A cascade of Ca(2+)/calmodulin-dependent protein kinases regulates the differentiation and functional activation of murine neutrophils

Early detection of colorectal cancer based on circular DNA and common clinical detection indicators

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer worldwide, and it is the second leading cause of death from cancer in the world, accounting for approximately 9% of all cancer deaths. Early detection of CRC is urgently needed in clinical practice.

AIM

To build a multi-parameter diagnostic model for early detection of CRC.

METHODS

Total 59 colorectal polyps (CRP) groups, and 101 CRC patients (38 early-stage CRC and 63 advanced CRC) for model establishment. In addition, 30 CRP groups, and 62 CRC patients (30 early-stage CRC and 32 advanced CRC) were separately included to validate the model. 51 commonly used clinical detection indicators and the 4 extrachromosomal circular DNA markers NDUFB7, CAMK1D, PIK3CD and PSEN2 that we screened earlier. Four multi-parameter joint analysis methods: binary logistic regression analysis, discriminant analysis, classification tree and neural network to establish a multi-parameter joint diagnosis model.

RESULTS

Neural network included carcinoembryonic antigen (CEA), ischemia-modified albumin (IMA), sialic acid (SA), PIK3CD and lipoprotein a (LPa) was chosen as the optimal multi-parameter combined auxiliary diagnosis model to distinguish CRP and CRC group, when it differentiated 59 CRP and 101 CRC, its overall accuracy was 90.8%, its area under the curve (AUC) was 0.959 (0.934, 0.985), and the sensitivity and specificity were 91.5% and 82.2%, respectively. After validation, when distinguishing based on 30 CRP and 62 CRC patients, the AUC was 0.965 (0.930-1.000), and its sensitivity and specificity were 66.1% and 70.0%. When distinguishing based on 30 CRP and 32 early-stage CRC patients, the AUC was 0.960 (0.916-1.000), with a sensitivity and specificity of 87.5% and 90.0%, distinguishing based on 30 CRP and 30 advanced CRC patients, the AUC was 0.970 (0.936-1.000), with a sensitivity and specificity of 96.7% and 86.7%.

CONCLUSION

We built a multi-parameter neural network diagnostic model included CEA, IMA, SA, PIK3CD and LPa for early detection of CRC, compared to the conventional CEA, it showed significant improvement.

Neutrophils promote T-cell activation through the regulated release of CD44-bound Galectin-9 from the cell surface during HIV infection

The interaction of neutrophils with T cells has been the subject of debate and controversies. Previous studies have suggested that neutrophils may suppress or activate T cells. Despite these studies, the interaction between neutrophils and T cells has remained a largely unexplored field. Here, based on our RNA sequencing (RNA-seq) analysis, we found that neutrophils have differential transcriptional and functional profiling depending on the CD4 T-cell count of the HIV-infected individual. In particular, we identified that neutrophils in healthy individuals express surface Galectin-9 (Gal-9), which is down-regulated upon activation, and is consistently down-regulated in HIV-infected individuals. However, down-regulation of Gal-9 was associated with CD4 T-cell count of patients. Unstimulated neutrophils express high levels of surface Gal-9 that is bound to CD44, and, upon stimulation, neutrophils depalmitoylate CD44 and induce its movement out of the lipid raft. This process causes the release of Gal-9 from the surface of neutrophils. In addition, we found that neutrophil-derived exogenous Gal-9 binds to cell surface CD44 on T cells, which promotes LCK activation and subsequently enhances T-cell activation. Furthermore, this process was regulated by glycolysis and can be inhibited by interleukin (IL)-10. Together, our data reveal a novel mechanism of Gal-9 shedding from the surface of neutrophils. This could explain elevated plasma Gal-9 levels in HIV-infected individuals as an underlying mechanism of the well-characterized chronic immune activation in HIV infection. This study provides a novel role for the Gal-9 shedding from neutrophils. We anticipate that our results will spark renewed investigation into the role of neutrophils in T-cell activation in other acute and chronic conditions, as well as improved strategies for modulating Gal-9 shedding.

This study shows that HIV-infected individuals have different neutrophil profiles depending on their CD4 T cell count. In particular, neutrophils express high levels of surface Gal-9 but this is shed upon stimulation; this exogenous Gal-9 binds to CD44 on T cells, which promotes LCK activation and subsequently enhances T cell activation.

LncRNA ILF3-AS1 Promotes the Progression of Colon Adenocarcinoma Cells Through the miR-619-5p/CAMK1D Axis

Introduction

Colon adenocarcinoma (COAD) is the third most common tumor of the digestive tract. Recent studies reported that lncRNA’s abnormal expression might play a vital role in the occurrence and development of COAD.

