Inhibition of plasminogen activator inhibitor-1 expression in vascular smooth muscle cells by protoporphyrins through a heme oxygenase-independent mechanism

Premature Macrophage Activation by Stored Red Blood Cell Transfusion Halts Liver Regeneration Post-Partial Hepatectomy in Rats

Liver resection is a common treatment for various conditions and often requires blood transfusions to compensate for operative blood loss. As partial hepatectomy (PHx) is frequently performed in patients with a pre-damaged liver, avoiding further injury is of paramount clinical importance. Our aim was to study the impact of red blood cell (RBC) resuscitation on liver regeneration. We assessed the impact of RBC storage time on liver regeneration following 50% PHx in rats and explored possible contributing molecular mechanisms using immunohistochemistry, RNA-Seq, and macrophage depletion. The liver was successfully regenerated after PHx when rats were transfused with fresh RBCs (F-RBCs). However, in rats resuscitated with stored RBCs (S-RBCs), the regeneration process was disrupted, as detected by delayed hepatocyte proliferation and lack of hypertrophy. The delayed regeneration was associated with elevated numbers of hemorrhage-activated liver macrophages (Mhem) secreting HO-1. Depletion of macrophages prior to PHx and transfusion improved the regeneration process. Gene expression profiling revealed alterations in numerous genes belonging to critical pathways, including cell cycle and DNA replication, and genes associated with immune cell activation, such as chemokine signaling and platelet activation and adhesion. Our results implicate activated macrophages in delayed liver regeneration following S-RBC transfusion via HO-1 and PAI-1 overexpression.

Expression and subcellular distribution of imp13 are regulated in brain development

Imp13, a member of importin-β superfamily, is found to be one of two bidirectional transport receptors in many nuclear transport activities in mammals. Several cargoes of imp13 have been identified; most of these are essential factors involved in cell cycle and development. The expression and localization of imp13 may influence its cargoes in playing their roles in appropriate time and space. To gain insight into the role of imp13 in brain development, we generated an anti-imp13 polyclonal antibody and investigated the expressions of imp13 in mouse embryonic brains during development, including E13.5, E15.5, E17.5, P0, and adult, at both transcriptional and translational levels. In addition, we performed immunohistochemical analysis and revealed that imp13 tends to be localized in the cytoplasm at the early stages and relocates into the nucleus at the late stages in neuronal cells of mouse brains. These findings suggested that the expression and localization of imp13 in brain tissues are regulated developmentally, which extends our knowledge of the dynamic presence of imp13. These observations also imply that imp13 contributes to the neural cell-specific cargo trafficking and potentially to other functions during brain development.