dependently increased the transcriptional activation of SPINK5 promoter and prevented DNCB-induced skin barrier damage by modulating events downstream of SPINK5, that is, KLK, PAR2 (protease activated receptor 2), and TSLP (thymic stromal lymphopoietin). LCE or diosmetin normalized immune response in DNCB treated SKH-1 hairless mice as determined by reductions in serum immunoglobulin E and interleukin-4 levels and numbers of lesion-infiltrating mast cells. Our results suggest that LCE and diosmetin are good candidates for the treatment of skin barrier-disrupting diseases such as Netherton syndrome or AD, and that they do so by regulating SPINK5/LEKTI.


Subject(s)
Dermatitis, Atopic , Lobelia , Serine Peptidase Inhibitor Kazal-Type 5/metabolism , Animals , Dermatitis, Atopic/drug therapy , Dermatitis, Atopic/metabolism , Dinitrochlorobenzene , Flavonoids , Humans , Lobelia/metabolism , Mice , Proteinase Inhibitory Proteins, Secretory/pharmacology
8.
Cell Mol Life Sci ; 79(2): 99, 2022 Jan 28.
Article in English | MEDLINE | ID: mdl-35089423

ABSTRACT

Angiotensin II (AngII) has potent cardiac hypertrophic effects mediated through activation of hypertrophic signaling like Wnt/ß-Catenin signaling. In the current study, we examined the role of protein arginine methyltransferase 7 (PRMT7) in cardiac function. PRMT7 was greatly decreased in hypertrophic hearts chronically infused with AngII and cardiomyocytes treated with AngII. PRMT7 depletion in rat cardiomyocytes resulted in hypertrophic responses. Consistently, mice lacking PRMT7 exhibited the cardiac hypertrophy and fibrosis. PRMT7 overexpression abrogated the cellular hypertrophy elicited by AngII, while PRMT7 depletion exacerbated the hypertrophic response caused by AngII. Similar with AngII treatment, the cardiac transcriptome analysis of PRMT7-deficient hearts revealed the alteration in gene expression profile related to Wnt signaling pathway. Inhibition of PRMT7 by gene deletion or an inhibitor treatment enhanced the activity of ß-catenin. PRMT7 deficiency decreases symmetric dimethylation of ß-catenin. Mechanistic studies reveal that methylation of arginine residue 93 in ß-catenin decreases the activity of ß-catenin. Taken together, our data suggest that PRMT7 is important for normal cardiac function through suppression of ß-catenin activity.


Subject(s)
Cardiomegaly/genetics , Myocardium/metabolism , Myocytes, Cardiac/metabolism , Protein-Arginine N-Methyltransferases/genetics , beta Catenin/genetics , Angiotensins , Animals , Cardiomegaly/chemically induced , Cardiomegaly/metabolism , Fibrosis , Gene Expression Profiling/methods , Humans , Male , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Myocardium/pathology , Protein-Arginine N-Methyltransferases/deficiency , RNA-Seq/methods , Wnt Signaling Pathway/genetics , beta Catenin/metabolism
9.
Sci Rep ; 11(1): 10822, 2021 05 24.
Article in English | MEDLINE | ID: mdl-34031528

ABSTRACT

The success of cancer chemotherapy is limited by multidrug resistance (MDR), which is mainly caused by P-glycoprotein (P-gp) overexpression. In the present study, we describe a novel microtubule inhibitor, 5-(N-methylmaleimid-3-yl)-chromone (SPC-160002), that can be used to overcome MDR. A synthetic chromone derivative, SPC-160002, showed a broad spectrum of anti-proliferative effects on various human cancer cells without affecting P-gp expression and its drug efflux function. Treatment with SPC-160002 arrested the cell cycle at the M phase, as evidenced using fluorescence-activated cell sorting analysis, and increased the levels of mitotic marker proteins, including cyclin B, pS10-H3, and chromosomal passenger complex. This mitotic arrest by SPC-160002 was mediated by promoting and stabilizing microtubule polymerization, similar to the mechanism observed in case of taxane-based drugs. Furthermore, SPC-160002 suppressed the growth and sphere-forming activity of cancer stem cells. Our data herein strongly suggest that SPC-160002, a novel microtubule inhibitor, can be used to overcome MDR and can serve as an attractive candidate for anticancer drugs.


