Dynamics of T Lymphocyte between the Periphery and the Brain from the Acute to the Chronic Phase Following Ischemic Stroke in Mice

Stroke causes systemic immunosuppression. T lymphocytes are involved in infarct size in the early stages of stroke. However, the phenotypes of T lymphocytes and their functions in peripheral immune organs and the brain have not been well analyzed in the acute and chronic phases of stroke. Here, we investigated pathological phenotypic alterations in the systemic immune response, especially changes in T lymphocytes, from one day to six months after ischemic stroke in mice. Impairment in thymocyte numbers, development, proliferation, and apoptosis were observed for up to two weeks. The number of mature T cells in the spleen and blood decreased and showed reduced interferon-γ production. Increased numbers of CD4-CD8-CD3+ double-negative T cells were observed in the mouse brain during the early stages of stroke, whereas interleukin (IL)-10+Foxp3+ regulatory T lymphocytes increased from two weeks during the chronic phase. These phenotypes correlated with body weight and neurological severity scores. The recovery of T lymphocyte numbers and increases in IL-10+Foxp3+ regulatory T lymphocytes may be important for long-term neurological outcomes. Dynamic changes in T lymphocytes between the acute and chronic phases may play different roles in pathogenesis and recovery. This study provides fundamental information regarding the T lymphocyte alterations from the brain to the peripheral immune organs following stroke.

Dynamics of T Lymphocyte between the Periphery and the Brain from the Acute to the Chronic Phase Following Ischemic Stroke in Mice

Stroke causes systemic immunosuppression. T lymphocytes are involved in infarct size in the early stages of stroke. However, the phenotypes of T lymphocytes and their functions in peripheral immune organs and the brain have not been well analyzed in the acute and chronic phases of stroke. Here, we investigated pathological phenotypic alterations in the systemic immune response, especially changes in T lymphocytes, from one day to six months after ischemic stroke in mice. Impairment in thymocyte numbers, development, proliferation, and apoptosis were observed for up to two weeks. The number of mature T cells in the spleen and blood decreased and showed reduced interferon-γ production. Increased numbers of CD4-CD8-CD3+ double-negative T cells were observed in the mouse brain during the early stages of stroke, whereas interleukin (IL)-10+Foxp3+ regulatory T lymphocytes increased from two weeks during the chronic phase. These phenotypes correlated with body weight and neurological severity scores. The recovery of T lymphocyte numbers and increases in IL-10+Foxp3+ regulatory T lymphocytes may be important for long-term neurological outcomes. Dynamic changes in T lymphocytes between the acute and chronic phases may play different roles in pathogenesis and recovery. This study provides fundamental information regarding the T lymphocyte alterations from the brain to the peripheral immune organs following stroke.

TLR5 Activation through NF-κB Is a Neuroprotective Mechanism of Postconditioning after Cerebral Ischemia in Mice

Postconditioning has been shown to protect the mouse brain from ischemic injury. However, the neuroprotective mechanisms of postconditioning remain elusive. We have found that toll-like receptor 5 (TLR5) plays an integral role in postconditioning-induced neuroprotection through Akt/nuclear factor kappa B (NF-κB) activation in cerebral ischemia. Compared to animals that received 30 min of transient middle cerebral artery occlusion (tMCAO) group, animals that also underwent postconditioning showed a significant reduction of up to 60.51% in infarct volume. Postconditioning increased phospho-Akt (p-Akt) levels and NF-κB translocation to the nucleus as early as 1 h after tMCAO and oxygen-glucose deprivation. Furthermore, inhibition of Akt by Akt inhibitor IV decreased NF-κB promoter activity after postconditioning. Immunoprecipitation showed that interactions between TLR5, MyD88, and p-Akt were increased from postconditioning both in vivo and in vitro. Similar to postconditioning, flagellin, an agonist of TLR5, increased NF-κB nuclear translocation and Akt phosphorylation. Our results suggest that postconditioning has neuroprotective effects by activating NF-κB and Akt survival pathways via TLR5 after cerebral ischemia. Additionally, the TLR5 agonist flagellin can simulate the neuroprotective mechanism of postconditioning in cerebral ischemia.

Anti-inflammatory Effect of Glucagon Like Peptide-1 Receptor Agonist, Exendin-4, through Modulation of IB1/JIP1 Expression and JNK Signaling in Stroke

