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1.
Exp Cell Res ; 439(1): 114090, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38740167

ABSTRACT

Dopamine D2 receptors (D2Rs) play crucial roles in regulating diverse physiological functions of the central nervous system and peripheral organs. D2Rs are also expressed in mammary glands. However, which cell types express D2Rs and whether they are involved in milk production remains unclear. The present findings revealed that D2Rs are expressed in the apical regions of the lateral membranes of mammary epithelial cells (MECs) in lactating mice. We also investigated the effects of the D2R agonist bromocriptine and/or antagonist domperidone on intracellular cAMP levels, milk protein production, and apoptosis in a lactation culture model of MECs that produce major milk components like lactating MECs in vivo. We found that bromocriptine decreased intracellular cAMP levels, whereas domperidone dose-dependently neutralized this effect. Bromocriptine also inhibited casein and lactoferrin production and suppressed activities of STAT5 and glucocorticoid receptors (GRs). Domperidone neutralized the inhibition of casein production as well as STAT5 and GR inactivation induced by bromocriptine. Furthermore, D2R activation by bromocriptine induced apoptosis and inactivated ERK, a signaling molecule responsible for promoting cell proliferation and survival. Domperidone attenuated ERK inactivation and apoptosis induced by bromocriptine. These findings suggest that D2Rs play regulatory roles in milk protein production and apoptosis in MECs.


Subject(s)
Apoptosis , Bromocriptine , Domperidone , Epithelial Cells , Lactation , Mammary Glands, Animal , Milk Proteins , Receptors, Dopamine D2 , Animals , Female , Mice , Apoptosis/drug effects , Bromocriptine/pharmacology , Cells, Cultured , Cyclic AMP/metabolism , Domperidone/pharmacology , Epithelial Cells/metabolism , Epithelial Cells/drug effects , Lactation/metabolism , Mammary Glands, Animal/cytology , Mammary Glands, Animal/metabolism , Milk Proteins/metabolism , Milk Proteins/genetics , Receptors, Dopamine D2/metabolism , Receptors, Dopamine D2/genetics , STAT5 Transcription Factor/metabolism
2.
Exp Cell Res ; 431(1): 113762, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37648075

ABSTRACT

Mammary epithelial cells (MECs) secrete milk into the mammary alveolar lumen during lactation. The secreted milk accumulates in the alveolar lumen until milk ejection occurs, and excess milk accumulation downregulates milk production in alveolar MECs. Intramammary hydrostatic pressure also increases in the alveolar lumen in a manner dependent on milk accumulation. In this study, we investigated whether high hydrostatic compression directly affects lactating MECs, using a commercial compression device and a lactation culture model of MECs, which have milk production ability and less permeable tight junctions. High hydrostatic compression at 100 kPa for 8 h decreased ß-casein and increased claudin-4 levels concurrently with inactivation of STAT5 and glucocorticoid receptor signaling pathways. In addition, high hydrostatic compression for 1 h inactivated STAT5 and activated p38 MAPK signaling. Furthermore, repeated rises and falls of the hourly hydrostatic compression induced activation of positive (Akt, mTOR) and negative (STAT3, NF-κB) signaling pathways for milk production concurrently with stimulation of casein and lactoferrin production in MECs. These results indicate that milk production-related signaling pathways in MECs change in response to hydrostatic compression. Hydrostatic compression of the alveolar lumen may directly regulate milk production in the alveolar MECs of lactating mammary glands.


Subject(s)
Milk , STAT5 Transcription Factor , Female , Animals , Mice , Lactation , Epithelial Cells , MAP Kinase Signaling System
3.
Exp Cell Res ; 430(1): 113698, 2023 09 01.
Article in English | MEDLINE | ID: mdl-37437770

ABSTRACT

Satellite cells are indispensable for skeletal muscle regeneration and hypertrophy by forming nascent myofibers (myotubes). They synthesize multi-potent modulator netrins (secreted subtypes: netrin-1, -3, and -4), originally found as classical neural axon guidance molecules. While netrin-1 and -3 have key roles in myogenic differentiation, the physiological significance of netrin-4 is still unclear. This study examined whether netrin-4 regulates myofiber type commitment and myotube formation. Initially, the expression profiles indicated that satellite cells isolated from the extensor digitorum longus muscle (EDL muscle: fast-twitch myofiber-abundant) expressed slightly more netrin-4 than the soleus muscle (slow-type abundant) cells. As netrin-4 knockdown inhibited both slow- and fast-type myotube formation, netrin-4 may not directly regulate myofiber type commitment. However, netrin-4 knockdown in satellite cell-derived myoblasts reduced the myotube fusion index, while exogenous netrin-4 promoted myotube formation, even though netrin-4 expression level was maximum during the initiation stage of myogenic differentiation. Furthermore, netrin-4 knockdown also inhibited MyoD (a master transcriptional factor of myogenesis) and Myomixer (a myoblast fusogenic molecule) expression. These data suggest that satellite cells synthesize netrin-4 during myogenic differentiation initiation to promote their own fusion, stimulating the MyoD-Myomixer signaling axis.


