scholarly journals The cytokine receptor DR3 identifies and activates thymic NKT17 cells

2021 ◽  
Author(s):  
Shunqun Luo ◽  
Nurcin Liman ◽  
Assiatu Crossman ◽  
Jung Hyun Park
Keyword(s):  
Molecular Mechanisms ◽  
Cytokine Receptor ◽  
Thymic Development ◽  
Activation Mechanisms ◽  
And Function ◽  
Barrier Tissues ◽  
Role And Function ◽  
Invariant Natural Killer

Invariant natural killer T (iNKT) cells are thymus-generated T cells with innate-like characteristics and effector function. Several functionally distinct iNKT subsets have been identified, but NKT17 is the only iNKT subset that produces the proinflammatory cytokine IL-17. NKT17 cells are generated in the thymus and then exported into the periphery to populate lymphoid organs and barrier tissues, such as the lung, to provide critical support in host defense. However, the molecular mechanisms that drive the thymic development and subset-specific activation of NKT17 cells remain mostly unknown. Here, we identify the cytokine receptor DR3, a member of the TNF receptor superfamily, being selectively expressed on NKT17 cells but absent on all other thymic iNKT subsets. We further demonstrate that DR3 ligation leads to the in vivo activation of thymic NKT17 cells and provides in vitro costimulatory effects upon α-GalCer-stimulation. Thus, our study reports the identification of a specific surface marker for thymic NKT17 cells that selectively triggers their activation both in vivo and in vitro. These findings provide new insights for deciphering the role and function of IL-17-producing NKT17 cells and for understanding the development and activation mechanisms of iNKT cells in general.

scholarly journals The Ubiquitously Expressed Csk Adaptor Protein Cbp Is Dispensable for Embryogenesis and T-Cell Development and Function

2005 ◽  
Vol 25 (23) ◽  
pp. 10533-10542 ◽  
Author(s):  
Marc-Werner Dobenecker ◽  
Christian Schmedt ◽  
Masato Okada ◽  
Alexander Tarakhovsky
Keyword(s):  
T Cell ◽  
Adaptor Protein ◽  
Regulatory Function ◽  
Loss Of Function ◽  
Thymic Development ◽  
Cell Functions ◽  
Carboxy Terminal ◽  
And Function

ABSTRACT Regulation of Src family kinase (SFK) activity is indispensable for a functional immune system and embryogenesis. The activity of SFKs is inhibited by the presence of the carboxy-terminal Src kinase (Csk) at the cell membrane. Thus, recruitment of cytosolic Csk to the membrane-associated SFKs is crucial for its regulatory function. Previous studies utilizing in vitro and transgenic models suggested that the Csk-binding protein (Cbp), also known as phosphoprotein associated with glycosphingolipid microdomains (PAG), is the membrane adaptor for Csk. However, loss-of-function genetic evidence to support this notion was lacking. Herein, we demonstrate that the targeted disruption of the cbp gene in mice has no effect on embryogenesis, thymic development, or T-cell functions in vivo. Moreover, recruitment of Csk to the specialized membrane compartment of “lipid rafts” is not impaired by Cbp deficiency. Our results indicate that Cbp is dispensable for the recruitment of Csk to the membrane and that another Csk adaptor, yet to be discovered, compensates for the loss of Cbp.

scholarly journals HIF-1–dependent repression of equilibrative nucleoside transporter (ENT) in hypoxia

2005 ◽  
Vol 202 (11) ◽  
pp. 1493-1505 ◽  
Author(s):  
Holger K. Eltzschig ◽  
Parween Abdulla ◽  
Edgar Hoffman ◽  
Kathryn E. Hamilton ◽  
Dionne Daniels ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Molecular Mechanisms ◽  
Hypoxia Inducible Factor ◽  
Nucleoside Transporter ◽  
In Vivo Models ◽  
Equilibrative Nucleoside Transporter ◽  
Hypoxia Inducible Factor 1 ◽  
And Function

