| 2013 |
Extracellular CIRP acts as a damage-associated molecular pattern (DAMP) that binds the TLR4-MD2 complex (as well as TLR4 and MD2 individually), stimulating TNF-α and HMGB1 release from macrophages and causing inflammatory tissue injury in vivo. Human CIRP amino acids 106–125 bind MD2 with high affinity as determined by surface plasmon resonance. |
Surface plasmon resonance binding assay; recombinant CIRP injection in vivo; CIRP-deficient mouse model; anti-CIRP antisera blockade |
Nature medicine |
High |
24097189
|
| 2020 |
eCIRP is a biologically active endogenous ligand of TREM-1 on macrophages. Surface plasmon resonance revealed strong binding between eCIRP and TREM-1, confirmed by FRET in macrophages. TREM-1 siRNA, decoy peptide LP17, and TREM-1-/- mice dramatically reduced eCIRP-induced inflammation. |
Surface plasmon resonance; FRET assay; TREM-1-/- mice; siRNA knockdown; inhibitory peptide M3 derived from eCIRP sequence |
JCI insight |
High |
32027618
|
| 2020 |
eCIRP binds IL-6 receptor (IL-6R) on macrophages, activating STAT3 phosphorylation and promoting macrophage endotoxin tolerance and M2 polarization. Blockade of IL-6R with neutralizing Ab inhibited eCIRP-induced p-STAT3 and restored LPS-stimulated TNF-α release. |
Biacore binding assay; FRET; immunostaining colocalization; STAT3 inhibitor (Stattic); anti-IL-6R neutralizing antibody; rmCIRP stimulation of macrophages |
JCI insight |
High |
32027619
|
| 2020 |
CIRBP nuclear import is mediated by two nonclassical nuclear localization signals: an RG/RGG-rich region recognized by Transportin-1 (TNPO1) and an RSY-rich region recognized by Transportin-3 (TNPO3). These interactions regulate nuclear localization, phase separation, and stress granule recruitment of CIRBP. |
Biophysical binding assays; cell-based localization experiments; mutagenesis of NLS regions; phase separation assays |
Proceedings of the National Academy of Sciences of the United States of America |
High |
32234784
|
| 2021 |
Phosphorylation of the CIRBP RG/RGG region by SRPK1 impairs liquid-liquid phase separation (LLPS), binding to TNPO1, and stress granule association in cells. Arginine methylation of the same region reciprocally regulates SRPK1-mediated phosphorylation, revealing interplay between these two PTMs. |
In vitro phosphorylation assay with SRPK1; LLPS assay; TNPO1 binding assay; cell-based SG recruitment; identification of two novel phosphorylation sites |
Frontiers in molecular biosciences |
High |
34738012
|
| 2012 |
Cirp directly binds Dyrk1b/Mirk kinase in the nucleus of undifferentiated spermatogonia, inhibiting Dyrk1b's binding to p27 (reducing p27 phosphorylation and destabilizing it) and inhibiting Dyrk1b-mediated phosphorylation of cyclin D1 (stabilizing cyclin D1), thereby promoting cell-cycle progression from G0/G1 to S phase. |
Cirp knockout mice; direct protein binding assays; co-immunoprecipitation; cell-cycle analysis; spermatogonial cell line knockdown; cyclin D1 and p27 protein level measurements |
Proceedings of the National Academy of Sciences of the United States of America |
High |
22711815
|
| 2015 |
CIRP associates with the active telomerase complex through direct binding to the RNA component TERC, regulates Cajal body localization of telomerase, and modulates TERT mRNA levels. CIRP inhibition by CRISPR-Cas9 or siRNA leads to reduced telomerase activity and shortened telomere length. |
Co-immunoprecipitation coupled with mass spectrometry; CRISPR-Cas9 and siRNA knockdown; telomerase activity assay; telomere length measurement; Cajal body localization assay |
Nucleic acids research |
High |
26673712
|
| 2016 |
Temperature-dependent accumulation of Cirbp mRNA is controlled primarily by regulation of splicing efficiency (fraction of pre-mRNA processed into mature mRNA), not transcription rate, and this post-transcriptional mechanism is widespread in temperature-dependent gene expression control. |
NIH3T3 fibroblasts exposed to simulated temperature cycles; genome-wide 'approach to steady-state' kinetics; mRNA/pre-mRNA quantification |
Genes & development |
High |
27633015
|
| 2018 |