Subject(s)
Muscle Fibers, Skeletal , Satellite Cells, Skeletal Muscle , Netrin-1/metabolism , Cells, Cultured , Muscle Fibers, Skeletal/metabolism , Muscle, Skeletal/metabolism , Cell Differentiation/physiology , Satellite Cells, Skeletal Muscle/metabolism
4.
J Mammary Gland Biol Neoplasia ; 28(1): 8, 2023 05 01.
Article in English | MEDLINE | ID: mdl-37126158

ABSTRACT

Mammary epithelial cells (MECs) are the only cell type that produces milk during lactation. MECs also form less-permeable tight junctions (TJs) to prevent the leakage of milk and blood components through the paracellular pathway (blood-milk barrier). Multiple factors that include hormones, cytokines, nutrition, and temperature regulate milk production and TJ formation in MECs. Multiple intracellular signaling pathways that positively and negatively regulate milk production and TJ formation have been reported. However, their regulatory mechanisms have not been fully elucidated. In addition, unidentified components that regulate milk production in MECs likely exist in foods, for example plants. Culture models of functional MECs that recapitulate milk production and TJs are useful tools for their study. Such models enable the elimination of indirect effects via cells other than MECs and allows for more detailed experimental conditions. However, culture models of MECs with inappropriate functionality may result in unphysiological reactions that never occur in lactating mammary glands in vivo. Here, I briefly review the physiological functions of alveolar MECs during lactation in vivo and culture models of MECs that feature milk production and less-permeable TJs, together with a protocol for establishment of MEC culture with functional TJ barrier and milk production capability using cell culture inserts.


Subject(s)
Lactation , Milk , Female , Animals , Milk/metabolism , Lactation/physiology , Mammary Glands, Animal/metabolism , Signal Transduction/physiology , Epithelial Cells/metabolism
5.
Exp Cell Res ; 420(1): 113352, 2022 11 01.
Article in English | MEDLINE | ID: mdl-36108712

ABSTRACT

Staphylococcus aureus causes subclinical mastitis; lipoteichoic acid (LTA) from S. aureus causes mastitis-like adverse effects on milk production by mammary epithelial cells (MECs). Here, we investigated the early effects of LTA from S. aureus on mouse MECs using a culture model, in which MECs produced milk components and formed less permeable tight junctions (TJs). In MECs of this model, Toll-like receptor 2 (receptor for LTA), was localized on the apical membrane, similar to MECs in lactating mammary glands. LTA weakened the TJ barrier within 1 h, concurrently with localization changes of claudin 4. LTA treatment for 24 h increased αS1-casein and decreased ß-casein levels. In MECs exposed to LTA, the activation level of signal transducer and activator of transcription 5 (major transcriptional factor for milk production) was low. LTA activated signaling pathways related to cell survival (extracellular signal-regulated kinase, heat shock protein 27, and Akt) and inflammation (p38, c-Jun N-terminal kinase, and nuclear factor κB). Thus, LTA caused abnormalities in casein production and weakened the TJs by affecting multiple signaling pathways in MECs. LTA-induced changes in signaling pathways were not uniform in all MECs. Such complex and semi-negative actions of LTA may contribute to subclinical mastitis caused by S. aureus.


Subject(s)
Mastitis , Staphylococcus aureus , Animals , Caseins/metabolism , Caseins/pharmacology , Claudin-4/metabolism , Epithelial Cells/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Female , HSP27 Heat-Shock Proteins/metabolism , HSP27 Heat-Shock Proteins/pharmacology , Humans , JNK Mitogen-Activated Protein Kinases/metabolism , Lactation/metabolism , Lipopolysaccharides/pharmacology , Mammary Glands, Animal , Mastitis/metabolism , Mice , Milk/metabolism , NF-kappa B/metabolism , Proto-Oncogene Proteins c-akt/metabolism , STAT5 Transcription Factor/metabolism , Signal Transduction , Staphylococcus aureus/metabolism , Teichoic Acids/pharmacology , Toll-Like Receptor 2/genetics , Toll-Like Receptor 2/metabolism
6.
Int J Mol Sci ; 25(1)2023 Dec 27.
Article in English | MEDLINE | ID: mdl-38203541

