ABSTRACT
Elevated levels of NEFA caused by negative energy balance in transition cows induce cellular dyshomeostasis. Ubiquitin-like modifier 1 ligating enzyme 1 (UFL1) can maintain cellular homeostasis and act as a critical regulator of stress responses besides functioning in the ubiquitin-like system. The objective of this study was to elucidate the UFL1 working mechanism on promoting cellular adaptations in bovine mammary epithelial cells (BMECs) in response to NEFA challenge, with an emphasis on the ER and mitochondrial function. The results showed that exogenous NEFA and UFL1 depletion resulted in the disorder of ER and mitochondrial homeostasis and the damage of BMEC integrity, overexpression of UFL1 effectively alleviated the NEFA-induced cellular dyshomeostasis. Mechanistically, our study found that UFL1 had a strong interaction with IRE1α and could modulate the IRE1α/XBP1 pathway of unfolded protein response in NEFA-stimulated BMECs, thereby contributing to the modulation of cellular homeostasis. These findings imply that targeting UFL1 may be a therapeutic alternative to relieve NEB-induced metabolic changes in perinatal dairy cows.
Subject(s)
Endoplasmic Reticulum , Endoribonucleases , Epithelial Cells , Homeostasis , Mammary Glands, Animal , Mitochondria , Protein Serine-Threonine Kinases , Signal Transduction , X-Box Binding Protein 1 , Animals , Cattle , Mitochondria/metabolism , Mitochondria/drug effects , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Epithelial Cells/metabolism , Epithelial Cells/drug effects , Epithelial Cells/pathology , Female , Mammary Glands, Animal/metabolism , Mammary Glands, Animal/cytology , Mammary Glands, Animal/pathology , Mammary Glands, Animal/drug effects , Endoribonucleases/metabolism , Endoribonucleases/genetics , X-Box Binding Protein 1/metabolism , X-Box Binding Protein 1/genetics , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/drug effects , Signal Transduction/drug effects , Unfolded Protein Response/drug effects , 3-Hydroxybutyric Acid/pharmacology , 3-Hydroxybutyric Acid/metabolism , Endoplasmic Reticulum Stress/drug effectsABSTRACT
Because the complexity of the external environment has put great pressure on the agricultural economy, making it vulnerable, it is necessary to promote a system of resilience in the agricultural economy so that Chinese agriculture can continue to persevere in the face of serious external uncertainties. Therefore, this paper investigates the spatio-temporal pattern and evolution of the distributional dynamics of China's county-level agricultural economic resilience based on 2000-2020 data covering 2,545 counties. The results are as follows: first, from 2000 to 2020, the mean value of China's county-level agricultural economic resilience showed an obvious upward trend, which indicates that China's agricultural economy gradually increased its ability to resist risks and continued to develop in a favourable manner. Specifically, the county-level agricultural economic resilience index of the northeast region grew the most significantly, while the index of county units in the western region was relatively low. Second, the centre of gravity of the spatial distribution of China's agricultural economic resilience gradually migrated to the northwest, showing a dominant direction from northeast to southwest and a tendency to develop from southeast to northwest. Third, the spatial differences in China's agricultural economic resilience generally showed an upward trend, while county-level differences were the main source of the overall differences, followed by inter-provincial differences, inter-municipal differences and inter-regional differences. Additionally, the contribution of county-level differences to the overall differences fluctuated within the range of 54%-58%. Fourth, there is a possibility of localized convergence in China's agricultural economic resilience, which is continuous in spatial effects and has obvious positively correlated spatial effects at different times and in different county spaces.
