scholarly journals Regulation of Exosome Secretion by Cellular Retinoic Acid Binding Protein 1 Contributes to Systemic Anti-inflammation

2021 ◽  
Author(s):  
Yi-Wei Lin ◽  
Jennifer Nhieu ◽  
Chin-Wen Wei ◽  
Yu-Lung Lin ◽  
Hiroyuki Kagechika ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Systemic Inflammation ◽  
Intercellular Communication ◽  
Clinical Relevance ◽  
Binding Protein ◽  
Embryonic Stem ◽  
Mapk Signaling ◽  
Negative Control ◽  
Negative Regulator

Abstract Background: Intercellular communications are important for maintaining normal physiological processes. An important intercellular communication is mediated by the exchange of membrane-enclosed extracellular vesicles. Among various vesicles, exosomes can be detected in a wide variety of biological systems, but the regulation and biological implication of exosome secretion/uptake remains largely unclear.Methods: Cellular retinoic acid (RA) binding protein 1 (Crabp1) knockout (CKO) mice were used for in vivo studies. Extracellular exosomes were monitored in CKO mice and relevant cell cultures including embryonic stem cell (CJ7), macrophage (Raw 264.7) and hippocampal cell (HT22) using Western blot and flow cytometry. Receptor Interacting Protein 140 (RIP140) was depleted by Crispr/Cas9-mediated gene editing. Anti-inflammatory maker was analyzed using qRT-PCR. Clinical relevance was accessed by mining multiple clinical datasets. Results: This study uncovers Crabp1 as a negative regulator of exosome secretion from neurons. Specifically, RIP140, a pro-inflammatory regulator, can be transferred from neurons, via Crabp1-regulated exosome secretion, into macrophages to promote their inflammatory polarization. Consistently, CKO mice, defected in the negative control of exosome secretion, have significantly elevated RIP140-containing exosomes in their blood and cerebrospinal fluid, and exhibit an increased vulnerability to systemic inflammation. Clinical relevance of this pathway is supported by patients’ data of multiple inflammatory diseases. Further, the action of Crabp1 in regulating exosome secretion involves its ligand and is mediated by its downstream target, the MAPK signaling pathway.Conclusions: This study presents the first evidence for the regulation of exosome secretion, which mediates intercellular communication, by RA-Crabp1 signaling. This novel mechanism can contribute to the control of systemic inflammation by transferring an inflammatory regulator, RIP140, between cells. This represents a new mechanism of vitamin A action that can modulate the homeostasis of system-wide innate immunity without involving gene regulation.

scholarly journals Regulation of exosome secretion by cellular retinoic acid binding protein 1 contributes to systemic anti-inflammation

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yi-Wei Lin ◽  
Jennifer Nhieu ◽  
Chin-Wen Wei ◽  
Yu-Lung Lin ◽  
Hiroyuki Kagechika ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Systemic Inflammation ◽  
Intercellular Communication ◽  
Clinical Relevance ◽  
Binding Protein ◽  
Embryonic Stem ◽  
Mapk Signaling ◽  
Negative Regulator ◽  
In Vivo Studies

Abstract Background Intercellular communications are important for maintaining normal physiological processes. An important intercellular communication is mediated by the exchange of membrane-enclosed extracellular vesicles. Among various vesicles, exosomes can be detected in a wide variety of biological systems, but the regulation and biological implication of exosome secretion/uptake remains largely unclear. Methods Cellular retinoic acid (RA) binding protein 1 (Crabp1) knockout (CKO) mice were used for in vivo studies. Extracellular exosomes were monitored in CKO mice and relevant cell cultures including embryonic stem cell (CJ7), macrophage (Raw 264.7) and hippocampal cell (HT22) using Western blot and flow cytometry. Receptor Interacting Protein 140 (RIP140) was depleted by Crispr/Cas9-mediated gene editing. Anti-inflammatory maker was analyzed using qRT-PCR. Clinical relevance was accessed by mining multiple clinical datasets. Results This study uncovers Crabp1 as a negative regulator of exosome secretion from neurons. Specifically, RIP140, a pro-inflammatory regulator, can be transferred from neurons, via Crabp1-regulated exosome secretion, into macrophages to promote their inflammatory polarization. Consistently, CKO mice, defected in the negative control of exosome secretion, have significantly elevated RIP140-containing exosomes in their blood and cerebrospinal fluid, and exhibit an increased vulnerability to systemic inflammation. Clinical relevance of this pathway is supported by patients’ data of multiple inflammatory diseases. Further, the action of Crabp1 in regulating exosome secretion involves its ligand and is mediated by its downstream target, the MAPK signaling pathway. Conclusions This study presents the first evidence for the regulation of exosome secretion, which mediates intercellular communication, by RA-Crabp1 signaling. This novel mechanism can contribute to the control of systemic inflammation by transferring an inflammatory regulator, RIP140, between cells. This represents a new mechanism of vitamin A action that can modulate the homeostasis of system-wide innate immunity without involving gene regulation.