Subject(s)
Chromones/pharmacology , Drug Resistance, Multiple/drug effects , Drug Resistance, Neoplasm/drug effects , Maleimides/chemistry , Neoplastic Stem Cells/metabolism , Tubulin Modulators/pharmacology , A549 Cells , ATP Binding Cassette Transporter, Subfamily B/metabolism , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Chromones/chemical synthesis , Chromones/chemistry , Gene Expression Regulation, Neoplastic/drug effects , HCT116 Cells , Hep G2 Cells , Humans , MCF-7 Cells , Neoplastic Stem Cells/drug effects , Tubulin Modulators/chemical synthesis , Tubulin Modulators/chemistry
10.
Exp Mol Med ; 53(5): 788-808, 2021 05.
Article in English | MEDLINE | ID: mdl-34006904

ABSTRACT

Protein methylation, a post-translational modification (PTM), is observed in a wide variety of cell types from prokaryotes to eukaryotes. With recent and rapid advancements in epigenetic research, the importance of protein methylation has been highlighted. The methylation of histone proteins that contributes to the epigenetic histone code is not only dynamic but is also finely controlled by histone methyltransferases and demethylases, which are essential for the transcriptional regulation of genes. In addition, many nonhistone proteins are methylated, and these modifications govern a variety of cellular functions, including RNA processing, translation, signal transduction, DNA damage response, and the cell cycle. Recently, the importance of protein arginine methylation, especially in cell cycle regulation and DNA repair processes, has been noted. Since the dysregulation of protein arginine methylation is closely associated with cancer development, protein arginine methyltransferases (PRMTs) have garnered significant interest as novel targets for anticancer drug development. Indeed, several PRMT inhibitors are in phase 1/2 clinical trials. In this review, we discuss the biological functions of PRMTs in cancer and the current development status of PRMT inhibitors in cancer therapy.


Subject(s)
Biomarkers, Tumor , Neoplasms/metabolism , Protein-Arginine N-Methyltransferases/metabolism , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Arginine/metabolism , Cell Cycle , DNA Damage , Disease Management , Disease Susceptibility , Drug Development , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Gene Expression Regulation, Neoplastic/drug effects , Humans , Methylation , Molecular Targeted Therapy , Neoplasms/drug therapy , Neoplasms/etiology , Neoplasms/pathology , Protein Processing, Post-Translational , Protein-Arginine N-Methyltransferases/antagonists & inhibitors , Protein-Arginine N-Methyltransferases/genetics
11.
J Ginseng Res ; 44(6): 799-807, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33192123

ABSTRACT

BACKGROUND: The skin acts as a barrier to protect organisms against harmful exogenous agents. Compound K (CK) is an active metabolite of ginsenoside Rb1, Rb2 and Rc, and researchers have focused on its skin protective efficacy. In this study, we hypothesized that increased expression of the serine protease inhibitor Kazal type-5 (SPINK5) may improve skin barrier function. METHODS: We screened several ginsenosides to increase SPINK5 gene promoter activity using a transactivation assay and found that CK can increase SPINK5 expression. To investigate the protective effect of CK on the skin barrier, RT-PCR and Western blotting were performed to investigate the expression levels of SPINK5, kallikrein 5 (KLK5), KLK7 and PAR2 in UVB-irradiated HaCaT cells. Measurement of transepidermal water loss (TEWL) and histological changes associated with the skin barrier were performed in a UVB-irradiated mouse model and a 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis-like model. RESULTS: CK treatment increased the expression of SPINK5 and decreased the expression of its downstream genes, such as KLKs and PAR2. In the UVB-irradiated mouse model and the DNCB-induced atopic dermatitis model, CK restored increased TEWL and decreased hydration and epidermal hyperplasia. In addition, CK normalized the reduced SPINK5 expression caused by UVB or DNCB, thereby restoring the expression of the proteins involved in desquamation to a level similar to normal. CONCLUSIONS: Our data showed that CK contributes to improving skin-barrier function in UVB-irradiated and DNCB-induced atopic dermatitis-like models through SPINK5. These results suggest that therapeutic attempts with CK might be useful in treating barrier-disrupted diseases.