ABSTRACT

The study of liquid biopsy with plasma samples is being conducted to identify biomarkers for clinical use. Exosomes, containing nucleic acids and metabolites, have emerged as possible sources for biomarkers. To evaluate the effectiveness of exosomes over plasma, we analyzed the small non-coding RNAs (sncRNAs) and metabolites extracted from exosomes in comparison to those directly extracted from whole plasma under both fasting and non-fasting conditions. We found that sncRNA profiles were not affected by fasting in either exosome or plasma samples. Our results showed that exosomal sncRNAs were found to have more consistent profiles. The plasma miRNA profiles contained high concentrations of cell-derived miRNAs that were likely due to hemolysis. We determined that certain metabolites in whole plasma exhibited noteworthy concentration shifts in relation to fasting status, while others did not. Here, we propose that (1) fasting is not required for a liquid biopsy study that involves both sncRNA and metabolomic profiling, as long as metabolites that are not influenced by fasting status are selected, and (2) the utilization of exosomal RNAs promotes robust and consistent findings in plasma samples, mitigating the impact of batch effects derived from hemolysis. These findings advance the optimization of liquid biopsy methodologies for clinical applications.


Subject(s)
Exosomes , MicroRNAs , RNA, Small Untranslated , Humans , Hemolysis , Fasting , Biomarkers , Liquid Biopsy , MicroRNAs/genetics
7.
J Mammary Gland Biol Neoplasia ; 27(2): 155-170, 2022 06.
Article in English | MEDLINE | ID: mdl-35581442

ABSTRACT

In the mammary glands during pregnancy, the alveolar buds are first branched from the mammary ducts after which they form the alveolar luminal structure for milk production postparturition. Body temperature could increase for several reasons, such as infectious disease and heat stress. We have previously reported that high temperature adversely effects on the lactation capacity of mouse mammary epithelial cells (MECs). However, it remains unclear how high temperature influences mammary morophogenesis during pregnancy. In this study, we investigated the effects of high temperature on this mammary alveolar development process using two types of culture models including embedded organoids of MECs in Matrigel; these models reproduced mammary alveolar bud induction and alveolar luminal formation. Results showed that a culture temperature of 41 °C repressed alveolar bud induction and inhibited alveolar luminal formation. In addition, the treatment at 41 °C decreased the number of proliferating mammary epithelial cells but did not affect cell migration. Levels of phosphorylated Akt, -ERK1/2, -HSP90, and -HSP27 were increased in organoids cultured at 41 °C. The specific inhibitors of HSP90 and HSP27 exacerbated the disruption of organoids at 41 °C but not at 37 °C. Furthermore, the organoids precultured at 37 and 41 °C in the alveolar luminal formation model showed differences in the expression levels of caseins and tight junction proteins, which express in MECs in lactating mammary glands, after induction of MEC differentiation by prolactin and dexamethasone treatment in vitro. These results suggest that elevated temperature directly hinders mammary alveolar development; however, heat shock proteins may mitigate the adverse effects of high temperatures.


Subject(s)
Lactation , Mammary Glands, Animal , Animals , Epithelial Cells/metabolism , Female , HSP27 Heat-Shock Proteins/metabolism , HSP27 Heat-Shock Proteins/pharmacology , Lactation/metabolism , Mammary Glands, Animal/metabolism , Mice , Pregnancy , Signal Transduction , Temperature
8.
Am J Physiol Cell Physiol ; 323(2): C520-C535, 2022 08 01.
Article in English | MEDLINE | ID: mdl-35759444

ABSTRACT

Skeletal muscle consists of slow and fast myofibers in which different myosin isoforms are expressed. Approximately 300 myosins form a single-thick filament in the myofibrils, where myosin is continuously exchanged. However, endogenous slow and fast myosin dynamics have not been fully understood. To elucidate those dynamics, here we generated mice expressing green fluorescence protein-tagged slow myosin heavy chain (GFP-Myh7) and Kusabira Orange fluorescence protein-tagged fast myosin heavy chain (KuO-Myh1). First, these mice enabled us to distinguish between GFP- and KuO-myofibers under fluorescence microscopy: GFP-Myh7 and KuO-Myh1 were exclusively expressed in slow myofibers and fast myofibers, respectively. Next, to monitor endogenous myosin dynamics, fluorescence recovery after photobleaching (FRAP) was conducted. The mobile fraction (Mf) of GFP-Myh7 and that of KuO-Myh1 were almost constant values independent of the regions of the myofibers and the muscle portions where the myofibers were isolated. Intriguingly, proteasome inhibitor treatment significantly decreased the Mf in GFP-Myh7 but not in KuO-Myh1 myofibers, indicating that the response to a disturbance in protein turnover depended on muscle fiber type. Taken together, the present results indicated that the mice we generated are promising tools not only for distinguishing between GFP- and KuO-myofibers but also for studying the dynamics of endogenous myosin isoforms by live-cell fluorescence imaging.


