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The composition of skeletal muscle fiber types affects the quality of livestock meat and human athletic performance and health. L-arginine (Arg), a semi-essential amino acid, has been observed to promote the formation of slow-twitch muscle fibers in animal models. However, the precise molecular mechanisms are still unclear. This study investigates the role of Arg in skeletal muscle fiber composition and mitochondrial function through the mTOR signaling pathway. In vivo, 4-week C56BL/6J male mice were divided into three treatment groups and fed a basal diet supplemented with different concentrations of Arg in their drinking water. The trial lasted 7 weeks. The results show that Arg supplementation significantly improved endurance exercise performance, along with increased SDH enzyme activity and upregulated expression of the MyHC I, MyHC IIA, PGC-1α, and NRF1 genes in the gastrocnemius (GAS) and quadriceps (QUA) muscles compared to the control group. In addition, Arg activated the mTOR signaling pathway in the skeletal muscle of mice. In vitro experiments using cultured C2C12 myotubes demonstrated that Arg elevated the expression of slow-fiber genes (MyHC I and Tnnt1) as well as mitochondrial genes (PGC-1α, TFAM, MEF2C, and NRF1), whereas the effects of Arg were inhibited by the mTOR inhibitor rapamycin. In conclusion, these findings suggest that Arg modulates skeletal muscle fiber type towards slow-twitch fibers and enhances mitochondrial functions by upregulating gene expression through the mTOR signaling pathway. [ABSTRACT FROM AUTHOR]

Numerous studies have demonstrated that individual proteins can moonlight. Eukaryotic Initiation translation factor 3, f subunit (eIF3f) is involved in critical biological functions; however, its role independent of protein translation in regulating colorectal cancer (CRC) is not characterized. Here, it is demonstrated that eIF3f is upregulated in CRC tumor tissues and that both Wnt and EGF signaling pathways are participating in eIF3f's oncogenic impact on targeting phosphoglycerate dehydrogenase (PHGDH) during CRC development. Mechanistically, EGF blocks FBXW7β‐mediated PHGDH ubiquitination through GSK3β deactivation, and eIF3f antagonizes FBXW7β‐mediated PHGDH ubiquitination through its deubiquitinating activity. Additionally, Wnt signals transcriptionally activate the expression of eIF3f, which also exerts its deubiquitinating activity toward MYC, thereby increasing MYC‐mediated PHGDH transcription. Thereby, both impacts allow eIF3f to elevate the expression of PHGDH, enhancing Serine–Glycine–One–Carbon (SGOC) signaling pathway to facilitate CRC development. In summary, the study uncovers the intrinsic role and underlying molecular mechanism of eIF3f in SGOC signaling, providing novel insight into the strategies to target eIF3f‐PHGDH axis in CRC. [ABSTRACT FROM AUTHOR]

Based on the brief introduction of the characteristics food-derived active peptides and immunomodulation principle of macrophage, the source and preparation of food-derived active peptides, the phenomenon of macrophage polarization, and the mechanism of food-derived active peptides regulating macrophage polarization to exert immunomodulatory effects were highlighted in the review. It pointed out that food-derived active peptides mainly included animal sources, plant sources, microbial sources and other active peptides, and their preparation methods mainly included enzymatic hydrolysis, physical assisted enzymatic hydrolysis, microbial fermentation, microbialenzyme synergy. The microbial-enzyme synergy method had the advantages of improving the degree of hydrolysis, conversion rate of protein and the quality of extracted peptide, which was a good method to prepare food-derived active peptides. Food-derived active peptides could regulate macrophage polarization to play an immunomodulatory role. The signal pathways including NF-κB, MAPK, and TLR4/ MyD88, which were important for regulating the polarization of macrophages. However, due to the complex relationship between macrophages and health, in the future, metabolomics, gene knockout and other new technologies should be used to study the effect of food-derived active peptides on regulating macrophage polarization and health from the aspects of macrophage functional diversity and synergistic effect of signaling pathways. It was expected that this review was able to provide theoretical basis for the application of food-derived active peptides in functional food. [ABSTRACT FROM AUTHOR]

