Increased tumor-infiltrating plasmacytoid dendritic cells express high levels of PD-L2 and affect CD8+ T lymphocyte infiltration in human laryngeal squamous cell carcinoma.

The infiltration and prognostic significance of tumor-infiltrating plasmacytoid dendritic cells (TI-pDC) have been elucidated in various human solid cancers. However, the infiltrating patterns and functional importance of TI-pDC in laryngeal squamous cell carcinoma (LSCC) remain unknown. In this study, flow cytometric analyses were conducted to characterize the infiltration of dendritic cells and T lymphocytes, along with their respective subgroups in tumor tissues (TT), para-carcinoma tissues (PT), and peripheral blood (PB) from LSCC patients. Immunohistochemical staining for CD4 and CD8, as well as immunofluorescence staining for CD123, were performed on serial tissue sections to investigate the co-localization of TI-pDC and tumor-infiltrating T lymphocytes (TIL) within the tumor microenvironment (TME). Our results demonstrated significantly lower percentages of all three DC subsets in PB compared to TT and PT. Notably, the pDC percentage was markedly higher in TT than in PT. Moreover, TI-pDC percentage was significantly elevated in N+ stage patients compared to those with N0 stage. The results of survival analysis consistently demonstrated that high levels of TI-pDC infiltration were indicative of a poor prognosis. Further investigation revealed a significant negative correlation between TI-pDC and CD8+ TILs; notably, pDCs expressed an inhibitory surface molecule PD-L2 rather than PD-L1 within PT. Collectively, our findings suggest that increased TI-pDC is associated with adverse outcomes in LSCC patients while exhibiting an inhibitory phenotype that may play a crucial role in suppressing CD8+ TILs within LSCC tumors. These results highlight the potential therapeutic strategy targeting PD-L2+ pDCs for immunotherapies against LSCC.

Transient inhibition of neutrophil functions enhances the antitumor effect of intravenously delivered oncolytic vaccinia virus.

Oncolytic viruses (OVs) possess the unique ability to selectively replicate within tumor cells, leading to their destruction, while also reversing the immunosuppression within the tumor microenvironment and triggering an antitumor immune response. As a result, OVs have emerged as one of the most promising approaches in cancer therapy. However, the effective delivery of intravenously administered OVs faces significant challenges imposed by various immune cells within the peripheral blood, hindering their access to tumor sites. Notably, neutrophils, the predominant white blood cell population comprising approximately 50%-70% of circulating white cells in humans, show phagocytic properties. Our investigation revealed that the majority of oncolytic vaccinia viruses (VV) are engulfed and degraded by neutrophils in the bloodstream. The depletion of neutrophils using the anti-LY6G Ab (1-A8) resulted in an increased accumulation of circulating oncolytic VV in the peripheral blood and enhanced deposition at the tumor site, consequently amplifying the antitumor effect. Neutrophils heavily rely on PI3K signaling to sustain their phagocytic process. Additionally, our study determined that the inhibition of the PI3Kinase delta isoform by idelalisib (CAL-101) suppressed the uptake of oncolytic VV by neutrophils. This inhibition led to a greater presence of oncolytic VV in both the peripheral blood and at the tumor site, resulting in improved efficacy against the tumor. In conclusion, our study showed that inhibiting neutrophil functions can significantly enhance the antitumor efficacy of intravenous oncolytic VV.

Prognostic significance and immune escape implication of tumor-infiltrating neutrophil plasticity in human head and neck squamous cell carcinoma.