Subject(s)
Myosin Heavy Chains , Animals , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Luminescent Proteins , Mice , Muscle Fibers, Skeletal/metabolism , Muscle, Skeletal/metabolism , Myosin Heavy Chains/genetics , Myosin Heavy Chains/metabolism , Myosins/genetics , Myosins/metabolism , Protein Isoforms/genetics , Protein Isoforms/metabolism
9.
Cell Tissue Res ; 389(3): 501-515, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35748981

ABSTRACT

Mammary epithelial cells (MECs) are the only cells capable of synthesizing lactose. During lactation, alveolar MECs secrete lactose through the apical membrane into the alveolar lumen, whereas alveolar tight junctions (TJs) block the leakage of lactose into the basolateral sides of the MECs. However, lactose leaks from the alveolar lumen into the blood plasma in the mastitis and after weaning. This exposes the basolateral membrane of MECs to lactose. The relationship between lactose in blood plasma and milk production has been suggested. The present study determined whether lactose exposure on the basolateral membrane of mouse MECs adversely affects milk production in vitro. Restricted exposure to lactose on the basolateral side of the MECs was performed using a culture model, in which MECs on the cell culture insert exhibit milk production and less-permeable TJs. The results indicated that lactose exposure on the basolateral side inhibited casein and lipid production in the MECs. Interestingly, lactose exposure on the apical side did not show detectable effects on milk production in the MECs. Basolateral lactose exposure also caused the inactivation of STAT5, a primary transcriptional factor for milk production. Furthermore, p38 and JNK were activated by basolateral lactose exposure. The activation of p38 and JNK following anisomycin treatment reduced phosphorylated STAT5, and inhibitors of p38 blocked the reduction of phosphorylated STAT5 by basolateral lactose exposure. These findings suggest that lactose functions as a partial inhibitor for milk production but only when it directly makes contact with the basolateral membrane of MECs.


Subject(s)
Mammary Glands, Animal , STAT5 Transcription Factor , Animals , Epithelial Cells/metabolism , Female , Lactation/metabolism , Lactose/metabolism , Lactose/pharmacology , Mice , Milk/metabolism , STAT5 Transcription Factor/metabolism , STAT5 Transcription Factor/pharmacology
10.
Cerebellum ; 21(6): 905-919, 2022 Dec.
Article in English | MEDLINE | ID: mdl-34676525

ABSTRACT

Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system, synthesized by two isoforms of glutamate decarboxylase (GAD): GAD65 and GAD67. GABA may act as a trophic factor during brain development, but its contribution to the development and maturation of cerebellar neural circuits is not known. To understand the roles of GABA in cerebellar organization and associated functions in motor coordination and balance, we examined GAD65 conventional knock out (KO) mice and mice in which GAD67 was eliminated in parvalbumin-expressing neurons (PV-Cre; GAD67flox/flox mice). We found aberrant subcellular localization of the Shaker-type K channel Kv1.1 in basket cell collaterals of PV-Cre; GAD67 flox/flox mice and abnormal projections from basket cells to Purkinje cells in both mouse strains. We also found that altered synaptic properties of basket cell terminals to Purkinje cells in PV-Cre; GAD67flox/flox mice. Furthermore, PV-Cre; GAD67 flox/flox mice exhibited abnormal motor coordination in the rotarod test. These results indicate that GABA signaling in the cerebellum is critical for establishing appropriate connections between basket cells and Purkinje cells and is associated with motor coordination in mice.


Subject(s)
Glutamate Decarboxylase , Purkinje Cells , Animals , Mice , Glutamate Decarboxylase/genetics , Purkinje Cells/metabolism , Parvalbumins/metabolism , gamma-Aminobutyric Acid , Cerebellum/metabolism , Mice, Knockout
11.
Exp Cell Res ; 400(2): 112472, 2021 03 15.
Article in English | MEDLINE | ID: mdl-33450209