Background and purpose: Evidence indicates that ferroptosis plays a key role in acute kidney injury induced by cisplatin. The Nrf2/NRF2 pathway regulates oxidative stress, lipid peroxidation and positively regulates cisplatin‐induced acute kidney injury, but its effect along with the alkaloid leonurine, found in motherwort, on ferroptosis after such acute kidney injury remains unclear. Experimental Approach: The anti‐ferroptotic effects of Nrf2 and leonurine were assessed in a mouse model of cisplatin‐induced acute kidney injury. In vitro, the effects of leonurine on erastin‐ and RSL3‐induced HK‐2 human PTEC ferroptosis were examined. Key Results: Nrf2 deletion induced ferroptosis‐related protein expression and iron accumulation in vivo, aggravating cisplatin‐induced acute kidney injury. Leonurine activated Nrf2 and prevented iron accumulation, lipid peroxidation and ferroptosis in vitro, being abolished in siNrf2‐treated cells. Moreover, leonurine potently inhibited cisplatin‐induced renal damage, as assessed by of serum creatinine, blood urea nitrogen, kidney injury molecule‐1 and NGAL. Importantly, leonurine activated the Nrf2 antioxidative pathway and preventing changes in ferroptosis‐related morphological and biochemical indicators, malondialdehyde level, SOD and GSH depletion, and GPX4 and xCT down‐regulation, in cisplatin‐induced acute kidney injury. Nrf2 KO mice were more susceptible to ferroptosis after cisplatin‐induced acute kidney injury than control mice. The protective effects of leonurine on acute kidney injury and ferroptosis were largely abolished in Nrf2 KO mice. Conclusion and Implications: These data suggest that renal protective effects of Nrf2 activation on cisplatin‐induced acute kidney injury are achieved, at least partially, by inhibiting lipid peroxide‐mediated ferroptosis, highlighting the potential of leonurine in acute kidney injury treatment. [ABSTRACT FROM AUTHOR]

Oxidative damage can lead to severe ovarian dysfunctions and even premature ovarian failure. Nrf2, a significant transcription factor that regulates the oxidative stress response of cells, declines with age. Daphnetin, as a kind of natural Chinese herbal medicine, can activate Nrf2 and further promote the antioxidant defense of cells. However, whether Daphnetin treatment can protect ovary from premature ovarian failure and the specific mechanism involved are not understood. This study aimed to investigate the protective function of Daphnetin against the ovarian aging induced by D-galactose in wild-type and Nrf2−/− mice. Female C57BL/6 mice with Wild-type and Nrf2−/− were divided into five groups separately and the premature ovarian failure model were established by D-galactose and then Daphnetin and VE were given for treatment. After 42 days, ovaries tissue and serum were collected for biochemical determination, H&E staining, Immunohistochemical staining and western blot analysis. In the WT-POF group, ovarian function was broke, and the expression of the ovarian senescence-associated protein P16 and the level of oxidative stress were significantly increased, while the expression of the anti-senescence protein klotho was significantly decreased. In addition, the expression of Nrf2 and the antioxidases GCLC, HO-1 and NQO1 were decreased, but TXNIP and NLRP3 were significantly increased. Furthermore, the characteristics of premature ovarian failure were more significant in Nrf2 knockout mice than in wild-type mice, especially the expression of NLRP3 and TXNIP. Moreover, daphnetin, an Nrf2 activator, rescued d-gal-induced POF in a dose-dependent manner, while the protective effect was weakened or even lost in Nrf2 knockout mice. Our results suggested that daphnetin is likely to be a candidate drug for premature ovarian failure treatment and it is mostly possible referred to the molecular mechanism of increasing Nrf2 expression and inhibiting NLRP3 activation in the ovarian aging process. [ABSTRACT FROM AUTHOR]