Tumor-infiltrating neutrophils play a crucial role in the progression of head and neck squamous cell carcinoma (HNSCC). Here, we aimed to statistically quantify the plasticity of HNSCC-infiltrating N2/N1 neutrophils and examine its impacts on survival and immune infiltration landscape. A retrospective study of 80 patients who underwent curative surgical resection for HNSCC between 2014 and 2017 was conducted in this study. HNSCC-infiltrating neutrophil phenotypes were classified using immunofluorescence staining, and the N2/N1 neutrophil plasticity was evaluated via the ratio of N2/N1 neutrophils. We then assessed the correlations between N2/N1 neutrophil plasticity, clinicopathological characteristics, and immune infiltration landscape using rigorous statistical methods. Infiltration variations of N1 and N2 neutrophils were observed between the tumor nest (TN) and tumor stroma (TS), with TN exhibiting higher N2 neutrophil infiltration and lower N1 neutrophil infiltration. High ratios of N2/N1 neutrophils were correlated with advanced TNM stage, large tumor size and invasion of adjacent tissue. High infiltration of N2 neutrophils was associated with decreased overall and relapse-free survival, which were opposite for N1 neutrophils. The independent prognostic role of N2/N1 neutrophil plasticity, particularly within the TN region, was confirmed by multivariate analyses. Moreover, the ratio of N2/N1 neutrophils within the TN region showed correlations with high CD8+ T cells infiltration and low FOXP3+ Tregs infiltration. We identify HNSCC-infiltrating N2/N1 neutrophil plasticity as a crucial prognostic indictor which potentially reflects the tumor microenvironment (TME) and immune escape landscape within HNSCC tissues. Further investigations and validations may provide novel therapeutic strategies for personalized immunomodulation in HNSCC patients.

Establishment and characterization of a novel hypopharyngeal squamous cell carcinoma cell line CZH1 with genetic abnormalities.

Hypopharyngeal squamous cell carcinoma (HPSCC) has the worst prognosis among head and neck squamous cell carcinomas. The lack of available tumor cell lines poses a significant obstacle to the development of efficient treatments for HPSCC. In this study, we successfully established a novel cell line, named CZH1, from the postcricoid region of a Chinese male patient with a T3N0M0 HPSCC. Short tandem repeat analysis confirmed the uniqueness of CZH1. The cell line was characterized by its phenotypes, biomarkers, and genetics. Importantly, CZH1 cells retained the typical features of epithelial malignancy, similar to the primary tumor tissue. Furthermore, CZH1 demonstrated a greater capacity for invasion and increased susceptibility to irradiation in comparison to FaDu, which is the most commonly used HPSCC cell line. Whole-exome sequencing analysis revealed that CZH1 cells had typical genomic features of HNSCC, including mutations of TP53 and amplifications of multiple transcripts. Therefore, our newly developed CZH1 cell line could serve as an efficient tool for the in vitro investigation of the etiology, pathogenesis, and preclinical treatment of HPSCC.

Trichosanthin alleviates streptozotocin-induced type 1 diabetes mellitus in mice by regulating the balance between bone marrow-derived IL6+ and IL10+ MDSCs.

Myeloid-derived suppressor cells (MDSCs) occupy a pivotal role in the intricate pathogenesis of the autoimmune disorder, Type 1 diabetes mellitus (T1DM). Since our previous work demonstrated that trichosanthin (TCS), an active compound of Chinese herb medicine Tian Hua Fen, regulated immune response, we aimed to clarify the efficacy and molecular mechanism of TCS in the treatment of T1DM. To this end, T1DM mouse model was established by streptozotocin (STZ) induction. The mice were randomly divided into normal control group (Ctl), T1DM group (STZ), TCS treated diabetic group (STZ + TCS) and insulin-treated diabetic group (STZ + insulin). Our comprehensive evaluation encompassed variables such as blood glucose, glycosylated hemoglobin, body weight, pertinent biochemical markers, pancreatic histopathology, and the distribution of immune cell populations. Furthermore, we meticulously isolated MDSCs from the bone marrow of T1DM mice, probing into the expressions of genes pertaining to the advanced glycation end product receptor (RAGE)/NF-κB signaling pathway through RT-qPCR. Evidently, TCS exhibited a substantial capacity to effectively counteract the T1DM-induced elevation in random blood glucose, glycosylated hemoglobin, and IL-6 levels in plasma. Pathological scrutiny underscored the ability of TCS to mitigate the damage incurred by islets. Intriguingly, TCS interventions engendered a reduction in the proportion of MDSCs within the bone marrow, particularly within the IL-6+ MDSC subset. In contrast, IL-10+ MDSCs exhibited an elevation following TCS treatment. Moreover, we observed a significant down-regulation of relative mRNA of pro-inflammatory genes, including arginase 1 (Arg1), inducible nitric oxide synthase (iNOS), RAGE and NF-κB, within MDSCs due to the influence of TCS. It decreases total MDSCs and regulates the balance between IL-6+ and IL-10+ MDSCs thus alleviating the symptoms of T1DM. TCS also down-regulates the RAGE/NF-κB signaling pathway, making it a promising alternative therapeutic treatment for T1DM. Collectively, our study offered novel insights into the underlying mechanism by which TCS serves as a promising therapeutic intervention for T1DM.

