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Supplementary Figure 2 from Activation of Hypoxia-Inducible Factor-1α Is Necessary for Lysophosphatidic Acid–Induced Vascular Endothelial Growth Factor Expression

Supplementary Figure 3 from Activation of Hypoxia-Inducible Factor-1α Is Necessary for Lysophosphatidic Acid–Induced Vascular Endothelial Growth Factor Expression

Purpose: Lysophosphatidic acid (LPA) plays an important role in mediating cell proliferation, survival, and tumor invasion and angiogenesis. This bioactive phospholipid at the concentration in ascitic fluid stimulates the growth of malignant ovarian tumors by increasing the expression of vascular endothelial growth factor (VEGF). In the present study, we investigated whether LPA activates hypoxia inducible factor-1 (HIF-1), a key transcriptional complex in tumor progression and metastasis, thereby increasing the expression of VEGF.Experimental Design: Immunoblotting, reverse transcription-PCR, ELISA, immunofluorescence, and chromatin immunoprecipitation assay were used to examine the expression of VEGF and HIF-1α in various cancer cells. Specific HIF-1α small interfering RNA was transfected to various cancer cells to determine the role of HIF-1α in LPA-induced VEGF expression.Results: LPA induced expressions of VEGF and HIF-1α in OVCAR-3, CAOV-3, PC-3, and SK-Hep1 cells but not in SKOV-3 and Hep-3B cells. In OVCAR-3 and PC-3 cells, the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin/p70S6K and p42/p44 mitogen-activated protein kinase pathways were required for LPA-induced HIF-1α and VEGF expressions, whereas only the phosphoinositide 3-kinase/mammalian target of rapamycin/p70S6K pathway was important in SK-Hep1 cells. Immunofluorescence microscopy assay showed translocation of HIF-1α to nucleus by LPA, and chromatin immunoprecipitation assay revealed the binding of HIF-1α to the promoter of VEGF by LPA. Importantly, we found that small interfering RNA–induced reduction of HIF-1α expression significantly attenuated VEGF expression by LPA.Conclusions: Our results show for the first time that LPA induces VEGF via HIF-1α activation and reveal a critical role of HIF-1α in LPA-induced cancer cell proliferation and angiogenesis.

Background Skeletal muscle wasting related to aging or pathological conditions is critically associated with the increased incidence and prevalence of secondary diseases including cardiovascular diseases, metabolic syndromes, and chronic inflammations. Much effort is made to develop agents to enhance muscle metabolism and function. Inonotus obliquus (I. obliquus; IO) is a mushroom popularly called chaga and has been widely employed as a folk medicine for inflammation, cardiovascular diseases, diabetes, and cancer in Eastern Europe and Asia. However, its effect in muscle health has not been explored. ObjectiveHere, we aimed to investigate the beneficial effect of IO extract in muscle regeneration and metabolism. MethodsThe effect of I. obliquus extract was investigated on myogenesis and myotube atrophy models of C2C12 myoblasts and muscle regeneration model of mice. The muscle stem cell proliferation and regeneration post muscle injury were employed to further confirm the effect of I. obliquus. The underlying mechanism of I. obliquus was also investigated by the mitochondrial content and oxidative muscle metabolism as well as the activation of AKT and PGC-1α expression. Results The treatment of IO in C2C12 myoblasts led to increased myogenic differentiation and alleviation of dexamethasone-induced myotube atrophy. Network pharmacological analysis using the identified specific chemical constituents of IO extracts predicted protein kinase B (AKT)-dependent mechanisms to promote myogenesis and muscle regeneration. Consistently, IO treatment resulted in the activation of AKT, which suppressed muscle-specific ubiquitin E3 ligases induced by dexamethasone. IO treatment in mice improved the regeneration of cardiotoxin-injured muscles accompanied by elevated proliferation and differentiation of muscle stem cells. Furthermore, it elevated the mitochondrial content and muscle oxidative metabolism accompanied by the induction of peroxisome proliferator-activated receptor γ coactivator α (PGC-1α). Conclusions Our current data suggest that I. obliquus is a promising natural agent in enhancing muscle regenerative capacity and oxidative metabolism thereby preventing muscle wasting.