Extracellular adenosine (Ado) has been implicated as central signaling molecule during conditions of limited oxygen availability (hypoxia), regulating physiologic outcomes as diverse as vascular leak, leukocyte activation, and accumulation. Presently, the molecular mechanisms that elevate extracellular Ado during hypoxia are unclear. In the present study, we pursued the hypothesis that diminished uptake of Ado effectively enhances extracellular Ado signaling. Initial studies indicated that the half-life of Ado was increased by as much as fivefold after exposure of endothelia to hypoxia. Examination of expressional levels of the equilibrative nucleoside transporter (ENT)1 and ENT2 revealed a transcriptionally dependent decrease in mRNA, protein, and function in endothelia and epithelia. Examination of the ENT1 promoter identified a hypoxia inducible factor 1 (HIF-1)–dependent repression of ENT1 during hypoxia. Using in vitro and in vivo models of Ado signaling, we revealed that decreased Ado uptake promotes vascular barrier and dampens neutrophil tissue accumulation during hypoxia. Moreover, epithelial Hif1α mutant animals displayed increased epithelial ENT1 expression. Together, these results identify transcriptional repression of ENT as an innate mechanism to elevate extracellular Ado during hypoxia.

scholarly journals Building neuromuscular junctions in vitro

Development ◽  
2020 ◽  
Vol 147 (22) ◽  
pp. dev193920
Author(s):  
Susie Barbeau ◽  
Julie Tahraoui-Bories ◽  
Claire Legay ◽  
Cécile Martinat
Keyword(s):  
Human Disease ◽  
Molecular Mechanisms ◽  
Neuromuscular Junctions ◽  
Ex Vivo ◽  
Culture Methods ◽  
Recent Developments ◽  
Chemical Synapses ◽  
And Function

ABSTRACTThe neuromuscular junction (NMJ) has been the model of choice to understand the principles of communication at chemical synapses. Following groundbreaking experiments carried out over 60 years ago, many studies have focused on the molecular mechanisms underlying the development and physiology of these synapses. This Review summarizes the progress made to date towards obtaining faithful models of NMJs in vitro. We provide a historical approach discussing initial experiments investigating NMJ development and function from Xenopus to mice, the creation of chimeric co-cultures, in vivo approaches and co-culture methods from ex vivo and in vitro derived cells, as well as the most recent developments to generate human NMJs. We discuss the benefits of these techniques and the challenges to be addressed in the future for promoting our understanding of development and human disease.

scholarly journals Oxidatively Modified LDL Suppresses Lymphangiogenesis via CD36 Signaling

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 331
Author(s):  
Bhupesh Singla ◽  
Hui-Ping Lin ◽  
WonMo Ahn ◽  
Joseph White ◽  
Gábor Csányi
Keyword(s):  
Cell Cycle ◽  
Molecular Mechanisms ◽  
Oxidized Ldl ◽  
Atherosclerotic Lesion ◽  
Tube Formation ◽  
Adventitial Layer ◽  
Oxidatively Modified ◽  
And Function

Arterial accumulation of plasma-derived LDL and its subsequent oxidation contributes to atherosclerosis. Lymphatic vessel (LV)-mediated removal of arterial cholesterol has been shown to reduce atherosclerotic lesion formation. However, the precise mechanisms that regulate LV density and function in atherosclerotic vessels remain to be identified. The aim of this study was to investigate the role of native LDL (nLDL) and oxidized LDL (oxLDL) in modulating lymphangiogenesis and underlying molecular mechanisms. Western blotting and immunostaining experiments demonstrated increased oxLDL expression in human atherosclerotic arteries. Furthermore, elevated oxLDL levels were detected in the adventitial layer, where LV are primarily present. Treatment of human lymphatic endothelial cells (LEC) with oxLDL inhibited in vitro tube formation, while nLDL stimulated it. Similar results were observed with Matrigel plug assay in vivo. CD36 deletion in mice and its siRNA-mediated knockdown in LEC prevented oxLDL-induced inhibition of lymphangiogenesis. In addition, oxLDL via CD36 receptor suppressed cell cycle, downregulated AKT and eNOS expression, and increased levels of p27 in LEC. Collectively, these results indicate that oxLDL inhibits lymphangiogenesis via CD36-mediated regulation of AKT/eNOS pathway and cell cycle. These findings suggest that therapeutic blockade of LEC CD36 may promote arterial lymphangiogenesis, leading to increased cholesterol removal from the arterial wall and reduced atherosclerosis.

