Differential and paradoxical roles of new-generation antidepressants in primary astrocytic inflammation.

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are commonly used new-generation drugs for depression. Depressive symptoms are thought to be closely related to neuroinflammation. In this study, we used up-to-date protocols of culture and stimulation and aimed to understand how astrocytes respond to the antidepressants. METHODS: Primary astrocytes were isolated and cultured using neurobasal-based serum-free medium. The cells were treated with a cytokine mixture comprising complement component 1q, tumor necrosis factor α, and interleukin 1α with or without pretreatments of antidepressants. Cell viability, phenotypes, inflammatory responses, and the underlying mechanisms were analyzed. RESULTS: All the SSRIs, including paroxetine, fluoxetine, sertraline, citalopram, and fluvoxamine, show a visible cytotoxicity within the range of applied doses, and a paradoxical effect on astrocytic inflammatory responses as manifested by the promotion of inducible nitric oxide synthase (iNOS) and/or nitric oxide (NO) and the inhibition of interleukin 6 (IL-6) and/or interleukin 1ß (IL-1ß). The SNRI venlafaxine was the least toxic to astrocytes and inhibited the production of IL-6 and IL-1ß but with no impact on iNOS and NO. All the drugs had no regulation on the polarization of astrocytic A1 and A2 types. Mechanisms associated with the antidepressants in astrocytic inflammation route via inhibition of JNK1 activation and STAT3 basal activity. CONCLUSIONS: The study demonstrated that the antidepressants possess differential cytotoxicity to astrocytes and function differently, also paradoxically for the SSRIs, to astrocytic inflammation. Our results provide novel pieces into understanding the differential efficacy and tolerability of the antidepressants in treating patients in the context of astrocytes.

[Relationship between Changes of Lymphocyte Subsets and Early Hematologic Response in Immunosuppressive Therapy of Severe Aplastic Anemia Patients].

OBJECTIVE: To explore the relationship between the change of lymphocyte subsets before and after immunosuppressive therapy (IST) with disease severity of severe aplastic anemia (SAA) and hematologic response to IST. METHODS: The clinical data of 94 patients with SAA/VSAA treated by r-ATG and CsA in our hospital from December 2009 to October 2011 was analyzed retrospectively. Among them, 26 patients who had sequential data of lymphocyte subsets and cytokines before and after treatment were enrolled. The relationship between lymphocyte subsets, cytokine level before IST and disease severity, as well as the relationship between changes if lymphocyte subsets, changes of cytokine and the HR after IST for 6 months was analyzed. RESULTS: There were no statistical differences in the ratio and absolute count of lymphocyte, the ratio and absolute count of each lymphocyte subsets, including CD3+T cells, CD3+CD4+T cells, CD3+CD8+T cells, CD3-CD16+1CD56+NK cells, and CD19+B cells, and the level of cytokines, such as IL-1, IL-2, IL-4, IL-6 and TNF-α before IST between SAA and VSAA groups. Also, there were no statistical difference in the levels of above-motional parameter at 3 and 6 months after IST. The ratio and absolute count of Lym, absolute count of CD3+T cells, absolute count of B cells and IL-2 level in response group after IST for 3 and 6 months was significant lower than those before IST. However, only ratio of Lym showed significant decrease after IST for 3 and 6 months in non-response group. After IST for 3 months, the absolute count of CD3+T and CD4+T cells in response group was significant higher than those in non-response group. CONCLUSION: The hematopoietic recovery and early hematologic remission may be affected by the intensity of immune suppression reflected from the changes of lymphocyte subsets and the immune reconstruction reflected from the recovery of lymphocyte subsets. The immune reconstruction is most significant within 3 months after IST.

DNA Methyltransferase 1 Is Dysregulated in Parkinson's Disease via Mediation of miR-17.