Trichosanthin-derived peptide Tk-PQ attenuates immune rejection in mouse tracheal allotransplant model by suppressing PI3K-Akt and inducing type II immune polarization.

Obliterative bronchiolitis (OB) is one of the main complications affecting long-term survival of post-lung transplantation patients. In this study, we evaluated the efficacy of Tk-PQ (a peptide derived from trichosanthin) in alleviating OB in a mouse ectopic tracheal transplant model. We found that post-transplantation treatment of Tk-PQ significant ameliorated OB symptoms including luminal occlusion, epithelial cells loss and fibrosis in the allograft. In addition, Tk-PQ promoted immune suppressive environment by inducing Th2 polarization and increasing Treg population which in turn led to elevated levels of anti-inflammatory cytokines IL-4, IL-10, IL-33 and decreased levels of pro-inflammatory IL-1ß. Mechanistically, we used transcriptome analysis of splenic T cells from allografted mice to show that Tk-PQ treatment down-regulated the PI3K-Akt signaling pathway. Indeed, the immune suppression phenotypes of Tk-PQ was recapitulated by a PI3K inhibitor LY294002. Taken together, Tk-PQ regulates post-transplantation immuno-rejection by modulating the balance of T cell response via the PI3K-Akt pathway, making it a promising peptide based immune rejection suppressant for patients receiving allotransplant.

High Expression of Tumor HLA-DR Predicts Better Prognosis and Response to Anti-PD-1 Therapy in Laryngeal Squamous Cell Carcinoma.

BACKGROUND: HLA-DR is expressed in epithelial and several types of tumor cells. However, the correlation between tumor-expressed HLA-DR (teHLA-DR) and patient outcome as well as its regulation on the tumor microenvironment (TME) of laryngeal squamous cell carcinoma (LSCC) are yet to be elucidated. METHODS: Hematoxylin and eosin (HE) staining were performed to define the tumor nest and stroma of LSCC tissue microarrays. teHLA-DR tumor cell, CD4+ and CD8+ tumor-infiltrating T lymphocytes (TITLs) were obtained and analyzed through double-labeling immunofluorescence and immunohistochemical staining. The recurrence-free (RFS) and overall survival (OS) curves were plotted using the Kaplan-Meier method and tested by the log-rank test method. Expression of teHLA-DR+ tumor cells and infiltration of T lymphocytes and their corresponding subgroups were analyzed by flow cytometry using fresh LSCC tissue samples. RESULTS: Our research discovered elevated expressions of multiple MHC-II-related genes in tumor compared to the adjacent normal tissue samples of LSCC patients. We also found that patients in the teHLA-DR high-expression group (teHLA-DRhigh) tend to have less tumor recurrence and better survival outcomes compared to those in the teHLA-DRlow group. Intriguingly, teHLA-DR+ tumor cells had significantly higher PD-L1 and PD-L2 expression and their TME showed increased infiltrated T lymphocytes (TITLs). Flow cytometry analysis and IHC staining indicated that CD4+ TITLs but not CD3+ total TITLs or CD8+ TITLs were significantly enriched in teHLA-DR+ tumors. CONCLUSIONS: teHLA-DR may be a predictive marker for favorable prognosis and response to anti-PD-1/PD-L1 therapy of LSCC, possibly due to the increased CD4+ TITLs in the TME.

CD206+ tumor-associated macrophages interact with CD4+ tumor-infiltrating lymphocytes and predict adverse patient outcome in human laryngeal squamous cell carcinoma.

