IL33 (Interleukin 33)/ST2 (Interleukin 1 Receptor-Like 1) Axis Drives Protective Microglial Responses and Promotes White Matter Integrity After Stroke.

Background and Purpose: Emerging evidence highlights the importance of IL33 (interleukin 33) and its receptor (ST2 [interleukin 1 receptor-like 1]) in normal brains and neurological disorders. This study explores the function of the IL33/ST2 signaling axis and a transcription factor STAT6 (signal transducer and activator of transcription 6) in white matter integrity and long-term recovery after stroke. Methods: Transient middle cerebral artery occlusion was induced in wild type, ST2 knockout, STAT6 knockout, and microglia/macrophage-depleted (by PLX5622 diet) mice. Sensorimotor and cognitive functions were evaluated. White matter integrity was measured by immunofluorescent staining, diffusion tensor imaging, electron microscopy, and electrophysiology. The death of oligodendrocytes and its precursor cells (OPC) and the microglia/macrophage responses were evaluated 3 days after stroke. Primary microglia-oligodendrocyte/OPC cocultures were used for mechanistic studies. Parametric tests (Student t test or ANOVA) or nonparametric Mann-Whitney U test were used for statistical analysis based on the numbers of groups, types of variables, and the structure of each data set. Results: ST2 deficiency exacerbates sensorimotor and cognitive deficits for 28 days after middle cerebral artery occlusion compared with wild-type mice, which was accompanied by deteriorated structural damages and impaired conduction of compound action potentials in white matter. ST2 knockout mice displayed increased death of oligodendrocytes and OPCs, and a concomitant exacerbation in neuroinflammation 3 days after stroke. Using microglia/macrophage-depleted mice and microglia-oligodendrocyte/OPC cocultures, we showed that IL33 protected oligodendrocytes and OPCs against ischemic injury in a microglia/macrophage dependent manner. Further mechanistic studies identified STAT6 as a molecule that mediates the protective effects of IL33/ST2 on oligodendrocytes in the ischemic brain. IL33 treatment failed to rescue oligodendrocytes and OPCs after stroke in STAT6 knockout mice. Conclusions: These results shed light on the IL33/ST2/STAT6 signaling as a potential immune regulatory mechanism to modulate microglia/macrophage activity, improve white matter integrity, and restore long-term neurological functions after stroke.

A Comprehensive Lifestyle Randomized Clinical Trial: Design and Initial Patient Experience.

BACKGROUND: Although epidemiological research demonstrates that there is an association between lifestyle factors and risk of breast cancer recurrence, progression of disease, and mortality, no comprehensive lifestyle change clinical trials have been conducted to determine if changing multiple risk factors leads to changes in biobehavioral processes and clinical outcomes in women with breast cancer. This article describes the design, feasibility, adherence to the intervention and data collection, and patient experience of a comprehensive lifestyle change clinical trial (CompLife). METHODS: CompLife is a randomized, controlled trial of a multiple-behavior intervention focusing on diet, exercise, and mind-body practice along with behavioral counseling to support change. The initial exposure to the intervention takes place during the 4 to 6 weeks of radiotherapy (XRT) for women with stage III breast cancer and then across the subsequent 12 months. The intervention group will have 42 hours of in-person lifestyle counseling during XRT (7-10 hours a week) followed by up to 30 hours of counseling via video connection for the subsequent 12 months (weekly sessions for 6 months and then monthly for 6 months). The primary outcome is disease-free survival. Multiple secondary outcomes are being evaluated, including: (1) biological pathways; (2) overall survival; (3) patient-reported outcomes; (4) dietary patterns/fitness levels, anthropometrics, and body composition; and (5) economic outcomes. Qualitative data of the patient experience in the trial is collected from exit interviews, concluding remarks, direct email correspondences, and web postings from patients. RESULTS: Fifty-five patients have been recruited and randomized to the trial to date. Accrual of eligible patients is high (72%) and dropout rates extremely low (5%). Attendance to the in-person sessions is high (95% attending greater than 80% of sessions) as well as to the 30 hours of video counseling (88% attending more than 70% of sessions). Adherence to components of the behavior change intervention is high and compliance with the intensive amount of data collection is exceptional. Qualitative data collected from the participants reveals testimonials supporting the importance of the comprehensive nature of intervention, especially the mind-body/mindfulness component and social support, and meaningful lifestyle transformations. CONCLUSION: Conducting a comprehensive, multicomponent, lifestyle change clinical trial for women with breast was feasible and collection of biobehavioral outcomes successful. Adherence to behavior change was high and patient experience was overwhelmingly positive.

Functional defects of NK cells treated with chloroquine mimic the lytic defects observed in perforin-deficient mice.

NK cells are the primary effectors mediating acute rejection of incompatible bone marrow cell grafts. To reduce rejection, we evaluated the ability of chloroquine (CHQ) to prevent perforin-dependent NK cell activity. Perforin is a key cytotoxic component released from the lytic granules of activated NK cells. Generation of functional perforin requires an acidic protease activity that occurs in the secretory, lytic lysosomes. Our hypothesis was that CHQ, a lysosomotropic reagent, would raise the pH of the acidic compartment in which perforin is processed and thereby block perforin maturation and cytotoxicity. We have measured NK cytotoxicity in vivo by clearance of YAC-1 tumor cells from the lungs and by rejection of incompatible bone marrow transplants and in vitro by cytolysis of YAC-1 and Jurkat cells. The engraftment of bone marrow cells was monitored by recolonization of the spleen with hemopoietic cells from transplants of MHC class I-deficient bone marrow cells into lethally irradiated recipient mice. Transplant rejection was compared in two inbred strains of mice: 129, which apparently use perforin-dependent cytotoxicity, and C57BL/6, in which rejection can be perforin-independent. CHQ treatment reduced NK cell activity in 129 mice in which perforin is important for mediating rejection. CHQ affected the fraction of NK cell cytolysis that was Fas independent. In addition, we found that CHQ prevents perforin processing by LAK cells in vitro. These data indicate that CHQ may impair rejection of incompatible bone marrow transplants and other functions mediated by NK and cytotoxic T cells.