Reverse Phase Proteomic Array Profiling of Asparagine Synthetase Expression in Newly Diagnosed Acute Myeloid Leukemia.

Asparaginase-based therapy is a cornerstone in acute lymphoblastic leukemia (ALL) treatment, capitalizing on the methylation status of the asparagine synthetase (ASNS) gene, which renders ALL cells reliant on extracellular asparagine. Contrastingly, ASNS expression in acute myeloid leukemia (AML) has not been thoroughly investigated, despite studies suggesting that AML with chromosome 7/7q deletions might have reduced ASNS levels. Here, we leverage reverse phase protein arrays to measure ASNS expression in 810 AML patients and assess its impact on outcomes. We find that AML with inv(16) has the lowest overall ASNS expression. While AML with deletion 7/7q had ASNS levels slightly lower than those of AML without deletion 7/7q, this observation was not significant. Low ASNS expression correlated with improved overall survival (46 versus 54 weeks, respectively, p = 0.011), whereas higher ASNS levels were associated with better response to venetoclax-based therapy. Protein correlation analysis demonstrated association between ASNS and proteins involved in methylation and DNA repair. In conclusion, while ASNS expression was not lower in patients with deletion 7/7q as initially predicted, ASNS levels were highly variable across AML patients. Further studies are needed to assess whether patients with low ASNS expression are susceptible to asparaginase-based therapy due to their inability to augment compensatory ASNS expression upon asparagine depletion.

Development and characterization of hydrogel-in-oleogel (bigel) systems and their application as a butter replacer for bread making.

BACKGROUND: Butter has been widely used in bakery products and it contains high level of saturated fats. However, excessive consumption of saturated fats would increase the risk of chronic disease. This study was to fabricate water-in-oil (W/O) type bigels as butter replacers to improve the quality attributes of breads. RESULTS: A stable water-in-oil (W/O) type bigel system was fabricated based on mixed oleogelators (rice bran wax and glycerol monostearate) and sodium alginate hydrogel. The ratios of oleogel to hydrogel could significantly affect the stability, microstructure and rheological properties of bigels. All of the bigels exhibited solid-like properties, with increased oleogel fractions, and the network structure of bigel became more compact and orderly with smaller sodium alginate gel particles. Meanwhile, the viscoelastic modulus and firmness of bigel increased, contributing to a higher stability. The bigel dough exhibited lower gel strength and relatively higher extensibility compared to the butter dough. Regardless of oleogel fractions, all the bigel produced bread with a higher specific volume and softer texture than the butter bread. When the oleogel fractions was less than 80%, increasing the oleogel fractions was more beneficial for improving the specific volume, softness and fluffy structure of bread. CONCLUSION: W/O type bigel as butter replacers showed great potential in improving the appearance, structure and textural properties of bread. © 2023 Society of Chemical Industry.

Heat shock factor 1 (HSF1-pSer326) predicts response to bortezomib-containing chemotherapy in pediatric AML: a COG report.

Bortezomib (BTZ) was recently evaluated in a randomized phase 3 clinical trial by the Children's Oncology Group (COG) that compared standard chemotherapy (cytarabine, daunorubicin, and etoposide [ADE]) vs standard therapy with BTZ (ADEB) for de novo pediatric acute myeloid leukemia (AML). Although the study concluded that BTZ did not improve outcome overall, we examined patient subgroups benefiting from BTZ-containing chemotherapy using proteomic analyses. The proteasome inhibitor BTZ disrupts protein homeostasis and activates cytoprotective heat shock responses. Total heat shock factor 1 (HSF1) and phosphorylated HSF1 (HSF1-pSer326) were measured in leukemic cells from 483 pediatric patients using reverse phase protein arrays. HSF1-pSer326 phosphorylation was significantly lower in pediatric AML compared with CD34+ nonmalignant cells. We identified a strong correlation between HSF1-pSer326 expression and BTZ sensitivity. BTZ significantly improved outcome of patients with low-HSF1-pSer326 with a 5-year event-free survival of 44% (ADE) vs 67% for low-HSF1-pSer326 treated with ADEB (P = .019). To determine the effect of HSF1 expression on BTZ potency in vitro, cell viability with HSF1 gene variants that mimicked phosphorylated (S326A) and nonphosphorylated (S326E) HSF1-pSer326 were examined. Those with increased HSF1 phosphorylation showed clear resistance to BTZ vs those with wild-type or reduced HSF1-phosphorylation. We hypothesize that HSF1-pSer326 expression could identify patients who benefit from BTZ-containing chemotherapy.