In the present study, we demonstrate the regulatory effects and mechanism of broussonin A and B, diphenylpropane derivatives isolated from Broussonetia kazinoki, on vascular endothelial growth factor-A (VEGF-A)-stimulated endothelial cell responses in vitro and microvessel sprouting ex vivo. Treatment with broussonin A or B suppressed VEGF-A-stimulated endothelial cell proliferation by regulating the expression of cell cycle-related proteins and the phosphorylation status of retinoblastoma protein. In addition, treatment with broussonin A or B abrogated VEGF-A-stimulated angiogenic responses including endothelial cell migration, invasion, tube formation and microvessel formation from rat aortic rings. These anti-angiogenic activities of broussonin A and B were mediated through inactivation of VEGF-A-stimulated downstream signalling pathways, localization of vascular endothelial-cadherin at cell-cell contacts, and down-regulation of integrin β1 and integrin-liked kinase. Furthermore, treatment with broussonin A or B inhibited proliferation and invasion of non-small cell lung cancer and ovarian cancer cells. Taken together, our findings suggest the pharmacological potential of broussonin A and B in the regulation of angiogenesis, cancer cell growth and progression.

Vascular smooth muscle cells (VSMCs) have remarkable plasticity in response to diverse environmental cues. Although these cells are versatile, chronic stress can trigger VSMC dysfunction, which ultimately leads to vascular diseases such as aortic aneurysm and atherosclerosis. Protein arginine methyltransferase 1 (Prmt1) is a major enzyme catalyzing asymmetric arginine dimethylation of proteins that are sources of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase. Although a potential role of Prmt1 in vascular pathogenesis has been proposed, its role in vascular function has yet to be clarified. Here, we investigated the role and underlying mechanism of Prmt1 in vascular smooth muscle contractility and function. The expression of PRMT1 and contractile-related genes was significantly decreased in the aortas of elderly humans and patients with aortic aneurysms. Mice with VSMC-specific Prmt1 ablation (smKO) exhibited partial lethality, low blood pressure and aortic dilation. The Prmt1-ablated aortas showed aortic dissection with elastic fiber degeneration and cell death. Ex vivo and in vitro analyses indicated that Prmt1 ablation significantly decreased the contractility of the aorta and traction forces of VSMCs. Prmt1 ablation downregulated the expression of contractile genes such as myocardin while upregulating the expression of synthetic genes, thus causing the contractile to synthetic phenotypic switch of VSMCs. In addition, mechanistic studies demonstrated that Prmt1 directly regulates myocardin gene activation by modulating epigenetic histone modifications in the myocardin promoter region. Thus, our study demonstrates that VSMC Prmt1 is essential for vascular homeostasis and that its ablation causes aortic dilation/dissection through impaired myocardin expression., Heart disease: A switch that helps hearts coordinate contraction A protein that stabilizes the contractile function of cardiac muscle may act as an important safeguard against cardiovascular disorders. Several studies have hinted that the enzyme protein arginine methyltransferase 1 (Prmt1) may help preserve healthy cardiovascular function, and researchers led by Sang-Jin Lee at AniMusCure and Jong-Sun Kang of Sungkyukwan University in Suwon, South Korea, have produced evidence strongly supporting this idea. Mice lacking Prmt1 in their heart muscle exhibited clear signs of cardiac dysfunction including degeneration of the contractile fibers that coordinate beating. The researchers subsequently determined that the absence of Prmt1 causes muscle cells to switch to a type associated with damage repair and synthesis, which is ill-suited to routine heart function. Similar switching has been seen in various heart disorders, and treatments that boost Prmt1 activity could confer robust protection against these disorders.