Superenhancer usages in single cancer form such as colorectal cancer (CRC) may provide novel efficient targeting candidates. It is unclear whether CRC contains recurrent superenhancers that confer a predisposition to malignancy. We investigated the superenhancer profile of CRC cell line HCT116 and compared it to that of a healthy sigmoid colon. We found that HCT116 had lost most of the normal colon superenhancer activities but gained a new set of tumor-favoring superenhancers that facilitate tumor proliferation, growth signalling, and hypoxia resistance. Inhibiting the superenhancers by JQ-1 treatment had significantly decreased the colony formation capability of HCT116. Then, by comparing the superenhancer genes and robust CRC upregulated genes, we identified a superenhancer associated with a common CRC upregulated oncogene, POU5f1B. POU5f1B overexpression is related to the worse outcome in CRCs. Via performing ChIP-PCR in 35 clinical samples and investigating CRC anti-H3K27ac ChiP-seq public dataset consisting of 36 samples, we further identified that the superenhancer of oncogene POU5F1B is recurrently activated in CRCs, taking 62 and 72 per cent, respectively. Moreover, JQ-1 treatment successfully inhibited the POU5F1B expression in 5 out of 6 POU5F1B superenhancer-positive samples. Therefore, we concluded that the superenhancer activation of POU5F1B contributes partially to its high expression in CRCs, in addition to the well-known gene amplification aetiology. [ABSTRACT FROM AUTHOR]

Human gastrointestinal malignancies are highly heterogeneous cancers. Clinically, heterogeneity largely contributes to tumor progression and resistance to therapy. Heterogeneity within gastrointestinal cancers is defined by molecular subtypes in genomic and transcriptomic analyses. Cancer stem cells (CSCs) have been demonstrated to be a major source of tumor heterogeneity; therefore, assessing tumor heterogeneity by CSC trait-guided classification of gastrointestinal cancers is essential for the development of effective therapies. CSCs share critical features with embryonic stem cells (ESCs). Molecular investigations have revealed that embryonic genes and developmental signaling pathways regulating the properties of ESCs or cell lineage differentiation are abnormally active and might be oncofetal drivers in certain tumor subtypes. Currently, multiple strategies allow comprehensive identification of tumor subtype-specific oncofetal signatures and evaluation of subtype-specific therapies. In this review, we summarize current knowledge concerning the molecular classification of gastrointestinal malignancies based on CSC features and elucidate their clinical relevance. We also outline strategies for molecular subtype identification and subtype-based therapies. Finally, we explore how clinical implementation of tumor classification by CSC subtype might facilitate the development of more effective personalized therapies for gastrointestinal cancers. [ABSTRACT FROM AUTHOR]

An urgent need exists to develop intra-arterial treatment for acute ischemic stroke in animal study. This study aimed to explore the beneficial effects of intra-arterial administration of human urinary kallidinogenase (HUK) on brain injury after permanent middle cerebral artery occlusion (pMCAO) in a rat model, and the potential underlying molecular mechanisms. Brain injury induced by pMCAO was evaluated through measuring neurological deficit scores, neuropathological changes, and inflammatory factors. Neurological deficits were observed 24 h after pMCAO and were alleviated by intra-arterial HUK treatment obviously. Inhibition of PI3K by LY294002 blocked the beneficial effect of HUK on neurological functions. In contrast to the pMCAO group, the intra-arterial HUK treatment group showed relatively more regularly arranged neurons and fewer pyknosis. Neurodegeneration, necrosis, infarct area and markers for brain injury were all ameliorated by intra-arterial HUK treatment. Moreover, a lower expression of inflammatory factors including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, and a higher expression of IL-10 were observed in the intra-arterial HUK treatment group than that in the pMCAO group. Additionally, when comparing with pMCAO group, a lower level of caspase-3, bax, and apoptotic rate, and a higher level of bcl-2, p-PI3K, p-AKT and p-FoxO1were observed in the pMCAO + HUK group. These results suggest that intra-arterial administration of HUK is a promising therapeutic strategy against pMCAO induced brain injury, and PI3K/AKT/FoxO1 signaling pathway may be involved in this process. [ABSTRACT FROM AUTHOR]