Prognostication of DNA Damage Response Protein Expression Patterns in Chronic Lymphocytic Leukemia.

Proteomic DNA Damage Repair (DDR) expression patterns in Chronic Lymphocytic Leukemia were characterized by quantifying and clustering 24 total and phosphorylated DDR proteins. Overall, three protein expression patterns (C1-C3) were identified and were associated as an independent predictor of distinct patient overall survival outcomes. Patients within clusters C1 and C2 had poorer survival outcomes and responses to fludarabine, cyclophosphamide, and rituxan chemotherapy compared to patients within cluster C3. However, DDR protein expression patterns were not prognostic in more modern therapies with BCL2 inhibitors or a BTK/PI3K inhibitor. Individually, nine of the DDR proteins were prognostic for predicting overall survival and/or time to first treatment. When looking for other proteins that may be associated with or influenced by DDR expression patterns, our differential expression analysis found that cell cycle and adhesion proteins were lower in clusters compared to normal CD19 controls. In addition, cluster C3 had a lower expression of MAPK proteins compared to the poor prognostic patient clusters thus implying a potential regulatory connection between adhesion, cell cycle, MAPK, and DDR signaling in CLL. Thus, assessing the proteomic expression of DNA damage proteins in CLL provided novel insights for deciphering influences on patient outcomes and expanded our understanding of the potential complexities and effects of DDR cell signaling.

DNA Damage Response-Related Proteins Are Prognostic for Outcome in Both Adult and Pediatric Acute Myelogenous Leukemia Patients: Samples from Adults and from Children Enrolled in a Children's Oncology Group Study.

The survival of malignant leukemic cells is dependent on DNA damage repair (DDR) signaling. Reverse Phase Protein Array (RPPA) data sets were assembled using diagnostic samples from 810 adult and 500 pediatric acute myelogenous leukemia (AML) patients and were probed with 412 and 296 strictly validated antibodies, respectively, including those detecting the expression of proteins directly involved in DDR. Unbiased hierarchical clustering identified strong recurrent DDR protein expression patterns in both adult and pediatric AML. Globally, DDR expression was associated with gene mutational statuses and was prognostic for outcomes including overall survival (OS), relapse rate, and remission duration (RD). In adult patients, seven DDR proteins were individually prognostic for either RD or OS. When DDR proteins were analyzed together with DDR-related proteins operating in diverse cellular signaling pathways, these expanded groupings were also highly prognostic for OS. Analysis of patients treated with either conventional chemotherapy or venetoclax combined with a hypomethylating agent revealed protein clusters that differentially predicted favorable from unfavorable prognoses within each therapy cohort. Collectively, this investigation provides insight into variable DDR pathway activation in AML and may help direct future individualized DDR-targeted therapies in AML patients.

Reverse Phase Protein Array Profiling Identifies Recurrent Protein Expression Patterns of DNA Damage-Related Proteins across Acute and Chronic Leukemia: Samples from Adults and the Children's Oncology Group.

DNA damage response (DNADR) recognition and repair (DDR) pathways affect carcinogenesis and therapy responsiveness in cancers, including leukemia. We measured protein expression levels of 16 DNADR and DDR proteins using the Reverse Phase Protein Array methodology in acute myeloid (AML) (n = 1310), T-cell acute lymphoblastic leukemia (T-ALL) (n = 361) and chronic lymphocytic leukemia (CLL) (n = 795) cases. Clustering analysis identified five protein expression clusters; three were unique compared to normal CD34+ cells. Individual protein expression differed by disease for 14/16 proteins, with five highest in CLL and nine in T-ALL, and by age in T-ALL and AML (six and eleven proteins, respectively), but not CLL (n = 0). Most (96%) of the CLL cases clustered in one cluster; the other 4% were characterized by higher frequencies of deletion 13q and 17p, and fared poorly (p < 0.001). T-ALL predominated in C1 and AML in C5, but both occurred in all four acute-dominated clusters. Protein clusters showed similar implications for survival and remission duration in pediatric and adult T-ALL and AML populations, with C5 doing best in all. In summary, DNADR and DDR protein expression was abnormal in leukemia and formed recurrent clusters that were shared across the leukemias with shared prognostic implications across diseases, and individual proteins showed age- and disease-related differences.