ABSTRACT

Lipopolysaccharide (LPS) and lipoteichoic acid (LTA) are cell wall components of Escherichia coli and Staphylococcus aureus, which cause clinical and subclinical mastitis, respectively. However, the reason of the difference in symptoms by pathogen type remains unclear. In this study, the influence of LPS and LTA on early response and milk production in lactating bovine mammary epithelial cells (BMECs) was comparatively investigated. The results showed that LPS decreased the secretion of ß-casein, lactose, and triglycerides, whereas LTA decreased the secretion of lactose and triglycerides but increased lactoferrin production without any influence on ß-casein secretion. In addition, the influence of milk lipid droplet size in BMECs and gene expression related to milk fat synthesis was different between LPS and LTA. LPS increased the gene expression of interleukin (IL)-1ß, tumor necrosis factor-α, and IL-8 through the activation of the nuclear factor-κB (NF-κB), p38, and c-Jun N-terminal kinase pathways, whereas LTA increased IL-1ß and CC chemokine ligand 5 expression through the activation of the NF-κB pathway. Moreover, these cytokines and chemokines differently affected the milk production ability of BMECs. These results suggested that the pathogen-specific symptoms may be related to the differences in the early response of BMECs to bacterial toxins.


Subject(s)
Lipopolysaccharides/pharmacology , Mammary Glands, Animal/metabolism , Milk Proteins/metabolism , Milk/metabolism , Teichoic Acids/pharmacology , Animals , Cattle , Chemokines/metabolism , Cytokines/metabolism , Female , Mammary Glands, Animal/drug effects
12.
Exp Cell Res ; 409(2): 112938, 2021 12 15.
Article in English | MEDLINE | ID: mdl-34800541

ABSTRACT

In lactating mammary glands, alveolar mammary epithelial cells (MECs) produce milk and form less-permeable tight junctions (TJs). However, alveolar TJs are weakened with a reduction in milk production in mammary glands due to mastitis or weaning in the presence of high levels of IL-1ß, IL-6, or TNF-α. In this study, using in vitro cultured model of MECs with milk-producing ability and lactation-specific TJs, we investigated whether the aforementioned cytokines affect MEC TJs. The results showed that TNF-α, IL-1ß, and IL-6 affected lactation-specific TJs in different ways. In particular, upon activation of p38 and JNK signalling, IL-1ß caused rapid disruption of TJs at tricellular contact points. IL-1ß treatment led to decreased CLDN3, CLDN4, and OCLN levels and a weakened TJ barrier. The adverse effects of IL-1ß on TJs were mimicked by anisomycin, which is an activator of p38 and JNK signalling, and were blocked by MEC pretreatment with a p38 inhibitor but not a JNK inhibitor. The mislocalization of tricellulin at tricellular contact areas was confirmed in MECs treated with IL-1ß or anisomycin. These results indicate that IL-1ß is a key cytokine that adversely affects the TJs between MECs by activating p38.


Subject(s)
Anisomycin/pharmacology , Claudin-3/metabolism , Claudin-4/metabolism , Interleukin-1beta/pharmacology , Lactation , Mammary Glands, Animal/pathology , Tight Junctions/pathology , Animals , Claudin-3/genetics , Claudin-4/genetics , Epithelial Cells/metabolism , Epithelial Cells/pathology , Female , Mammary Glands, Animal/metabolism , Mice , Milk/chemistry , Protein Synthesis Inhibitors/pharmacology , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors
13.
Biosci Biotechnol Biochem ; 87(1): 45-53, 2022 Dec 21.
Article in English | MEDLINE | ID: mdl-36331254

ABSTRACT

Tuberous sclerosis complex 2 (TSC2) is a tumor-suppressor protein. A loss of TSC2 function induces hyperactivation of mechanistic target of rapamycin (mTOR). The C-terminal region of TSC2 contains a calmodulin (CaM) binding region and the CaM-TSC2 interaction contributes to proper mTOR activity. However, other downstream signaling pathways/effectors activated by the CaM-TSC2 complex have not been fully elucidated. In this study, we found that activation of Ca2+/CaM signaling resulted in the translocation of membrane-associated TSC2 to the nucleus and suppressed the transcriptional activity of the vitamin D receptor (VDR). TSC2 was released from the membrane in an activated CaM-dependent state in rat brain and HeLa cells. It subsequently formed a transcriptional complex to partially suppress the transcription of CYP24A1, a well-known VDR target gene. These data suggest, in part, that TSC2 attenuates VDR-associated transcriptional regulation via Ca2+/CaM signaling.