BACKGROUND: Tumor-associated macrophages (TAMs) are major component in the tumor microenvironment (TME) and play regulatory role in tumor progression. We aimed to investigate the infiltration and prognostic value of TAMs in laryngeal squamous cell carcinoma (LSCC) and to reveal the underlying mechanism of TAM subgroups in tumorigenesis. METHODS: Hematoxylin and eosin (HE) staining were performed to define the tumor nest and stroma of LSCC tissue microarrays. CD206 + /CD163 + and iNOS + TAM infiltrating profiles were obtained and analyzed through double-labeling immunofluorescence and immunohistochemical staining. The recurrence-free (RFS) and overall survival (OS) curves based on the infiltration of TAMs were plotted using the Kaplan-Meier method. Infiltration of macrophages, T lymphocytes and their corresponding subgroups were analyzed in fresh LSCC tissue samples by flow cytometry. RESULTS: We found that CD206+ rather than CD163+ M2-like TAMs were the most enriched population in the TME of human LSCC. CD206+ macrophages localized mostly in the tumor stroma (TS) rather than the tumor nest (TN) region. In contrast, relatively low infiltration of iNOS+ M1-like TAMs were found in the TS and almost none in the TN region. High level of TS CD206+ TAM infiltration correlated with poor prognosis. Interestingly, we identified a HLA-DRhigh CD206+ macrophage subgroup that was significantly associated with the tumor-infiltrating CD4+ T lymphocytes and showed different surface costimulatory molecule expression than that of the HLA-DRlow/-CD206+ subgroup. Taken together, our results indicate that HLA-DRhigh-CD206+ is a highly activated subgroup of CD206 + TAMs that may interact with CD4 + T cells through MHC-II axis and promote tumorigenesis.

Effect of renal function on the risk of thrombocytopaenia in patients receiving linezolid therapy: A systematic review and meta-analysis.

AIMS: The association of renal function and linezolid-induced thrombocytopaenia (LIT) remains controversial. We performed a meta-analysis to determine whether impaired renal function is associated with an increased LIT risk. METHODS: We conducted a systematic search of PubMed, EMBASE and the Cochrane Library from inception to February 2021 for eligible studies evaluating the relationship between renal function and LIT. Indicators of renal function included renal impairment (RI), severe RI, haemodialysis status, creatinine clearance rate (Ccr) and estimated glomerular filtration rate (eGFR). Unadjusted and adjusted estimates and 95% confidence intervals (CIs) were calculated separately using a random-effect model. RESULTS: A total of 24 studies with 3580 patients were included in the meta-analysis. RI patients had an increased LIT risk compared to non-RI patients in both the unadjusted (OR 3.54; 95% CI 2.27, 5.54; I2 = 77.7%) and adjusted analyses (OR 2.51; 95% CI 1.82, 3.45; I2 = 17.9%). This association persisted in the subset of studies involving only patients receiving a fixed conventional dose (600 mg every 12 h) and other subgroup analyses by ethnicity, sample size and study quality. Moreover, the LIT risk was significantly higher in patients with severe RI and haemodialysis than in patients without severe RI and haemodialysis. The eGFR and Ccr were significantly lower in LIT patients than in non-LIT patients. CONCLUSIONS: Impaired renal function is associated with an increased risk of LIT. A reduced linezolid dose may be considered in RI patients at a low risk of treatment failure, ideally guided by therapeutic drug monitoring.

lncRNA MRUL Suppressed Non-Small Cell Lung Cancer Cells Proliferation and Invasion by Targeting miR-17-5p/SRSF2 Axis.