Clinical relevance of proteomic profiling in de novo pediatric acute myeloid leukemia: a Children's Oncology Group study.

Pediatric acute myeloid leukemia (AML) remains a fatal disease for at least 30% of patients, stressing the need for improved therapies and better risk stratification. As proteins are the unifying feature of (epi)genetic and environmental alterations, and are often targeted by novel chemotherapeutic agents, we studied the proteomic landscape of pediatric AML. Protein expression and activation levels were measured in 500 bulk leukemic patients' samples and 30 control CD34+ cell samples, using reverse phase protein arrays with 296 strictly validated antibodies. The multistep MetaGalaxy analysis methodology was applied and identified nine protein expression signatures (PrSIG), based on strong recurrent protein expression patterns. PrSIG were associated with cytogenetics and mutational state, and with favorable or unfavorable prognosis. Analysis based on treatment (i.e., ADE vs. ADE plus bortezomib) identified three PrSIG that did better with ADE plus bortezomib than with ADE alone. When PrSIG were studied in the context of cytogenetic risk groups, PrSIG were independently prognostic after multivariate analysis, suggesting a potential value for proteomics in combination with current classification systems. Proteins with universally increased (n=7) or decreased (n=17) expression were observed across PrSIG. Certain proteins significantly differentially expressed from normal could be identified, forming a hypothetical platform for personalized medicine.

Intervention of Tyrosine Hydroxylase Expression Alters Joint Inflammation and Th17/Treg Imbalance in Collagen-Induced Arthritis.

BACKGROUND/AIMS: Neuroendocrine dysregulation has been associated with rheumatoid arthritis (RA). Tyrosine hydroxylase (TH), a rate-limiting enzyme for synthesis of neuroendocrine hormones such as epinephrine, is also expressed in T lymphocytes and regulates balance between helper T (Th) 17 cells and regulatory T (Treg) cells. Herein, we aimed to show that TH expression in joints alleviates joint inflammation and Th17/Treg imbalance in collagen-induced arthritis (CIA), an animal model of RA, and these effects may be implemented by the mechanism of epinephrine action on α1-adrenoreceptor (α1-AR) in T cells. METHODS: CIA was prepared by intradermal injection of collagen type II in tail base of DBA1/J mice. On the 33rd day post-immunization, lentiviral vectors encoding TH or TH shRNA were injected into ankle joints of CIA mice. Limb inflammation of the mice was assessed beginning from day 21 until day 69 post-immunization by measurement of limb swelling, erythema and rigidity. Th17 and Treg differentiation and function in ankle joints were assessed on day 69 post-immunization by test of the expression of Th17 transcriptional factor ROR-γt and the levels of proinflammatory cytokines interleukin (IL)-17 and IL-22 as well as the expression of Treg transcriptional factor Foxp3 and the levels of antiinflammatory cytokines transforming growth factor (TGF)-ß1 and IL-10. T cells were obtained from the spleen of mice that had been immunized with collagen type II 41 day earlier and treated with epinephrine or α1-AR agonist phenylephrine in vitro. Flow cytometry was used to analyze the percentages of CD25-IL-17+ cells and CD25+Foxp3+ cells in CD4+ T cells. RESULTS: TH gene overexpression in ankle joints of CIA mice reduced limb inflammation and Th17-related transcription factor expression and inflammatory cytokine production but increased Treg-related antiinflammatory cytokine production in the joints. In contrast, TH gene silence in ankle joints of CIA mice enhanced limb inflammation and Th17 cell activity but decreased Treg cell function in the joints. Epinephrine upregulated α1-AR expression in T cells derived from CIA mice. Both epinephrine and phenylephrine reduced CIA-induced Th17 transcription factor expression and inflammatory cytokine production but enhanced Treg antiinflammatory cytokine production in vitro. CONCLUSION: Upregulating TH expression in joints alleviates joint inflammation and Th17/Treg imbalance in CIA at least partially by enhancing epinephrine action on α1-AR in T cells.