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., Cancer therapy: Exploring possible enzyme targets Understanding the roles, regulation and downstream targets of a family of enzymes involved in cancer development could improve future therapies. Yong Kee Kim at Sookmyung Women’s University, Seoul, South Korea, and co-workers reviewed current knowledge of protein arginine methyltransferases (PRMTs), their influence on cell cycle regulation and DNA damage responses in cancer, and their potential as anti-cancer targets. PRMTs act as catalysts in modification of the amino acid arginine. This process is critical to healthy cellular function, and its disruption is linked to cancer development. The overexpression of certain PRMTs is a driving factor in cancer tumor growth, metastasis and poor prognosis. PRMT inhibitors are showing promise in clinical trials for B-cell lymphoma and various solid tumors. Combined therapies targeting more than one PRMT could prove valuable.

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., Hwang et al. show that the activity of PRMT5 methyltransferase is regulated by Src kinase-mediated phosphorylation at Y324 in response to DNA damage. They also show that PRMT5 participates in NHEJ repair by regulating 53BP1 protein levels and is critical for cellular survival after DNA damage.

Background Perturbation in cell adhesion and growth factor signalling in satellite cells results in decreased muscle regenerative capacity. Cdon (also called Cdo) is a component of cell adhesion complexes implicated in myogenic differentiation, but its role in muscle regeneration remains to be determined. Methods We generated inducible satellite cell‐specific Cdon ablation in mice by utilizing a conditional Cdon allele and Pax7 CreERT2. To induce Cdon ablation, mice were intraperitoneally injected with tamoxifen (tmx). Using cardiotoxin‐induced muscle injury, the effect of Cdon depletion on satellite cell function was examined by histochemistry, immunostaining, and 5‐ethynyl‐2'‐deoxyuridine (EdU) incorporation assay. Isolated myofibers or myoblasts were utilized to determine stem cell function and senescence. To determine pathways related to Cdon deletion, injured muscles were subjected to RNA sequencing analysis. Results Satellite cell‐specific Cdon ablation causes impaired muscle regeneration with fibrosis, likely attributable to decreased proliferation, and senescence, of satellite cells. Cultured Cdon‐depleted myofibers exhibited 32 ± 9.6% of EdU‐positive satellite cells compared with 58 ± 4.4% satellite cells in control myofibers (P < 0.05). About 32.5 ± 3.7% Cdon‐ablated myoblasts were positive for senescence‐associated β‐galactosidase (SA‐β‐gal) while only 3.6 ± 0.5% of control satellite cells were positive (P < 0.001). Transcriptome analysis of muscles at post‐injury Day 4 revealed alterations in genes related to mitogen‐activated protein kinase signalling (P < 8.29 e−5) and extracellular matrix (P < 2.65 e−24). Consistent with this, Cdon‐depleted tibialis anterior muscles had reduced phosphorylated extracellular signal‐regulated kinase (p‐ERK) protein levels and expression of ERK targets, such as Fos (0.23‐fold) and Egr1 (0.31‐fold), relative to mock‐treated control muscles (P < 0.001). Cdon‐depleted myoblasts exhibited impaired ERK activation in response to basic fibroblast growth factor. Cdon ablation resulted in decreased and/or mislocalized integrin β1 activation in satellite cells (weak or mislocalized integrin1 in tmx = 38.7 ± 1.9%, mock = 21.5 ± 6%, P < 0.05), previously linked with reduced fibroblast growth factor (FGF) responsiveness in aged satellite cells. In mechanistic studies, Cdon interacted with and regulated cell surface localization of FGFR1 and FGFR4, likely contributing to FGF responsiveness of satellite cells. Satellite cells from a progeria model, Zmpste24 −/− myofibers, showed decreased Cdon levels (Cdon‐positive cells in Zmpste24−/− = 63.3 ± 11%, wild type = 90 ± 7.7%, P < 0.05) and integrin β1 activation (weak or mislocalized integrin β1 in Zmpste24−/− = 64 ± 6.9%, wild type = 17.4 ± 5.9%, P < 0.01). Conclusions Cdon deficiency in satellite cells causes impaired proliferation of satellite cells and muscle regeneration via aberrant integrin and FGFR signalling.