12.
Biomol Ther (Seoul) ; 28(6): 542-548, 2020 Nov 01.
Article in English | MEDLINE | ID: mdl-32938818

ABSTRACT

Naturally derived diosmetin and its glycoside diosmin are known to be effective in treating inflammatory disease. This study was performed to determine whether diosmin and diosmetin have the effect of improving atopic dermatitis in a 2,4-dinitrochlorobenzen (DNCB)-induced atopic dermatitis (AD) model. DNCB was used to establish AD model in hairless mice. Skin moisture, serum immunoglobulin E (IgE), interleukin 4 (IL-4), and histological analysis were performed to measure the effectiveness of diosmin and diosmetine to improve AD. IL-4 levels were also measured in RBL-2H3 cells. Administration of diosmetin or diosmin orally inhibited the progress of DNCB-induced AD-like lesions in murine models by inhibiting transdermal water loss (TEWL) and increasing skin hydration. Diosmetin or diosmin treatment also reduced IgE and IL-4 levels in AD-induced hairless mouse serum samples. However, in the in vitro assay, only diosmetin, not diosmin, reduced the expression level of IL-4 mRNA in RBL-2H3 cells. Diosmin and diosmetine alleviated the altered epidermal thickness and immune cell infiltration in AD. Diosmin is considered effective in the cure of AD and skin inflammatory diseases by being converted into diosmetin in the body by pharmacokinetic metabolism. Thus, oral administration of diosmetin and diosmin might be a useful agent for the treatment of AD and cutaneous inflammatory diseases.

13.
Commun Biol ; 3(1): 428, 2020 08 05.
Article in English | MEDLINE | ID: mdl-32759981

ABSTRACT

PRMT5 participates in various cellular processes, including transcription regulation, signal transduction, mRNA splicing, and DNA repair; however, its mechanism of regulation is poorly understood. Here, we demonstrate that PRMT5 is phosphorylated at residue Y324 by Src kinase, a negative regulator of its activity. Either phosphorylation or substitution of the Y324 residue suppresses PRMT5 activity by preventing its binding with the methyl donor S-adenosyl-L-methionine. Additionally, we show that PRMT5 activity is associated with non-homologous end joining (NHEJ) repair by methylating and stabilizing p53-binding protein 1 (53BP1), which promotes cellular survival after DNA damage. Src-mediated phosphorylation of PRMT5 and the subsequent inhibition of its activity during the DNA damage process blocks NHEJ repair, leading to apoptotic cell death. Altogether, our findings suggest that PRMT5 regulates DNA repair through Src-mediated Y324 phosphorylation in response to DNA damage.


Subject(s)
Neoplasms/genetics , Protein-Arginine N-Methyltransferases/genetics , Tumor Suppressor p53-Binding Protein 1/genetics , src-Family Kinases/genetics , A549 Cells , DNA Breaks, Double-Stranded , DNA Damage/genetics , DNA End-Joining Repair/genetics , DNA Methylation/genetics , HeLa Cells , Histones/genetics , Humans , MCF-7 Cells , Neoplasms/pathology , Phosphorylation , Protein Binding , Protein Processing, Post-Translational/genetics
14.
Front Oncol ; 10: 764, 2020.
Article in English | MEDLINE | ID: mdl-32582535

ABSTRACT

Multidrug resistance (MDR), which is a significant impediment to the success of cancer chemotherapy, is attributable to various defensive mechanisms in cancer. Initially, overexpression of ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp) was considered the most important mechanism for drug resistance; hence, many investigators for a long time focused on the development of specific ABC transporter inhibitors. However, to date their efforts have failed to develop a clinically applicable drug, leaving only a number of problems. The concept of cancer stem cells (CSCs) has provided new directions for both cancer and MDR research. MDR is known to be one of the most important features of CSCs and thus plays a crucial role in cancer recurrence and exacerbation. Therefore, in recent years, research targeting CSCs has been increasing rapidly in search of an effective cancer treatment. Here, we review the drugs that have been studied and developed to overcome MDR and CSCs, and discuss the limitations and future perspectives.