Dopamine receptor D2 on CD4+ T cells is protective against neuroinflammation and neurodegeneration in a mouse model of Parkinson's disease.

Parkinson's disease (PD) is a chronic neurodegenerative disease. Recently, neuroinflammation driven by CD4+ T cells has been involved in PD pathophysiology. Human and murine lymphocytes express all the five subtypes of dopamine receptors (DRs), DRD1 to DRD5. However, roles of DRs particularly DRD2 expressed on CD4+ T cells in PD remain elucidated. Global Drd1- or Drd2-knockout (Drd1-/- or Drd2-/-) mice or CD4+ T cell-specific Drd2-knockout (Drd2fl/fl/CD4Cre) mice were intraperitoneally injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD with the different mutants. On the 7th day following MPTP injection, mice were assessed for dopaminergic neurodegeneration, locomotor impairments, microglial activation, as well as CD4+ T-cell differentiation and function. Furthermore, in vitro CD4+ T cells were exposed to DRD2 agonist and antagonist and then differentiation and function of the cells were determined. MPTP induced dopaminergic neuronal loss in the nigrostriatal system, motor coordinative and behavioral impairments, microglial activation, and CD4+ T-cell polarization to pro-inflammatory T-helper (Th)1 and Th17 phenotypes. Importantly, either Drd2-/- or Drd2fl/fl/CD4Cre mice manifested more severe dopaminergic neurodegeneration, motor deficits, microglial activation, and CD4+ T-cell bias towards Th1 and Th17 phenotypes in response to MPTP, but Drd1-/- did not further alter MPTP intoxication. DRD2 agonist sumanirole inhibited shift of CD4+ T cells obtained from MPTP-intoxicated mice to Th1 and Th17 phenotypes and DRD2 antagonist L-741,626 reversed sumanirole effects. These findings suggest that DRD2 expressed on CD4+ T cells is protective against neuroinflammation and neurodegeneration in PD. Thus, developing a therapeutic strategy of stimulating DRD2 may be promising for mitigation of PD.

Role of MSC-derived galectin 3 in the AML microenvironment.

In acute myeloid leukemia (AML), high Galectin 3 (LGALS3) expression is associated with poor prognosis. The role of LGALS3 derived from mesenchymal stromal cells (MSC) in the AML microenvironment is unclear; however, we have recently found high LGALS3 expression in MSC derived from AML patients is associated with relapse. In this study, we used reverse phase protein analysis (RPPA) to correlate LGALS3 expression in AML MSC with 119 other proteins including variants of these proteins such as phosphorylated forms or cleaved forms to identify biologically relevant pathways. RPPA revealed that LGALS3 protein was positively correlated with expression of thirteen proteins including MYC, phosphorylated beta-Catenin (p-CTNNB1), and AKT2 and negatively correlated with expression of six proteins including integrin beta 3 (ITGB3). String analysis revealed that proteins positively correlated with LGALS3 showed strong interconnectivity. Consistent with the RPPA results, LGALS3 suppression by shRNA in MSC resulted in decreased MYC and AKT expression while ITGB3 was induced. In co-culture, the ability of AML cell to adhere to MSC LGALS3 shRNA transductants was reduced compared to AML cell adhesion to MSC control shRNA transductants. Finally, use of novel specific LGALS3 inhibitor CBP.001 in co-culture of AML cells with MSC reduced viable leukemia cell populations with induced apoptosis and augmented the chemotherapeutic effect of AraC. In summary, the current study demonstrates that MSC-derived LGALS3 may be critical for important biological pathways for MSC homeostasis and for regulating AML cell localization and survival in the leukemia microenvironmental niche.

FZR1 loss increases sensitivity to DNA damage and consequently promotes murine and human B-cell acute leukemia.