Methods

In the present study, we investigated the expression of ILF3-AS1 in COAD cell lines, human normal colon epithelial cell line, patient tumor tissues and adjacent normal tissues by real-time quantitative PCR (RT-qPCR). Small interfering RNAs (siRNAs) were transfected into COAD cells to inhibit the expression of ILF3-AS1. The effects of ILF3-AS1 on cell proliferation, migration, invasion and apoptosis were measured by CCK-8 assay, transwell migration and invasion assay, and flow cytometry apoptosis assay, respectively. The direct binding of ILF3-AS1 and miR-619-5p/CAMK1D was validated by the luciferase reporter assay. The expression of CAMK1D and epithelial-mesenchymal transformation (EMT)-related proteins was detected by Western Blot analysis. Besides, in vivo experiments were conducted to demonstrate the oncogenic role of ILF3-AS1 in COAD.

Results

The results showed that the expression of ILF3-AS1 was significantly higher in COAD tissue than in normal adjacent samples, and this conclusion was confirmed in the available public datasets. After ILF3-AS1 knockdown, the proliferation of COAD cell lines SW480 and HT29 was significantly inhibited. At the same time, the apoptosis was increased, and the invasion and migration abilities were decreased. After further exploring the mechanisms, we found that ILF3-AS1 serves as a competitive endogenous RNA of mir-619-5p. It can bind to mir-619-5p and reduce its expression, thus regulating the target gene CAMK1D. In addition, we found that high expression of ILF3-AS1 was significantly associated with tumor grade, tumor size, and distant metastasis in COAD samples. In vivo experiments confirmed that ILF3-AS1 promotes tumor growth in COAD models.

Conclusion

The present study demonstrated that ILF3-AS1 plays an oncogenic role in COAD through regulating the miR-619-5p/CAMK1D axis, and inhibition of ILF3-AS1 may pave the way for COAD treatment.

Inhibition of Calcium/Calmodulin-Dependent Protein Kinase Kinase β Is Detrimental in Hypoxia⁻Ischemia Neonatal Brain Injury

Neonatal hypoxia–ischemia (HI) is a major cause of death and disability in neonates. HI leads to a dramatic rise in intracellular calcium levels, which was originally thought to be detrimental to the brain. However, it has been increasingly recognized that this calcium signaling may also play an important protective role after injury by triggering endogenous neuroprotective pathways. Calcium/calmodulin-dependent protein kinase kinase β (CaMKK β) is a major kinase activated by elevated levels of intracellular calcium. Here we evaluated the functional role of CaMKK β in neonatal mice after HI in both acute and chronic survival experiments. Postnatal day ten wild-type (WT) and CaMKK β knockout (KO) mouse male pups were subjected to unilateral carotid artery ligation, followed by 40 min of hypoxia (10% O₂ in N₂). STO-609, a CaMKK inhibitor, was administered intraperitoneally to WT mice at 5 minutes after HI. TTC (2,3,5-triphenyltetrazolium chloride monohydrate) staining was used to assess infarct volume 24 h after HI. CaMKK β KO mice had larger infarct volume than WT mice and STO-609 increased the infarct volume in WT mice after HI. In chronic survival experiments, WT mice treated with STO-609 showed increased tissue loss in the ipsilateral hemisphere three weeks after HI. Furthermore, when compared with vehicle-treated mice, they showed poorer functional recovery during the three week survival period, as measured by the wire hang test and corner test. Loss of blood–brain barrier proteins, a reduction in survival protein (Bcl-2), and an increase in pro-apoptotic protein Bax were also seen after HI with CaMKK β inhibition. In conclusion, inhibition of CaMKK β exacerbated neonatal hypoxia–ischemia injury in mice. Our data suggests that enhancing CaMKK signaling could be a potential target for the treatment of hypoxic–ischemic brain injury.