The two broad histological subtypes of lung cancer are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), which are the leading causes of cancer-related death in the world. Long noncoding RNAs (lncRNAs) have been verified to be critical in the regulation of cancer development. The present study identified and elucidated the regulatory roles of a novel lncRNA MRUL in NSCLC. The results showed that MRUL was overexpressed in NSCLC samples and correlated with the poor prognosis of patients who had NSCLC. Moreover, this research has for the first time demonstrated that MRUL acted as an oncogenetic lncRNA in NSCLC. Knockdown of MRUL considerably repressed NSCLC cell proliferation, invasion, and migration. The bioinformatics analysis showed that MRUL was involved in regulating multiple RNA splicing and proliferation-related biological processes, such as mRNA splicing, RNA splicing, mRNA processing, mRNA 3'-end processing, mRNA splice site selection, and DNA replication. By combining bioinformatics analysis and experimental validation, we found that MRUL regulated NSCLC progression through promoting SRSF2 by sponging miR-17 in NSCLC cells. The discoveries indicated that MRUL could be a therapeutic target and a potential diagnostic for NSCLC.

HAGLROS is overexpressed and promotes non-small cell lung cancer migration and invasion.

INTRODUCTION: Non-small cell lung cancer was one of the most common and deadly cancers worldwide. Long non-coding RNAs had been implicated in multiple human cancers, including non-small cell lung cancer. In this study, we focused on a novel long non-coding RNA, HAGLROS, in non-small cell lung cancer. MATERIAL AND METHODS: In this study, we used GEPIA dataset to analyse the expression levels of HAGLROS in non-small cell lung cancer samples and normal tissues. Then, we analysed Kaplan-Meier Plotter database to reveal the association between HAGLROS expression and overall survival time in patients with non-small cell lung cancer. Moreover, we used small interfering RNA-mediated knockdown to reduce HAGLROS expression in A549 and H1299 cells. Cell Counting Kit-8 assay was used to detect the effect of HAGLROS on cell proliferation. Transwell assays were used to determine the effect of HAGLROS on cell migration and invasion. Co-expression analysis and bioinformatics analysis were conducted to predict the potential functions of HAGLROS in non-small cell lung cancer. RESULTS: We identified HAGLROS was significantly overexpressed in non-small cell lung cancer samples compared to normal tissues. Higher expression of HAGLROS was significantly associated with shorter overall survival time in patients with non-small cell lung cancer. Moreover, we found knockdown of HAGLROS in non-small cell lung cancer cells remarkably suppressed tumour proliferation, migration and invasion. By conducting bioinformatics analysis, we found HAGLROS was involved in regulating multiple cancer-related pathways, including Spliceosome, DNA replication, cell cycle, chromosome segregation and sister chromatid segregation. CONCLUSIONS: Our results for the first time demonstrated HAGLROS may serve as a target for new therapies in non-small cell lung cancer.

CXCL8high inflammatory B cells in the peripheral blood of patients with biliary atresia are involved in disease progression.

Biliary atresia (BA), the most common cause of pediatric end-stage liver disease, results from fibroinflammatory obstruction of the intrahepatic and extrahepatic bile ducts. The etiology of BA has been extensively studied, and inflammation and imbalanced immune system have been identified as the main pathogenesis of BA. B cells play roles in innate and adaptive immunity, but few studies have investigated the role of B cells in BA. This study aimed to elucidate the role of B cells in the development of BA. The percentage and numbers of total B cells (23.81 ± 11.14%，P < 0.0001, 1.22 ± 0.67 × 109 L-1 , P = 0.0014) and immature B cells (25.33 ± 14.32%, P = 0.0013, 0.19 ± 0.20 × 109 L-1 , P < 0.0001) were significantly increased in the peripheral blood of patients with BA and the number of total B cells was positively correlated with gamma-glutamyl-transpeptidase in the serum of BA. High C-X-C motif chemokine ligand 8 (CXCL8) levels were detected in the serum of patients with BA. As an important source of CXCL8, B cells from patients with BA secreted more CXCL8 into peripheral blood than those from control patients. Moreover, immature B cells can secrete more CXCL8 than mature B cells, and B cells secreted CXCL8 upon activation of the nuclear factor-κB pathway. Taken together, the results revealed that B cells have a strong ability to secrete CXCL8, which is associated with the pathogenesis of BA, and exert a proinflammatory effect on the development of BA.

Peptide Tk-PQ induces immunosuppression in skin allogeneic transplantation via increasing Foxp3+ Treg and impeding nuclear translocation of NF-κB.