FZR1 (fizzy-related protein homolog; also known as CDH1 [cell division cycle 20 related 1]) functions in the cell cycle as a specific activator of anaphase-promoting complex or cyclosome ubiquitin ligase, regulating late mitosis, G1 phase, and activation of the G2-M checkpoint. FZR1 has been implicated as both a tumor suppressor and oncoprotein, and its precise contribution to carcinogenesis remains unclear. Here, we examined the role of FZR1 in tumorigenesis and cancer therapy by analyzing tumor models and patient specimens. In an Fzr1 gene-trap mouse model of B-cell acute lymphoblastic leukemia (B-ALL), mice with Fzr1-deficient B-ALL survived longer than those with Fzr1-intact disease, and sensitivity of Fzr1-deficient B-ALL cells to DNA damage appeared increased. Consistently, conditional knockdown of FZR1 sensitized human B-ALL cell lines to DNA damage-induced cell death. Moreover, multivariate analyses of reverse-phase protein array of B-ALL specimens from newly diagnosed B-ALL patients determined that a low FZR1 protein expression level was an independent predictor of a longer remission duration. The clinical benefit of a low FZR1 expression level at diagnosis was no longer apparent in patients with relapsed B-ALL. Consistent with this result, secondary and tertiary mouse recipients of Fzr1-deficient B-ALL cells developed more progressive and radiation-resistant disease than those receiving Fzr1-intact B-ALL cells, indicating that prolonged inactivation of Fzr1 promotes the development of resistant clones. Our results suggest that reduction of FZR1 increases therapeutic sensitivity of B-ALL and that transient rather than tonic inhibition of FZR1 may be a therapeutic strategy.

IL-17A exacerbates neuroinflammation and neurodegeneration by activating microglia in rodent models of Parkinson's disease.

Neuroinflammation has been involved in pathogenesis of Parkinson's disease (PD), a chronic neurodegenerative disease characterized neuropathologically by progressive dopaminergic neuronal loss in the substantia nigra (SN). We recently have shown that helper T (Th)17 cells facilitate dopaminergic neuronal loss in vitro. Herein, we demonstrated that interleukin (IL)-17A, a proinflammatory cytokine produced mainly by Th17 cells, contributed to PD pathogenesis depending on microglia. Mouse and rat models for PD were prepared by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or striatal injection of 1-methyl-4-phenylpyridinium (MPP+), respectively. Both in MPTP-treated mice and MPP+-treated rats, blood-brain barrier (BBB) was disrupted and IL-17A level increased in the SN but not in cortex. Effector T (Teff) cells that were adoptively transferred via tail veins infiltrated into the brain of PD mice but not into that of normal mice. The Teff cell transfer aggravated nigrostriatal dopaminergic neurodegeneration, microglial activation and motor impairment. Contrarily, IL-17A deficiency alleviated BBB disruption, dopaminergic neurodegeneration, microglial activation and motor impairment. Anti-IL-17A-neutralizing antibody that was injected into lateral cerebral ventricle in PD rats ameliorated the manifestations mentioned above. IL-17A activated microglia but did not directly affect dopaminergic neuronal survival in vitro. IL-17A exacerbated dopaminergic neuronal loss only in the presence of microglia, and silencing IL-17A receptor gene in microglia abolished the IL-17A effect. IL-17A-treated microglial medium that contained higher concentration of tumor necrosis factor (TNF)-α facilitated dopaminergic neuronal death. Further, TNF-α-neutralizing antibody attenuated MPP+-induced neurotoxicity. The findings suggest that IL-17A accelerates neurodegeneration in PD depending on microglial activation and at least partly TNF-α release.

Acetylcholine suppresses microglial inflammatory response via α7nAChR to protect hippocampal neurons.

Neuroinflammation is principally linked to glial function and has been demonstrated to participate in the pathogenesis of Alzheimer's disease, a neurodegenerative disorder characterized by beta-amyloid ccumulation and neurotransmission disruption. Previous findings suggest acetylcholine exerts anti-inflammatory and neuroprotective properties in several neurodegenerative disorders. However, the underlying mechanisms remain elusive. Here evaluation of the influence of acetylcholine on neuroinflammation and neurodegeneration in Alzheimer's disease is reported and further neuroprotective mechanisms are investigated. Investigation of microglia in lipopolysaccharide-induced hippocampal neuronal toxicity employed α7nAChR gene silencing and demonstrated that both the anti-inflammatory and neuroprotective effects of acetylcholine rely on α7nAChR pathways. As expected, in neuron-microglia co-cultures lipopolysaccharide induced an increase in expression of pro-inflammatory factors, including inducible nitric oxide synthase, interleukin-1α, and tumor necrosis factor-α, and decreased expression of neurotrophic factors such as insulin-like growth factor-1, and neuronal apoptosis. Acetylcholine protects against lipopolysaccharide-elicited neuronal injury by inhibiting the microglial inflammatory response and promoting microglial neurotrophic factor production via the action of α7nAChR on microglia. These findings establish that ACh activates α7nAChR in microglia, which in turn protects hippocampal neurons.