Genome-wide association study of cell-mediated immune response in chicken

Cell-mediated immunity (CMI) causes the intracellular destruction of the antigen or elimination of the host cell to make animals resistant against exogenous antigens and cancers. In this study, a genome-wide association study (GWAS) was carried out to identify genomic regions associated with CMI in chicken using chicken 60k high-density single nucleotide polymorphism (SNP) array. Genomic relationships were taken into account to adjust for population structure. In order to account for multiple testing, chromosome-wise false discovery rate was controlled at 5% and 10% levels. Moreover, a comparison of the power of fixed and mixed linear models based on genomic inflation factor was carried out. Mixed linear model (MLM) had better inflation rate, and therefore the results from MLM were used for subsequent analysis. Three significantly associated SNPs (FDR < 0.05) on chromosome 24 and linkage group E22C19W28_E50C23, and three suggestively associated SNPs (FDR < 0.1) on chromosome 1, 5 and 16 were identified. Pathway analysis showed that two biological pathways, which are related to immune response, were strongly associated with the candidate genes surrounding identified SNPs, and their influences were mostly on antigen processing and presentation, and cellular structure.

Cooperative Activity of GABP with PU.1 or C/EBPε Regulates Lamin B Receptor Gene Expression, Implicating Their Roles in Granulocyte Nuclear Maturation

Nuclear segmentation is a hallmark feature of mammalian neutrophil differentiation, but the mechanisms that control this process are poorly understood. Gene expression in maturing neutrophils requires combinatorial actions of lineage-restricted and more widely expressed transcriptional regulators. Examples include interactions of the widely expressed ETS transcription factor, GA-binding protein (GABP), with the relatively lineage-restricted E-twenty-six (ETS) factor, PU.1, and with CCAAT enhancer binding proteins, C/EBPα and C/EBPε. Whether such cooperative interactions between these transcription factors also regulate the expression of genes encoding proteins that control nuclear segmentation is unclear. We investigated the roles of ETS and C/EBP family transcription factors in regulating the gene encoding the lamin B receptor (LBR), an inner nuclear membrane protein whose expression is required for neutrophil nuclear segmentation. Although C/EBPε was previously shown to bind the Lbr promoter, surprisingly, we found that neutrophils derived from Cebpe null mice exhibited normal Lbr gene and protein expression. Instead, GABP provided transcriptional activation through the Lbr promoter in the absence of C/EBPε, and activities supported by GABP were greatly enhanced by either C/EBPε or PU.1. Both GABP and PU.1 bound Ets sites in the Lbr promoter in vitro, and in vivo within both early myeloid progenitors and differentiating neutrophils. These findings demonstrate that GABP, PU.1, and C/EBPε cooperate to control transcription of the gene encoding LBR, a nuclear envelope protein that is required for the characteristic lobulated morphology of mature neutrophils.

Annexin A1 Is a Physiological Modulator of Neutrophil Maturation and Recirculation Acting on the CXCR4/CXCL12 Pathway

Neutrophil production and traffic in the body compartments is finely controlled, and the strong evidences support the role of CXCL12/CXCR4 pathway on neutrophil trafficking to and from the bone marrow (BM). We recently showed that the glucocorticoid-regulated protein, Annexin A1 (AnxA1) modulates neutrophil homeostasis and here we address the effects of AnxA1 on steady-state neutrophil maturation and trafficking. For this purpose, AnxA1(-/-) and Balb/C wild-type mice (WT) were donors of BM granulocytes and mesenchymal stem cells and blood neutrophils. In vivo treatments with the pharmacological AnxA1 mimetic peptide (Ac2-26) or the formyl peptide receptor (FPR) antagonist (Boc-2) were used to elucidate the pathway of AnxA1 action, and with the cytosolic glucocorticoid antagonist receptor RU 38486. Accelerated maturation of BM granulocytes was detected in AnxA1(-/-) and Boc2-treated WT mice, and was reversed by treatment with Ac2-26 in AnxA1(-/-) mice. AnxA1 and FPR2 were constitutively expressed in bone marrow granulocytes, and their expressions were reduced by treatment with RU38486. Higher numbers of CXCR4(+) neutrophils were detected in the circulation of AnxA1(-/-) or Boc2-treated WT mice, and values were rescued in Ac2-26-treated AnxA1(-/-) mice. Although circulating neutrophils of AnxA1(-/-) animals were CXCR4(+) , they presented reduced CXCL12-induced chemotaxis. Moreover, levels of CXCL12 were reduced in the bone marrow perfusate and in the mesenchymal stem cell supernatant from AnxA1(-/-) mice, and in vivo and in vitro CXCL12 expression was re-established after Ac2-26 treatment. Collectively, these data highlight AnxA1 as a novel determinant of neutrophil maturation and the mechanisms behind blood neutrophil homing to BM via the CXCL12/CXCR4 pathway. J. Cell. Physiol. 231: 2418-2427, 2016. © 2016 Wiley Periodicals, Inc.