The loss of skeletal muscle mass and function is a serious consequence of chronic diseases and aging. BST204 is a purified ginseng (the root of Panax ginseng) extract that has been processed using ginsenoside-[Formula: see text]-glucosidase and acid hydrolysis to enrich ginsenosides Rg3 and Rh2 from the crude ginseng. BST204 has a broad range of health benefits, but its effects and mechanism on muscle atrophy are currently unknown. In this study, we have examined the effects and underlying mechanisms of BST204 on myotube formation and myotube atrophy induced by tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]). BST204 promotes myogenic differentiation and multinucleated myotube formation through Akt activation. BST204 prevents myotube atrophy induced by TNF-[Formula: see text] through the activation of Akt/mTOR signaling and down-regulation of muscle-specific ubiquitin ligases, MuRF1, and Atrogin-1. Furthermore, BST204 treatment in atrophic myotubes suppresses mitochondrial reactive oxygen species (ROS) production and regulates mitochondrial transcription factors such as NRF1 and Tfam, through enhancing the activity and expression of peroxisome proliferator-activated receptor-[Formula: see text] coactivator1[Formula: see text] (PGC1[Formula: see text]). Collectively, our findings indicate that BST204 improves myotube formation and PGC1[Formula: see text]-mediated mitochondrial function, suggesting that BST204 is a potential therapeutic or neutraceutical remedy to intervene muscle weakness and atrophy.

Angiotensin II (AngII) has potent cardiac hypertrophic effects mediated through activation of hypertrophic signaling like Wnt/b-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 displayed 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 b-Catenin. PRMT7 deficiency decreases symmetric dimethylation of b-Catenin. Mechanistic studies reveal that methylation of arginine residue 93 in b-Catenin decreases the activity of b-Catenin. Taken together, our data suggest that PRMT7 is important for normal cardiac function through suppression of b-Catenin activity.

With emerging data on the various functions of neuroglobin (Ngb), such as neuroprotection and neurogenesis, we investigated the role of Ngb in the neurovascular unit (NVU) of the brain. To study the distribution and function of Ngb after cerebral ischemia, transient middle cerebral artery occlusion (tMCAO) was performed in mice. Brain immunostaining and fluorescence-activated cell sorting were used to analyze the role of Ngb according to the location and cell type. In normal brain tissue, it was observed that Ngb was distributed not only in neurons but also around the brain's blood vessels. Interestingly, Ngb was largely expressed in platelet-derived growth factor receptor β (PDGFRβ)-positive pericytes in the NVU. After tMCAO, Ngb levels were significantly decreased in the core of the infarct, and Ngb and PDGFRβ-positive pericytes were detached from the vasculature. In contrast, in the penumbra of the infarct, PDGFRβ-positive pericytes expressing Ngb were increased compared with that in the core of the infarct. Moreover, the cerebral blood vessels, which have Ngb-positive PDGFRβ pericytes, showed reduced blood-brain barrier (BBB) leakage after tMCAO. It showed that Ngb-positive PDGFRβ pericytes stayed around the endothelial cells and reduced the BBB leakage in the NVU. Our results indicate that Ngb may play a role in attenuating BBB leakage in part by its association with PDGFRβ. In this study, the distribution and function of Ngb in the pericytes of the cerebrovascular system have been elucidated, which contributes to the treatment of stroke through a new function of Ngb.