CIRP selectively binds the 5' UTR of p27Kip1 mRNA and enhances its translation. In cells exposed to mild hypothermia, induced CIRP correlated with increased p27Kip1 5'UTR reporter translation and p27Kip1 protein accumulation; shRNA-mediated CIRP knockdown prevented this induction. p27Kip1 KO MEFs showed no increase in doubling time under cold stress, unlike WT cells. |
RNA binding assay; reporter translation assay; shRNA knockdown; p27Kip1 KO MEFs; mild hypothermia induction |
Nucleic acids research |
High |
29361038
|
| 2006 |
Cirp protects cells from TNF-α-induced apoptosis by activating the ERK pathway: Cirp transduction into Cirp-deficient fibroblasts increased phosphorylated ERK and suppressed TNF-α-induced caspase-8 activation. The ERK-specific inhibitor PD98059 abrogated Cirp's cytoprotective effect. |
Cirp transduction into Cirp-deficient mouse fibroblasts; ERK inhibitor (PD98059); caspase-8 activation assay; apoptosis assay at 37°C and 32°C |
Biochimica et biophysica acta |
Medium |
16569452
|
| 2012 |
CIRP binds specific mRNAs in testis (identified by RIP-Chip and biotin pull-down), predominantly through a (Un)(n≥2) core recognition sequence, and stabilizes the bound mRNAs. Target mRNAs are associated with translation regulation, antioxidant activity, and reproduction. |
RIP-Chip (RNA-binding protein immunoprecipitation-microarray); biotin pull-down assay; mRNA stability assays |
FEBS letters |
Medium |
22819822
|
| 2017 |
Extracellular CIRP induces ER stress in lung tissue via TLR4 activation. In CIRP-/- septic mice, ER stress markers (BiP, pIRE1α, sXBP1, CHOP, cleaved caspase-12) were not elevated, whereas TLR4 KO mice showed no ER stress induction after recombinant CIRP injection. |
CIRP-/- and TLR4-/- mouse models; cecal ligation and puncture sepsis; recombinant CIRP injection; Western blot for ER stress markers |
Scientific reports |
Medium |
28128330
|
| 2020 |
eCIRP-induced ICAM-1+ neutrophil generation is mediated by TREM-1, and ICAM-1 on neutrophils activates Rho GTPase to promote NETosis. Blockade of ICAM-1 decreased Rho activation, and Rho inhibition decreased rmCIRP-induced NET formation. |
TREM-1-/- mice; TREM-1 inhibitor LP17; ICAM-1-/- neutrophils; Rho activation assay; rmCIRP stimulation; flow cytometry |
FASEB journal |
Medium |
32506691
|
| 2021 |
eCIRP impairs macrophage bacterial phagocytosis by activating STAT3 phosphorylation, which promotes STAT3-βPIX complex formation, preventing βPIX from activating Rac1 and thereby reducing ARP2 and p-cofilin expression needed for actin remodeling. STAT3 inhibition rescued phagocytic dysfunction. |
CIRP-/- mice; rmCIRP stimulation of macrophages; co-immunoprecipitation of STAT3-βPIX complex; STAT3 inhibitor stattic; actin remodeling assays; in vivo bacterial load measurement |
Cellular & molecular immunology |
Medium |
36471113
|
| 2021 |
eCIRP activates STING through TLR4/MyD88/TRIF pathways, leading to pTBK1 and pIRF3 activation and type I IFN production, exacerbating hemorrhagic shock. STING-/- mice showed reduced lung inflammation and mortality; TLR4-/-, MyD88-/-, and TRIF-/- macrophages failed to activate STING downstream of eCIRP. |
STING-/-, TLR4-/-, MyD88-/-, TRIF-/- mouse models; rmCIRP injection; Western blot for pTBK1 and pIRF3; cytokine measurement; controlled hemorrhage model |
JCI insight |
Medium |
34291735
|
| 2024 |
Lactate accumulation during sepsis promotes lactylation of CIRP in macrophages, causing its release. Internalized eCIRP (via TLR4-mediated endocytosis by pulmonary vascular endothelial cells) competitively binds ZBP1, blocking TRIM32-mediated proteasomal degradation of ZBP1, stabilizing ZBP1 and enhancing ZBP1-RIPK3-dependent PANoptosis. |
CLP sepsis model; Casp8-/-, Ripk3-/-, Zbp1-/- mice; measurement of CIRP lactylation; co-immunoprecipitation of eCIRP-ZBP1 and ZBP1-TRIM32; TLR4-mediated endocytosis tracking |
Military Medical Research |
Medium |
39465383
|
| 2019 |
Chronic hypoxia induces hypermethylation of the Cirbp promoter, suppressing CIRP expression and preventing cold-stress induction. CIRP deficiency attenuates hypothermic cardioprotection by downregulating the cardiac ubiquinone biosynthesis pathway, reducing CoQ10, increasing oxidative stress, and impairing ATP production. |
