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1.
Iperception ; 15(2): 20416695241238692, 2024.
Article in English | MEDLINE | ID: mdl-38577221

ABSTRACT

In a spatial Stroop task, eye-gaze targets produce a reversed congruency effect (RCE) with faster responses when gaze direction and location are incongruent than congruent. On the other hand, non-social directional targets (e.g., arrows) elicit a spatial Stroop effect (SSE). The present study examined whether other social stimuli, such as head orientation, trigger the RCE. Participants judged the target direction of the head or the gaze while ignoring its location. While the gaze target replicated the RCE, the head target produced the SSE. Moreover, the head target facilitated the overall responses relative to the gaze target. These results suggest that the head, a salient directional feature, overrides the social significance. The RCE may be specific to gaze stimuli, not to social stimuli in general. The head and gaze information differentially affect our attentional mechanisms and enable us to bring about smooth social interactions.

2.
Traffic Inj Prev ; 25(3): 454-462, 2024.
Article in English | MEDLINE | ID: mdl-38478461

ABSTRACT

OBJECTIVE: In vehicle frontal collisions, it is crucial that the lap belt is designed to engage with the anterior superior iliac spine (ASIS) of occupants for a reliable restraint. This study aims to understand the influence of different seated postures on the geometrical relationship of the seat belt and the pelvis for various occupants using 3D upright and supine computed tomography (CT) systems. METHODS: The 3D shapes of bones and soft tissues around the pelvis were acquired through a CT scan for 30 participants. They were seated in a rigid seat equipped with a lap belt simulating the front seat of a small car, and wore a lap belt in three seated postures: upright, slouched and reclined. Parameters related to the likelihood of submarining occurrences, such as belt-ASIS overlap (an index for assessing the potential engagement of the lap belt with the ASIS) and the belt-pelvis angle (the difference between the belt angle and the normal direction of the anterior edge of the ilium) were compared. RESULTS: It was observed that the pelvis angle tilted rearward as the hip point was positioned forward and seatback angle increased. This can be seen in the slouched and reclined posture. The belt-pelvis angle was comparable between the slouched and the reclined postures, and was closer to zero (indicating that the lap belt path is closer to perpendicular to the anterior edge of the ilium) compared to the upright posture. In contrast, the belt-ASIS overlap increased with an increasing flesh margin of the ASIS and shallower belt angle. This suggests that the belt-pelvis angle is influenced by the seated posture whereas the belt-ASIS overlap is dependent more on an individual's anthropometry. The plot of belt-pelvis angle and belt-ASIS overlap exhibited significant variability among participants. CONCLUSIONS: The belt-pelvis angle and the belt-ASIS overlap of individuals will provide valuable information for understanding the current belt-fit location and predicting submarining occurrences for individuals in various postures when designing restraint systems.


Subject(s)
Accidents, Traffic , Seat Belts , Humans , Anthropometry/methods , Posture , Biomechanical Phenomena , Tomography
3.
Q J Exp Psychol (Hove) ; : 17470218241232981, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38320865

ABSTRACT

Numerous studies have shown that the gaze of others produces a special attentional process, such as the eye contact effect or joint attention. This study investigated the attentional process triggered by various types of gaze stimuli (i.e., human, cat, fish, koala, and robot gaze). A total of 300 university students participated in five experiments. They performed a spatial Stroop task in which five types of gaze stimuli were presented as targets. Participants were asked to judge the direction of the target (left or right) irrespective of its location (left or right). The results showed that the social gaze targets (i.e., human and cat gaze) produced a reversed congruency effect. In contrast to the social gaze targets, the non-social gaze (i.e., fish and robot) target did not produce the reversed congruency effect (Experiments 2, 2B, 3, and 4). These results suggest that attention to the gaze of socially communicable beings (i.e., humans and cats) is responsible for the reversed congruency effect. Our findings support the notion that the theory of mind or social interaction plays an important role in producing specific attentional processes in response to gaze stimuli.