Subject(s)
Agriculture , Spatio-Temporal Analysis , China , Agriculture/economics , Humans , Economic DevelopmentABSTRACT
A precise investigation of NbO has been carried out by advanced electron microscopy combined with powder and single crystal X-ray diffraction (XRD). The structure of pristine NbO has been determined as Pm-3â m space group (SG) with a = 4.211â Å and the positions of Nb and O at the 3c and 3d Wyckoff positions, respectively, which is consistent with previous report based on powder XRD data. Electron beams induced a structural transition, which was investigated and explained by combining electron diffraction and atomic-resolution imaging. The results revealed that the electron beam stimulated both Nb and O atom-migrations within each fcc sublattice, and that the final structure was SG Fm-3â m with a = 4.29â Å, Nb and O at the 4a and 4b with 75 % occupancy and same chemical composition. Antiphase planar defects were discovered in the pristine NbO and related to the structural transformation. Theoretical calculations performed by density functional theory (DFT) supported the experimental conclusions.
Subject(s)
Electrons , Niobium , Niobium/chemistry , Powders , Crystallography, X-Ray , Microscopy, ElectronABSTRACT
There are many treatments for nasopharyngeal carcinoma (NPC), but none of them are very effective. Radiotherapy is used extensively in NPC treatment, but radioresistance is a major problem. Graphene oxide (GO) has been previously studied in cancer treatment, and this study is aimed to explore its role in radiosensitization of NPC. Therefore, graphene oxide nanosheets were prepared, and the relationship between GO and radioresistance was explored. The GO nanosheets were synthesized by a modified Hummers' method. The morphologies of the GO nanosheets were characterized by field-emission environmental scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphological changes and radiosensitivity of C666-1 and HK-1 cells with or without the GO nanosheets were observed by an inverted fluorescence microscopy and laser scanning confocal microscopy (LSCM). Colony formation assay and Western Blot were applied for analysis of NPC radiosensitivity. The as-synthesized GO nanosheets have lateral dimensions (sizes â¼1 µm) and exhibit a thin wrinkled two-dimensional lamellar structure with slight folds and crimped edges (thickness values â¼1 nm). C666-1 cells with the GO was significantly changed the morphology of cells postirradiation. The full field of view visualized by a microscope showed the shadow of dead cells or cell debris. The synthesized graphene oxide nanosheets inhibited cell proliferation, promoted cell apoptosis, and inhibited the expression of Bcl-2 in C666-1 and HK-1 cells but increased the level of Bax. The GO nanosheets could affect the cell apoptosis and reduce the pro-survival protein Bcl-2 related to the intrinsic mitochondrial pathway. The GO nanosheets could enhance radiosensitivity, which might be a radioactive material in NPC cells.
Subject(s)
Graphite , Nasopharyngeal Neoplasms , Humans , Graphite/pharmacology , Graphite/chemistry , Microscopy, Electron, Transmission , Nasopharyngeal Carcinoma/metabolism , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Neoplasms/radiotherapy , Nasopharyngeal Neoplasms/metabolism , Nasopharyngeal Neoplasms/pathologyABSTRACT
Non-esterified fatty acids (NEFA) and ß-hydroxybutyrate (BHBA) are the metabolites of fat mobilization initiated by negative energy balance (NEB) during the perinatal period in dairy cows, which have an adverse effect on cell physiology of various bovine cell types. The aim of this study was to explore the biological roles of NEFA and BHBA on provoking oxidative stress and inflammatory responses in bovine mammary epithelial cells (BMECs). RNA sequencing analysis showed that there are 1343, 48, and 1725 significantly differentially expressed genes (DEGs) in BMECs treated with NEFA, BHBA and their combination. GO functional analysis revealed that the DEGs were significantly enriched in "response to oxidative stress" and "inflammatory response". Further study demonstrated that NEFA and BHBA elevated the malondialdehyde (MDA) and reactive oxygen species (ROS) accumulation and reduced the total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activity to cause oxidative stress. In addition, expression of inflammatory markers (NO, TNF-α, IL-6, and IL-1ß) were increased after NEFA and BHBA stimulation. Mechanistically, our data showed that NEFA and BHBA activated the MAPK signaling pathway. Collectively, our results indicate that NEFA and BHBA induce oxidative stress and inflammatory response probably via the MAPK signaling pathway in BMECs.