Rat CPB model; Cirbp-KO and Cirbp-transgenic rats; methylation analysis of Cirbp promoter in neonatal cardiomyocytes and human specimens; cardiac proteomics; CoQ10 measurement |
Science translational medicine |
High |
31019028
|
| 2024 |
CIRBP suppression in aged donor hearts attenuates hypothermic cardioprotection by decreasing DHODH expression, compromising DHODH-mediated ubiquinone (CoQ) reduction, leading to cardiac lipid peroxidation and ferroptosis after transplantation. |
Rat heart transplantation model; Cirbp-KO rats; RNA-Seq; cardiac proteomics; DHODH expression measurement; lipid peroxidation assay |
The Journal of clinical investigation |
Medium |
38690728
|
| 2018 |
CIRBP binds the 3'-UTR of HIF-1α mRNA to increase its mRNA stability in bladder cancer cells, thereby inducing HIF-1α expression and promoting cancer cell proliferation and migration. |
RNA immunoprecipitation; 3'UTR binding assay; CIRBP overexpression/knockdown; mRNA stability assay |
Cell death & disease |
Medium |
30315244
|
| 2021 |
CIRP directly binds the 3'UTR of Atp5g3 mRNA to regulate mitochondrial homeostasis and ATP biogenesis under hypoxic stress, and sustains protein levels of respiratory chain complexes II (SDHB) and IV (MT-CO1). |
3'UTR binding assay; Cirbp KO and overexpression; respiratory complex protein level measurement; ATP measurement; hypoxia model |
The Science of the total environment |
Medium |
34715218
|
| 2021 |
CIRBP promotes ferroptosis in renal ischemia-reperfusion injury by interacting with ELAVL1 (HuR), which activates ferritinophagy. CIRBP-ELAVL1 interaction was confirmed by co-immunoprecipitation and fluorescence colocalization. Silencing CIRBP inhibited ferritinophagy and ferroptosis. |
Co-immunoprecipitation; fluorescence colocalization; siCIRBP; autophagy inhibitor; si-ELAVL1; anti-CIRP antibody mouse model of IR injury |
Journal of cellular and molecular medicine |
Medium |
34114349
|
| 2021 |
CIRP binds to p53 mRNA (RIP assay) and regulates ferroptosis in pancreatic cancer cells through the p53/GPX4 pathway: cold-induced CIRBP expression was associated with decreased GPX4 and increased DPP4, NOX1, FTH1, Fe2+ accumulation, and ROS. |
RNA immunoprecipitation (RIP); CIRBP overexpression/knockdown; cold induction; ferroptosis marker measurement; ferroptosis inhibitor rescue |
Journal of immunology research |
Low |
36061308
|
| 2021 |
CIRP directly binds the 3'UTR of PSD95 mRNA to post-transcriptionally regulate PSD95 protein levels; overexpression of Cirbp in hippocampus rescues hypobaric hypoxia-induced reduction of PSD95 and attenuates dendritic spine injury and cognitive deficits. |
3'UTR binding assay; Cirbp overexpression via stereotaxic injection; PSD95 protein quantification; dendritic spine morphology analysis; behavioral memory tests |
Molecular brain |
Medium |
34419133
|
| 2021 |
eCIRP induces macrophage extracellular trap (MET) formation through sequential activation of caspase-1 and gasdermin D (GSDMD). Caspase-1 and GSDMD inhibitors (z-VAD-fmk and disulfiram) significantly decreased rmCIRP-induced MET formation in THP-1 macrophages. |
Time-lapse fluorescence microscopy; SYTOX Orange staining; Western blot for cleaved caspase-1 and GSDMD; pharmacological inhibitors; primary peritoneal macrophages |
Frontiers in immunology |
Medium |
35003095
|
| 2022 |
eCIRP induces ferroptosis in macrophages and lung tissue during sepsis by decreasing GPX4 expression and increasing lipid ROS in a TLR4-dependent manner. TLR4-/- macrophages showed attenuated GPX4 depression and lipid ROS increase after rmCIRP treatment. |
RAW 264.7 cells and TLR4-/- peritoneal macrophages; GPX4 expression; lipid ROS measurement; ferroptosis inhibitor ferrostatin-1; CIRP-/- mice CLP model; eCIRP inhibitor C23 |
Frontiers in immunology |
Medium |
35844517
|
| 2012 |
A mild-cold responsive element (MCRE, octanucleotide 5'-TCCCCGCC-3') in the cirp 5' flanking region is bound by the transcription factor Sp1, which translocates more to the nucleus at 32°C than 37°C. Sp1 overexpression increased endogenous Cirp and reporter expression; Sp1 downregulation had the opposite effect. MCRE mutation abolished these effects. |