scholarly journals Integrative genomic analysis of early neurogenesis reveals a temporal genetic program for differentiation and specification of preplate and Cajal-Retzius neurons

2018 ◽  
Author(s):  
Jia Li ◽  
Lei Sun ◽  
Xue-Liang Peng ◽  
Xiao-Ming Yu ◽  
Shao-Jun Qi ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Molecular Mechanisms ◽  
Genomic Analysis ◽  
Molecular Heterogeneity ◽  
Sequencing Analysis ◽  
Cortical Function ◽  
Early Neurogenesis ◽  
And Function

AbstractNeurogenesis in the developing neocortex begins with the generation of the preplate, which consists of early born neurons including Cajal-Retzius (CR) cells and subplate neurons. Here, utilizing the Ebf2-EGFP transgenic mouse in which EGFP initially labels the preplate neurons then persists in CR cells, we reveal the dynamic transcriptome profiles of early neurogenesis and CR cell differentiation. At E15.5 when Ebf2-EGFP+ cells are mostly CR neurons, single-cell sequencing analysis of purified Ebf2-EGFP+ cells uncovers molecular heterogeneity in CR neurons, but without apparent clustering of cells with distinct regional origins. Along a pseudotemporal trajectory these cells are classified into three different developing states, revealing genetic cascades from early generic neuronal differentiation to late fate specification during the establishment of CR neuron identity and function. Further genome-wide RNA-seq and ChIP-seq analyses at multiple early neurogenic stages have revealed the temporal gene expression dynamics of early neurogenesis and distinct histone modification patterns in early differentiating neurons. We have also identified a new set of coding genes and lncRNAs involved in early neuronal differentiation and validated with functional assays In Vitro and In Vivo. Our findings shed light on the molecular mechanisms governing the early differentiation steps during cortical development, especially CR neuron biology, and help understand the developmental basis for cortical function and diseases.

scholarly journals Peiminine Suppresses RANKL-Induced Osteoclastogenesis by Inhibiting the NFATc1, ERK, and NF-κB Signaling Pathways

2021 ◽  
Vol 12 ◽  
Author(s):  
Mengbo Zhu ◽  
Wenbin Xu ◽  
Jiuzhou Jiang ◽  
Yining Wang ◽  
Yanjing Guo ◽  
...  
Keyword(s):  
Bone Loss ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Inhibitory Effect ◽  
Chinese Herbal ◽  
Novel Approach ◽  
Series Of Experiments ◽  
And Function

Osteoclasts (OCs) play an important role in osteoporosis, a disease that is mainly characterized by bone loss. In our research, we aimed to identify novel approach for regulating osteoclastogenesis and thereby treating osteoporosis. Previous studies have set a precedent for screening traditional Chinese herbal extracts for effective inhibitors. Peiminine is an alkaloid extracted from the bulb of Fritillaria thunbergii Miq that reportedly has anticancer and anti-inflammatory effects. Thus, the potential inhibitory effect of peiminine on OC differentiation was investigated via a series of experiments. According to the results, peiminine downregulated the levels of specific genes and proteins in vitro and consequently suppressed OC differentiation and function. Based on these findings, we further investigated the underlying molecular mechanisms and identified the NF-κB and ERK1/2 signaling pathways as potential targets of peiminine. In vivo, peiminine alleviated bone loss in an ovariectomized mouse model.