ABSTRACT
Herein, we show how electron microscopy can provide atomic-level understanding of FAPbBr3, where electron diffraction and high-resolution imaging were combined allowing not only the characterization of the pristine material but also the identification of different intermediates upon its structural disintegration. Additionally, a minor tetragonal phase was also identified whose structure was also solved.
ABSTRACT
Elevated concentrations of non-esterified fatty acid (NEFA) induced by negative energy balance (NEB) during the transition period of dairy cows is known to be toxic for multiple bovine cell types. However, the effect of NEFA in bovine mammary epithelial cells (BMECs) remains unclear. The present study aimed to explore the role and molecular mechanism of NEFA in endoplasmic reticulum (ER) stress and the subsequent apoptosis in BMECs. The results showed that NEFA increased ER stress and activated the three unfolded protein response (UPR) signaling sub-pathways by upregulating the expression of GRP78, HSP70, XBP1, ATF6, phosphor-PERK, and phosphor-IRE1α. We also found that NEFA dose-dependently induced apoptosis in BMECs, as indicated by flow cytometry analysis and increased apoptotic gene expression. RNA-seq analysis revealed that NEFA induced apoptosis in BMECs, probably via the ATF4-CHOP axis. Mechanistically, our data showed that NEFA increased reactive oxygen species (ROS) levels, resulting in the activation of the MAPK signaling pathway. Moreover, quercetin, a well-known antioxidant, was found to alleviate ER stress-mediated apoptosis in NEFA-treated BMECs. Collectively, our results suggest that NEFA induces ER stress-mediated apoptosis, probably via the ROS/MAPK signaling pathway, as quercetin has been shown to alleviate ER stress-mediated apoptosis in NEFA-treated BMECs.
ABSTRACT
Mechanistic target of rapamycin complex 2 (mTORC2) is a multi-subunit kinase complex, central to multiple essential signaling pathways. Two core subunits, Rictor and mSin1, distinguish it from the related mTORC1 and support context-dependent phosphorylation of its substrates. mTORC2 structures have been determined previously; however, important questions remain, particularly regarding the structural determinants mediating substrate specificity and context-dependent activity. Here, we used cryo-EM to obtain high-resolution structures of the human mTORC2 apo-complex in the presence of substrates Akt and SGK1. Using functional assays, we then tested predictions suggested by substrate-induced structural changes in mTORC2. For the first time, we visualized in the apo-state the side chain interactions between Rictor and mTOR that sterically occlude recruitment of mTORC1 substrates and confer resistance to the mTORC1 inhibitor rapamycin. Also in the apo-state, we observed that mSin1 formed extensive contacts with Rictor via a pair of short α-helices nestled between two Rictor helical repeat clusters, as well as by an extended strand that makes multiple weak contacts with Rictor helical cluster 1. In co-complex structures, we found that SGK1, but not Akt, markedly altered the conformation of the mSin1 N-terminal extended strand, disrupting multiple weak interactions while inducing a large rotation of mSin1 residue Arg-83, which then interacts with a patch of negatively charged residues within Rictor. Finally, we demonstrate mutation of Arg-83 to Ala selectively disrupts mTORC2-dependent phosphorylation of SGK1, but not of Akt, supporting context-dependent substrate selection. These findings provide new structural and functional insights into mTORC2 specificity and context-dependent activity.