Subject(s)
Calmodulin , Tuberous Sclerosis , Rats , Humans , Animals , Calmodulin/metabolism , Vitamin D3 24-Hydroxylase/metabolism , Calcium/metabolism , HeLa Cells , Tuberous Sclerosis Complex 2 Protein/metabolism , TOR Serine-Threonine Kinases/metabolism
14.
J Mammary Gland Biol Neoplasia ; 26(4): 387-397, 2021 12.
Article in English | MEDLINE | ID: mdl-35015201

ABSTRACT

Heat stress and mastitis adversely affect milk production in dairy ruminants. Although the udder temperature is elevated in both conditions, the influence of this local temperature rise on milk production and immune function of ruminant mammary glands remains unclear. To address this question, we heated the mammary glands of goats by covering one half of the udder with a disposable heating pad for 24 h, the other uncovered half served as a control. Sixteen Tokara goats (1-5 parity) and three Shiba goats (1-2 parity) at the mid-lactation stage were individually housed, fed 0.6 kg of hay cubes and 0.2 kg of barley per day, and had free access to water and trace-mineralized salt blocks. Milk samples were collected every 6 h for 24 h after covering (n = 16), and deep mammary gland tissue areas were collected after 24 h (n = 5). The concentrations of antimicrobial components [lactoferrin, ß-defensin-1, cathelicidin-2, cathelicidin-7, and immunoglobulin A (IgA)] in milk were measured by the enzyme-linked immunosorbent assay (ELISA). The localization of IgA was examined by immunohistochemistry. The mRNA expression and protein concentrations of C-C motif chemokine ligand-28 (CCL-28) and interleukin (IL)-8 in the mammary gland tissue were measured using quantitative polymerase chain reaction and ELISA, respectively. The somatic cell count in milk was significantly higher in the local heat-treatment group than in the control group after 12 h of treatment. The treatment group had significantly higher concentrations of cathelicidin-2 and IgA than the control group after 24 h of treatment. In addition, the number of IgA-positive cells in the mammary stromal region and the concentration of CCL-28 in the mammary glands were increased by local heat treatment. In conclusion, a local rise in udder temperature enhanced the innate immune function in mammary glands by increasing antimicrobial components.


Subject(s)
Anti-Infective Agents , Mammary Glands, Animal , Animals , Anti-Infective Agents/metabolism , Female , Goats/genetics , Immunity , Immunoglobulin A/metabolism , Lactation , Mammary Glands, Animal/metabolism , Milk/metabolism , Pregnancy
15.
Dev Biol ; 468(1-2): 14-25, 2020 12 01.
Article in English | MEDLINE | ID: mdl-32946790

ABSTRACT

A mammalian embryo experiences the first cell segregation at the blastocyst stage, in which cells giving form to the embryo are sorted into two lineages; trophectoderm (TE) and inner cell mass (ICM). This first cell segregation process is governed by cell position-dependent Hippo signaling, which is a phosphorylation cascade determining whether Yes-associated protein 1 (YAP1), one of the key components of the Hippo signaling pathway, localizes within the nucleus or cytoplasm. YAP1 localization determines the transcriptional on/off switch of a key gene, Cdx2, required for TE differentiation. However, the control mechanisms involved in YAP1 nucleocytoplasmic shuttling post blastocyst formation remain unknown. This study focused on the mechanisms involved in YAP1 release from TE nuclei after blastocoel contraction in bovine blastocysts. The blastocysts contracted by blastocoel fluid aspiration showed that the YAP1 translocation from nucleus to cytoplasm in the TE cells was concomitant with the protruded actin cytoskeleton. This YAP1 release from TE nuclei in the contracted blastocysts was prevented by actin disruption and stabilization. In contrast, Y27632, which is a potent inhibitor of Rho-associated coiled-coil containing protein kinase 1/2 (ROCK) activity, was found to promote YAP1 nuclear localization in the TE cells of contracted blastocysts. Meanwhile, lambda protein phosphatase (LPP) treatment inducing protein dephosphorylation could not prevent YAP1 release from TE nuclei in the contracted blastocysts, indicating that YAP1 release from TE nuclei does not depend on the Hippo signaling pathway. These results suggested that blastocyst contraction causes YAP1 release from TE nuclei through actin cytoskeleton remodeling in a Hippo signaling-independent manner. Thus, the present study raised the possibility that YAP1 subcellular localization is controlled by actin cytoskeletal organization after the blastocyst formation. Our results demonstrate diverse regulatory mechanisms for YAP1 nucleocytoplasmic shuttling in TE cells.