In the fission yeast, two Tor isoforms, Tor1 and Tor2, oppositely regulate gene expression of amino acid permeases. To elucidate the transcriptional machinery for these regulations, here we have employed the cap analysis of gene expression (CAGE), a method of analyzing expression profiles and identifying transcriptional start sites (TSSs). The loss of Tor1 decreased, and Tor2 inhibition by its temperature sensitive mutation increased, mRNA expression of isp5+, per1+, put4+ and SPBPB2B2.01. In contrast, the loss of Tor1 increased, and Tor2 inhibition decreased, the expression of cat1+. These changes were confirmed by semi-quantitative RT-PCR. These opposite effects by the loss of Tor1 and Tor2 inhibition appeared to occur evenly across multiple TSSs for the respective genes. The motif discovery analysis based on the CAGE results identified the GATA motifs as a potential cis-regulatory element for Tor-mediated regulation. In the luciferase reporter assay, the loss of Tor1 reduced, and Tor2 inhibition and nitrogen depletion increased, the activity of isp5+ promoter as well as that of a GATAAG reporter. One of the GATAAG motifs in isp5+ promoter was critical for its transcriptional activity, and a GATA transcription factor Gaf1 was critical for the activities of isp5+ promoter and the GATAAG reporter. Furthermore, Tor2 inhibition and nitrogen depletion induced nuclear localization of Gaf1 from the cytosol and its dephosphorylation. These results suggest that Tor2 inhibition, which is known to be induced by nitrogen depletion, promotes nuclear localization of Gaf1, thereby inducing isp5+ transcription through Gaf1 binding to the GATAAG motif in its promoter. Since Gaf1 was also critical for transcription of per1+ and put4+, Tor-Gaf1 signaling may coordinate transcription of multiple amino acid permeases according to nutrient availability. [ABSTRACT FROM AUTHOR]

The stress protein heme oxygenase-1 (HO-1) is upregulated and co-localizes to pathological features, including tauopathies in the brains of individuals with Alzheimer's disease. However, the relationship between HO-1 and Alzheimer's disease remains unclear. In our previous research, the long-term overexpression of HO-1 was shown to promote tau aggregation by inducing tau phosphorylation in the mouse brain. In this study, we found that the long-term overexpression of HO-1 led to cognitive decline in transgenic mice, as determined by the water maze test, and that HO-1 can affect two pathways for tauopathy. Through one pathway, HO-1 promotes the expression of CDK5 by accumulating reactive oxygen species, which are produced by HO-1 downstream products of iron in neuro2a cell lines and mouse brain. Through the second pathway, HO-1 induces tau truncation at D421 in vivo and in vitro. Clearly, there is a HO-1-dependent mechanism responsible for tau protein phosphorylation and tau truncation in vivo and in vitro. Taken together, our results suggest that HO-1 plays an important role in the disease process of tauopathies in AD. [ABSTRACT FROM AUTHOR]