In-depth phosphoproteomic analysis of royal jelly derived from western and eastern honeybee species

The proteins in royal jelly (RJ) play a pivotal role in the nutrition, immune defense, and cast determination of honeybee larvae and have a wide range of pharmacological and health-promoting functions for humans as well. Although the importance of post-translational modifications (PTMs) in protein function is known, investigation of protein phosphorylation of RJ proteins is still very limited. To this end, two complementary phosphopeptide enrichment materials (Ti(4+)-IMAC and TiO2) and high-sensitivity mass spectrometry were applied to establish a detailed phosphoproteome map and to qualitatively and quantitatively compare the phosphoproteomes of RJ produced by Apis mellifera ligustica (Aml) and Apis cerana cerana (Acc). In total, 16 phosphoproteins carrying 67 phosphorylation sites were identified in RJ derived from western bees, and nine proteins phosphorylated on 71 sites were found in RJ produced by eastern honeybees. Of which, eight phosphorylated proteins were common to both RJ samples, and the same motif ([S-x-E]) was extracted, suggesting that the function of major RJ proteins as nutrients and immune agents is evolutionary preserved in both of these honeybee species. All eight overlapping phosphoproteins showed significantly higher abundance in Acc-RJ than in Aml-RJ, and the phosphorylation of Jelleine-II (an antimicrobial peptide, TPFKLSLHL) at S(6) in Acc-RJ had stronger antimicrobial properties than that at T(1) in Aml-RJ even though the overall antimicrobial activity of Jelleine-II was found to decrease after phosphorylation. The differences in phosphosites, peptide abundance, and antimicrobial activity of the phosphorylated RJ proteins indicate that the two major honeybee species employ distinct phosphorylation strategies that align with their different biological characteristics shaped by evolution. The phosphorylation of RJ proteins are potentially driven by the activity of extracellular serine/threonine protein kinase FAM20C-like protein (FAM20C-like) through the [S-x-E] motif, which is supported by evidence that mRNA and protein expression of FAM20C-like protein kinase are both found in the highest level in the hypopharyngeal gland of nurse bees. Our data represent the first comprehensive RJ phosphorylation atlas, recording patterns of phosphorylated RJ protein abundance and antibacterial activity of some RJ proteins in two major managed honeybee species. These data constitute a firm basis for future research to better understand the biological roles of each RJ protein for honeybee biology and human health care.

Inhibition of calcium/calmodulin-dependent protein kinase kinase β and calcium/calmodulin-dependent protein kinase IV is detrimental in cerebral ischemia

BACKGROUND AND PURPOSE

Elevation of intracellular calcium was traditionally thought to be detrimental in stroke pathology. However, clinical trials testing treatments that block calcium signaling have failed to improve outcomes in ischemic stroke. Emerging data suggest that calcium may also trigger endogenous protective pathways after stroke. Calcium/calmodulin-dependent protein kinase kinase (CaMKK) is a major kinase activated by rising intracellular calcium. Compelling evidence has suggested that CaMKK and its downstream kinase CaMK IV are critical in neuronal survival when cells are under ischemic stress. We examined the functional role of CaMKK/CaMK IV signaling in stroke.

METHODS

We used a middle cerebral artery occlusion model in mice.

RESULTS

Our data demonstrated that pharmacological and genetic inhibition of CaMKK aggravated stroke injury. Additionally, deletion of CaMKK β, one of the 2 CaMKK isoforms, reduced CaMK IV activation, and CaMK IV deletion in mice worsened stroke outcome. Finally, CaMKK β or CaMK IV knockout mice had exacerbated blood-brain barrier disruption evidenced by increased hemorrhagic transformation and activation of matrix metalloproteinase. We observed transcriptional inactivation including reduced levels of histone deacetylase 4 phosphorylation in mice with CaMKK β or CaMK IV deletion after stroke.

CONCLUSIONS

Our data have established that the CaMKK/CaMK IV pathway is a key endogenous protective mechanism in ischemia. Our results suggest that this pathway serves as an important regulator of blood-brain barrier integrity and transcriptional activation of neuroprotective molecules in stroke.