4.
Traffic Inj Prev ; 25(2): 147-155, 2024.
Article in English | MEDLINE | ID: mdl-38019483

ABSTRACT

OBJECTIVE: The engagement of the lap belt with the pelvis is critical for occupant safety during vehicle frontal crashes to prevent occupant submarining. This study aims to develop a predictive model for submarining risk based on anthropometric parameters and lap belt positioning using finite element (FE) analyses. METHODS: FE analyses were conducted using human body models representing various body shapes (a 50th percentile male, low and high BMI males, and a 5th percentile female) in three seated postures (standard, reclined, and slouched). The lap belt-ASIS overlap and the belt-pelvis angle were used as key parameters for predicting submarining risk. A logistic regression analysis was utilized to correlate submarining occurrence with the initial values of these two parameters at the beginning of impact. Subsequently, this submarining prediction model was applied to computer tomography (CT) measurements of human subjects in different seated postures (upright, reclined, and slouched), and submarining risks were calculated based on the developed model. RESULTS: FE simulations indicated that submarining was more likely to occur as the initial belt-pelvis angle approached zero and there was a smaller initial belt-ASIS overlap. The logistic regression analysis demonstrated that the initial belt-pelvis angle and belt-ASIS overlap were statistically significant for predicting submarining risk. The derived model effectively distinguished submarining occurrence based on the initial values of these two parameters. The application of the submarining model to CT measurements of human subjects showed that submarining risk was lower in the order of upright, slouched, and reclined postures. In the reclined posture, the high submarining risk was attributed to a small belt-ASIS overlap and a rearward-tilted pelvis angle; whereas in the slouched posture, the risk was mostly associated with a rearward-tilted pelvis angle. CONCLUSIONS: The submarining prediction model was developed based on the belt-pelvis angle and the belt-ASIS overlap. This predictive model may help to design restraint systems for various body types and seated postures of occupants.


Subject(s)
Accidents, Traffic , Automobiles , Humans , Male , Female , Seat Belts , Anthropometry/methods , Pelvis/diagnostic imaging , Biomechanical Phenomena
5.
Sci Rep ; 13(1): 18829, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37914726

ABSTRACT

Enamel forming ameloblasts move away from the dentino-enamel junction and also move relative to each other to establish enamel shape during the secretory stage of enamel development. Matrix metalloproteinase-20 (MMP20) is a tooth specific proteinase essential for proper enamel formation. We previously reported that MMP20 cleaves cadherins and may regulate ameloblast movement. Here, we used an Amelx promoter driven tdTomato reporter to label mouse ameloblasts. With these transgenic mice, we assessed ameloblast mobility group dynamics and gene expression. Three-dimensional imaging of mouse ameloblasts were observed in hemi-mandibles by using a tissue clearing technique. The three-dimensional ameloblast layer in Tg(Amelx-Mmp20) mice that overexpress MMP20 was uneven and the ameloblasts migrated away from this layer. Mouse ameloblast movement toward incisal tips was monitored by ex vivo time-lapse imaging. Gene expression related to cell migration and adhesion was analyzed in ameloblasts from wild-type mice, Mmp20-/- mice with no functional MMP20 and from Tg(Amelx-Mmp20) overexpressing mice. Gene expression was altered in Mmp20-/- and Tg(Amelx-Mmp20) mice compared to wild type. Among the genes assessed, those encoding laminins and a gap junction protein were upregulated in Mmp20-/- mice. New techniques and findings described in this study may lead to an improved understanding of ameloblast movement during enamel formation.