Reporter gene assay (CAT); chromatin immunoprecipitation; immunohistochemistry; Sp1 overexpression/downregulation; MCRE mutagenesis; multiple cell lines |
BMC biotechnology |
Medium |
23046908
|
| 2004 |
Upregulation of CIRP by hypoxia is independent of HIF-1α and HIF-1β and does not require mitochondria. Nuclear run-on assays demonstrated that hypoxia-induced CIRP expression occurs at the level of gene transcription. Respiratory chain inhibitors (NaN3 and cyanide) blocked this response, but cells depleted of mitochondria still upregulated CIRP during hypoxia. |
HIF-1α-deficient (Z-33) and HIF-1β-deficient (Hepa-1 c4) cell lines; actinomycin-D; in vitro nuclear run-on assay; mitochondria-depleted cells; respiratory chain inhibitors |
Journal of cell science |
Medium |
15075239
|
| 2009 |
CIRP expression is modulated by alternative transcription start sites generating three major 5'-UTR transcripts with different translational properties. The longest 32°C-enriched transcript exhibits IRES-like activity, and its levels and stability are increased at mild hypothermia, contributing to CIRP protein upregulation. |
5'-UTR transcript characterization; IRES reporter assay; transcript stability measurement at different temperatures; NIH-3T3 cells |
RNA (New York, N.Y.) |
Medium |
19398494
|
| 2013 |
TNF and TGFβ (but not IL-1β, IL-6, IFNα, or IFNγ) impair CIRBP expression in fibroblasts and neuronal cells; CIRBP depletion increases susceptibility of cells to TNF-mediated inhibition of clock gene (period genes, PAR-bZip) expression, revealing CIRBP as a regulator of circadian clock gene amplitude downstream of cytokine signaling. |
Cirp depletion; cytokine stimulation; clock gene expression measurement in fibroblasts and neuronal cells |
The Journal of biological chemistry |
Medium |
24337574
|
| 2021 |
CIRP directly binds to OGFR mRNA and represses OGFR expression by reducing mRNA stability. CIRBP deficiency enables OGF-OGFR signaling to promote chemotherapy-induced cardiomyocyte apoptosis; exogenous CIRBP delivery to mouse myocardium mitigated doxorubicin-induced cardiac apoptosis. |
mRNA stability assay; RNA immunoprecipitation; CIRBP/OGFR overexpression/knockdown; AAV-mediated myocardial CIRBP delivery; cardiac apoptosis measurement |
International journal of biological sciences |
Medium |
35541895
|
| 2015 |
CIRP inhibits DNA damage-induced apoptosis by regulating p53: CIRP knockdown increased p53 levels and pro-apoptotic gene expression, while CIRP overexpression decreased p53 levels and upregulated anti-apoptotic genes. Effect placed CIRP upstream of p53 in DNA damage apoptosis pathway. |
CIRP overexpression and siRNA knockdown; etoposide-induced DNA damage; p53 and apoptosis gene expression measurement; Western blot |
Biochemical and biophysical research communications |
Low |
26188505
|
| 2021 |
CIRP directly binds CTNNB1 mRNA at its 3'- and 5'-UTRs (confirmed by RNA immunoprecipitation and biotin pull-down), enhancing CTNNB1 mRNA stability and promoting IRES-mediated CTNNB1 protein synthesis, leading to activation of Wnt/β-catenin signaling and downstream targets in NSCLC. |
RNA immunoprecipitation; biotin pull-down; mRNA decay assay; luciferase reporter (IRES); CIRBP overexpression/knockdown in multiple cell lines; in vivo xenograft |
Journal of experimental & clinical cancer research |
Medium |
34465343
|
| 2021 |
eCIRP induces TREM-1 expression in alveolar type II (ATII) cells and triggers IL-6 and CXCL2 production via TREM-1. TREM-1-/- ATII cells showed reduced cytokine release after rmCIRP treatment, and TREM-1 antagonist peptides (M3, LP17) significantly decreased this response. |
Primary ATII cell isolation; TREM-1-/- mice; rmCIRP stimulation; TREM-1 antagonist peptides; flow cytometry; ELISA |
Frontiers in cell and developmental biology |
Medium |
32984356
|
| 2022 |
eCIRP induces acute kidney injury via TREM-1 on renal endothelial cells. TREM-1-/- mice injected with rmCIRP showed attenuated AKI markers (BUN, creatinine, NGAL) and reduced renal ICAM-1 expression. M3 peptide blocked eCIRP activation of human renal glomerular endothelial cells. |
