Background: Alzheimer's Disease (AD) is a neuropathological condition marked by cognitive deterioration and chronic neuroinflammation. Previous investigations have unveiled a strong correlation between the gut microbiota and the progression of AD. In this study, our objective is to probe the effects of Parabacteroides distasonis ( P.distasonis ), previously found to be conspicuously diminished in AD patients, on the APP/PS1 mice model. Methods: : To assess the impact of orally administered P.distasonis on gut microbiota and metabolites, we utilized 16s rDNA sequencing and GC-MS to analyze gut composition and short-chain fatty acids in APP/PS1 mice after one month of P.distasonis gavage. To investigate the effects of P.distasonis administration over a six-month period on APP/PS1 mice, we evaluated cognitive function using novel object recognition and Y-maze tests, assessed intestinal barrier integrity and AD-related pathological features with immunofluorescence, and analyzed immune cell subpopulations in intestine, blood, spleen, and brain tissues via flow cytometry. The Luminex assay was employed to detect inflammatory cytokine secretion in the same regions. Results: : One-month oral administration of P.distasonis modulated the gut microbiota, elevated butyrate levels. Six-month oral administration of P.distasonis improved cognitive function in APP/PS1 mice, reducing Aβ deposition and inhibiting glial cell proliferation. It also amplified Treg cells within the gut, concomitant with the decreased Th1 proliferation and intestinal inflammation. Additionally, we observed the migration of peripheral CD4 + T cells to the brain through chemotaxis, accompanied by an increase in Treg cells and higher levels of anti-inflammatory factors such as IL-10 and TGF-β in the brain. Collectively, these multifaceted effects contributed to the alleviation of neuroinflammation. Conclusion: These findings underscore the potential of transplanting P.distasonis in alleviating AD-related pathology, suggesting a role for gut microbiota in neuroinflammation attenuation.

Metabolites are thought as the end products in cellular regulatory processes and their levels show the strongest relationships with the phenotype. Previously, we showed that the administration of Clostridium butyricum MIYAIRI 588 (CBM 588) upregulated protectin D1, an anti-inflammatory lipid metabolite, in colon tissue under antibiotic therapy. However, how CBM 588 induces protectin D1 expression and whether the metabolite has anti-inflammatory effects on antibiotic-induced inflammation are unclear. Therefore, here, we evaluated the effect of CBM 588 on lipid metabolism and protectin D1 in gut protection from antibiotic-induced intestinal disorders. In the CBM 588 treatment group, expression levels of genes encoding lipid receptors related to the conversion of DHA to protectin D1, such as polyunsaturated fatty acid (PUFA) receptors, G-protein coupled receptor 120 (GPR120), and 15-lipoxygenase (LOX), were increased in colon tissue. CD4+ cells producing interleukin (IL)-4, the main component of T helper type 2 (Th2) cells that can activate 15-LOX, also increased in CBM 588-treated groups even after clindamycin co-administration. In addition, similar to CBM 588, exogenously administered protectin D1 reduced inflammatory cytokines, while IL-10 and TGF-β1, works as anti-inflammatory cytokines, were increased. Our data revealed that CBM 588 activated 15-LOX to enhance protectin D1 production by increasing IL-4-producing CD4+ cell population in the intestinal tract. Additionally, CBM 588-induced protectin D1 clearly upregulated IL-10-producing CD4+ cells to control antibiotic-induced gut inflammation. We provide new insights into CBM 588-mediated lipid metabolism induction for the treatment of gut inflammatory diseases.
Copyright © 2020 Ariyoshi, Hagihara, Eguchi, Fukuda, Iwasaki, Oka, Takahashi, Yamagishi and Mikamo.