Subject(s)
Ameloblasts , Matrix Metalloproteinase 20 , Mice , Animals , Ameloblasts/metabolism , Matrix Metalloproteinase 20/metabolism , Mice, Transgenic , Cadherins/metabolism , Gene Expression
6.
Q J Exp Psychol (Hove) ; : 17470218231203187, 2023 Oct 17.
Article in English | MEDLINE | ID: mdl-37705449

ABSTRACT

In the spatial Stroop task, an arrow target produces a spatial Stroop effect, whereas a gaze target elicits a reversed congruency effect. The reversed congruency effect has been explained by the unique attentional mechanisms of eye gaze. However, recent studies have shown that not only gaze but arrow targets produced a reversed congruency effect when embedded in a complex background. The present study investigated whether non-gaze targets produce a reversed congruency effect. In Experiments 1 and 2, we used the tongue, which is not commonly used to indicate spatial directions in daily life, as a target in the spatial Stroop task, in addition to the conventional gaze and arrows. In Experiment 3, we used arrow stimuli embedded in a complex background as a target. Participants judged the left/right direction of the target presented in the left or right visual field. Although arrow and gaze targets replicated previous findings (spatial Stroop and reversed congruency effect, respectively), the tongue target produced a reversed congruency effect (Experiments 1 and 2). The spatial Stroop effect of arrow targets disappeared when they were in a complex background (Experiment 3). These results are inconsistent with previous accounts emphasising the unique status of eye gaze. We propose that temporal decay of the location code and response inhibition are responsible for the reversal of spatial interference.

7.
Immunohorizons ; 7(1): 140-158, 2023 01 01.
Article in English | MEDLINE | ID: mdl-36695731

ABSTRACT

Aire, the defect of which is responsible for the development of autoimmunity, is predominantly expressed in medullary thymic epithelial cells, and it controls a wide variety of genes, including those of tissue-restricted Ags, for establishing thymic tolerance. Aire is also expressed from APCs in the periphery, called extrathymic Aire-expressing cells (eTACs), and their complementing role to thymic tolerance has been suggested. eTACs are composed of two distinct classes of APCs, conventional dendritic cell (cDC)-type and group 3 innate lymphoid cell (ILC3)-like-type expressing retinoic acid receptor-related orphan receptor γt (RORγt). Although the essential role of Aire in the latter in the Th17-mediated immune response against Candida albicans has been reported, the role of Aire in the cDC-type eTACs for this action has not been examined. Furthermore, the significance of Aire in the production of the transcriptome of the cDC-type eTACs remains unknown. We have approached these issues using a high-fidelity Aire-reporter mouse strain. We found that although the cDC-type eTACs dominated ILC3-like-type eTACs in number and they served as efficient APCs for the immune response against an exogenous Ag as well as for the C. albicans-specific Th17 immune response, loss of Aire in cDC-type eTACs showed no clear effect on these functions. Furthermore, loss of Aire showed no major impact on the transcriptome from cDC-type eTACs. These results suggested that Aire in cDC-type eTACs may not have a cell-intrinsic role in the immune response in contrast to the role of Aire in ILC3-like-type eTACs.


Subject(s)
Antigen Presentation , Transcriptome , Animals , Mice , Dendritic Cells , Immunity, Innate , Lymphocytes , CD11c Antigen/immunology
8.
Psychon Bull Rev ; 30(3): 974-982, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36307577

ABSTRACT

In a spatial Stroop task, the eye-gaze target produces the reversed congruency effect-responses become shorter when the gaze direction and its location are incongruent than when they are congruent. The present study examined the face inversion effect on the gaze spatial Stroop task to clarify whether the holistic face processing or part-based processing of the eyes is responsible for the reversed congruency effect. In Experiment 1, participants judged the gaze direction of the upright or inverted face with a neutral expression presented either in the left or right visual field. In Experiment 2, we examined whether face inversion interacted with facial expressions (i.e., angry, happy, neutral, and sad). Face inversion disrupted holistic face processing, slowing down the overall performance relative to the performance with upright faces. However, face inversion did not affect the reversed congruency effect. These results further support the parts-based processing account and suggest that while faces are processed holistically, the reversed congruency effect, relying on the extracted local features (i.e., eyes), may be processed in a part-based manner.