Histone Modification Patterns Using RPPA-Based Profiling Predict Outcome in Acute Myeloid Leukemia Patients.

Posttranslational histone tail modifications are known to play a role in leukemogenesis and are therapeutic targets. A global analysis of the level and patterns of expression of multiple histone-modifying proteins (HMP) in acute myeloid leukemia (AML) and the effect of different patterns of expression on outcome and prognosis has not been investigated in AML patients. Here we analyzed 20 HMP by reverse phase protein array (RPPA) in a cohort of 205 newly diagnosed AML patients. Protein levels were correlated with patient and disease characteristics, including survival and mutational state. We identified different protein clusters characterized by higher (more on) or lower (more off) expression of HMP, relative to normal CD34+ cells. On state of HMP was associated with poorer outcome compared to normal-like and a more off state. FLT3 mutated AML patients were significantly overrepresented in the more on state. DNA methylation related mutations showed no correlation with the different HMP states. In this study, we demonstrate for the first time that HMP form recurrent patterns of expression and that these significantly correlate with survival in newly diagnosed AML patients.

Norepinephrine Inhibits Th17 Cells via ß2-Adrenergic Receptor (ß2-AR) Signaling in a Mouse Model of Rheumatoid Arthritis.

BACKGROUND Norepinephrine (NE), a neurotransmitter released from the sympathetic nerves, has been shown to be involved in rheumatoid arthritis (RA). However, its role in the sympathetic nervous system in RA is divergent. Herein, we demonstrate that the sympathetic neurotransmitter NE exerts an anti-inflammatory effect in collagen-induced arthritis (CIA), a mouse model of RA, by inhibiting Th17 cell differentiation and function via ß2-adrenergic receptor (ß2-AR) signaling. MATERIAL AND METHODS CIA was prepared by intradermal injection of collagen type II in the tail base of DBA1/J mice. On the 41st day post-immunization, the mice were used as CIA models. CD4+ T cells from the spleen were purified using magnetic cell sorting and activated with anti-CD3 anti-CD28 antibodies. Th17 cells were polarized from the CD4+ T cells using various antibodies and cytokines. RESULTS Co-expression of CD4 and ß2-AR was observed in spleens of both intact and CIA mice. The ß2-AR expression in the ankle and spleen was downregulated in CIA mice. CIA induced increases in production of interleukin (IL)-17 and IL-22, CD25-IL-17+ cell percentage, and ROR-γt expression in CD4+ T cells. Importantly, NE reduced the CIA-induced CD4+ T cell shift towards Th17 phenotype, and the ß2-AR antagonist ICI118551 blocked the NE effect. Moreover, the ß2-AR agonist terbutaline (Terb) inhibited CIA-induced CD4+ T cell proliferation and shift towards Th17 phenotype, and the protein kinase A (PKA) inhibitor H-89 abolished the agonist effect. Terb also reduced CIA-induced Th17 enhancement, and H-89 impaired the Terb effect. CONCLUSIONS NE inhibits Th17 cell differentiation and function in CIA condition by activation of ß2-AR/PKA signaling.

[Acetylcholine suppresses microglial inflammatory response in rats via acting on microglial α7nAChR].