Ginsenoside Rg3 (Rg3), amplified by iterative heating processing with fresh ginseng, has a broad range of pharmacological activities and improves mitochondrial biogenesis in skeletal muscle. However, thus far no study has examined how Rg3 affects myotube growth or muscle atrophy, to the best of the authors' knowledge. The present study was conducted to examine the myogenic effect of Rg3 on dexamethasone (DEX)-induced myotube atrophy and the underlying molecular mechanisms. Rg3 activated Akt/mammalian target of rapamycin signaling to prevent DEX-induced myotube atrophy thereby stimulating the expression of muscle-specific genes, including myosin heavy chain and myogenin, and suppressing muscle-specific ubiquitin ligases as demonstrated by immunoblotting and immunostaining assays. Furthermore, Rg3 efficiently prevented DEX-triggered mitochondrial dysfunction of myotubes through peroxisome proliferator-activated receptor-γ coactivator1α activities and its mitochondrial biogenetic transcription factors, nuclear respiratory factor-1 and mitochondrial transcription factor A. These were confirmed by immunoblotting, luciferase assays, RT-qPCR and mitochondrial analysis measuring the levels of ROS, ATP and membrane potential. By providing a mechanistic insight into the effect of Rg3 on myotube atrophy, the present study suggested that Rg3 has potential as a therapeutic or nutraceutical remedy to intervene in muscle aging or diseases including cancer cachexia.

Background: The ginsenoside Rg1 has been shown to exert various pharmacological activities with health benefits. Previously, we have reported that Rg1 promoted myogenic differentiation and myotube growth in C2C12 myoblasts. In this study, the in vivo effect of Rg1 on fiber-type composition and oxidative metabolism in skeletal muscle was examined. Methods: To examine the effect of Rg1 on skeletal muscle, 3-month-old mice were treated with Rg1 for 5 weeks. To assess muscle strength, grip strength tests were performed, and the lower hind limb muscles were harvested, followed by various detailed analysis, such as histological staining, immunoblotting, immunostaining, and real-time quantitative reverse transcription polymerase chain reaction. In addition, to verify the in vivo data, primary myoblasts isolated from mice were treated with Rg1, and the Rg1 effect on myotube growth was examined by immunoblotting and immunostaining analysis. Results: Rg1 treatment increased the expression of myosin heavy chain isoforms characteristic for both oxidative and glycolytic muscle fibers; increased myofiber sizes were accompanied by enhanced muscle strength. Rg1 treatment also enhanced oxidative muscle metabolism with elevated oxidative phosphorylation proteins. Furthermore, Rg1-treated muscles exhibited increased levels of anabolic S6 kinase signaling. Conclusion: Rg1 improves muscle functionality via enhancing muscle gene expression and oxidative muscle metabolism in mice. Keywords: Atrophy, Exercise-specific signaling, Ginsenoside, Rg1, Skeletal muscle

MyoD functions as a master regulator to induce muscle-specific gene expression and myogenic differentiation. Here, we demonstrate a positive role of Protein arginine methyltransferase 7 (Prmt7) in MyoD-mediated myoblast differentiation through p38MAPK activation. Prmt7 depletion in primary or C2C12 myoblasts impairs cell cycle withdrawal and myogenic differentiation. Furthermore, Prmt7 depletion decreases the MyoD-reporter activities and the MyoD-mediated myogenic conversion of fibroblasts. Together with MyoD, Prmt7 is recruited to the Myogenin promoter region and Prmt7 depletion attenuates the recruitment of MyoD and its coactivators. The mechanistic study reveals that Prmt7 methylates p38MAPKα at the arginine residue 70, thereby promoting its activation which in turn enhances MyoD activities. The arginine residue 70 to alanine mutation in p38MAPKα impedes MyoD/E47 heterodimerization and the recruitment of Prmt7, MyoD and Baf60c to the Myogenin promoter resulting in blunted Myogenin expression. In conclusion, Prmt7 promotes MyoD-mediated myoblast differentiation through methylation of p38MAPKα at arginine residue 70.