Subject(s)
Anger , Fixation, Ocular , Humans , Eye , Happiness , Visual Fields , Facial Expression
9.
Cell Rep ; 40(10): 111314, 2022 09 06.
Article in English | MEDLINE | ID: mdl-36070692

ABSTRACT

Host immune response via Th17 cells against oral pathobionts is a key mediator in periodontitis development. However, where and how the Th17-type immune response is induced during the development of periodontitis is not well understood. Here, we demonstrate that gut translocation of the oral pathobiont Porphyromonas gingivalis (Pg) exacerbates oral pathobiont-induced periodontitis with enhanced Th17 cell differentiation. The oral pathobiont-responsive Th17 cells are differentiated in Peyer's patches and translocated systemically in the peripheral immune tissues. They are also capable of migrating to and accumulating in the mouth upon oral infection. Development of periodontitis via the oral pathobiont-responsive Th17 cells is regulated by the intestinal microbiome, and altering the intestinal microbiome composition with antibiotics affects the development of periodontitis. Our study highlights that pathobiont-responsive Th17 cells in the gut-mouth axis and the intestinal microbiome work together to provoke inflammatory oral diseases, including periodontitis.


Subject(s)
Gastrointestinal Microbiome , Periodontitis , Humans , Porphyromonas gingivalis/physiology , Th17 Cells
10.
Stapp Car Crash J ; 65: 49-90, 2021 11.
Article in English | MEDLINE | ID: mdl-35512785

ABSTRACT

In vehicle collisions, the lap belt should engage the anterior superior iliac spine (ASIS). In this study, threedimensional (3D) shapes of bones and soft tissues around the pelvis were acquired using a computed tomography (CT) scan of 10 male and 10 female participants wearing a lap belt. Standing, upright sitting, and reclined postures were scanned using an upright CT and a supine CT scan system. In the upright sitting posture, the thigh height was larger with a higher BMI while the ASIS height did not change significantly with BMI. As a result, the height of the ASIS relative to the thigh (ASIS-thigh height) became smaller as the BMI increased. Because the thigh height of females was smaller than that of males, the ASIS-thigh height was larger for females than for males. As the ASIS-thigh height was larger, the overlap of the lap belt with the ASIS increased. Thus, the lap belt overlapped more with the ASIS for the females than for the males. The abdomen outer shape is characterized by the trouser cord formed valley, the torso/thigh junction, and the anterior convexity formed between them depending on the adipose tissues. The abdomen outer shapes changed from the standing, the reclined posture to the upright sitting posture. In the reclined sitting posture, the lap belt is positioned upward and rearward relative to the ASIS, and the overlap of the lap belt with the ASIS was smaller compared to the upright posture.


Subject(s)
Accidents, Traffic , Seat Belts , Equipment Design , Female , Humans , Male , Research Subjects , Seat Belts/adverse effects , Tomography, X-Ray Computed
11.
Exp Anim ; 69(2): 250-260, 2020 Apr 24.
Article in English | MEDLINE | ID: mdl-32009087

ABSTRACT

Maternal immune activation (MIA) by an infection is considered to be an important environmental factor of fetal brain development. Recent animal model on MIA induced by polyinosinic:polycytidylic acid, a mimic of viral infection, demonstrates that maternal IL-17A signaling is required for the development of autism spectrum disorder (ASD)-like behaviors of offspring. However, there is little information on bacterial infection. In this study, we aim to elucidate the influence of MIA induced by lipopolysaccharide (LPS) to mimic a bacterial infection on fetal brain development. We demonstrated that LPS-induced MIA promoted ASD-like behaviors in mouse offspring. We further found that LPS exposure induced acute phase immune response: elevation of serum IL-17A levels in MIA mothers, upregulation of Il17a mRNA expression and increase of IL-17A-producing γδ T cells in the uterus, and upregulation of Il17ra mRNA expression in the fetal brain. Blocking of IL-17A in LPS-induced MIA ameliorated ASD-like behaviors in offspring. Our data suggest that bacterial-induced maternal IL-17A pathway promotes ASD-like behaviors in offspring.