DNA replication stress induces the transcriptional activation of rhp51+, a fission yeast recA homolog required for repair of DNA double strand breaks. However, the mechanism by which DNA replication stress activates rhp51+ transcription is not understood. The promoter region of rhp51+ contains two damage-responsive elements (DREs) and two MluI cell cycle box (MCB) motifs. Using luciferase reporter assays, we examined the role of these elements in rhp51+ transcription. The full-length rhp51+ promoter and a promoter fragment containing MCB motifs only, but not a fragment containing DREs, mediated transcriptional activation upon DNA replication stress. Removal of the MCB motifs from the rhp51+ promoter abolished the induction of rhp51+ transcription by DNA replication stress. Consistent with a role for MCB motifs in rhp51+ transcription activation, deletion of the MBF (MCB-binding factor) co-repressors Nrm1 and Yox1 precluded rhp51+ transcriptional induction in response to DNA replication stress. Using cells deficient in checkpoint signaling molecules, we found that the Rad3-Cds1/Chk1 pathway partially mediated rhp51+ transcription in response to DNA replication stress, suggesting the involvement of unidentified checkpoint signaling pathways. Because MBF is critical for G1/S transcription, we examined how the cell cycle affected rhp51+ transcription. The transcription of rhp51+ and cdc18+, an MBF-dependent G1/S gene, peaked simultaneously in synchronized cdc25-22 cells. Furthermore, DNA replication stress maintained transcription of rhp51+ similarly to cdc18+. Collectively, these results suggest that MBF and its regulators mediate rhp51+ transcription in response to DNA replication stress, and underlie rhp51+ transcription at the G1/S transition. [ABSTRACT FROM AUTHOR]

Background: FRAT1 positively regulates the Wnt/β-catenin signaling pathway by inhibiting GSK-3-mediated phosphorylation of β-catenin. It was originally characterized as a protein frequently rearranged in advanced T cell lymphoma, but has recently also been identified as a proto-oncogene involved in tumorigenesis. Our previous studies showed that FRAT1 was dramatically overexpressed in gliomas and its expression level was significantly increased along with clinicopathological grades. Methods: In the current study, we used RT-PCR and Western blotting to assess the mRNA and protein levels of FRAT1 in three glioma cell lines. In addition, to evaluate its functional role in gliomas, we examined the effects of FRAT1 knockdown on proliferation, migration and invasion in vitro and tumor growth in vivo using glioblastoma U251 cells and RNAi. Results: FRAT1 was highly expressed in all three glioma cell lines. RNAi-mediated down-regulation of endogenous FRAT1 in human glioblastoma U251 cells resulted in suppression of cell proliferation, arrest of cell cycle, inhibition of cell migration and invasion in vitro. Moreover, FRAT1 depletion significantly impaired tumor xenograft growth in nude mice. Conclusions: Our results highlight the potential role of FRAT1 in tumorigenesis and progression of glioblastoma. These findings provide a biological basis for FRAT1 as a potential molecular marker for improved pathological grading and as a novel candidate therapeutic target for glioblastoma management. [ABSTRACT FROM AUTHOR]

Cobalt is an essential micronutrient but is toxic when present in excess. To study cobalt homeostasis we performed a genome-wide screen for deletion strains that show sensitivity or resistance to CoCl. Among 54 cobalt-sensitive strains, 18 are supersensitive strains, which are involved in histidine biosynthetic process, ubiquitination, mitochondria function, membrane trafficking, transporter and a variety of other known functions or still unknown functions. Furthermore, we identified 56 cobalt-resistant deletion strains, which are mainly involved in mitochondria function, signal transduction, ubiquitination, and gene expression and chromatin remodeling. Notably, deletion of the zhf1 gene, encoding a zinc ion transporter, confers supersensitivity to cobalt and overexpression of the zhf1 gene confers marked tolerance to cobalt, indicating that Zhf1 play key roles in cobalt detoxification. Interestingly, all the histidine-auxotrophic mutants displayed cobalt sensitivity and deletion of cationic amino acid transporter Cat1, which was shown to be involved in histidine uptake, suppressed the CoCl-sensitive growth defect of the his2 mutants, suggesting that CoCl may be transported into the cell together with histidine via histidine transporters including Cat1. In addition, we obtained results suggesting that the E2 ubiquitin conjugating enzyme Rhp6 and Sty1 stress MAP kinase pathway are involved in the regulation of cobalt homeostasis. Altogether, our genome-wide study demonstrates for the first time the mechanisms of cobalt homeostasis, particularly its uptake and detoxification in fission yeast. [ABSTRACT FROM AUTHOR]

