ABSTRACT
Intracranial aneurysms (IAs) and potential IA rupture are one of the direct causes of permanent brain damage and mortality. Interestingly, the major risk factors of IA development, including hemodynamic stress, hypertension, smoking, and genetic predispositions, are closely associated with a proinflammatory immune status. Therefore, we examined the roles of CD4(+) T cells in IA pathogenesis. IA patients exhibited peripheral CD4(+) T-cell imbalance, with overrepresented T helper 1 (Th1) and Th17 activities and underrepresented Th2 and regulatory T (Treg) activities, including increased IFN-γ, TNF-α, and IL-17 production and decreased IL-10 production from total CD4(+) T cells. Chemokine receptors CXCR3 and CCR6 were used to identify Th1, Th2, and Th17 cell subsets, and CD4(+)CD25(hi) was used to identify Treg cells. Based on these markers, the data then showed altered cytokine production by each cell type and shifted subpopulation frequency. Moreover, this shift in frequency was directly correlated with IA severity. To examine the underlying mechanism of CD4(+) T cell skewing, we cocultured CD4(+) T cells with autologous monocytes and found that coculture with monocytes could significantly increase IFN-γ and IL-17 production through contact-independent mechanisms, demonstrating that monocytes could potentially contribute to the altered CD4(+) T cell composition in IA. Analyzing mRNA transcripts revealed significantly upregulated IL-1ß and TNF-α expression by monocytes from IA patients. We found a loss of CD4(+) T cell subset balance that was likely to promote a higher state of inflammation in IA, which may exacerbate the disease through a positive feedback loop.
Subject(s)
CD4-Positive T-Lymphocytes/pathology , Intracranial Aneurysm/immunology , Adult , Aged , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Case-Control Studies , Female , Humans , Interferon-gamma/metabolism , Interleukin-10/metabolism , Interleukin-17/metabolism , Intracranial Aneurysm/pathology , Male , Middle Aged , Receptors, CCR6/genetics , Receptors, CCR6/metabolism , Receptors, CXCR3/genetics , Receptors, CXCR3/metabolism , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Evidence has shown that inflammation acts as a critical contributor to the pathogenesis of intracranial aneurysm (IA), a potentially devastating clinical problem. T cell immunoglobulin and mucin protein 3 (Tim-3) is a negative regulatory molecule and plays important roles in the inflammation process. In the current study, we investigated the expression of Tim-3 and its correlation with tumor necrosis factor alpha (TNF-α) in IA patients. Data showed that both messenger RNA (mRNA) level and protein level of Tim-3 were significantly decreased in CD4+ T cells and CD8+ T cells from IA patients than from healthy controls (P < 0.001). However, expression of Tim-3 was not altered in monocytes between patients and healthy donors. Further analyses revealed that patients with ruptured aneurysm had significantly lower level of Tim-3 in CD8+ T cells than those with un-ruptured aneurysm. In addition, a negative correlation between serum level of TNF-α and the expression of Tim-3 in CD4+ T cells was observed in IA patients. Similar correlation was also identified in CD8+ T cells from IA patients. Our study suggests that Tim-3 may participate in the development and progression of IA by probably its negative regulation on TNF-α.
Subject(s)
CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Down-Regulation/physiology , Intracranial Aneurysm/diagnosis , Intracranial Aneurysm/metabolism , Membrane Proteins/biosynthesis , Adult , Aged , Female , Hepatitis A Virus Cellular Receptor 2 , Humans , Male , Middle AgedABSTRACT
The key signaling networks regulating glioma cell proliferation remain poorly defined. The leucine-rich repeat containing G-protein coupled receptor 4 (Lgr4) has been implicated in intestinal, gastric, and epidermal cell functions. We investigated whether Lgr4 functions in glioma cells and found that Lgr4 expression was significantly increased in glioma tissues. In addition, Lgr4 overexpression promoted while its knockdown using small interfering RNA oligos inhibited glioma cell proliferation. In addition, Wnt/ß-catenin signaling was activated in cells overexpressing Lgr4. Therefore, our results revealed that Lgr4 activates Wnt/ß-catenin signaling to regulate glioma cell proliferation.
Subject(s)
Cell Proliferation/drug effects , Glioma/metabolism , Glioma/pathology , Receptors, G-Protein-Coupled/metabolism , Wnt Proteins/metabolism , beta Catenin/metabolism , Blotting, Western , Humans , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Real-Time Polymerase Chain Reaction , Receptors, G-Protein-Coupled/antagonists & inhibitors , Receptors, G-Protein-Coupled/genetics , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Wnt Proteins/genetics , beta Catenin/geneticsABSTRACT
Phytochemical investigation of the ethanol extract of the bulbs of Lycoris caldwellii afforded four new alkaloids, (+)-N-methoxylcarbonyl-nandigerine (1), (+)-N-methoxycarbonyl-lindcarpine (2), (+)-10-O-methylhernovine N-oxide (3), and (+)-3-hydroxy-anhydrolycorine N-oxide (4). Structural elucidation of all the compounds were performed by spectral methods such as 1D and 2D (¹H-¹H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. All the alkaloids were in vitro evaluated for their cytotoxic activities against eight tumor cell lines (BEN-MEN-1, CCF-STTG1, CHG-5, SHG-44, U251, BGC-823, HepG2, and SK-OV-3). Alkaloids 1 and 2 exhibited particular cytotoxic activities against astrocytoma and glioma cell lines with IC50 of 9.2-11.3 µM and 10.4-12.2 µM respectively.