Subject(s)
Autistic Disorder/genetics , Behavior, Animal , Interleukin-17 , Signal Transduction , Animals , Mice
12.
Med Mycol J ; 60(2): 29-37, 2019.
Article in English | MEDLINE | ID: mdl-31155569

ABSTRACT

We previously reported that Candida albicans responded to mild heat stress in a range of temperature elevations simulating fever, and concluded that mild heat stress increases susceptibility to antifungal drugs. In this study, we show that mild heat stress causes a morphological change in hyphae during the process of biofilm formation. We found that mild heat stress extended the period of hyphal stage maintenance in C. albicans biofilm. Although the rate of hyphal change from yeast form to hyphal form reached the maximum within 3 hr, later, almost every cell quickly reverted to the yeast growth phase within 6 hr at 37°C but not at 39°C, or under mild heat stress. Electron microscopy using a smart specimen preparation technique revealed that mild heat stress significantly increased the thickness of the inner cell wall accompanied by a decrease in density of the outer cell wall in the hyphae of C. albicans biofilm. To identify the gene responsible for the morphological changes associated with mild heat stress, we performed microarray gene expression analysis. Eleven genes were upregulated and 17 genes were downregulated under mild heat stress in biofilm cells. The increased PHR1 gene expression in response to mild heat stress was confirmed in quantitative RT-PCR analysis. The mutant upregulated PHR1 expression showed the same sensitivity against antifungal drug micafungin as dependent on mild heat stress. Our findings point to possible therapeutic effects of hyperthermia as well as to the effect of fever during infections.


Subject(s)
Biofilms , Candida albicans/cytology , Candida albicans/physiology , Cell Wall/pathology , Fever/microbiology , Hot Temperature , Stress, Physiological/genetics , Stress, Physiological/physiology , Antifungal Agents/pharmacology , Candida albicans/genetics , Candida albicans/ultrastructure , Candidiasis/therapy , Cell Wall/ultrastructure , Down-Regulation/genetics , Drug Resistance, Fungal/genetics , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression/genetics , Gene Expression Regulation, Fungal/genetics , Hyphae , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Micafungin/pharmacology , Microscopy, Electron , Time Factors
13.
Sci Rep ; 8(1): 8452, 2018 05 31.
Article in English | MEDLINE | ID: mdl-29855532

ABSTRACT

Biofilms are well-organised communities of microbes embedded in a self-produced extracellular matrix (e.g., curli amyloid fibers) and are associated with chronic infections. Therefore, development of anti-biofilm drugs is important to combat with these infections. Previously, we found that flavonol Myricetin inhibits curli-dependent biofilm formation by Escherichia coli (IC50 = 46.2 µM). In this study, we tested activities of seven Myricetin-derivatives to inhibit biofilm formation by E. coli K-12 in liquid culture. Among them, only Epigallocatechin gallate (EGCG), a major catechin in green tea, inhibited biofilm formation of K-12 (IC50 = 5.9 µM) more efficiently than Myricetin. Transmission electron microscopy and immunoblotting analyses demonstrated that EGCG prevented curli production by suppressing the expression of curli-related proteins. Quantitative RT-PCR analysis revealed that the transcripts of csgA, csgB, and csgD were significantly reduced in the presence of EGCG. Interestingly, the cellular level of RpoS, a stationary-phase specific alternative sigma factor, was reduced in the presence of EGCG, whereas the rpoS transcript was not affected. Antibiotic-chase experiments and genetic analyses revealed that EGCG accelerated RpoS degradation by ATP-dependent protease ClpXP in combination with its adaptor RssB. Collectively, these results provide significant insights into the development of drugs to treat chronic biofilm-associated infections.