Methamphetamine-associated cardiomyopathy is the leading cause of death linked with illicit drug use. Here we show that Sigmar1 is a therapeutic target for methamphetamine-associated cardiomyopathy and defined the molecular mechanisms using autopsy samples of human hearts, and a mouse model of "binge and crash" methamphetamine administration. Sigmar1 expression is significantly decreased in the hearts of human methamphetamine users and those of "binge and crash" methamphetamine-treated mice. The hearts of methamphetamine users also show signs of cardiomyopathy, including cellular injury, fibrosis, and enlargement of the heart. In addition, mice expose to "binge and crash" methamphetamine develop cardiac hypertrophy, fibrotic remodeling, and mitochondrial dysfunction leading to contractile dysfunction. Methamphetamine treatment inhibits Sigmar1, resulting in inactivation of the cAMP response element-binding protein (CREB), decreased expression of mitochondrial fission 1 protein (FIS1), and ultimately alteration of mitochondrial dynamics and function. Therefore, Sigmar1 is a viable therapeutic agent for protection against methamphetamine-associated cardiomyopathy.

Emerging evidence suggests comprehensive immune profiling represents a highly promising, yet insufficiently tapped approach to identify potentially prognostic signatures for periodontitis. In this report, we agnostically identified a periodontitis-associated inflammatory expression network with multiple biomarkers identified within gingival crevicular fluid samples from study participants by applying principal component analysis. We identified an IL-17-dominated trait that is associated with periodontal disease and is inversely modified by the level of IL-10. IL-10 mitigated chemokine CXCL5 and CXCL1 expressions in IL-17-stimulated peripheral blood monocytic cells and peripheral blood monocytic cell-derived macrophages. Il10-deficient mice presented more bone loss, which was associated with more Il17 and IL-17-mediated chemokine and cytokine expression at the transcriptional levels in comparison with control wild-type mice in both the Porphyromonas gingivalis-induced experimental murine periodontitis and ligature-induced alveolar bone-loss models. The dampening effect of IL-10 on the excessive signaling of IL-17 appeared to be mediated by innate immune cells populations rather than by gingival epithelial cells, which are the major cell target for IL-17 signaling. Additionally, elevated IL-17 response in Il10-deficient mice specifically elicited an M1-skewing macrophage phenotype in the gingiva that was associated with the advanced bone loss in the ligature model. In summary, IL-17 dominated an inflammatory network characteristic of periodontitis, and IL-10 dampens this excessive IL-17-mediated periodontitis trait.
Copyright © 2020 by The American Association of Immunologists, Inc.

Herpes simplex virus type-1 (HSV-1) can cause severe ocular infection and blindness. We have previously shown that the HSV-1 VC2 vaccine strain is protective in mice and guinea pigs against genital herpes infection following vaginal challenge with HSV-1 or HSV-2. In this study, we evaluated the efficacy of VC2 intramuscular vaccination in mice against herpetic keratitis following ocular challenge with lethal human clinical strain HSV-1(McKrae). VC2 vaccination in mice produced superior protection and morbidity control in comparison to its parental strain HSV-1(F). Specifically, after HSV-1(McKrae) ocular challenge, all VC2 vaccinated- mice survived, while 30% of the HSV-1(F)- vaccinated and 100% of the mock-vaccinated mice died post challenge. VC2-vaccinated mice did not exhibit any symptoms of ocular infection and completely recovered from initial conjunctivitis. In contrast, HSV-1(F)-vaccinated mice developed time-dependent progressive keratitis characterized by corneal opacification, while mock-vaccinated animals exhibited more severe stromal keratitis characterized by immune cell infiltration and neovascularization in corneal stroma with corneal opacification. Cornea in VC2-immunized mice exhibited significantly increased infiltration of CD3+ T lymphocytes and decreased infiltration of Iba1+ macrophages in comparison to mock- or HSV-1(F)-vaccinated groups. VC2 immunization produced higher virus neutralization titers than HSV-1(F) post challenge. Furthermore, VC-vaccination significantly increased the CD4 T central memory (TCM) subsets and CD8 T effector memory (TEM) subsets in the draining lymph nodes following ocular HSV-1 (McKrae) challenge, then mock- or HSV-1(F)-vaccination. These results indicate that VC2 vaccination produces a protective immune response at the site of challenge to protect against HSV-1-induced ocular pathogenesis.