Subject(s)
Immediate-Early Proteins , Monomeric GTP-Binding Proteins , Protein Serine-Threonine Kinases , Proto-Oncogene Proteins c-akt , Rapamycin-Insensitive Companion of mTOR Protein , Humans , Immediate-Early Proteins/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Monomeric GTP-Binding Proteins/metabolism , Phosphorylation , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Rapamycin-Insensitive Companion of mTOR Protein/genetics , Rapamycin-Insensitive Companion of mTOR Protein/metabolism , Sirolimus/pharmacology , Transcription Factors/metabolismABSTRACT
Mastitis, an inflammation of the mammary gland, is a complex disease that affects the health of dairy cows worldwide. Sodium butyrate (SB) is a short-chain fatty acid that has recently been shown to have antioxidant, anti-inflammatory and anti-apoptotic potential in various cells types, although its role in bovine mammary epithelial cells (bMECs) has not been comprehensively reported. Therefore, the aim of this study was to assess the protective effect of sodium butyrate on Lipopolysaccharide (LPS)-induced mastitis model in vitro and to elucidate the possible underlying molecular mechanisms. The in vitro mastitis model was designed to investigate the regulatory effect of SB on LPS-induced inflammatory conditions in bMECs, with particular emphasis on oxidative stress, inflammatory response, apoptosis, and mitochondrial dysfunction. The results showed that SB co-treatment markedly prevented LPS-induced death of bMECs in a concentration-dependent manner. In addition, SB attenuated LPS-induced oxidative stress (OS) (Increased Intracellular ROS, MDA, and decreased SOD, GSH-Px and CAT activity), thereby reduced inflammation (increased expression of IL-6, IL-Iß, and TNF-α), and apoptosis (Increased the expression of caspases and Bax and decreased Bcl-2) via inhibiting NF-kB and caspase/bax signaling pathways. Furthermore, the protective effect of SB was also associated with the activation of endogenous antioxidant system (Nrf2, Keap1, NQO-1 and HO-1). Nrf2 silencing significantly abolished the protective effect of SB on bMECs. In conclusion, our findings suggest that SB has a significant protective effect on LPS-induced OS, inflammatory responses and apoptosis by activating Nrf2 and inhibiting NF-kB and ROS-mediated mitochondrial dysfunction. These results propose that SB may be an important regulator of OS and its subsequent inflammatory responses, and thus could be used as a therapeutic agent for bovine mastitis.
Subject(s)
Lipopolysaccharides , Mastitis , Animals , Apoptosis , Butyric Acid/metabolism , Butyric Acid/pharmacology , Butyric Acid/therapeutic use , Caspases/metabolism , Cattle , Epithelial Cells/metabolism , Female , Humans , Inflammation/drug therapy , Inflammation/metabolism , Kelch-Like ECH-Associated Protein 1/metabolism , Lipopolysaccharides/pharmacology , Mastitis/metabolism , NF-E2-Related Factor 2/metabolism , NF-kappa B/metabolism , Oxidative Stress , Reactive Oxygen Species/metabolism , bcl-2-Associated X Protein/metabolismABSTRACT
Considering the differences in cognitive aging among older adults, this study examined how older adults process different types of graphic icons in visual search tasks. Fifty-four medical-related icons, including flat icons (FIs), FIs plus text (FIs + text), skeuomorphic icons (SIs), and SIs plus text (SIs + text), were created. The participants were divided into two groups-cognitively normal (CN) and mild cognitive impairment (MCI)-to complete a visual search task. According to the eye-tracking data of the participants, the search performance of the CN group was significantly better than that of the MCI group. In terms of icon types, all older adults performed better at searching for the combinations of icon and text, especially SI + text, which showed the smallest difference in the search performance between the MCI and CN groups. All older adults performed poorly when searching for FIs. The findings of this study considered the differences in cognitive aging among older adults and provided a useful reference for the icon and interface design of graphical user interfaces.
Subject(s)
Cognitive Aging , Cognitive Dysfunction , Aged , Aging/psychology , HumansABSTRACT
The biological functions of exosomes and microRNAs (miRs) in nasopharyngeal carcinoma (NPC) remain largely unexplored. Here, miR-197-3p was screened and identified, and whose level was reduced in serum and exosomes of patients with NPC. MiR-197-3p might be a good diagnostic and prognostic indicator. Our data showed that miR-197-3p expression was closely related to radioresistance, apoptosis, proliferation, migration, and survival of NPC. Inhibition of miR-197-3p expression in vitro could promote the proliferation and migration of NPC cells, while promotion of miR-197-3p expression in vivo could significantly inhibit the growth and enhance the radiosensitivity of NPC cells. From the perspective of mechanism, miR-197-3p could inhibit AKT/mTOR phosphorylation activation, inhibit an activated pathway of AKT/mTOR, target Heat Shock 70-kDa Protein 5(HSPA5) related to endoplasmic reticulum homeostasis, inhibit HSPA5-mediated autophagy, and reverse the radioresistance of NPC. Interestingly, exosomal miR-197-3p (EXO-miR-197-3p) reduced the proliferation and migration potential of NPC cells in vitro, and tumor growth and radioresistance of NPC cells in vivo. EXO-miR-197-3p inhibited NPC progression and radioresistance by regulating AKT/mTOR phosphorylation activation and HSPA5-mediated autophagy. In conclusion, our results highlight the potential of EXO-miR-197-3p as an effective radiosensitizer and therapeutic agent for refractory NPC.