Microglia are the main immune cells in the central nervous system. In the present study, the mechanism for acetylcholine (ACh) inhibiting microglial inflammatory response was investigated. Primary culture of microglia was isolated from cerebral cortex of Sprague-Dawley (SD) rats. Lipopolysaccharide (LPS) was used to activate the microglia to induce inflammatory response, and then the microglia were treated with ACh for 24 h. Protein expressions of several inflammatory factors, insulin-like growth factor 1 (IGF-1) and α7 nicotinic acetylcholine receptor (α7nAChR) were detected by Western blot. Release of inflammatory factors and IGF-1 into media was detected by ELISA. After α7nAChR gene silence was achieved by lentivirus-transfection of α7nAChR-shRNA, the change of ACh effect was observed. The results showed that LPS induced microglial activation, up-regulated inducible nitric oxide synthase (iNOS) protein expression, increased the expressions and release of IL-1ß and TNF-α, and decreased the expression and release of the neurotrophic factor, IGF-1. ACh could reverse these effects of LPS. Meanwhile, LPS reduced the protein expression of α7nAChR on the microglial cells, whereas ACh could reverse the effect. Silencing of α7nAChR gene in microglia abolished the ability of ACh to inhibit LPS-induced inflammatory responses. These results suggest that ACh exerts its protection against LPS-induced microglial inflammation via acting on α7nAChR on microglia, which may provide a novel target for the treatment of neuro-inflammatory diseases.

Treg Cells Protect Dopaminergic Neurons against MPP+ Neurotoxicity via CD47-SIRPA Interaction.

BACKGROUND/AIMS: Regulatory T (Treg) cells have been associated with neuroprotection by inhibiting microglial activation in animal models of Parkinson's disease (PD), a progressive neurodegenerative disease characterized by dopaminergic neuronal loss in the nigrostriatal system. Herein, we show that Treg cells directly protect dopaminergic neurons against 1-methyl-4-phenylpyridinium (MPP+) neurotoxicity via an interaction between the two transmembrane proteins CD47 and signal regulatory protein α (SIRPA). METHODS: Primary ventral mesencephalic (VM) cells or VM neurons were pretreated with Treg cells before MPP+ treatment. Transwell co-culture of Treg cells and VM neurons was used to assess the effects of the Treg cytokines transforming growth factor (TGF)-ß1 and interleukin (IL)-10 on dopaminergic neurons. Live cell imaging system detected a dynamic contact of Treg cells with VM neurons that were stained with CD47 and SIRPA, respectively. Dopaminergic neuronal loss, which was assessed by the number of tyrosine hydroxylase (TH)-immunoreactive cells, was examined after silencing CD47 in Treg cells or silencing SIRPA in VM neurons. RESULTS: Treg cells prevented MPP+-induced dopaminergic neuronal loss and glial inflammatory responses. TGF-ß1 and IL-10 secreted from Treg cells did not significantly prevent MPP+-induced dopaminergic neuronal loss in transwell co-culture of Treg cells and VM neurons. CD47 and SIRPA were expressed by Treg cells and VM neurons, respectively. CD47-labeled Treg cells dynamically contacted with SIRPA-labeled VM neurons. Silencing CD47 gene in Treg cells impaired the ability of Treg cells to protect dopaminergic neurons against MPP+ toxicity. Similarly, SIRPA knockdown in VM neurons reduced the ability of Treg cell neuroprotection. Rac1/Akt signaling pathway in VM neurons was activated by CD47-SIRPA interaction between Treg cells and the neurons. Inhibiting Rac1/Akt signaling in VM neurons compromised Treg cell neuroprotection. CONCLUSION: Treg cells protect dopaminergic neurons against MPP+ neurotoxicity by a cell-to-cell contact mechanism underlying CD47-SIRPA interaction and Rac1/Akt activation.

High-throughput profiling of signaling networks identifies mechanism-based combination therapy to eliminate microenvironmental resistance in acute myeloid leukemia.

The bone marrow microenvironment is known to provide a survival advantage to residual acute myeloid leukemia cells, possibly contributing to disease recurrence. The mechanisms by which stroma in the microenvironment regulates leukemia survival remain largely unknown. Using reverse-phase protein array technology, we profiled 53 key protein molecules in 11 signaling pathways in 20 primary acute myeloid leukemia samples and two cell lines, aiming to understand stroma-mediated signaling modulation in response to the targeted agents temsirolimus (MTOR), ABT737 (BCL2/BCL-XL), and Nutlin-3a (MDM2), and to identify the effective combination therapy targeting acute myeloid leukemia in the context of the leukemia microenvironment. Stroma reprogrammed signaling networks and modified the sensitivity of acute myeloid leukemia samples to all three targeted inhibitors. Stroma activated AKT at Ser473 in the majority of samples treated with single-agent ABT737 or Nutlin-3a. This survival mechanism was partially abrogated by concomitant treatment with temsirolimus plus ABT737 or Nutlin-3a. Mapping the signaling networks revealed that combinations of two inhibitors increased the number of affected proteins in the targeted pathways and in multiple parallel signaling, translating into facilitated cell death. These results demonstrated that a mechanism-based selection of combined inhibitors can be used to guide clinical drug selection and tailor treatment regimens to eliminate microenvironment-mediated resistance in acute myeloid leukemia.