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. Keywords: Akt/mTOR signaling, Hypertrophy, Myoblast differentiation, Rb1, Rb2

The unique ability of retroviruses to integrate genes into host genomes is of great value for long-term expression in gene therapy, but only when integrations occur at safe genomic sites. To reap the benefit of using retroviruses without severe detrimental effects, we developed several murine leukemia virus (MLV)-based gammaretroviral vectors with safer integration patterns by perturbing the structure of the integrase via insertion of DNA-binding zinc-finger domains (ZFDs) into an internal position of the enzyme. ZFD insertion significantly reduced the inherent, strong MLV integration preference for genomic regions near transcriptional start sites (TSSs), which are the most dangerous spots. The altered retroviral integration pattern was related to increased formation of residual primer-binding site sequences at the 3′ end of proviruses. Several ZFD insertion mutants showed lower frequencies of integrations into the TSS genome regions when having the residual primer-binding site sequences in the proviruses. Our findings not only can extend the use of retroviruses in biomedical applications, but also provide a glimpse into the mechanisms underlying retroviral integration. Keywords: gammaretroviral vectors, DNA-binding protein domain, integrase, primer-binding site, transcriptional start sites

BST204 is a purified ginseng dry extract that has an inhibitory effect on lipopolysaccharide-induced inflammatory responses, but its effect on muscle atrophy is yet to be investigated. In this study, C2C12 myoblasts were induced to differentiate for three days followed by the treatment of dexamethasone (DEX), a corticosteroid drug, with vehicle or BST204 for one day and subjected to immunoblotting, immunocytochemistry, qRT-PCR and biochemical analysis for mitochondrial function. BST204 alleviates the myotube atrophic effect mediated by DEX via the activation of protein kinase B/mammalian target of rapamycin (Akt/mTOR) signaling. Through this pathway, BST204 suppresses the expression of muscle-specific E3 ubiquitin ligases contributing to the enhanced myotube formation and enlarged myotube diameter in DEX-treated myotubes. In addition, BST204 treatment significantly decreases the mitochondrial reactive oxygen species production in DEX-treated myotubes. Furthermore, BST204 improves mitochondrial function by upregulating the expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) in DEX-induced myotube atrophy. This study provides a mechanistic insight into the effect of BST204 on DEX-induced myotube atrophy, suggesting that BST204 has protective effects against the toxicity of a corticosteroid drug in muscle and promising potential as a nutraceutical remedy for the treatment of muscle weakness and atrophy.

Sarcopenia refers to the gradual loss of skeletal muscle mass and function along with aging and is a social burden due to growing healthcare cost associated with a super-aging society. Therefore, researchers have established guidelines and tests to diagnose sarcopenia. Several studies have been conducted actively to reveal the cause of sarcopenia and find an economic therapy to improve the quality of life in elderly individuals. Sarcopenia is caused by multiple factors such as reduced regenerative capacity, imbalance in protein turnover, alteration of fat and fibrotic composition in muscle, increased reactive oxygen species, dysfunction of mitochondria and increased inflammation. Based on these mechanisms, nonpharmacological and pharmacological strategies have been developed to prevent and treat sarcopenia. Although several studies are currently in progress, no treatment is available yet. This review presents the definition of sarcopenia and summarizes recent understanding on the detailed mechanisms, diagnostic criteria, and strategies for prevention and treatment.