Subject(s)
Actin Cytoskeleton/metabolism , Blastocyst/metabolism , Cell Nucleus/metabolism , Cytoplasm/metabolism , Ectoderm/metabolism , Transcription Factors/metabolism , Actin Cytoskeleton/genetics , Active Transport, Cell Nucleus , Animals , Blastocyst/cytology , Cattle , Cell Nucleus/genetics , Cytoplasm/genetics , Ectoderm/cytology , Transcription Factors/genetics
16.
Cell Tissue Res ; 384(2): 435-448, 2021 May.
Article in English | MEDLINE | ID: mdl-33433684

ABSTRACT

Mastitis causes a decrease in milk yield and abnormalities in milk components from dairy cows. Escherichia coli and the E. coli lipopolysaccharide (LPS) cell wall component directly downregulate milk production in bovine mammary epithelial cells (BMECs). However, the detailed mechanism by which this occurs in BMECs remains unclear. Various membrane proteins, such as immune sensors (Toll-like receptors, TLR), nutrient transporters (glucose transporter and aquaporin), and tight junction proteins (claudin and occludin) are involved in the onset of mastitis or milk production in BMECs. In this study, we investigated the influence of LPS on membrane proteins using an in vitro culture model. This mastitis model demonstrated a loss of glucose transporter-1 and aquaporin-3 at lateral membranes and a decrease in milk production in response to LPS treatment. LPS disrupted the tight junction barrier and caused compositional changes in localization of claudin-3 and claudin-4, although tight junctions were maintained to separate the apical membrane domains and the basolateral membrane domains. LPS did not significantly affect the expression level and subcellular localization of epidermal growth factor receptor in lactating BMECs with no detectable changes in MEK1/2-ERK1/2 signaling. In contrast, NFκB was concurrently activated with temporal translocation of TLR-4 in the apical membranes, whereas TLR-2 was not significantly influenced by LPS treatment. These findings indicate the importance of investigating the subcellular localization of membrane proteins to understand the molecular mechanism of LPS in milk production in mastitis.


Subject(s)
Epithelial Cells/metabolism , Lipopolysaccharides/adverse effects , Mammary Glands, Animal/physiopathology , Animals , Cattle , Female , Lactation
17.
J Nutr ; 151(9): 2705-2713, 2021 09 04.
Article in English | MEDLINE | ID: mdl-34224565

ABSTRACT

BACKGROUND: White rice and its unrefined form, brown rice, contain numerous compounds that are beneficial to human health. However, the starch content of rice can contribute to obesity, a main risk factor for nonalcoholic fatty liver disease (NAFLD). OBJECTIVES: We investigated the effect of rice consumption on NAFLD and its underlying molecular mechanism. METHODS: We randomly divided 7-week-old male obese Zucker (fa/fa) rats, an animal model of NAFLD, into 3 groups (n = 10 each) fed 1 of 3 diets for 10 weeks: a control diet (Cont; AIN-93G diet; 53% cornstarch), a white rice diet (WR; AIN-93G diet with cornstarch replaced with white rice powder), or a brown rice diet (BR; AIN-93G diet with cornstarch replaced with brown rice powder). Liver fat accumulation and gene expression related to lipid and vitamin A metabolisms, including retinoic acid (RA) signaling, were analyzed. RESULTS: Hepatic lipid values were significantly decreased in the BR group compared with the Cont group, by 0.4-fold (P < 0.05). The expression of genes related to hepatic fatty acid oxidation, such as carnitine palmitoyltransferase 2, was approximately 2.1-fold higher in the BR group than the Cont group (P < 0.05). The expression of peroxisomal acyl-coenzyme A oxidase 1 and acyl-CoA dehydrogenase medium chain was also significantly increased, by 1.6-fold, in the BR group compared with the Cont group (P < 0.05). The expression of VLDL-secretion-related genes, such as microsomal triglyceride transfer protein, was also significantly higher in the BR group (2.4-fold; P < 0.05). Furthermore, aldehyde dehydrogenase 1 family member A1, an RA synthase gene, was 2-fold higher in the BR group than the Cont group (P < 0.05). CONCLUSIONS: Brown rice prevented development of NAFLD in obese Zucker (fa/fa) rats. The beneficial effects of pregelatinized rice on NAFLD could be manifested as increased fatty acid oxidation and VLDL secretion, which are regulated by RA signaling.


Subject(s)
Non-alcoholic Fatty Liver Disease , Oryza , Animals , Lipid Metabolism , Lipids , Liver/metabolism , Male , Non-alcoholic Fatty Liver Disease/metabolism , Obesity/complications , Obesity/metabolism , Rats , Rats, Zucker , Tretinoin/metabolism
18.
Br J Psychiatry ; : 1-8, 2021 Aug 02.
Article in English | MEDLINE | ID: mdl-35049468