scholarly journals LARVICIDAL ACTIVITY OF LANTANA INDICA AND VITEX NEGUNDO ON CULEX QUINQUEFASCIATUS

2018 ◽  
Vol 11 (5) ◽  
pp. 414
Author(s):  
Rathnasagar K ◽  
Thiyagaraj Anand
Keyword(s):  
Larvicidal Activity ◽  
Culex Quinquefasciatus ◽  
Binding Protein ◽  
Inhibitory Effect ◽  
Negative Control ◽  
Vitex Negundo ◽  
Leaf Extracts ◽  
Active Compounds ◽  
Sterol Binding

Objectives: The activity of two different leaf extracts of Lantana indica and Vitex negundo is tested against the 3rd and 4th instar Culex quinquefasciatus larvae to evaluate the potency of the extracts as a larvicide and to find an ecologically sustainable alternative to chemical insecticides. A bioinformatics screening approach was performed to evaluate the in vivo results.Methods: The obtained larvae’s from nearby water sources were tested with N, N-diethyl-meta-toluamide (DEET) as the positive control which is the commercial chemical mosquito repellent and the solvents used for the respective plant extracts act as the negative control. Petroleum ether (PE), ethyl acetate (EA) and an aqueous (AQ) extract were prepared for both L. indica and V. negundo extracts, and its larvicidal activity was tested. A docking based approach was used to study the inhibitory effect of known active compounds from L. indica and V. negundo against acetylcholine esterase (AChE) and sterol binding protein as targets.Results: On comparing the results between three plants extract for its larvicidal activity, the EA extract of V. negundo and L. indica is found to be potent with a low LC50 value. Further, the docking studies between active compounds of L. indica and V. negundo with AChE and Sterol binding protein as targets showed that the compound tangeritin-1 had a good docking score compared to DEET and could be a natural alternative for larvicidal activity in the mosquito.Conclusion: Individual activity of tangeritin-1 could be further studied with mosquito mortality studies and molecular simulations and develop tangeritin-1 as a potential larvicidal compound for commercial use.

scholarly journals Targeted Deletion of the Lipopolysaccharide (LPS)-binding Protein Gene Leads to Profound Suppression of LPS Responses Ex Vivo, whereas In Vivo Responses Remain Intact

1997 ◽  
Vol 186 (12) ◽  
pp. 2051-2056 ◽  
Author(s):  
Mark M. Wurfel ◽  
Brian G. Monks ◽  
Robin R. Ingalls ◽  
Russell L. Dedrick ◽  
Russell Delude ◽  
...  
Keyword(s):  
Lipid Transfer Protein ◽  
Ex Vivo ◽  
Binding Protein ◽  
Embryonic Stem ◽  
Cellular Responses ◽  
Tnf Α ◽  
Deficient Mice ◽  
Lps Binding

Gram-negative bacterial lipopolysaccharide (LPS) stimulates phagocytic leukocytes by interacting with the cell surface protein CD14. Cellular responses to LPS are markedly potentiated by the LPS-binding protein (LBP), a lipid-transfer protein that binds LPS aggregates and transfers LPS monomers to CD14. LBP also transfers LPS to lipoproteins, thereby promoting the neutralization of LPS. LBP present in normal plasma has been shown to enhance the LPS responsiveness of cells in vitro. The role of LBP in promoting LPS responsiveness in vivo was tested in LBP-deficient mice produced by gene targeting in embryonic stem cells. Whole blood from LBP-deficient animals was 1,000-fold less responsive to LPS as assessed by the release of tumor necrosis factor (TNF)-α. Blood from gene-targeted mice was devoid of immunoreactive LBP, essentially incapable of transferring LPS to CD14 in vitro, and failed to support cellular responses to LPS. These activities were restored by the addition of exogenous recombinant murine LBP to the plasma. Despite these striking in vitro findings, no significant differences in TNF-α levels were observed in plasma from wild-type and LBP-deficient mice injected with LPS. These data suggest the presence of an LBP-independent mechanism for responding to LPS. These LBP knockout mice may provide a tool for discovering the nature of the presumed second mechanism for transferring LPS to responsive cells.

scholarly journals MKP-3 Has Essential Roles as a Negative Regulator of the Ras/Mitogen-Activated Protein Kinase Pathway during Drosophila Development

2004 ◽  
Vol 24 (2) ◽  
pp. 573-583 ◽  
Author(s):  
Myungjin Kim ◽  
Guang-Ho Cha ◽  
Sunhong Kim ◽  
Jun Hee Lee ◽  
Jeehye Park ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cell Fate ◽  
Photoreceptor Cells ◽  
Mapk Signaling ◽  
Negative Regulator ◽  
Mitogen Activated Protein Kinase ◽  
Loss Of Function ◽  
Wing Vein ◽  
Mitogen Activated Protein