15.
J Ginseng Res ; 44(3): 435-441, 2020 May.
Article in English | MEDLINE | ID: mdl-32372865

ABSTRACT

BACKGROUND: As a process of aging, skeletal muscle mass and function gradually decrease. It is reported that ginsenoside Rb1 and Rb2 play a role as AMP-activated protein kinase activator, resulting in regulating glucose homeostasis, and Rb1 reduces oxidative stress in aged skeletal muscles through activating the phosphatidylinositol 3-kinase/Akt/Nrf2 pathway. We examined the effects of Rb1 and Rb2 on differentiation of the muscle stem cells and myotube formation. METHODS: C2C12 myoblasts treated with Rb1 and/or Rb2 were differentiated and induced to myotube formation, followed by immunoblotting for myogenic marker proteins, such as myosin heavy chain, MyoD, and myogenin, or immunostaining for myosin heavy chain or immunoprecipitation analysis for heterodimerization of MyoD/E-proteins. RESULTS: Rb1 and Rb2 enhanced myoblast differentiation through accelerating MyoD/E-protein heterodimerization and increased myotube hypertrophy, accompanied by activation of Akt/mammalian target of rapamycin signaling. In addition, Rb1 and Rb2 induced the MyoD-mediated transdifferentiation of the rhabdomyosarcoma cells into myoblasts. Furthermore, co-treatment with Rb1 and Rb2 had synergistically enhanced myoblast differentiation through Akt activation. CONCLUSION: Rb1 and Rb2 upregulate myotube growth and myogenic differentiation through activating Akt/mammalian target of rapamycin signaling and inducing myogenic conversion of fibroblasts. Thus, our first finding indicates that Rb1 and Rb2 have strong potential as a helpful remedy to prevent and treat muscle atrophy, such as age-related muscular dystrophy.

16.
Nat Commun ; 11(1): 612, 2020 01 30.
Article in English | MEDLINE | ID: mdl-32001712

ABSTRACT

The kinase Aurora B forms the chromosomal passenger complex (CPC) together with Borealin, INCENP, and Survivin to mediate chromosome condensation, the correction of erroneous spindle-kinetochore attachments, and cytokinesis. Phosphorylation of histone H3 Thr3 by Haspin kinase and of histone H2A Thr120 by Bub1 concentrates the CPC at the centromere. However, how the CPC is recruited to chromosome arms upon mitotic entry is unknown. Here, we show that asymmetric dimethylation at Arg2 on histone H3 (H3R2me2a) by protein arginine methyltransferase 6 (PRMT6) recruits the CPC to chromosome arms and facilitates histone H3S10 phosphorylation by Aurora B for chromosome condensation. Furthermore, in vitro assays show that Aurora B preferentially binds to the H3 peptide containing H3R2me2a and phosphorylates H3S10. Our findings indicate that the long-awaited key histone mark for CPC recruitment onto mitotic chromosomes is H3R2me2a, which is indispensable for maintaining appropriate CPC levels in dynamic translocation throughout mitosis.


Subject(s)
Arginine/metabolism , Aurora Kinase B/metabolism , Chromosome Segregation , Chromosomes, Human/metabolism , Histones/metabolism , Nuclear Proteins/metabolism , Protein-Arginine N-Methyltransferases/metabolism , Amino Acid Sequence , Breast Neoplasms/pathology , Centromere/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Cytokinesis , Demethylation , Disease Progression , Female , HeLa Cells , Histones/chemistry , Humans , MCF-7 Cells , Methylation , Mitosis , Phosphorylation , RNA, Small Interfering/metabolism
17.
Int J Mol Med ; 43(6): 2462-2470, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30942395

ABSTRACT

The present study demonstrated that protein arginine methyltransferase 6 (PRMT6) negatively regulates the activity of peroxisome proliferator­activated receptor γ (PPARγ). The results indicated that the overexpression of PRMT6 inhibited the transactivity of PPARγ and subsequently decreased the expression levels of PPARγ target genes. Contrarily, the depletion or inhibition of PRMT6 increased PPARγ reporter activity and the expression of its target genes. It was also confirmed that PRMT6 was involved in the process of adipocyte differentiation. In addition, PRMT6 interacted with, but did not methylate, PPARγ. PRMT6 bound to the PPAR­responsive regulatory element of the adipocyte Protein 2 (aP2) promoter in conjunction with PPARγ and generated the repressive epigenetic mark arginine 2 on histone H3 asymmetric di­methylation, which suppressed aP2 gene expression. Therefore, PRMT6 may serve as an important regulator of PPARγ activity in adipogenic differentiation and may be an attractive therapeutic target for human metabolic diseases.