Subject(s)
MicroRNAs , Nasopharyngeal Neoplasms , Radiation-Sensitizing Agents , Autophagy/genetics , Cell Line, Tumor , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Nasopharyngeal Carcinoma/genetics , Nasopharyngeal Carcinoma/radiotherapy , Nasopharyngeal Neoplasms/genetics , Nasopharyngeal Neoplasms/metabolism , Nasopharyngeal Neoplasms/radiotherapy , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolismABSTRACT
Oxidative stress is the downstream of various adverse stresses which impairs meat quality of broiler chickens. Yet, the specific molecular mechanisms of oxidative stress in meat quality of broiler thigh muscle remains unclear. This study investigated the effects and mechanisms of H2O2-induced oxidative stress on meat quality of broiler thigh muscle, with particular emphasis on apoptosis and autophagy and the ROS/NF-κB signaling pathway. The results showed that 10%H2O2-treated broilers exhibited significantly higher drip loss and shear force and lower pH24h and muscle weight. Moreover, the ROS formation, the contents of oxidation products, the expressions of caspases (3, 6, 8, 9), Beclin1, and LC3-II/LC3-I were significantly increased, whereas the levels of antioxidation products and the expression of phosphorylation of NF-κBp65 were significantly decreased. These findings from the present study indicating that H2O2-induced oxidative stress significantly impaired the meat quality by inducing apoptosis and abnormal autophagy via ROS/NF-κB signaling pathway in the broiler thigh muscle.
Subject(s)
Chickens , Hydrogen Peroxide , Meat , Muscle, Skeletal , NF-kappa B , Animals , Apoptosis/drug effects , Autophagy/drug effects , Hydrogen Peroxide/pharmacology , Meat/analysis , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , NF-kappa B/metabolism , Oxidative Stress/drug effects , Reactive Oxygen Species/metabolism , Signal Transduction , ThighABSTRACT
MOTIVATION: Cryo-electron microscopy (cryo-EM) is a widely used technology for ultrastructure determination, which constructs the 3D structures of protein and macromolecular complex from a set of 2D micrographs. However, limited by the electron beam dose, the micrographs in cryo-EM generally suffer from the extremely low signal-to-noise ratio (SNR), which hampers the efficiency and effectiveness of downstream analysis. Especially, the noise in cryo-EM is not simple additive or multiplicative noise whose statistical characteristics are quite different from the ones in natural image, extremely shackling the performance of conventional denoising methods. RESULTS: Here, we introduce the Noise-Transfer2Clean (NT2C), a denoising deep neural network (DNN) for cryo-EM to enhance image contrast and restore specimen signal, whose main idea is to improve the denoising performance by correctly learning the noise distribution of cryo-EM images and transferring the statistical nature of noise into the denoiser. Especially, to cope with the complex noise model in cryo-EM, we design a contrast-guided noise and signal re-weighted algorithm to achieve clean-noisy data synthesis and data augmentation, making our method authentically achieve signal restoration based on noise's true properties. Our work verifies the feasibility of denoising based on mining the complex cryo-EM noise patterns directly from the noise patches. Comprehensive experimental results on simulated datasets and real datasets show that NT2C achieved a notable improvement in image denoising, especially in background noise removal, compared with the commonly used methods. Moreover, a case study on the real dataset demonstrates that NT2C can greatly alleviate the obstacles caused by the SNR to particle picking and simplify the identifying of particles. AVAILABILITYAND IMPLEMENTATION: The code is available at https://github.com/Lihongjia-ict/NoiseTransfer2Clean/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Subject(s)
Algorithms , Neural Networks, Computer , Cryoelectron Microscopy/methods , Signal-To-Noise Ratio , Proteins , Image Processing, Computer-Assisted/methodsABSTRACT
