Placental chorionic plate-derived mesenchymal stem cells ameliorate severe acute pancreatitis by regulating macrophage polarization via secreting TSG-6

Abstract Background Mesenchymal stem cells (MSCs) hold promising potential to treat systemic inflammatory diseases including severe acute pancreatitis (SAP). In our previous study, placental chorionic plate-derived MSCs (CP-MSCs) were found to possess superior immunoregulatory capability. However, the therapeutic efficacy of CP-MSCs on SAP and their underlying mechanism remain unclear. Methods The survival and colonization of exogenous CP-MSCs were observed by bioluminescence imaging and CM-Dil labeling in rodent animal models of SAP. The therapeutic efficacy of CP-MSCs on SAP rats was evaluated by pathology scores, the levels of pancreatitis biomarkers as well as the levels of inflammatory factors in the pancreas and serum. The potential protective mechanism of CP-MSCs in SAP rats was explored by selectively depleting M1 or M2 phenotype macrophages and knocking down the expression of TSG-6. Results Exogenous CP-MSCs could survive and colonize in the injured tissue of SAP such as the lung, pancreas, intestine, and liver. Meanwhile, we found that CP-MSCs alleviated pancreatic injury and systemic inflammation by inducing macrophages to polarize from M1 to M2 in SAP rats. Furthermore, our data suggested that CP-MSCs induced M2 polarization of macrophages by secreting TSG-6, and TSG-6 played a vital role in alleviating pancreatic injury and systemic inflammation in SAP rats. Notably, we found that a high inflammation environment could stimulate CP-MSCs to secrete TSG-6. Conclusion Exogenous CP-MSCs tended to colonize in the injured tissue and reduced pancreatic injury and systemic inflammation in SAP rats through inducing M2 polarization of macrophages by secreting TSG-6. Our study provides a new treatment strategy for SAP and initially explains the potential protective mechanism of CP-MSCs on SAP rats

TREM (Triggering Receptor Expressed on Myeloid Cells)-1 Inhibition Attenuates Neuroinflammation via PKC (Protein Kinase C) δ/CARD9 (Caspase Recruitment Domain Family Member 9) Signaling Pathway after Intracerebral Hemorrhage in Mice

Background and Purpose: Intracerebral hemorrhage (ICH) is a devastating subtype of stroke with high mortality and disability. Inflammatory response promotes secondary brain injury after ICH. TREM (triggering receptor expressed on myeloid cells)-1 is a key regulator of inflammation. The aim of this study was to evaluate the role of TREM-1 in neuroinflammatory response after ICH in mice. Methods: CD1 mice (n=275) were used in this study. Mice were subjected to ICH by autologous blood injection. TREM-1 knockout CRISPR was administered intracerebroventricularly to evaluate the role of TREM-1 after ICH. A selective TREM-1 inhibitor, LP17, was administered intranasally 2 hours after ICH. To elucidate TREM-1 signaling pathway, CARD9 (caspase recruitment domain family member 9) activation CRISPR was administered with LP17 and TREM-1 activating anti-mouse TREM-1 monoclonal antibody (mAb) was administered with Rottlerin, a specific PKC (protein kinase C) δ inhibitor. Lastly, to evaluate the role of HMGB1 (high-mobility group box 1) in TREM-1 mediated microglia activation, glycyrrhizin, an inhibitor of HMBG1 was administered with TREM-1 activating mAb. Neurobehavioral test, brain water content, Western blot, immunofluorescence staining, and coimmunoprecipitation was performed. Results: TREM-1 knockout reduced ICH-induced neurobehavioral deficits and neuroinflammatory response. The temporal expression of HMGB1, TREM-1, PKC δ, and CARD9 increased after ICH. TREM-1 was expressed on microglia. Intranasal administration of LP17 significantly decreased brain edema and improved neurobehavioral outcomes at 24 and 72 hours after ICH. LP17 promoted M2 microglia polarization and reduced proinflammatory cytokines after ICH, which was reversed with CARD9 activation CRISPR. TREM-1 mAb increased neurobehavior deficits, proinflammatory cytokines, and reduced M2 microglia after ICH, which was reversed with Rottlerin. HMBG1 interaction with TREM-1 increased after ICH, and glycyrrhizin reduced neuroinflammation and promoted M2 microglia which was reversed with TREM-1 mAb. Conclusions: This study demonstrated that TREM-1 enhanced neuroinflammation by modulating microglia polarization after ICH, and this regulation was partly mediated via PKC δ/CARD9 signaling pathway and increased HMGB1 activation of TREM-1

Prominent Josephson tunneling between twisted single copper oxide planes of Bi2Sr2-xLaxCuO6+y

Abstract Josephson tunneling in twisted cuprate junctions provides a litmus test for the pairing symmetry, which is fundamental for understanding the microscopic mechanism of high temperature superconductivity. This issue is rekindled by experimental advances in van der Waals stacking and the proposal of an emergent d+id-wave. So far, all experiments have been carried out on Bi2Sr2CaCu2O8+x (Bi-2212) with double CuO2 planes but show controversial results. Here, we investigate junctions made of Bi2Sr2-xLaxCuO6+y (Bi-2201) with single CuO2 planes. Our on-site cold stacking technique ensures uncompromised crystalline quality and stoichiometry at the interface. Junctions with carefully calibrated twist angles around 45° show strong Josephson tunneling and conventional temperature dependence. Furthermore, we observe standard Fraunhofer diffraction patterns and integer Fiske steps in a junction with a twist angle of 45.0±0.2°. Together, these results pose strong constraints on the d or d+id-wave pairing and suggest an indispensable isotropic pairing component

The enhanced x-ray timing and polarimetry mission – eXTP: an update on its scientific cases, mission profile and development status

The enhanced x-ray timing and polarimetry mission (eXTP) is a flagship observatory for x-ray timing, spectroscopy and polarimetry developed by an international consortium. Thanks to its very large collecting area, good spectral resolution and unprecedented polarimetry capabilities, eXTP will explore the properties of matter and the propagation of light in the most extreme conditions found in the universe. eXTP will, in addition, be a powerful x-ray observatory. The mission will continuously monitor the x-ray sky, and will enable multi-wavelength and multi-messenger studies. The mission is currently in phase B, which will be completed in the middle of 2022