Aberrant DNA methylation is closely associated with the pathogenesis of Parkinson's disease (PD). DNA methyltransferases (DNMTs) are the enzymes for establishment and maintenance of DNA methylation patterns. It has not been clearly defined how DNMTs respond in PD and what mechanisms are associated. Models of PD were established by treatment of five different neurotoxins in cells and intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in mice. Plasma samples of PD patients were also used. Western blot, real-time PCR, immunostaining, and/or luciferase reporter were employed. DNA methylation was analyzed by the bisulfite sequencing analysis. Protein expression of DNMT1, but not of DNMT3A and DNMT3B, was reduced in the cellular and mouse models of PD. Paradoxically, mRNA levels of DNMT1 were increased in these models. After ruling out the possibility of protein degradation, we screened a set of miRNAs that potentially targeted DNMT1 3'-UTR by luciferase reporters and expression abundancies. miR-17 was identified for further investigation with miR-19a of low expression as a parallel comparison. Although exogenous transfection of either miR-17 or miR-19a mimics could inhibit DNMT1 expression, results of miRNA inhibitors showed that miR-17, but not miR-19a, endogenously regulated DNMT1 and the subsequent DNA methylation. Furthermore, levels of miR-17 were elevated in the neurotoxin-induced PD models and the plasma of PD patients. This study demonstrates that the miR-17-mediated DNMT1 downregulation underlies the aberrant DNA methylation in PD. Our results provide a link bridging environmental insults and epigenetic changes and implicate miR-17 in therapeutical modulation of DNA methylation in PD.

Selenoprotein T Promotes Proliferation and G1-to-S Transition in SK-N-SH Cells: Implications in Parkinson's Disease.

BACKGROUND: Selenium is prioritized to the brain mainly for selenoprotein expression. Selenoprotein T (SELENOT) protects dopaminergic, postmitotic neurons in a mouse model of Parkinson's disease (PD). OBJECTIVE: We hypothesized a proliferative role of SELENOT in neural cells. METHODS: To assess SELENOT status in PD, sedated male C57BL/6 mice at 10-12 wk of age were injected with 6-hydroxydopamine in neurons, and human peripheral blood mononuclear cells were isolated from 9 healthy subjects (56% men, 68-y-old) and 11 subjects with PD (64% men, 63-y-old). Dopaminergic neural progenitor-like SK-N-SH cells with transient SELENOT overexpression or knockdown were maintained in the presence or absence of the antioxidant N-acetyl-l-cysteine and the calcium channel blocker nimodipine. Cell cycle, proliferation, and signaling parameters were determined by immunoblotting, qPCR, and flow cytometry. RESULTS: SELENOT mRNA abundance was increased (P < 0.05) in SK-N-SH cells treated with 1-methyl-4-phenylpyridinium iodide (3.5-fold) and peripheral blood mononuclear cells from PD patients (1.6-fold). Likewise, SELENOT was expressed in tyrosine hydroxylase-positive dopaminergic neurons of 6-hydroxydopamine-injected mice. Knockdown of SELENOT in SK-N-SH cells suppressed (54%; P < 0.05) 5-ethynyl-2'-deoxyuridine incorporation but induced (17-47%; P < 0.05) annexin V-positive cells, CASPASE-3 cleavage, and G1/S cell cycle arrest. SELENOT knockdown and overexpression increased (88-120%; P < 0.05) and reduced (37-42%; P < 0.05) both forkhead box O3 and p27, but reduced (51%; P < 0.05) and increased (1.2-fold; P < 0.05) cyclin-dependent kinase 4 protein abundance, respectively. These protein changes were diminished by nimodipine or N-acetyl-l-cysteine treatment (24 h) at steady-state levels. While the N-acetyl-l-cysteine treatment did not influence the reduction in the amount of calcium (13%; P < 0.05) by SELENOT knockdown, the nimodipine treatment reversed the decreased amount of reactive oxygen species (33%; P < 0.05) by SELENOT overexpression. CONCLUSIONS: These cellular and mouse data link SELENOT to neural proliferation, expanding our understanding of selenium protection in PD.

Hyperoside inhibits lipopolysaccharide-induced inflammatory responses in microglial cells via p38 and NFκB pathways.

Hyperoside (quercetin-3-O-ß-d-galactoside) is an active compound isolated from herbs. Neuroinflammation is a key mechanism involved in neurodegenerative disorders including Parkinson's disease. In this study, we aimed to investigate the potentiality of hyperoside in inhibiting microglia-mediated neuroinflammation. BV2 microglial cells were pretreated with hyperoside and stimulated with lipopolysaccharide (LPS). The results showed that hyperoside significantly inhibited LPS-induced production of nitric oxide and pro-inflammatory cytokines including IL-1ß and TNF-α, as well as the expression of inducible nitric oxide synthase. Similar results were observed in primary microglial cells isolated from neonatal mice. Analyses in MAPK and NFκB signaling combined with specific inhibitors suggested that hyperoside attenuated the LPS-induced inflammatory responses via p38 and NFκB pathways. Furthermore, hyperoside suppressed reactive microglia-mediated neurotoxicity as evidenced by conditioned media culture, but had no direct impact on MPP+-induced toxicity in SH-SY5Y neuroblastoma cells. Collectively, our data suggest that hyperoside may serve as a protective agent by alleviating microglia activation in disorders such as Parkinson's disease.