Tumor Evasion of the Immune System: Inhibiting p38 MAP Kinase Signaling Restores the Function of Dendritic Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2512-2512
Author(s):  
Qing Yi ◽  
Siqing Wang ◽  
Jing Yang ◽  
Jianfei Wang ◽  
Michele Wezeman ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
P38 Mapk ◽  
Neutralizing Antibodies ◽  
Molecular Mechanisms ◽  
P38 Map Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Myeloma Cells ◽  
And Function

Abstract Dendritic cells (DCs) from cancer patients are functionally defective, however, molecular mechanisms underlying are still poorly understood. In this study, we used the murine 5TGM1 myeloma model to examine the effect and mechanism of tumor-derived factors on the differentiation and function of DCs. Myeloma cells (5TGM1) or tumor culture conditioning medium (TCCM) were shown to inhibit differentiation and function of BM-derived DCs (BMDCs), evidenced by the downregulated expression of DC-related surface molecules, decreased IL-12 but increased IL-10 secretion, and compromised capacity of the cells to activate allospecific T cells in vitro. Similar results were obtained with other murine myeloma cells MOPC-315 and MPC-11. Moreover, TCCM-treated BMDCs were inferior to normal BMDCs at priming tumor-specific humoral and cellular immune responses in vivo (in the 5TGM1 mouse model). Neutralizing antibodies against IL-6, IL-10, and TGF-β partially abrogated the effects. TCCM treatment activated p38 mitogen-activated protein kinase (MAPK) and JNK but inhibited extracellular signal-related kinase (ERK). Inhibiting p38 MAPK by three different specific inhibitors was found to restore the phenotype, cytokine secretion, and function of TCCM-treated BMDCs. Vaccinating mice with BMDCs obtained from cultures in which both TCCM and p38 inhibitor were added was as efficacious as normal BMDCs at inducing tumor-specific antibody, type-1 (IFN-γ) T-cell, and CTL responses. Thus, our results suggest that tumor-induced p38 MAPK activation and ERK inhibition in DCs may be a new mechanism for tumor evasion, and regulating these signaling pathways in vivo or during DC differentiation may provide new strategies for generating potent DC vaccines for immunotherapy of multiple myeloma and other tumors.

scholarly journals Lactobacillus acidophilus upregulates intestinal NHE3 expression and function

2012 ◽  
Vol 303 (12) ◽  
pp. G1393-G1401 ◽  
Author(s):  
Varsha Singh ◽  
Geetu Raheja ◽  
Alip Borthakur ◽  
Anoop Kumar ◽  
Ravinder K. Gill ◽  
...  
Keyword(s):  
Lactobacillus Acidophilus ◽  
Molecular Mechanisms ◽  
Major Mechanism ◽  
Protein Levels ◽  
Nacl Absorption ◽  
Human Colonic Adenocarcinoma Cell ◽  
And Function ◽  
Exchange Activity

A major mechanism of electroneutral NaCl absorption in the human ileum and colon involves coupling of Na+/H+ and Cl−/HCO3− exchangers. Disturbances in these mechanisms have been implicated in diarrheal conditions. Probiotics such as Lactobacillus have been indicated to be beneficial in the management of gastrointestinal disorders, including diarrhea. However, the molecular mechanisms underlying antidiarrheal effects of probiotics have not been fully understood. We have previously demonstrated Lactobacillus acidophilus (LA) to stimulate Cl−/HCO3− exchange activity via an increase in the surface levels and expression of the Cl−/HCO3− exchanger DRA in vitro and in vivo. However, the effects of LA on NHE3, the Na+/H+ exchanger involved in the coupled electroneutral NaCl absorption, are not known. Current studies were, therefore, undertaken to investigate the effects of LA on the function and expression of NHE3 and to determine the mechanisms involved. Treatment of Caco2 cells with LA or its conditioned culture supernatant (CS) for 8–24 h resulted in a significant increase in Na+/H+ exchange activity, mRNA, and protein levels of NHE3. LA-CS upregulation of NHE3 function and expression was also observed in SK-CO15 cells, a human colonic adenocarcinoma cell line. Additionally, LA treatment increased NHE3 promoter activity, suggesting involvement of transcriptional mechanisms. In vivo, mice gavaged with live LA showed significant increase in NHE3 mRNA and protein expression in the ileum and colonic regions. In conclusion, LA-induced increase in NHE3 expression may contribute to the upregulation of intestinal electrolyte absorption and might underlie the potential antidiarrheal effects of probiotics.