BACKGROUND: Regulation of the endoplasmic reticulum (ER) stress pathway is critical to mammary epithelial cell function throughout pregnancy, lactation, and involution. Treatment with trans-10, cis-12 conjugated linoleic acid (t10c12CLA) suppresses mammary lipogenesis and stimulates the ER stress pathway. The ER stress pathway includes tribbles pseudokinase 3 (TRB3), a protein that regulates cellular energy and insulin signaling. OBJECTIVES: Our objective was to describe the effect of TRB3 deficiency on milk fat synthesis and determine if TRB3 deficiency protects against suppression of mammary lipogenesis. METHODS: First, mammary Trb3 expression was observed throughout pregnancy and lactation using ancillary microarray data (n = 4/time point). Second, intake, litter growth, and milk clot fatty acid (FA) profile of Trb3 knockout (KO) C57BL/6N mice were compared with wild-type (WT) and heterozygous (HET) mice throughout first (n ≥ 8/group) and second (n ≥ 6/group) lactation. Lastly, the interaction between Trb3 genotype and 2 treatments that suppress mammary lipogenesis, t10c12CLA and high safflower oil (HO) diet, was investigated in a 2 × 2 factorial design (n ≥ 6/group). RESULTS: Trb3 expression was higher during late pregnancy and lactation. Trb3 KO and HET mice had lower feed intake, dam weight, and litter growth throughout first, but not second, lactation than WT mice. Treatment with t10c12CLA decreased litter growth (28%; P < 0.0001) and feed intake (8%; P < 0.0001) regardless of Trb3 genotype. When fed the HO diet, Trb3 KO mice had 17% higher mammary de novo synthesized FAs (<16 carbons; P int = 0.002) than WT mice. Mammary ER stress and lipogenic genes were mostly unaltered by Trb3 deficiency. CONCLUSIONS: Overall, TRB3 plays a minor role in regulating mammary lipogenesis, because Trb3 deficiency had only a limited protective effect against diet-induced suppression of lipogenesis.
ABSTRACT
(1) Objective: Sleep problems have become one of the current serious public health issues. The purpose of this research was to construct an ideal pressure distribution model for head and neck support through research on the partitioned support surface of a pillow in order to guide the development of ergonomic pillows. (2) Methods: Seven typical memory foam pillows were selected as samples, and six subjects were recruited to carry out a body pressure distribution experiment. The average value of the first 10% of the samples in the comfort evaluation was calculated to obtain the relative ideal body pressure distribution matrix. Fuzzy clustering was performed on the ideal matrix to obtain the support surface partition. The ideal body pressure index of each partition was calculated, and a hierarchical analysis of each partition was then performed to determine the pressure sensitivity weight of each partition. Using these approaches, the key ergonomic node coordinates of the partitions of four different groups of people were extracted. The ergonomic node coordinates and the physical characteristics of the material were used to design a pillow prototype. Five subjects were recruited for each of the four groups to repeat the body pressure distribution experiment to evaluate the pillow prototype. (3) Results: An ideal support model with seven partitions, including three partitions in the supine position and four partitions in the lateral position, was constructed. The ideal body pressure distribution matrix and ideal body pressure indicators and pressure sensitivity weights for each partition were provided. The pillow that was designed and manufactured based on this model reproduced the ideal pressure distribution matrix evaluated by various groups of people. (4) Conclusion: The seven-partition ideal support model can effectively describe the head and neck support requirements of supine and lateral positions, which can provide strong support for the development of related products.