ABSTRACT Mitogen-activated protein kinase (MAPK) phosphatase 3 (MKP-3) is a well-known negative regulator in the Ras/extracellular signal-regulated kinase (ERK)-MAPK signaling pathway responsible for cell fate determination and proliferation during development. However, the physiological roles of MKP-3 and the mechanism by which MKP-3 regulates Ras/Drosophila ERK (DERK) signaling in vivo have not been determined. Here, we demonstrated that Drosophila MKP-3 (DMKP-3) is critically involved in cell differentiation, proliferation, and gene expression by suppressing the Ras/DERK pathway, specifically binding to DERK via the N-terminal ERK-binding domain of DMKP-3. Overexpression of DMKP-3 reduced the number of photoreceptor cells and inhibited wing vein differentiation. Conversely, DMKP-3 hypomorphic mutants exhibited extra photoreceptor cells and wing veins, and its null mutants showed striking phenotypes, such as embryonic lethality and severe defects in oogenesis. All of these phenotypes were highly similar to those of the gain-of-function mutants of DERK/rl. The functional interaction between DMKP-3 and the Ras/DERK pathway was further confirmed by genetic interactions between DMKP-3 loss-of-function mutants or overexpressing transgenic flies and various mutants of the Ras/DERK pathway. Collectively, these data provide the direct evidences that DMKP-3 is indispensable to the regulation of DERK signaling activity during Drosophila development.

scholarly journals Polypyrimidine tract-binding protein blocks miRNA-124 biogenesis to enforce its neuronal-specific expression in the mouse

2018 ◽  
Vol 115 (47) ◽  
pp. E11061-E11070 ◽  
Author(s):  
Kyu-Hyeon Yeom ◽  
Simon Mitchell ◽  
Anthony J. Linares ◽  
Sika Zheng ◽  
Chia-Ho Lin ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Rna Binding ◽  
Binding Protein ◽  
Embryonic Stem ◽  
Specific Expression ◽  
Stem Loop ◽  
Polypyrimidine Tract Binding Protein ◽  
Precursor Rna

MicroRNA (miRNA)-124 is expressed in neurons, where it represses genes inhibitory for neuronal differentiation, including the RNA binding protein PTBP1. PTBP1 maintains nonneuronal splicing patterns of mRNAs that switch to neuronal isoforms upon neuronal differentiation. We find that primary (pri)-miR-124-1 is expressed in mouse embryonic stem cells where mature miR-124 is absent. PTBP1 binds to this precursor RNA upstream of the miRNA stem–loop to inhibit mature miR-124 expression in vivo and DROSHA cleavage of pri-miR-124-1 in vitro. This function for PTBP1 in repressing miR-124 biogenesis defines an additional regulatory loop in the already intricate interplay between these two molecules. Applying mathematical modeling to examine the dynamics of this regulation, we find that the pool of pri-miR-124 whose maturation is blocked by PTBP1 creates a robust and self-reinforcing transition in gene expression as PTBP1 is depleted during early neuronal differentiation. While interlocking regulatory loops are often found between miRNAs and transcriptional regulators, our results indicate that miRNA targeting of posttranscriptional regulators also reinforces developmental decisions. Notably, induction of neuronal differentiation observed upon PTBP1 knockdown likely results from direct derepression of miR-124, in addition to indirect effects previously described.

scholarly journals TATA-Binding Protein Mutants That Increase Transcription from Enhancerless and Repressed Promoters In Vivo

2000 ◽  
Vol 20 (5) ◽  
pp. 1478-1488 ◽  
Author(s):  
Joseph V. Geisberg ◽  
Kevin Struhl
Keyword(s):  
Binding Protein ◽  
Tata Binding Protein ◽  
Negative Regulator ◽  
Unusual Structure ◽  
Enhancer Element ◽  
Pol Ii ◽  
Activator Proteins ◽  
Pol Iii