ABSTRACT

BACKGROUND: We have developed the bispectral electroencephalography (BSEEG) method for detection of delirium and prediction of poor outcomes. AIMS: To improve the BSEEG method by introducing a new EEG device. METHOD: In a prospective cohort study, EEG data were obtained and BSEEG scores were calculated. BSEEG scores were filtered on the basis of standard deviation (s.d.) values to exclude signals with high noise. Both non-filtered and s.d.-filtered BSEEG scores were analysed. BSEEG scores were compared with the results of three delirium screening scales: the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), the Delirium Rating Scale-Revised-98 (DRS) and the Delirium Observation Screening Scale (DOSS). Additionally, the 365-day mortalities and the length of stay (LOS) in the hospital were analysed. RESULTS: We enrolled 279 elderly participants and obtained 620 BSEEG recordings; 142 participants were categorised as BSEEG-positive, reflecting slower EEG activity. BSEEG scores were higher in the CAM-ICU-positive group than in the CAM-ICU-negative group. There were significant correlations between BSEEG scores and scores on the DRS and the DOSS. The mortality rate of the BSEEG-positive group was significantly higher than that of the BSEEG-negative group. The LOS of the BSEEG-positive group was longer compared with that of the BSEEG-negative group. BSEEG scores after s.d. filtering showed stronger correlations with delirium screening scores and more significant prediction of mortality. CONCLUSIONS: We confirmed the usefulness of the BSEEG method for detection of delirium and of delirium severity, and prediction of patient outcomes with a new EEG device.

19.
J Interv Cardiol ; 2021: 9022326, 2021.
Article in English | MEDLINE | ID: mdl-34867108

ABSTRACT

OBJECTIVE: Coil embolization (CE) for coronary artery perforation (CAP) has not been thoroughly evaluated. This study aimed to evaluate the extent of myocardial damage and impact on cardiac function after CE for CAP. METHODS: A total of 110 consecutive patients treated with CE for CAP were retrospectively identified. The degree of myocardial damage and impact on cardiac function were evaluated. RESULTS: Forty-nine (44.5%) cases involved chronic total occlusions. A guidewire was the cause of perforation in 97 (88.2%) patients. The success rate of CE was 98.2%. Almost all patients were prescribed either antiplatelet drugs or anticoagulant medication or both. Patients with perforation types III and IV were found to be prone to creatinine kinase (CK) elevation and epicardial main vessel perforation, thereby causing myocardial damage. No changes were noted in the ejection fraction (EF) in patients with type V distal perforation and collateral channel perforation, while patients with perforation of the epicardial main vessel may show impaired cardiac function afterward. CONCLUSIONS: CE is safe and effective for treating CAP, especially when collateral channels and distal vessels are involved. Meanwhile, efforts should be taken to prevent CAP in epicardial main vessels since it may be difficult to treat with CS and cause myocardial damage when bailed out with CE leading to vessel sacrifice. We found that it was not necessary to change the anticoagulant regimen after CE owing to its ability to achieve robust hemostasis.


Subject(s)
Coronary Artery Disease , Coronary Angiography , Humans , Retrospective Studies , Treatment Outcome
20.
Endocr J ; 68(3): 371-374, 2021 Mar 28.
Article in English | MEDLINE | ID: mdl-33177251

ABSTRACT

Postpartum thyroiditis (PPT) is characterized by mild thyrotoxicosis occurring within one year of parturition commonly followed by transient hypothyroidism. Having genetic background of autoimmune thyroid disorders is a risk factor for it because the immune reactivation during postpartum period is a trigger for PPT. Pandemic of COVID-19: caused by SARS-CoV-2 infection is a global health problem, and occurrence of Graves' disease and Hashimoto's thyroiditis after the viral infection have been reported but occurrence of PPT with COVID-19 has never been reported. A 29-year-old woman developed general fatigue four and a half months after parturition, and was diagnosed as having PPT: one month before, she had COVID-19. Hereafter, we define the date of delivery as Day 0 to make timeline clear. SARS-CoV-2 infection was diagnosed by PCR on Day 103, its disappearance from the upper airway confirmed on Day 124, and the thyroiditis diagnosed on Day 136. She had been euthyroid on Day 0 and 95, but thyrotoxic on Day 136. Serum thyroglobulin (Tg) concentration was normal in the presence of anti-Tg antibody, other thyroid-related autoantibodies were negative, and by ultrasonography, the thyroid gland was normal in size and no evidence of increased vascularity. Thyroid function returned to normal by Day 172 without any specific drug therapy. In conclusion, although a clear causal relationship could not be found, we documented the world's first case of PPT developed following COVID-19.


Subject(s)
COVID-19 , Postpartum Thyroiditis/immunology , Adult , Autoantibodies/immunology , Female , Humans , Postpartum Thyroiditis/blood , Postpartum Thyroiditis/physiopathology , Recovery of Function , Remission, Spontaneous , SARS-CoV-2 , Thyroglobulin/blood
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