ABSTRACT
UFL1 is an ufmylation (a novel post-translational modification) E3 ligase, mainly located in the endoplasmic reticulum (ER), that has emerged as a significant regulator of several physiological and pathological processes. Yet its physiological function in milk synthesis in bovine mammary epithelial cells (BMECs) remains unknown. In this study, we investigated the effects of UFL1 in milk protein and fat synthesis-related gene expression, with a particular emphasis on the role of UFL1 in LPS-treated BMECs. Results showed that UFL1 depletion significantly reduced the expression of milk protein and fat synthesis-related gene and mTOR phosphorylation in both normal and LPS-treated BMECs. Overexpression of UFL1 enhanced the activation of the mTOR and milk protein and fat synthesis-related gene expression. Collectively, these above results strongly demonstrate that UFL1 could regulate milk protein and fat synthesis-related gene expression of BMECs probably via the mTOR signaling pathway.
Subject(s)
Glycolipids/biosynthesis , Glycoproteins/biosynthesis , Mammary Glands, Animal/metabolism , Milk Proteins/biosynthesis , Signal Transduction , TOR Serine-Threonine Kinases/metabolism , Ubiquitin-Protein Ligases/physiology , Animals , Cattle , Epithelial Cells/metabolism , Female , Flow Cytometry , Gene Expression Regulation , Lipid Droplets , Mammary Glands, Animal/cytology , Real-Time Polymerase Chain Reaction , Ubiquitin-Protein Ligases/metabolismABSTRACT
The purpose of this study was to assess the effects of acetate and ß-hydroxybutyrate alone or in combination on lipogenic genes and their associated regulatory proteins in dairy cow mammary epithelial cells (DCMEC) using quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, lipid droplet staining and a triglyceride content detection kit, to determine whether SCFA are related to milk fat synthesis regulation in DCMEC. Our experiment shows that addition of different concentrations of acetate, ß-hydroxybutyrate and their combinations to DCMEC increase in relative mRNA abundance of lipogenic genes and key transcription factors suggest an increase in lipogenic capacity, which is supported by an increased in cytosolic triglyceride content. Similarly, the protein expression level of acetyl-coenzyme A carboxylase (ACACA), fatty acid synthase (FASN) and sterol-coenzyme desaturase-1 (SCD1) genes and the transcription factor sterol regulatory element-binding protein-1 (SREBP1) were found to be increased by addition of acetate, ß-hydroxybutyrate and their combinations. The expression pattern of fat-related genes and proteins showed similar trends in almost all treatments, suggesting that common transcription factor are regulating these genes. These results show that acetate and ß-hydroxybutyrate regulate fat synthesis, further confirming that SCFAs work by targeting genes to activate the SREBP1 and insulin-induced gene 1 protein (INSIG1) signalling pathways in DCMEC.
Subject(s)
3-Hydroxybutyric Acid/pharmacology , Acetates/pharmacology , Epithelial Cells/metabolism , Gene Expression Regulation/drug effects , Lipid Droplets/metabolism , Lipogenesis/genetics , Mammary Glands, Animal/cytology , Triglycerides/metabolism , Animals , Cattle , Cell Survival/drug effects , Cell Survival/genetics , Dairying , Fatty Acids/biosynthesis , Female , Lipogenesis/drug effects , Milk/metabolism , Staining and LabelingABSTRACT
Nucleosomes are dynamic entities with wide-ranging compositional variations. Human histone variants H2A.B and H2A.Z.2.2 play critical roles in multiple biological processes by forming unstable nucleosomes and open chromatin structures, but how H2A.B and H2A.Z.2.2 confer these dynamic features to nucleosomes remains unclear. Here, we report cryo-EM structures of nucleosome core particles containing human H2A.B (H2A.B-NCP) at atomic resolution, identifying large-scale structural rearrangements in the histone octamer in H2A.B-NCP. H2A.B-NCP compacts approximately 103 bp of DNA wrapping around the core histones in approximately 1.2 left-handed superhelical turns, in sharp contrast to canonical nucleosome encompassing approximately 1.7 turns of DNA. Micrococcal nuclease digestion assay reveals that nineteen H2A.B-specific residues, including a ROF ("regulating-octamer-folding") sequence of six consecutive residues, are responsible for loosening of H2A.B-NCPs. Unlike H2A.B-NCP, the H2A.Z.2.2-containing nucleosome (Z.2.2-NCP) adopts a less-extended structure and compacts around 125 bp of DNA. Further investigation uncovers a crucial role for the H2A.Z.2.2-specific ROF in both H2A.Z.2.2-NCP opening and SWR1-dependent histone replacement. Taken together, these first high-resolution structure of unstable nucleosomes induced by histone H2A variants elucidate specific functions of H2A.B and H2A.Z.2.2 in enhancing chromatin dynamics.