CD133+ cells in glioblastoma multiforme (GBM) display glioma stem cell (GSC) properties and have been considered to be the culprit in tumor recurrence, justifying the exploration of potential therapeutic modalities targeting CD133+ cells. Such strategies require a drug-delivery vehicle, and increasingly, the unique properties of PEGylated liposomes are being exploited for this purpose. More advanced liposomal delivery studies have suggested conjugation of CD133 antibodies as a suitable method for targeting GSCs. For targeting studies, GSCs separated from U87 GBM cells using a magnetic bead separation method were challenged with liposomes encapsulating gemcitabine (GEM) conjugated with a CD133 monoclonal antibody (PEG-lipo-CD133-GEM). An in vitro study showed that conjugation of CD133 antibody significantly enhanced the cytotoxicity of GEM through endocytosis of CD133 surface markers overexpressed on GSCs. The anti-tumor effect of PEG-lipo-CD133-GEM was 15 times higher than that of free GEM, presumably reflecting the specific targeting of the CD133 surface marker by PEG-lipo-CD133-GEM and the enhanced stability and cytotoxicity through the PEGylated liposome formulation in xenograft models. Moreover, monitoring of body weight changes showed that the use of PEGylated liposomes significantly reduced the toxicity of GEM. Taken together, our studies demonstrate that PEG-lipo-CD133-GEM shows promise for the treatment of gliomas in vitro and in xenograft models.

Preservation of muscle stem cell function is critical for muscle homeostasis and the regenerative capacity of stem cells declines with age, leading to muscle loss. Previously, daidzein, a natural isoflavone from Leguminosae, has been shown to prevent TNF-α-induced muscle atrophy. However, the molecular mechanisms of daidzein in these processes are currently unknown. In this study, we demonstrate a positive effect of black soybean extract (BS Ext) and daidzein on myoblast differentiation and myotube growth. Daidzein prevents dexamethasone-induced myotube atrophy through Akt activation. The promyogenic effect of BS Ext and daidzein is mediated through two promyogenic kinases, Akt and p38MAPK that in turn activates a key myogenic transcription factor MyoD. Additionally, BS Ext and daidzein promote myotube growth through Akt/mTOR/S6K pathway. Finally, daidzein augments MyoD-dependent myogenic conversion of mouse embryonic fibroblasts. Taken together, our data suggest that daidzein promotes myogenic differentiation and myotube hypertrophy through p38 and Akt/mTOR/S6K pathway.

Background Ginsenoside Rg1 belongs to protopanaxatriol-type ginsenosides and has diverse pharmacological activities. In this report, we investigated whether Rg1 could upregulate muscular stem cell differentiation and muscle growth. Methods C2C12 myoblasts, MyoD-transfected 10T1/2 embryonic fibroblasts, and HEK293T cells were treated with Rg1 and differentiated for 2 d, subjected to immunoblotting, immunocytochemistry, or immunoprecipitation. Results Rg1 activated promyogenic kinases, p38MAPK (mitogen-activated protein kinase) and Akt signaling, that in turn promote the heterodimerization with MyoD and E proteins, resulting in enhancing myogenic differentiation. Through the activation of Akt/mammalian target of rapamycin pathway, Rg1 induced myotube growth and prevented dexamethasone-induced myotube atrophy. Furthermore, Rg1 increased MyoD-dependent myogenic conversion of fibroblast. Conclusion Rg1 upregulates promyogenic kinases, especially Akt, resulting in improvement of myoblast differentiation and myotube growth.

In this study, we aimed to demonstrate the antidiabetic potential of (E)-N-(4-(3-(5-bromo-4-hydroxy-2-methoxyphenyl)acryloyl) phenyl)-4-tert-butylbenzamide (SN158) through peroxisome proliferator-activated receptor (PPAR)-α/γ dual activation. SN158 interacted with both PPARα and PPARγ, and increased their transcriptional activities. Simultaneously, SN158 treatment led to an increase in adipogenic differentiation of 3T3-L1 preadipocytes and fatty acid oxidation in hepatocytes. In addition, glucose uptake in myotubes was significantly increased by SN158 treatment. Finally, SN158 significantly lowered the plasma levels of glucose, triglycerides, and free fatty acids in ob/ob mice without severe weight gain and hepatomegaly. These results suggest that SN158 can be useful as a potential therapeutic agent against type 2 diabetes and related metabolic disorders by alleviating glucose and lipid abnormalities.

