Features of and Mechanisms Underlying Insulitis In aly/aly Male Mice as an Animal Model of Autoimmune Pancreatitis: Activation of CD11c+, CD4+, and Th2 Cells and Predominant Destruction of β-cells

Diabetes mellitus (DM) is observed in patients with autoimmune pancreatitis (AIP). The development of DM in AIP is believed to be due to blood flow obstruction of the endocrine gland that accompanies pancreatitis, as well as injury to the islets caused by inflammation. The latter is called insulitis and the detailed mechanisms underlying its development are not yet clear. The aim of the present study was to elucidate the mechanisms involved in the development of insulitis in AIP using aly mice as an animal model of AIP: results in aly/aly male mice, as the AIP group, were compared with those inaly/+ male mice as a control group. Mice in both groups were killed between 16 and 48 weeks of age, and pancreatitis and insulitis were evaluated histologically. Inflammatory and endocrine cells were evaluated by immunofluorescence staining with anti-CD4, anti-CD8, anti-CD11b, and anti-CD11c antibodies, as well as immunohistochemical analyses using insulin and glucagon antibodies. Plasma levels and the pancreatic content of interferon (IFN)-γ (as a Th1-secreted cytokine) and interleukin (IL)-4 (as a Th2-secreted cytokine) were determined. Pancreatitis was seen in aly/aly mice from 16 weeks of age and it developed gradually thereafter. Insulitis also developed gradually and was seen in mice after 24 weeks of age in association with a decrease in the number of islets. CD11c+ cells and CD4+ T cells were seen to infiltrate into the islets. Although the number of β-cells decreased with time, the number of α-cells was maintained until mice were 48 weeks of age. IFN-γ content peaked in mice at 16 weeks of age and declined rapidly from 20 weeks. There were two peaks in IL-4 content, one at 16 weeks and the other at 32 weeks, suggesting an association between IL-4 content and advanced insulitis after 32 weeks. In conclusion, the results suggest that insulitis in AIP is induced predominantly by the infiltration of CD11c+ cells and CD4+ T cells into the islets, and progression is facilitated by the imbalance of the activation of Th2 rather than Th1. Furthermore, insulitis in AIP predominantly involves β-cells rather than α-cells

DECIGO pathfinder

DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article

The status of DECIGO

DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) is the planned Japanese space gravitational wave antenna, aiming to detect gravitational waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz and 10 Hz and thus to open a new window for gravitational wave astronomy and for the universe. DECIGO will consists of three drag-free spacecraft arranged in an equilateral triangle with 1000 km arm lengths whose relative displacements are measured by a differential Fabry-Perot interferometer, and four units of triangular Fabry-Perot interferometers are arranged on heliocentric orbit around the sun. DECIGO is vary ambitious mission, we plan to launch DECIGO in era of 2030s after precursor satellite mission, B-DECIGO. B-DECIGO is essentially smaller version of DECIGO: B-DECIGO consists of three spacecraft arranged in an triangle with 100 km arm lengths orbiting 2000 km above the surface of the earth. It is hoped that the launch date will be late 2020s for the present

Therapeutic Effect of an Immunomodulator on Pancreatic Endocrine Secretion Disorder and Insulitis in an Animal Model of Autoimmune Pancreatitis

Adrenocortical hormones are effective in many, but not all, cases of autoimmune pancreatitis （AIP）. While effective treatment for refractory and recurrent cases of AIP has not been established, immunomodulators are sometimes used. We examined the therapeutic effect of the immunomodulator FK506 against AIP using an animal model: aly/aly male mice. Mice were divided into three groups based on FK506 dose: 1mg/kg, 2mg/kg, and non-administration （pancreatitis） groups. Pancreatic exocrine gland injury was regarded as pancreatitis and pancreatic endocrine injury was regarded as insulitis. Histological evaluation of pancreatic tissue at 16 and 24 weeks of age was performed quantitatively using ImageJ software, and the three groups were compared. The pancreatitis group developed pancreatitis at 24 weeks of age, but onset of pancreatitis was suppressed in the 1mg group. However, pancreatitis development was not suppressed in the 2mg group, and pancreatitis developed from as early as 16 weeks of age. In the pancreatitis group, insulitis resulted in morphological changes such as shrinkage of pancreatic islets of Langerhans as inflammatory cell infiltration into pancreatic acinar cells became stronger. No significant difference was observed between the 1mg group and the pancreatitis group in the islet area but, in the 2mg group, there was significant reduction in area compared to the pancreatitis group and the 1mg group. Although administration of FK506 at a low dose had an effect of suppressing the onset of pancreatitis, administration at a higher dose appeared to exacerbate pancreatitis