ABSTRACT Using a genetic screen, we isolated three TATA-binding protein (TBP) mutants that increase transcription from promoters that are repressed by the Cyc8-Tup1 or Sin3-Rpd3 corepressors or that lack an enhancer element, but not from an equivalently weak promoter with a mutated TATA element. Increased transcription is observed when the TBP mutants are expressed at low levels in the presence of wild-type TBP. These TBP mutants are unable to support cell viability, and they are toxic in strains lacking Rpd3 histone deacetylase or when expressed at higher levels. Although these mutants do not detectably bind TATA elements in vitro, genetic and chromatin immunoprecipitation experiments indicate that they act directly at promoters and do not increase transcription by titration of a negative regulatory factor(s). The TBP mutants are mildly defective for associating with promoters responding to moderate or strong activators; in addition, they are severely defective for RNA polymerase (Pol) III but not Pol I transcription. These results suggest that, with respect to Pol II transcription, the TBP mutants specifically increase expression from core promoters. Biochemical analysis indicates that the TBP mutants are unaffected for TFIID complex formation, dimerization, and interactions with either the general negative regulator NC2 or the N-terminal inhibitory domain of TAF130. We speculate that these TBP mutants have an unusual structure that allows them to preferentially access TATA elements in chromatin templates. These TBP mutants define a criterion by which promoters repressed by Cyc8-Tup1 or Sin3-Rpd3 resemble enhancerless, but not TATA-defective, promoters; hence, they support the idea that these corepressors inhibit the function of activator proteins rather than the Pol II machinery.

scholarly journals All-Trans Retinoic Acid Induces Cellular Retinol-Binding Protein in Human Skin In Vivo

1995 ◽  
Vol 105 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Gary J. Fisher ◽  
Ambati P. Reddy ◽  
Subhash C. Datta ◽  
Sewon Kang ◽  
Jong Y. Yi ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Human Skin ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Cellular Retinol Binding Protein

scholarly journals Negative Control of the Myc Protein by the Stress-Responsive Kinase Pak2

2004 ◽  
Vol 24 (4) ◽  
pp. 1582-1594 ◽  
Author(s):  
Zhongdong Huang ◽  
Jolinda A. Traugh ◽  
J. Michael Bishop
Keyword(s):  
Cellular Response ◽  
Cellular Proliferation ◽  
Suppressor Gene ◽  
Negative Control ◽  
Negative Regulator ◽  
Serine Threonine Kinase ◽  
Response To Stress ◽  
Nih 3T3

ABSTRACT Pak2 is a serine/threonine kinase that participates in the cellular response to stress. Among the potential substrates for Pak2 is the protein Myc, encoded by the proto-oncogene MYC. Here we demonstrate that Pak2 phosphorylates Myc at three sites (T358, S373, and T400) and affects Myc functions both in vitro and in vivo. Phosphorylation at all three residues reduces the binding of Myc to DNA, either by blocking the requisite dimerization with Max (through phosphorylation at S373 and T400) or by interfering directly with binding to DNA (through phosphorylation at T358). Phosphorylation by Pak2 inhibits the ability of Myc to activate transcription, to sustain cellular proliferation, to transform NIH 3T3 cells in culture, and to elicit apoptosis on serum withdrawal. These results indicate that Pak2 is a negative regulator of Myc, suggest that inhibition of Myc plays a role in the cellular response to stress, and raise the possibility that Pak2 may be the product of a tumor suppressor gene.

scholarly journals The Borrelia hermsii Factor H Binding Protein FhbA Is Not Required for Infectivity in Mice or for Resistance to Human ComplementIn Vitro

2014 ◽  
Vol 82 (8) ◽  
pp. 3324-3332 ◽  
Author(s):  
Lindy M. Fine ◽  
Daniel P. Miller ◽  
Katherine L. Mallory ◽  
Brittney K. Tegels ◽  
Christopher G. Earnhart ◽  
...  
Keyword(s):  
Genetic Manipulation ◽  
Binding Protein ◽  
Factor H ◽  
Negative Regulator ◽  
Human Complement ◽  
Relapsing Fever ◽  
Borrelia Hermsii ◽  
Content Type

ABSTRACTThe primary causative agent of tick-borne relapsing fever in North America isBorrelia hermsii. It has been hypothesized thatB. hermsiievades complement-mediated destruction by binding factor H (FH), a host-derived negative regulator of complement.In vitro,B. hermsiiproduces a single FH binding protein designated FhbA (FH binding protein A). The properties and ligand binding activity of FhbA suggest that it plays multiple roles in pathogenesis. It binds plasminogen and has been identified as a significant target of a B1b B cell-mediated IgM response in mice. FhbA has also been explored as a potential diagnostic antigen forB. hermsiiinfection in humans. The ability to test the hypothesis that FhbA is a critical virulence factorin vivohas been hampered by the lack of well-developed systems for the genetic manipulation of the relapsing fever spirochetes. In this report, we have successfully generated aB. hermsiifhbAdeletion mutant (theB. hermsiiYORΔfhbAstrain) through allelic exchange mutagenesis. Deletion offhbAabolished FH binding by the YORΔfhbAstrain and eliminated cleavage of C3b on the cell surface. However, the YORΔfhbAstrain remained infectious in mice and retained resistance to killingin vitroby human complement. Collectively, these results indicate thatB. hermsiiemploys an FhbA/FH-independent mechanism of complement evasion that allows for resistance to killing by human complement and persistence in mice.

Sign in / Sign up

Export Citation Format

Share Document