Solid organ transplantation is used as the last resort for patients with end-stage disease, but allograft rejection is an unsolved problem. Here, we showed that Tk-PQ, a peptide derived from trichosanthin, had an immune-suppressive effect without obvious cytotoxicity in vitro and in a mouse skin allo-transplantation model. In vitro, treatment of Tk-PQ administrated type 2 T helper cell (Th2)/regulatory T-cell (Treg) cytokines, and increased the ratio of CD4+CD25+Foxp3+ Treg by repressing the PI3K/mTOR pathway. In addition, Tk-PQ decreased NF-κB activation to downregulate pro-inflammatory cytokines. Tk-PQ treatment in the mouse skin transplantation model also caused the similar molecular and cellular phenotypes. Furthermore, Tk-PQ enhanced the suppressive function of Treg by increasing Foxp3 expression, and substantially improved allograft survival. These finding demonstrate that Tk-PQ has the potential to be used in clinical allogeneic transplantation.

Interleukin-6 identified as an important factor in hypoxia- and aldehyde dehydrogenase-based gefitinib adaptive resistance in non-small cell lung cancer cells.

Gefitinib resistance and relapse of the disease were the greatest challenges facing clinical therapy of non-small-cell lung cancer (NSCLC). Of note, regarding the hypoxia condition in solid tumor tissues in vivo, roles of hypoxia in gefitinib adaptive resistance and its association with lung cancer stem cells (LCSCs) have not been fully elucidated. In the present study, the role of hypoxia in gefitinib adaptive resistance and its association with aldehyde dehydrogenase (ALDH)-based LCSC gefitinib resistance were comparatively studied using RNA-sequencing (RNA-seq) technology. Co-treatment of PC9 cells with gefitinib and hypoxia (1% O2) significantly enhanced adaptive resistance compared with gefitinib or hypoxia treatment alone. An ALDEFLUOR assay demonstrated that there was a significant increase of ALDH expression level in hypoxia and gefitinib co-treated PC9 cells, in addition to a higher ratio of G0/G1 quiescent cell enrichment and acquisition of epithelial-mesenchymal transition. RNA-seq analysis revealed that interleukin-6 (IL-6) is an important common factor in hypoxia and ALDH-based gefitinib resistance, supported by inflammation-associated tumor necrosis factor, nuclear factor-κB and Janus kinase-signal transducer and activator of transcription signaling pathway enrichment. Furthermore, exposure of PC9 and HCC827 cells to IL-6 increased gefitinib adaptive resistance. Consequently, IL-6 expression level was a poor prognostic marker for patients with NSCLC and adenocarcinoma. Thus, targeting IL-6 combined with tyrosine kinase inhibitor treatment may be promising in NSCLC clinical therapy in the future.

Role of α7-nicotinic acetylcholine receptor in nicotine-induced invasion and epithelial-to-mesenchymal transition in human non-small cell lung cancer cells.

Nicotine via nicotinic acetylcholine receptors (nAChRs) stimulates non-small cell lung cancer (NSCLC) cell invasion and epithelial to mesenchymal transition (EMT) which underpin the cancer metastasis. However, the receptor subtype-dependent effects of nAChRs on NSCLC cell invasion and EMT, and the signaling pathway underlying the effects remain not fully defined. We identified that nicotine induced NSCLC cell invasion, migration, and EMT; the effects were suppressed by pharmacological intervention using α7-nAChR selective antagonists or by genetic intervention using α7-nAChR knockdown via RNA inference. Meanwhile, nicotine induced activation of MEK/ERK signaling in NSCLC cells; α7-nAChR antagonism or MEK/ERK signaling pathway inhibition suppressed NSCLC cell invasion and EMT marker expression. These results indicate that nicotine induces NSCLC cell invasion, migration, and EMT; the effects are mediated by α7-nAChRs and involve MEK/ERK signaling pathway. Delineating the effect of nicotine on the NSCLC cell invasion and EMT at receptor subtype level would improve the understanding of cancer biology and offer potentials for the exploitation of selective ligands for the control of the cancer metastasis.

Adrenergic DNA damage of embryonic pluripotent cells via ß2 receptor signalling.