Glucagon like peptide-1 (GLP-1) stimulates glucose-dependent insulin secretion. Dipeptidyl peptidase-4 (DPP-4) inhibitors, which block inactivation of GLP-1, are currently in clinical use for type 2 diabetes mellitus. Recently, GLP-1 has also been reported to have neuroprotective effects in cases of cerebral ischemia. We therefore investigated the neuroprotective effects of GLP-1 receptor (GLP-1R) agonist, exendin-4 (ex-4), after cerebral ischemia-reperfusion injury. Transient middle cerebral artery occlusion (tMCAO) was induced in rats by intracerebroventricular (i.c.v.) administration of ex-4 or ex9-39. Oxygen-glucose deprivation was also induced in primary neurons, bEnd.3 cells, and BV-2. Ischemia-reperfusion injury reduced expression of GLP-1R. Additionally, higher oxidative stress in SOD2 KO mice decreased expression of GLP-1R. Downregulation of GLP-1R by ischemic injury was 70% restored by GLP-1R agonist, ex-4, which resulted in significant reduction of infarct volume. Levels of intracellular cyclic AMP, a second messenger of GLP-1R, were also increased by 2.7-fold as a result of high GLP-1R expression. Moreover, our results showed that ex-4 attenuated pro-inflammatory cyclooxygenase-2 (COX-2) and prostaglandin E₂ after MCAO. C-Jun NH₂ terminal kinase (JNK) signaling, which stimulates activation of COX-2, was 36% inhibited by i.c.v. injection of ex-4 at 24 h. Islet-brain 1 (IB1), a scaffold regulator of JNK, was 1.7-fold increased by ex-4. GLP-1R activation by ex-4 resulted in reduction of COX-2 through increasing IB1 expression, resulting in anti-inflammatory neuroprotection during stroke. Our study suggests that the anti-inflammatory action of GLP-1 could be used as a new strategy for the treatment of neuroinflammation after stroke accompanied by hyperglycemia.

Prognostic Influence of BCL2 on Molecular Subtypes of Breast Cancer / 한국유방암학회지

PURPOSE: We aimed to reveal the prognostic influence of B-cell CLL/lymphoma 2 (BCL2) on molecular subtypes of breast cancer. METHODS: We analyzed 9,468 patients with primary breast cancer. We classified molecular subtypes according to the National Comprehensive Cancer Network (NCCN) and St. Gallen guidelines, mainly on the basis of the expression of hormonal receptor (HR), human epidermal growth factor receptor 2 (HER2), and Ki-67. RESULTS: Regarding NCCN classification, BCL2 was a strong favorable prognostic factor in the HR(+)/HER2(–) subtype (p<0.001) and a marginally significant favorable prognosticator in the HR(+)/HER2(+) subtype (p=0.046). BCL2 had no prognostic impact on HR(–)/HER2(+) and HR(–)/HER2(–) subtypes. In relation to St. Gallen classification, BCL2 was a strong favorable prognosticator in luminal A and luminal B/HER2(–) subtypes (both p<0.001). BCL2 was a marginally significant prognosticator in the luminal B/HER2(+) subtype (p=0.046), and it was not a significant prognosticator in HER2 or triple negative (TN) subtypes. The prognostic effect of BCL2 was proportional to the stage of breast cancer in HR(+)/HER2(–), HR(+)/HER2(+), and HR(–)/HER2(–) subtypes, but not in HR(–)/HER2(+) subtype. BCL2 was not a prognostic factor in TN breast cancer regardless of epidermal growth factor receptor expression. CONCLUSION: The prognostic influence of BCL2 was different across molecular subtypes of breast cancer, and it was largely dependent on HR, HER2, Ki-67, and the stage of cancer. BCL2 had a strong favorable prognostic impact only in HR(+)/HER2(–) or luminal A and luminal B/HER2(–) subtypes, particularly in advanced stages. Further investigations are needed to verify the prognostic influence of BCL2 on molecular subtypes of breast cancer and to develop clinical applications for prognostication using BCL2.

Selective Estrogen Receptor Modulation by Larrea nitida on MCF-7 Cell Proliferation and Immature Rat Uterus

Larrea nitida is a plant that belongs to the Zygophyllaceae family and is widely used in South America to treat inflammatory diseases, tumors and menstrual pain. However, its pharmacological activity remains unclear. In this study we evaluated the property of selective estrogen receptor modulator (SERM) of Larrea nitida extracts (LNE) as a phytoestrogen that can mimic, modulate or disrupt the actions of endogenous estrogens, depending on the tissue and relative amount of other SERMs. To investigate the property of SERM of LNE, we performed MCF-7 cell proliferation assays, estrogen response element (ERE)-luciferase reporter gene assay, human estrogen receptor (hER) binding assays and in vivo uterotrophic assay. To gain insight into the active principles, we performed a bioassay-guided analysis of LNE employing solvents of various polarities and using classical column chromatography, which yielded 16 fractions (LNs). LNE showed high binding affinities for hERalpha and hERbeta with IC50 values of 1.20x10(-7) g/ml and 1.00x10(-7) g/ml, respectively. LNE induced 17beta-estradiol (E2)-induced MCF-7 cell proliferation, however, it reduced the proliferation in the presence of E2. Furthermore, LNE had an atrophic effect in the uterus of immature rats through reducing the expression level of progesterone receptor (PR) proteins. LN08 and LN10 had more potent affinities for binding on hER alpha and beta than other fractions. Our results indicate that LNE had higher binding affinities for hERbeta than hERalpha, and showed SERM properties in MCF-7 breast cancer cells and the rat uterus. LNE may be useful for the treatment of estrogen-related conditions, such as female cancers and menopause.