Subject(s)
Bacterial Proteins/metabolism , Biofilms/drug effects , Escherichia coli/physiology , Flavonoids/pharmacology , Bacterial Proteins/genetics , Biofilms/growth & development , Catechin/analogs & derivatives , Catechin/pharmacology , Flavonoids/chemistry , Gene Expression Regulation, Bacterial/drug effects , Sigma Factor/genetics , Sigma Factor/metabolism
14.
FEMS Yeast Res ; 18(3)2018 05 01.
Article in English | MEDLINE | ID: mdl-29462298

ABSTRACT

Candida albicans is a human commensal that causes opportunistic infections. Th17 cells provide resistance against mucosal infection with C. albicans; however, the T cell antigens remain little known. Our final goal is to find effective T cell antigens of C. albicans that are responsible for immunotherapy against candidiasis. Here, we prepared fractions including cytosol, membrane and cell wall from yeast and mycelial cells. Proteins derived from a membrane fraction of mycelial cells effectively induced differentiation of CD4+ T cells into IL-17A-producing Th17 cells. To confirm the immunological response in vivo of proteins from mycelial membrane, we performed adoptive transfer experiments using ex vivo stimulated CD4+ T cells from IL-17A-GFP reporter mice. Mycelial membrane-differentiated CD4+ Th17 cells adoptively transferred intravenously prevented oral candidiasis by oral infection of C. albicans, compared with control anti-CD3-stimulated CD4+ T cells. This was confirmed by the clinical score and the number of neutrophils on the infected tissues. These data suggest that effective T cell antigens against candidiasis could be present in the membrane protein fraction of mycelial cells. The design of novel vaccination strategies against candidiasis will be our next step.


Subject(s)
Candidiasis, Oral/prevention & control , Fungal Proteins/pharmacology , Mycelium/chemistry , Th17 Cells/immunology , Adoptive Transfer , Animals , Antigens, Fungal/immunology , Antigens, Fungal/pharmacology , Candida albicans/immunology , Candidiasis, Oral/immunology , Cell Differentiation , Female , Fungal Proteins/immunology , Male , Mice , Mice, Inbred C57BL , Mycelium/immunology , Th17 Cells/cytology
15.
Stapp Car Crash J ; 62: 67-91, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30608993

ABSTRACT

Chest injuries occur frequently in frontal collisions. During impact, tension in the lap belt is transferred to the inboard shoulder belt, which compresses the lower ribs of the occupant. In this research, inboard shoulder belt and lap belt geometries and forces were investigated to reduce chest deflection. First, the inboard shoulder belt geometry was changed by the lap/shoulder belt (L/S) junction for the rear seat occupant in sled tests using Hybrid III finite element simulation, sled tests and THOR simulation. As the L/S junction was closer to the ASIS (anterior superior iliac spine), chest deflection of the Hybrid III was smaller. The L/S junction around the ilium has the potential to reduce chest deflection without significant increase of head excursion. For THOR, although the chest deflection reduction effect due to closer L/S junction to the ASIS was observed, chest deflection was still substantially large since the lap belt overrode the ASIS. Second, measures to hook the ASIS of the THOR by the lap belt were examined. Sled tests at 30 and 50 km/h were conducted with THOR in the rear seat, and it was demonstrated that the outboard lap belt and buckle pretensioners improved the lap belt and ASIS interaction, and were also useful in reducing the deflection at the inboard-side of the lower chest. Finally, the lap belt overlap with the ASIS was compared among 10 volunteers, Hybrid III, and THOR. Some volunteers had the ASIS located at the torso-thigh junction, and the lap belt did not overlap the ASIS sufficiently. However, although the ASIS location of THOR is also at the torso-thigh junction, the lap belt overlapped the ASIS because of the abdomen's and femur's shape. In the future, it will be necessary to consider that the outboard lap belt and buckle pretensioners are also effective for the ASIS restraint of all human car occupants.