Embryonic pluripotent cells are sensitive to genotoxicity though they need more stringent genome integrity to avoid compromising multiple cell lineages and subsequent generations. However it remains unknown whether the cells are susceptible to adrenergic stress which can induce somatic cell genome lesion. We have revealed that adrenergic stress mediators cause DNA damage of the cells through the ß2 adrenergic receptor/adenylate cyclase/cAMP/PKA signalling pathway involving an induction of intracellular reactive oxygen species (ROS) accumulation. The adrenergic stress agonists adrenaline, noradrenaline, and isoprenaline caused DNA damage and apoptosis of embryonic stem (ES) cells and embryonal carcinoma stem cells. The effects were mimicked by ß2 receptor-coupled signalling molecules and abrogated by selective blockade of ß2 receptors and inhibition of the receptor signalling pathway. RNA interference targeting ß2 receptors of ES cells conferred the cells the ability to resist the DNA damage and apoptosis. In addition, adrenergic stimulation caused a consistent accumulation of ROS in the cells and the effect was abrogated by ß2 receptor blockade; quenching of ROS reversed the induced DNA damage. This finding will improve the understanding of the stem cell regulatory physiology/pathophysiology in an adrenergic receptor subtype signalling mechanism.

ß2-Adrenoreceptor-Mediated Proliferation Inhibition of Embryonic Pluripotent Stem Cells.

Adrenoreceptors (ARs) are widely expressed and play essential roles throughout the body. Different subtype adrenoceptors elicit distinct effects on cell proliferation, but knowledge remains scarce about the subtype-specific effects of ß2-ARs on the proliferation of embryonic pluripotent stem (PS) cells that represent different characteristics of proliferation and cell cycle regulation with the somatic cells. Herein, we identified a ß2-AR/AC/cAMP/PKA signaling pathway in embryonic PS cells and found that the pathway stimulation inhibited proliferation and cell cycle progression involving modulating the stem cell growth and cycle regulatory machinery. Embryonic stem (ES) cells and embryonal carcinoma stem (ECS) cells expressed functional ß-ARs coupled to AC/cAMP/PKA signaling. Agonistic activation of ß-ARs led to embryonic PS cell cycle arrest and proliferation inhibition. Pharmacological and genetic analyzes using receptor subtype blocking and RNA interference approaches revealed that this effect selectively depended on ß2-AR signaling involving the regulation of AKT, ERK, Rb, and Cyclin E molecules. Better understanding of the effects of ß2-ARs on embryonic PS cell proliferation and cycle progression may provide new insights into stem cell biology and afford the opportunity for exploiting more selective ligands targeting the receptor subtype for the modulation of stem cells.

Simultaneous determination of the repertoire of classical neurotransmitters released from embryonal carcinoma stem cells using online microdialysis coupled with hydrophilic interaction chromatography-tandem mass spectrometry.

Dynamic, continuous, and simultaneous multi-analysis of transmitters is important for the delineation of the complex interactions between the neuronal and intercellular communications. But the analysis of the whole repertoire of classical transmitters of diverse structure is challenging due to their different physico-chemical properties and to their high polarity feature which leads to poor retention in traditional reversed-phase columns during LC-MS analysis. Here, an online microdialysis coupled with hydrophilic interaction chromatography-tandem mass spectrometry (online MD-HILIC-MS/MS) detection method was developed for the simultaneous measurement of the repertoire of classical transmitters (acetylcholine, serotonin, dopamine, norepinephrine, glutamate, GABA, and glycine). Stable isotope labeled internal standards and authentic matrix have been applied to guarantee reliable results. The method was successfully employed to reveal the characteristics of transmitter release from embryonal carcinoma stem cells. The method features simple procedure (no sample preparation), high recovery (≥ 73%), high accuracy (89.36%≤RE≤116.89%), good reproducibility (2.18%≤ RSD ≤14.56%), and sensitive limits of detection (2 pg for acetylcholine, serotonin, and glutamate, 10 pg for dopamine, norepinephrine, GABA, and glycine). It can be flexibly applied to determine the contents of the classical transmitters in other biological matrix samples with minor changes.