Transforming growth factor-ß1 acts via TßR-I on microglia to protect against MPP(+)-induced dopaminergic neuronal loss.

Neuroinflammation is associated with pathogenesis of Parkinson's disease (PD), a neurodegenerative disorder characterized by a progressive loss of dopaminergic (DAergic) neurons within the substantia nigra. Transforming growth factor (TGF)-ß1 exerts anti-inflammatory and neuroprotective properties. However, it is unclear if microglia are required for TGF-ß1 neuroprotection in PD. Here we used both shRNA and pharmacologic inhibition to determine the role of microglial TGF-ß receptor (TßR)-I and its downstream signaling pathways in 1-methyl-4-phenylpyridinium (MPP(+))-induced DAergic neuronal toxicity. As expected, MPP(+) reduced the number of tyrosine hydroxylase (TH)-immunoreactive cells in ventral mesencephalic cell cultures. We found that MPP(+) activated microglia as determined by an upregulation in expression of CD11b and inducible nitric oxide synthase (iNOS), an increase in expression and secretion of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß, and a decrease in expression and secretion of the neurotrophic factor, insulin-like growth factor (IGF)-1. Pretreatment with TGF-ß1 significantly inhibited all these changes caused by MPP(+). Expression of microglial TßR-I was upregulated by TGF-ß1. Silencing of the TßR-I gene in microglia abolished both the neuroprotective and anti-inflammatory properties of TGF-ß1. TGF-ß1 increased microglial p38 MAPK and Akt phosphorylation, both of which were blocked by the p38 inhibitor SB203580 and the PI3K inhibitor LY294002, respectively. Pretreatment of microglia with either SB203580 or LY294002 impaired the ability of TGF-ß1 to inhibit MPP(+)-induced DAergic neuronal loss and microglial activation. These findings establish that TGF-ß1 activates TßR-I and its downstream p38 MAPK and PI3K-Akt signaling pathways in microglia to protect against DAergic neuronal loss that characterizes in PD.

Dopamine receptors modulate T lymphocytes via inhibition of cAMP-CREB signaling pathway.

OBJECTIVES: We have previously reported that dopamine D2-like receptors including D2, D3 and D4 receptors are more important in mediating modulation of T cells than dopamine D1-like receptors (D1 and D5 receptors). Here we aimed to clarify the role of D2-like receptors in regulation of differentiation and function of T lymphocyte subsets, including helper T (Th)1, Th2, Th17 and regulatory T (Treg) cells. METHODS: Lymphocytes, separated from the mesenteric lymph nodes of mice, were stimulated with concanavalin A (Con A) and treated with the D2-like receptor agonist quinpirole or the antagonist haloperidol. Expression of lymphocyte cytokines and transcription factors and dopamine D2, D3 and D4 receptors were measured by real-time quantitative polymerase chain reaction and Western blot assay. Meanwhile, cAMP and phosphorylated cAMP-response element-binding (CREB) levels in the lymphocytes were examined by enzyme-linked immunosorbent assay and Western blot assay, respectively. RESULTS: Activation of D2-like receptors with the agonist quinpirole upregulated the expression of Th2- and Treg-specific transcription factors and cytokines in Con A-activated lymphocytes, but downregulated the expression of Th1- and Th17-specific transcription factors and cytokines. Simultaneously, quinpirole increased dopamine D3 and D4 receptor expression, but did not alter D2 receptor expression. However, quinpirole reduced both cAMP and phosphorylated CREB levels in Con A-activated lymphocytes. All these quinpirole effects were blocked by haloperidol, an antagonist of D2-like receptors. CONCLUSIONS: D2-like receptors, principally dopamine D3 and D4 receptors, promote differentiation and function of T lymphocytes towards anti-inflammatory T cell subsets by a negative link to cAMP-CREB pathway.