Subject(s)
Accidents, Traffic , Seat Belts , Shoulder , Thorax , Biomechanical Phenomena , Equipment Design , Humans
16.
Sci Rep ; 7(1): 17402, 2017 12 12.
Article in English | MEDLINE | ID: mdl-29234109

ABSTRACT

Interleukin (IL)-17-producing T helper (Th17) cells are crucial for host defense against extracellular microbes and pathogenesis of autoimmune diseases. Here we show that the AP-1 transcription factor JunB is required for Th17 cell development. Junb-deficient CD4+ T cells are able to develop in vitro into various helper T subsets except Th17. The RNA-seq transcriptome analysis reveals that JunB is crucial for the Th17-specific gene expression program. Junb-deficient mice are completely resistant to experimental autoimmune encephalomyelitis, a Th17-mediated inflammatory disease, and naive T helper cells from such mice fail to differentiate into Th17 cells. JunB appears to activate Th17 signature genes by forming a heterodimer with BATF, another AP-1 factor essential for Th17 differentiation. The mechanism whereby JunB controls Th17 cell development likely involves activation of the genes for the Th17 lineage-specifying orphan receptors RORγt and RORα and reduced expression of Foxp3, a transcription factor known to antagonize RORγt function.


Subject(s)
Cell Differentiation/physiology , Th17 Cells/metabolism , Transcription Factors/metabolism , 3T3 Cells , Animals , Basic-Leucine Zipper Transcription Factors/metabolism , Cell Line, Tumor , Encephalomyelitis, Autoimmune, Experimental/metabolism , Encephalomyelitis, Autoimmune, Experimental/pathology , Encephalomyelitis, Autoimmune, Experimental/prevention & control , HEK293 Cells , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Mice , Mice, Inbred C57BL , Mice, Transgenic , Nuclear Receptor Subfamily 1, Group F, Member 1/metabolism , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , Proto-Oncogene Proteins c-jun/metabolism , Psoriasis/metabolism , Psoriasis/pathology , Transcription Factors/genetics
17.
Int J Inflam ; 2017: 1324735, 2017.
Article in English | MEDLINE | ID: mdl-28523202

ABSTRACT

Activation of naive CD4+ T cells results in the development of several distinct subsets of effector Th cells, including Th2 cells that play a pivotal role in allergic inflammation and helminthic infections. SWAP-70-like adapter of T cells (SLAT), also known as Def6 or IBP, is a guanine nucleotide exchange factor for small GTPases, which regulates CD4+ T cell inflammatory responses by controlling Ca2+/NFAT signaling. In this study, we have identified a novel alternatively spliced isoform of SLAT, named SLAT2, which lacks the region encoded by exons 2-7 of the Def6 gene. SLAT2 was selectively expressed in differentiated Th2 cells after the second round of in vitro stimulation, but not in differentiated Th1, Th17, or regulatory T (Treg) cells. Functional assays revealed that SLAT2 shared with SLAT the ability to enhance T cell receptor- (TCR-) mediated activation of NFAT and production of IL-4 but was unable to enhance TCR-induced adhesion to ICAM-1. Ectopic expression of SLAT2 or SLAT in Jurkat T cells resulted in the expression of distinct forms of filopodia, namely, short versus long ones, respectively. These results demonstrate that modulating either SLAT2 or SLAT protein expression could play critical roles in cytokine production and actin reorganization during inflammatory immune responses.