Lamin B receptor regulates the growth and maturation of myeloid progenitors via its sterol reductase domain: implications for cholesterol biosynthesis in regulating myelopoiesis

Lamin B receptor (LBR) is a bifunctional nuclear membrane protein with N-terminal lamin B and chromatin-binding domains plus a C-terminal sterol Δ(14) reductase domain. LBR expression increases during neutrophil differentiation, and deficient expression disrupts neutrophil nuclear lobulation characteristic of Pelger-Huët anomaly. Thus, LBR plays a critical role in regulating myeloid differentiation, but how the two functional domains of LBR support this role is currently unclear. We previously identified abnormal proliferation and deficient functional maturation of promyelocytes (erythroid, myeloid, and lymphoid [EML]-derived promyelocytes) derived from EML-ic/ic cells, a myeloid model of ichthyosis (ic) bone marrow that lacks Lbr expression. In this study, we provide new evidence that cholesterol biosynthesis is important to myeloid cell growth and is supported by the sterol reductase domain of Lbr. Cholesterol biosynthesis inhibitors caused growth inhibition of EML cells that increased in EML-derived promyelocytes, whereas cells lacking Lbr exhibited complete growth arrest at both stages. Lipid production increased during wild-type neutrophil maturation, but ic/ic cells exhibited deficient levels of lipid and cholesterol production. Ectopic expression of a full-length Lbr in EML-ic/ic cells rescued both nuclear lobulation and growth arrest in cholesterol starvation conditions. Lipid production also was rescued, and a deficient respiratory burst was corrected. Expression of just the C-terminal sterol reductase domain of Lbr in ic/ic cells also improved each of these phenotypes. Our data support the conclusion that the sterol Δ(14) reductase domain of LBR plays a critical role in cholesterol biosynthesis and that this process is essential to both myeloid cell growth and functional maturation.

A cell-intrinsic role for CaMKK2 in granulocyte lineage commitment and differentiation

Granulocytes serve a critical function in host organisms by recognizing and destroying invading microbes, as well as propagating and maintaining inflammation at sites of infection. However, the molecular pathways underpinning the development of granulocytes are poorly understood. Here, we identify a role for CaMKK2 in the restriction of granulocytic fate commitment and differentiation of myeloid progenitor cells. Following BMT, engraftment by Camkk2(-/-) donor cells resulted in the increased production of mature granulocytes in the BM and peripheral blood. Similarly, Camkk2(-/-) mice possessed elevated numbers of CMP cells and exhibited an accelerated granulopoietic phenotype in the BM. Camkk2(-/-) myeloid progenitors expressed increased levels of C/EBPα and PU.1 and preferentially differentiated into Gr1(+)Mac1(+) granulocytes and CFU-G in vitro. During normal granulopoiesis in vivo or G-CSF-induced differentiation of 32D myeloblast cells in vitro, CaMKK2 mRNA and protein were decreased as a function of time and were undetectable in mature granulocytes. Expression of ectopic CaMKK2 in Camkk2(-/-) CMPs was sufficient to rescue aberrant granulocyte differentiation and when overexpressed in 32D cells, was also sufficient to impede granulocyte differentiation in a kinase activity-dependent manner. Collectively, our results reveal a novel role for CaMKK2 as an inhibitor of granulocytic fate commitment and differentiation in early myeloid progenitors.

Activation of the aryl hydrocarbon receptor by the calcium/calmodulin-dependent protein kinase kinase inhibitor 7-oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid (STO-609)

This study was designed to analyze the effects of the Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) inhibitor STO-609 (7-oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid) toward the aryl hydrocarbon receptor (AhR) pathway because Ca2+/calmodulin-dependent protein kinase (CaMK) Ialpha, known as a downstream CaMKK effector, has been recently shown to contribute to the AhR cascade. STO-609 failed to alter up-regulation of the AhR target CYP1A1 in response to the potent AhR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in MCF-7 cells. STO-609, used at a 25 muM concentration known to fully inhibit CaMKK activity, was surprisingly found to markedly induce CYP1A1 expression and activity by itself in MCF-7 cells; it similarly up-regulated various other AhR target genes in human macrophages. STO-609-related CYP1A1 induction was prevented by chemical inhibition or small interfering RNA-mediated knockdown expression of AhR. Moreover, STO-609 was demonstrated to physically interact with the ligand-binding domain of AhR, as assessed by TCDD binding competition assay, and to induce AhR translocation to the nucleus. As already reported for AhR agonists, STO-609 triggered the increase of [Ca2+](i) and activation of CaMKIalpha, whose inhibition through the use of the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester or the CaMK inhibitor KN-93 (2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine), respectively, prevented STO-609-mediated CYP1A1 activity induction. Taken together, these results demonstrate that the CaMKK inhibitor STO-609 can act as an AhR ligand and, in this way, fully activates the Ca2+/CaMKIalpha/AhR cascade. Such data, therefore, make unlikely any contribution of CaMKK activity to the AhR pathway and, moreover, suggest that caution may be required when using STO-609 as a specific inhibitor of CaMKKs.