Subject(s)
Adipogenesis , PPAR gamma/metabolism , Protein-Arginine N-Methyltransferases/metabolism , 3T3-L1 Cells , Animals , Cell Line , Fatty Acid-Binding Proteins/genetics , Histones/genetics , Humans , Methylation , Mice , Promoter Regions, Genetic , Protein Interaction Maps
19.
Biochem Biophys Res Commun ; 510(4): 621-628, 2019 03 19.
Article in English | MEDLINE | ID: mdl-30739791

ABSTRACT

Previous reports have shown that PPARß/δ agonists ameliorate insulin resistance associated with type 2 diabetes mellitus (T2DM). To determine the role of PPARß/δ in tumor necrosis factor α (TNFα)-mediated insulin resistance, we investigated expression levels of adiponectin and insulin receptor (IR) in response to treatment with the PPARß/δ agonist GW501516 with or without TNFα, a proinflammatory cytokine, in differentiated 3T3-L1 adipocytes. GW501516 induced adipocyte differentiation and the expression of adiponectin in a dose-dependent manner in differentiated adipocytes. TNFα treatment reduced adiponectin expression at the end of differentiation. This effect was reversed by GW501516 co-treatment with TNFα. TNFα treatment decreased adipogenic marker genes such as PPARγ, aP2, resistin, and GLUT4, and GW501516 reversed the effects of TNFα. GW501516 treatment increased the expression of insulin receptor and inhibited TNFα-mediated repression of insulin receptor. Our results showed that GW501516 abrogated TNFα-induced insulin resistance. In summary, our study demonstrated that the PPARß/δ agonist, GW501516 reversed TNFα-induced decreases in adipocyte differentiation and adiponectin expression, and improved insulin sensitivity by increasing the expression of insulin receptor. Therefore, PPARδ may be a promising therapeutic target for treatment of insulin resistance in patients with T2DM.


Subject(s)
Adiponectin/metabolism , PPAR delta/agonists , PPAR-beta/agonists , Receptor, Insulin/metabolism , Thiazoles/pharmacology , Tumor Necrosis Factor-alpha/metabolism , 3T3-L1 Cells , Adipocytes/drug effects , Adipocytes/metabolism , Animals , Insulin Resistance , Mice , PPAR delta/metabolism , PPAR-beta/metabolism
20.
Biomolecules ; 10(1)2019 12 29.
Article in English | MEDLINE | ID: mdl-31905797

ABSTRACT

To investigate the potential effects of acorn shells on atopic dermatitis (AD), we utilized oxazolone (OX)- or 2,4-dinitrochlorobenzene (DNCB)-induced AD-like lesion mouse models. Our research demonstrates that Acorn shell extract (ASE) improved the progression of AD-like lesions, including swelling, which were induced by oxazolone on Balb/c mouse ears. Additionally, ASE significantly decreased the ear thickness (OX: 0.42 ± 0.01 mm, OX-ASE: 0.32 ± 0.02 mm) and epidermal thickness (OX: 75.3 ± 32.6 µm, OX-ASE: 46.1 ± 13.4 µm). The continuous DNCB-induced AD mouse model in SKH-1 hairless mice demonstrated that ASE improved AD-like symptoms, including the recovery of skin barrier dysfunction, Immunoglobulin E hyperproduction (DNCB: 340.1 ± 66.8 ng/mL, DNCB-ASE: 234.8 ± 32.9 ng/mL) and an increase in epidermal thickness (DNCB: 96.4 ± 21.9 µm, DNCB-ASE: 52.4 ± 16.3 µm). In addition, we found that ASE suppressed the levels of AD-involved cytokines, such as Tumor Necrosis Factor α, IL-1ß, IL-25 and IL-33 in both animal models. Furthermore, gallic acid and ellagic acid isolated from ASE suppressed ß-hexosaminidase release and IL-4 expression in RBL-2H3 cells. The acorn shell and its active phytochemicals have potential as a new remedy for the improvement of atopic dermatitis and other inflammatory diseases.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Dermatitis, Atopic/drug therapy , Phytochemicals/pharmacology , Plant Extracts/pharmacology , Quercus/chemistry , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/isolation & purification , Cell Line, Tumor , Cytokines/antagonists & inhibitors , Cytokines/biosynthesis , Dermatitis, Atopic/metabolism , Dermatitis, Atopic/pathology , Dinitrochlorobenzene/chemistry , Dinitrochlorobenzene/pharmacology , Disease Models, Animal , Female , Mice , Mice, Hairless , Mice, Inbred BALB C , Oxazolone/chemistry , Oxazolone/pharmacology , Phytochemicals/chemistry , Phytochemicals/isolation & purification , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Rats
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