19.
Nat Commun ; 8: 13946, 2017 01 09.
Article in English | MEDLINE | ID: mdl-28067314

ABSTRACT

Mutations of DOCK8 in humans cause a combined immunodeficiency characterized by atopic dermatitis with high serum IgE levels. However, the molecular link between DOCK8 deficiency and atopic skin inflammation is unknown. Here we show that CD4+ T cells from DOCK8-deficient mice produce large amounts of IL-31, a major pruritogen associated with atopic dermatitis. IL-31 induction critically depends on the transcription factor EPAS1, and its conditional deletion in CD4+ T cells abrogates skin disease development in DOCK8-deficient mice. Although EPAS1 is known to form a complex with aryl hydrocarbon receptor nuclear translocator (ARNT) and control hypoxic responses, EPAS1-mediated Il31 promoter activation is independent of ARNT, but in collaboration with SP1. On the other hand, we find that DOCK8 is an adaptor and negative regulator of nuclear translocation of EPAS1. Thus, EPAS1 links DOCK8 deficiency to atopic skin inflammation via IL-31 induction in CD4+ T cells.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/genetics , CD4-Positive T-Lymphocytes/immunology , Dermatitis, Atopic/genetics , Guanine Nucleotide Exchange Factors/genetics , Interleukins/genetics , Active Transport, Cell Nucleus , Animals , Aryl Hydrocarbon Receptor Nuclear Translocator/genetics , Aryl Hydrocarbon Receptor Nuclear Translocator/immunology , Basic Helix-Loop-Helix Transcription Factors/deficiency , Basic Helix-Loop-Helix Transcription Factors/immunology , CD4-Positive T-Lymphocytes/pathology , Cell Nucleus/immunology , Cell Nucleus/metabolism , Cytosol/immunology , Cytosol/metabolism , Dermatitis, Atopic/immunology , Dermatitis, Atopic/pathology , Disease Models, Animal , Female , Gene Expression Regulation , Guanine Nucleotide Exchange Factors/deficiency , Guanine Nucleotide Exchange Factors/immunology , Heterozygote , Immunoglobulin E/genetics , Immunoglobulin E/immunology , Interleukins/immunology , Male , Mice , Mice, Knockout , Promoter Regions, Genetic , Protein Transport , Signal Transduction , Sp1 Transcription Factor/genetics , Sp1 Transcription Factor/immunology
20.
FEMS Yeast Res ; 17(1)2017 02.
Article in English | MEDLINE | ID: mdl-27915244

ABSTRACT

Protamine peptide (PP) derived from salmon is a 14-mer with 10 arginine residues. We investigated the in vitro and in vivo antifungal activity of PP against Candida albicans PP showed a concentration-dependent dual mode of action, with fungicidal activity and inhibitory activity for hyphal development in vitro. At lethal concentrations of PP, intracellular accumulation of PP was energy-dependent but independent of endocytosis, and resulted in ATP efflux and the generation of reactive oxygen species in the cells. PP at sublethal concentrations inhibited hyphal development in C. albicans by binding to the cell surface. Though antifungal activity of PP was inactivated by high concentrations of NaCl, the antifungal activity of the synthetic cyclic (via a disulfide bond) form of PP (cyclic PP) was not. Cyclic PP also showed the concentration-dependent dual mode of action, and had five-fold greater antifungal activity than PP. The advantage of antifungal activity of cyclic PP compared with PP in vitro resulted in a high in vivo efficacy in a murine oral candidiasis model. Oral treatment with cyclic PP inhibited hyphal development of C. albicans on mouse tongues and protected against the development of severe candidiasis. This study shows the therapeutic potential of cyclic PP as an antifungal peptide against C. albicans.


Subject(s)
Antifungal Agents/metabolism , Candida albicans/drug effects , Heparin Antagonists/metabolism , Peptides, Cyclic/metabolism , Protamines/metabolism , Adenosine Triphosphate/metabolism , Animals , Antifungal Agents/therapeutic use , Candida albicans/growth & development , Candida albicans/physiology , Candidiasis, Oral/drug therapy , Disease Models, Animal , Heparin Antagonists/therapeutic use , Hyphae/drug effects , Hyphae/growth & development , Mice , Microbial Viability/drug effects , Peptides, Cyclic/therapeutic use , Protamines/therapeutic use , Reactive Oxygen Species/metabolism , Salmon , Treatment Outcome
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