TREM-1-/- mice; rmCIRP IV injection; renal function markers; primary human renal glomerular endothelial cells; M3 inhibitory peptide |
Frontiers in physiology |
Medium |
36246143
|
| 1998 |
Cirp is constitutively and diurnally expressed in the brain; Cirp mRNA levels oscillate in the suprachiasmatic nucleus and cerebral cortex (rising during daytime, falling at night), are absent in constant darkness, and are not present in 3-day-old mice, suggesting light-dependent regulation of Cirp in circadian rhythm circuits. |
Northern blot; immunohistochemistry; constant darkness control; developmental stage comparison |
Biochemical and biophysical research communications |
Medium |
9571190
|
| 2018 |
CIRBP specifically binds pre-miR-329 (but not pri-miR-329) in RBP immunoprecipitation experiments after hindlimb ischemia, suggesting a role in posttranscriptional regulation of 14q32 microRNA processing. |
RNA pull-down SILAC mass spectrometry; RBP immunoprecipitation; hindlimb ischemia mouse model; CRISPR/Cas9 HADHB-/- cells |
Molecular therapy. Nucleic acids |
Low |
30665182
|
| 2020 |
Under PRRSV infection, CIRBP translocates from the nucleus to the cytoplasm and is present in cytoplasmic stress granules. Overexpression of CIRBP promoted inflammatory cytokine expression and oxidative stress (iNOS, ROS) via the NF-κB pathway in infected macrophages. |
Immunofluorescence for CIRBP localization; stress granule colocalization; CIRBP overexpression; NF-κB pathway inhibitor; cytokine and ROS measurement |
International immunopharmacology |
Low |
32593159
|
| 2021 |
CIRP and HuR competitively bind Claudin1 mRNA; CIRP binding suppresses Claudin1 expression while HuR binding enhances it. This competition regulates intestinal mucosal barrier function in ulcerative colitis. Validated by RNA immunoprecipitation and dual-luciferase reporter assay. |
RNA immunoprecipitation; dual-luciferase reporter assay; CIRP and HuR overexpression/knockdown; transepithelial electrical resistance; in vivo DSS colitis model |
BioFactors |
Medium |
33638934
|
| 2023 |
A synthetic poly(A) tail mimic (A12) selectively and strongly binds the RNA-binding motif of eCIRP, preventing eCIRP binding to TLR4. A12 attenuated eCIRP-induced macrophage MAPK and NF-κB activation and inflammatory cytokine production in vitro and in vivo. |
Direct binding assay (A12-eCIRP RBM interaction); macrophage stimulation; NF-κB and MAPK activation assays; CLP sepsis model; bacterial load measurement |
Journal of immunology |
Medium |
37585248
|
| 2021 |
eCIRP impairs Rab26 in macrophages, reducing Rab26-mediated surface transport of EPOR, resulting in decreased macrophage EPOR surface expression and impaired M2 polarization. EPO treatment failed to promote M2 polarization in Rab26 KO macrophages, confirming the Rab26-EPOR axis. |
Rab26 KO macrophages; myeloid-specific EPOR-deficient mice; anti-CIRP antibody treatment; EPOR surface expression assay; macrophage polarization measurement |
Frontiers in immunology |
Medium |
34925338
|
| 2018 |
TGF-β2 and TGF-β3 directly downregulate CIRBP mRNA and protein expression in germ cells (GC2-spd). In vivo, heat-induced CIRBP downregulation in mouse testes is mediated by TGF-β upregulation; local TGF-β antagonist injection attenuated heat-induced CIRBP downregulation. |
In vitro TGF-β isoform treatment of GC2-spd cells; in vivo local testicular injection of TGF-β antagonist; CIRBP mRNA and protein quantification |
Andrology |
Medium |
30461215
|
| 2024 |
CIRP maintains GluR1 (AMPA receptor subunit) stability on neuronal cell membranes by binding GluR1 mRNA; hypobaric hypoxia reduces CIRP expression and the CIRP-GluR1 interaction, causing GluR1 redistribution to cytoplasm, synaptic loss, and memory impairment. Cirp KO mice phenocopied this deficit. |
Cirp KO mice; hypobaric hypoxia model; mRNA binding assay; GluR1 surface vs. cytoplasmic protein distribution; dendritic spine and synapse counting; behavioral memory tests; Tat-C16 peptide rescue |
CNS neuroscience & therapeutics |
Medium |
39315498
|