PKCζ in prostate cancer cells represses the recruitment and M2 polarization of macrophages in the prostate cancer microenvironment.

Tumor-associated macrophages are key regulators of the complex interplay between tumor and tumor microenvironment. M2 Macrophages, one type of tumor-associated macrophages, are involved in prostate cancer growth and progression. Protein kinase C zeta has been shown to suppress prostate cancer cell growth, invasion, and metastasis as a tumor suppressor; however, its role in chemotaxis and activation of tumor-associated macrophages remains unclear. Here, we investigated the role of protein kinase C zeta of prostate cancer cells in regulation of macrophage chemotaxis and M2 phenotype activation. Immunohistochemistry was performed to analyze the expression of protein kinase C zeta and the number of CD206+ M2 macrophages in human prostate tissue. Macrophage chemotaxis and polarization were examined using Transwell migration assays and a co-culture system. Quantitative real-time polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were used to detect M2 markers, protein kinase C zeta, interleukin-4, and interleukin-10 expression. We found the expression of protein kinase C zeta increased in prostate cancer tissues, especially in the early stage, and was negatively associated with tumor grade and the number of CD206+ macrophages. Inhibition of protein kinase C zeta expression in prostate cancer cells promoted chemotaxis of peripheral macrophages and acquisition of M2 phenotypic features. These results were further supported by the finding that silencing of endogenous protein kinase C zeta promoted the expression of prostate cancer cell-derived interleukin-4 and interleukin-10. These results suggest that protein kinase C zeta plays an important role in reducing infiltration of tumor-associated macrophages and activation of a pro-tumor M2 phenotype, which may constitute an important mechanism by which protein kinase C zeta represses cancer progression.

[High-dose cyclophosphamide for severe aplastic anemia associated with ß-thalassemia: a case report and literatures review].

OBJECTIVE: To investigate the clinical features and therapeutic method for severe aplastic anemia (SAA) associated with ß-thalassemia, and to improve the recognition of the disease. METHODS: One patient hospitalized for pancytopenia was reported and the related literatures were reviewed. RESULTS: A 14-years old girl who presented with anemia from her childhood was hospitalized for acute onset of pancytopenia. Routine blood test showed that WBC count was 1.28×109/L, hemoglobin 65 g/L, platelet count 18×109/L, reticulocyte count 2×109/L, neutrophil count 0.03×109/L and mean corpuscular volume 59.6 fl, respectively. Both bone marrow aspiration and biopsy showed hypoplasia. Her red blood cells presented as microcytic hypochromic and target erythrocytes were common on peripheral blood smear. DNA analysis of the patient and her mother showed exon 17 heterozygous ß-thalassemia (c.52 A>T). A diagnosis of SAA associated with ß-thalassemia was clarified and high-dose cyclophosphamide (HD-CTX, 1.2 g/d×4 d) plus cyclosporine were offeved, which eventually led to a complete hematologic remission 12 months later. CONCLUSION: This was the first report of SAA associated with ß-thalassemia, and the regimen of HD-CTX led to a complete hematologic remission.

[Pure red cell aplasia with thymoma/T-cell large granular lymphocyte leukemia: two cases report and literatures review].

OBJECTIVE: To investigate the clinical and laboratory features of 2 cases of pure red cell aplasia (PRCA) with thymoma/T-cell large granular lymphocyte leukemia (T-LGLL), and to improve the recognition of the disease and the role of lymphocyte in its mechanism. METHODS: Two cases of PRCA with thymoma/T-LGLL were reported and the related literatures were reviewed. RESULTS: Case 1 was a 63-years old male with hemoglobin level of 54 g/L at admission. Case 2 was a 52-years old female with hemoglobin level of 79 g/L at admission. They were both diagnosed as PRCA with thymoma before admission to our hospital and had no benefit from their thymectomy. Further examinations in our hospital showed that CD3⁺CD4⁻CD8⁺CD57⁺ large granular lymphocytes amplified with clonal TCR rearrangement in their peripheral blood. The diagnosis of PRCA with thymoma/T-LGLL was clarified. Case 1 did not respond to any of the frontline therapies while case 2 responded completely to cyclosporine. CONCLUSION: Both thymoma and T-LGLL could be the cause of secondary PRCA, lymphocyte proliferation may play critical role in the pathogenesis.