Abstract: MicroRNAs (miRNAs) are endogenous noncoding RNAs that downregulate gene expression by inhibiting translation or promoting mRNA degradation. Although over one-third of miRNAs are located within the intronic regions of transcription units, the expression of such “intron-derived” (or “intronic”) miRNAs and their relationship with their host gene remain a mystery. Here, we show that miR-483-5p, which is located within the second intron of the insulin-like growth factor (Igf2) gene, is downregulated in mouse Hepa1–6 cells in a direct correlation with the Igf2 transcript by chromeceptin, an inhibitor of Igf2 at the transcriptional level. Furthermore, miR-483-5p overexpression and knockdown regulates the suppressor of cytokine signalling 3 (Socs3) and Igf2 mRNAs, respectively. Finally, Socs3, a key putative leptin-resistant factor in obesity, is identified as a direct target of miR-483-5p. These data suggest that miR-483-5p can be coexpressed together with its host gene, Igf2, and revealed the link between this miRNA and the IGF2 growth factor. In addition, these observations not only provide supporting evidence for the codependent expression of intronic miRNAs and their host genes in vitro, but also give insight into the role of miR-483-5p in metabolism regulation and tumourigenesis. [ABSTRACT FROM AUTHOR]

In this study, caffeic acid-graft-chitosan/polylactic acid (CA-g-CS/PLA) packaging was shown to be effective in enhancing the storage stability of postharvest Agaricus bisporus, and its regulatory pathway was further elucidated. Results showed that expression levels of essential genes in the mitogen-activated protein kinase (MAPK) signaling pathway such as Sho1 , Ssk2 , Pbs2 , and Hog1 were upregulated in CA-g-CS/PLA packaging group. Furthermore, the accumulation of stress-resistant compounds was promoted by the packaging. Glycerol, γ-aminobutyric acid (GABA), proline, and glutamate were 2.6, 2, 1.4, and 2.3 times higher respectively than the PE group at the end of storage and their associated metabolic enzyme activities were promoted, similarly. Moreover, through correlation analysis, the pathway was shown to be related to the synthesis of stress-resistant compounds. These findings indicated that CA-g-CS/PLA packaging acted synergistically through both the synthesis of stress-resistant compounds and regulation of the MAPK signaling pathway to delay quality deterioration of postharvest A. bisporus. [Display omitted] • Caffeic acid grafted chitosan/polylactic acid (CA-g-CS/PLA) is applied for packaging. • CA-g-CS/PLA regulates the MAPK signaling pathway in A. bisporus. • CA-g-CS/PLA promotes the synthesis of stress-resistant compounds in A. bisporus. • CA-g-CS/PLA maintains the storage stability of postharvest A. bisporus. [ABSTRACT FROM AUTHOR]

Diabetic cardiomyopathy represents severe heart complications, and is the leading cause of morbidity and mortality among patients with diabetes. Although a few microRNAs (miRNAs) have been implicated in diabetes-related complications, a functional association between miRNAs and cardiac dysfunction in diabetic cardiomyopathy remains to be demonstrated. Our results show that miR-483-3p is upregulated in streptozotocin-induced diabetic mice, and cultured cardiomyocytes mimicking hyperglycemia. Overexpressing miR-483-3p in transgenic mice with diabetes mellitus (DM) exacerbated cardiomyocyte apoptosis by transcriptionally repressing insulin growth factor 1 (IGF1). Therefore, we have uncovered a novel signaling pathway, involving miR-483-3p-IGF1, that promotes myocardial cell apoptosis under high blood-glucose condition. Further, our study indicates that miR-483-3p could be a potential therapeutic target for managing diabetes-associated heart complications. [ABSTRACT FROM AUTHOR]