Subject(s)
Histones/metabolism , Nucleosomes/metabolism , Amino Acid Sequence , Chromatin/metabolism , Chromatin Assembly and Disassembly/physiology , DNA/metabolism , Humans , Models, Molecular , Protein Binding/physiologyABSTRACT
In the perinatal period of dairy cows, negative energy balance (NEB) is likely to occur, which increases the level of non-esterified fatty acids (NEFA) in the follicular fluid, hinders the proliferation of granulosa cells (GCs), and thus endangers the development of oocytes and the fecundity of dairy cows. We found that there were oxidative stress and inflammatory response in the serum of cows with perinatal ketosis. Whether the oxidative stress induced by NEFA is involved in the pyroptosis and inflammation of GCs remains unclear. After NEFA treatment, the expression of NLRP3 and caspase-1 and the release of inflammatory cytokines IL-1ß were increased in a dose-dependent manner, indicating that NEFA may contribute to pyroptosis. Besides, NEFA stimulation induced oxidative stress, resulting in the phosphorylation of NF-κB, and increased the production of interleukin (IL)-6 and nitric oxide (NO), indicating that NEFA may induce inflammation in GCs. However, the NEFA-mediated effects were observably reversed when the GCs were pre-treated with antioxidant and radical scavenger, N-acetylcysteine (NAC). Taken together, our results reveal that NEFA can induce pyroptosis and inflammation through NLRP3 inflammasome and TLR4/NF-κB pathway, respectively, and NAC can alleviate these conditions.
Subject(s)
Acetylcysteine/pharmacology , Fatty Acids, Nonesterified/toxicity , Granulosa Cells/pathology , Inflammation/pathology , Pyroptosis/drug effects , Animals , Cattle , Cell Survival/drug effects , Female , Granulosa Cells/drug effects , Inflammation Mediators/metabolism , Ketosis/pathology , Models, Biological , Oxidation-Reduction/drug effects , Oxidative Stress/drug effects , Up-Regulation/drug effectsABSTRACT
Ubiquitin-like modifier 1 ligating enzyme 1 (UFL1) has been characterized as a ubiquitin-like (Ubl) protein that affects a range of cellular processes across various pathways. In this study, mouse mammary epithelial cells (HC11 cell line) and UFL1 knockout (KO) mice were used to establish UFL1 knockdown models to explore the influence of UFL1 on milk protein and fat synthesis in the mouse mammary gland and the underlying mechanisms. This is the first study to show UFL1 localization in mouse mammary epithelial cells. UFL1 depletion by transfected UFL1 siRNA (siUFL1) caused aggravated apoptosis. In addition, UFL1 depletion suppressed milk protein synthesis-related protein level in vivo and in vitro. Conversely, ACACA and FASN expressions increased in UFL1-deficient mice. Moreover, UFL1 depletion increased triglyceride synthesis levels and inhibited the p-JNK expression. Importantly, the expression of proteins related to milk protein synthesis was decreased in JNK- and UFL1-deficient cells, whereas proteins related to milk fat synthesis showed the opposite trend, indicating that UFL1 affects milk protein and fat synthesis via the suppression of JNK activation. Overall, our findings indicate that UFL1 plays a key role in mammary milk and fat synthesis via JNK activation.