Abstract 16596: Immune Evasion by Human Neonatal Cardiac Mesenchymal Stem Cells Demonstrates Therapeutic Application in Myocardial Infarction

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Muthukumar Gunasekaran ◽  
Rachana Mishra ◽  
Progyaparamita Saha ◽  
Aakash Shah ◽  
Lauren Davidson ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Immune Evasion ◽  
Molecular Mechanisms ◽  
Cell Retention ◽  
Over Expression ◽  
And Function

Immune rejection of transplanted stem cells is a major stumbling block in designing effective therapy for myocardial infarction. Human neonatal cardiac mesenchymal stem cells (nMSCs) showed superior cardiac functional recovery compared to adult MSCs in immune competent rat MI model. However, molecular mechanisms underlying immune evasion by transplanted nMSCs in the infarcted myocardium remain unexplored. In this investigation, we demonstrate for the first-time the expression, regulation and function of CD47 in human nMSCs and its novel mechanism of immune evasion increases its regenerative potential in rat MI model. Transplanted nMSCs showed significant increased cell retention, reduced phagocytosis and CD68 + cells compared to aMSCs in rat MI model. Comparative proteomic analysis by LC-MS/MS on nMSCs and aMSCs showed that CD47 higher in nMSCs. Increased CD47 expression in nMSCs inhibited phagocytosis compared to aMSCs in vitro and in vivo . Further, CD47 blockade in nMSCs using anti-CD47, siRNA and shRNA lentiviral based approaches increased in vitro , in vivo phagocytosis, CD68 + cells and reduced cell retention and MI recovery in vivo . Microarray analysis and validation showed miR-34a was significantly higher in aMSCs than nMSCs. To unravel CD47 regulation in aMSCs, we performed target scan analysis that predicted miR-34a binds on CD47. Further, miR-34a over expression in nMSCs reduced CD47 expression, increased in vitro and in vivo phagocytosis and reduced cell retention and MI recovery. In conclusion, increased CD47 expression in nMSCs inhibit phagocytosis by CD47/SIRPα immune regulatory axis to demonstrates its immune evasion potential and its therapeutic applications in myocardial infarction.

scholarly journals Integrative genomic analysis of early neurogenesis reveals a temporal genetic program for differentiation and specification of preplate and Cajal-Retzius neurons

PLoS Genetics ◽  
2021 ◽  
Vol 17 (3) ◽  
pp. e1009355
Author(s):  
Jia Li ◽  
Lei Sun ◽  
Xue-Liang Peng ◽  
Xiao-Ming Yu ◽  
Shao-Jun Qi ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Molecular Mechanisms ◽  
Genomic Analysis ◽  
Sequencing Analysis ◽  
Temporal Gene Expression ◽  
Developing Neocortex ◽  
Early Neurogenesis ◽  
And Function

Neurogenesis in the developing neocortex begins with the generation of the preplate, which consists of early-born neurons including Cajal-Retzius (CR) cells and subplate neurons. Here, utilizing the Ebf2-EGFP transgenic mouse in which EGFP initially labels the preplate neurons then persists in CR cells, we reveal the dynamic transcriptome profiles of early neurogenesis and CR cell differentiation. Genome-wide RNA-seq and ChIP-seq analyses at multiple early neurogenic stages have revealed the temporal gene expression dynamics of early neurogenesis and distinct histone modification patterns in early differentiating neurons. We have identified a new set of coding genes and lncRNAs involved in early neuronal differentiation and validated with functional assays in vitro and in vivo. In addition, at E15.5 when Ebf2-EGFP+ cells are mostly CR neurons, single-cell sequencing analysis of purified Ebf2-EGFP+ cells uncovers molecular heterogeneities in CR neurons, but without apparent clustering of cells with distinct regional origins. Along a pseudotemporal trajectory these cells are classified into three different developing states, revealing genetic cascades from early generic neuronal differentiation to late fate specification during the establishment of CR neuron identity and function. Our findings shed light on the molecular mechanisms governing the early differentiation steps during cortical development, especially CR neuron differentiation.

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