To overcome the muscle atrophy, such as cachexia and sarcopenia, we tried to find myogenic agents from medicinal plants. From myogenic extract of Coptis japonica, we purified six isoquinoline alkaloids and evaluated their effects on transactivation of myoD and MHC expression in C2C12 cells during differentiation process. Among obtained compounds, magnoflorine most efficiently enhanced the myoblast differentiation by activating the p38 MAP kinase and Akt pathway, and also increased the number of multinucleated and cylinder-shaped myotubes. These results propose that magnoflorine from Coptis japonica might be a promising lead compound for the development of anti-muscle atrophy drug.

Figure S1. Analysis of ginsenosides in BST204. (A) Ginsenoside profile of BST204 were evaluated by high performance liquid chromatography (HPLC). (B) Structures of the dominating ginsenosides in BST204

In this study, we investigated the effects and molecular mechanisms of 2‐phenylbenzimidazole‐5‐sulphonic acid (PBSA), an ultraviolet B protecting agent used in sunscreen lotions and moisturizers, on ovarian cancer cell responses and tumour angiogenesis. PBSA treatment markedly blocked mitogen‐induced invasion through down‐regulation of matrix metalloproteinase (MMP) expression and activity in ovarian cancer SKOV‐3 cells. In addition, PBSA inhibited mitogen‐induced cell proliferation by suppression of cyclin‐dependent kinases (Cdks), but not cyclins, leading to pRb hypophosphorylation and G1 phase cell cycle arrest. These anti‐cancer activities of PBSA in ovarian cancer cell invasion and proliferation were mediated by the inhibition of mitogen‐activated protein kinase kinase 3/6‐p38 mitogen‐activated protein kinase (MKK3/6‐p38MAPK) activity and subsequent down‐regulation of MMP‐2, MMP‐9, Cdk4, Cdk2 and integrin β1, as evidenced by treatment with p38MAPK inhibitor SB203580. Furthermore, PBSA suppressed the expression and secretion of vascular endothelial growth factor in SKOV‐3 cells, leading to inhibition of capillary‐like tubular structures in vitro and angiogenic sprouting ex vivo. Taken together, our results demonstrate the pharmacological effects and molecular targets of PBSA on modulating ovarian cancer cell responses and tumour angiogenesis, and suggest further evaluation and development of PBSA as a promising chemotherapeutic agent for the treatment of ovarian cancer.

The present study demonstrated that protein arginine methyltransferase 6 (PRMT6) negatively regulates the activity of peroxisome proliferator‑activated 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 PPAR‑responsive 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 di‑methylation, 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.

Neuritogenesis is a critical event for neuronal differentiation and neuronal circuitry formation during neuronal development and regeneration. Our previous study revealed a critical role of a guidance receptor BOC in a neuronal differentiation and neurite outgrowth. However, regulatory mechanisms for BOC signaling pathway remain largely unexplored. In the current study, we have identified Small glutamine-rich tetratricopeptide repeat (TPR)-containing b (SGTb) as a BOC interacting protein through yeast two-hybrid screening. Like BOC, SGTb is highly expressed in brain and P19 embryonal carcinoma (EC) cells differentiated into neuronal cells. BOC and SGTb proteins co-precipitate in mouse brain and differentiated P19 EC cells. Furthermore, BOC and SGTb co-localize in neurites and especially are concentrated at the tip of neurites in various neuronal cells. SGTb depletion attenuates neuronal differentiation of P19 cells through reduction of the surface level of BOC. Additionally, SGTb depletion causes BOC localization at neurite tip, coinciding with decreased p-JNK levels critical for actin cytoskeleton remodeling. The overexpression of SGTb or BOC restores JNK activation in BOC or SGTb-depleted cells, respectively. Finally, SGTb elevates the level of surface-resident BOC in BOC-depleted cells, restoring JNK activation. Taken together, our data suggest that SGTb interacts with BOC and regulates its surface level and consequent JNK activation, thereby promoting neuronal differentiation and neurite outgrowth.