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Accumulation of amyloid beta-peptides (Abeta) in the brain has been linked with memory loss in Alzheimer's disease and its animal models. However, the synaptic mechanism by which Abeta causes memory deficits remains unclear. We previously showed that acute application of Abeta inhibited long-term potentiation (LTP) in the hippocampal perforant path via activation of calcineurin, a Ca2+ -dependent protein phosphatase. This study examined whether Abeta could also inhibit Ca2+/calmodulin dependent protein kinase II (CaMKII), further disrupting the dynamic balance between protein kinase and phosphatase during synaptic plasticity. Immunoblot analysis was conducted to measure autophosphorylation of CaMKII at Thr286 and phosphorylation of the GluR1 subunit of AMPA receptors in single rat hippocampal slices. A high-frequency tetanus applied to the perforant path significantly increased CaMKII autophosphorylation and subsequent phosphorylation of GluR1 at Ser831, a CaMKII-dependent site, in the dentate area. Acute application of Abeta1-42 inhibited dentate LTP and associated phosphorylation processes, but was without effect on phosphorylation of GluR1 at Ser845, a protein kinase A-dependent site. These results suggest that activity-dependent CaMKII autophosphorylation and AMPA receptor phosphorylation are essential for dentate LTP. Disruption of such mechanisms could directly contribute to Abeta-induced deficits in hippocampal synaptic plasticity and memory.

The T cell immunoglobulin and mucin domain-containing molecules (TIM) protein family, which is expressed by T cells, plays a crucial role in regulating host adaptive immunity and tolerance. However, its role in local inflammation, such as innate immunity-dominated organ ischemia-reperfusion injury (IRI), remains unknown. Liver IRI occurs frequently after major hepatic resection or liver transplantation. Using an antagonistic anti-TIM-1 antibody (Ab), we studied the role of TIM-1 signaling in the model of partial warm liver ischemia followed by reperfusion. Anti-TIM-1 Ab monotherapy ameliorated the hepatocellular damage and improved liver function due to IR, as compared with controls. Histological examination has revealed that anti-TIM-1 Ab treatment decreased local neutrophil infiltration, inhibited sequestration of T lymphocytes, macrophages, TIM-1 ligand-expressing TIM-4 ؉ cells, and reduced liver cell apoptosis. Intrahepatic neutrophil activity and induction of proinflammatory cytokines/ chemokines were also reduced in the treatment group. In parallel in vitro studies, anti-TIM-1 Ab suppressed interferon-␥ (IFN-␥) production in concanavalin A (conA)-stimulated spleen T cells, and diminished tumor necrosis factor ␣ (TNF-␣)/interleukin (IL)-6 expression in a macrophage/spleen T cell coculture system. This is the first study to provide evidence for the novel role of TIM-1 signaling in the mechanism of liver IRI. TIM-1 regulates not only T for the role of cell activation but may also affect macrophage function in the local inflammation response. These results provide compelling data for further investigation of TIM-1 pathway in the mechanism of IRI, to improve liver function, expand the organ donor pool, and improve the overall success of liver transplantation. (HEPATOLOGY 2010;51:1363-1372 T he T cell immunoglobulin mucin (TIM) family of cell surface proteins has attracted much attention as potential regulators of the immune system. The TIM family is located on chromosome 11B1.1 in mice and consists of four identified members (TIM-1, -2, -3, and -4) and four putative members . In humans, the TIM family is located on chromosome 5q33.2 and consists of three members, TIM-1, TIM-3, and TIM-4. All are predicted to be type I membrane proteins that share a characteristic immunoglobulin

Background A neutrophil elastase (NE) inhibitor, Sivelestat, has been approved for the treatment of acute lung injury associated with systemic inflammation in humans. Some reports have also shown its protective effects in liver inflammatory states. We have recently documented the importance of NE in the pathophysiology of liver ischemia and reperfusion injury (IRI), a local Ag-independent inflammation response. This study was designed to explore putative cytoprotective functions of clinically available Sivelestat in liver IRI. Methods Partial warm ischemia was produced in the left and middle hepatic lobes of C57BL/6 mice for 90 min, followed by 6 or 24 h of reperfusion. Mice were given Sivelestat (100 mg/kg, s.c.) at 10 min prior to ischemia, 10 min prior to reperfusion, and at 1 h and 3 h of reperfusion thereafter. Results Sivelestat treatment significantly reduced serum ALT levels and NE activity, as compared with controls. Histological liver examination has revealed that unlike in controls, Sivelestat ameliorated the hepatocellular damage and decreased local neutrophil activity and infiltration. The expression of pro-inflammatory cytokines (TNF-α, IL-6), chemokines (CXCL-1, CXCL-2, CXCL-10) and TLR4 was significantly reduced in the treatment group, along with diminished apoptosis via caspase-3 pathway. Moreover, in vitro studies confirmed downregulation of pro-inflammatory cytokine and chemokine programs in mouse macrophage cell cultures, along with depression of innate TLR4 signaling. Conclusion Sivelestat-mediated NE inhibition may represent an effective therapeutic option in liver transplantation and other inflammation disease states.

Hepatocellular carcinoma (HCC) is the fifth most common malignancy and is the third leading cause of cancer death worldwide. Recently, the multitargeted kinase inhibitor sorafenib was shown to be the first systemic agent to improve survival in advanced HCC. Unlike other malignancies such as breast cancer, in which molecular subtypes have been clearly defined (i.e., luminal, HER2 amplified, basal, etc.) and tied to effective molecular therapeutics (hormone blockade and trastuzumab, respectively), in HCC this translational link does not exist. Molecular profiling studies of human HCC have identified unique molecular subtypes of the disease. We hypothesized that a panel of human HCC cell lines would maintain molecular characteristics of the clinical disease and could then be used as a model for novel therapeutics. Twenty human HCC cell lines were collected and RNA was analyzed using the Agilent microarray platform. Profiles from the cell lines in vitro recapitulate previously described subgroups from clinical material. Next, we evaluated whether molecular subgroup would have predictive value for response to the Src/Abl inhibitor dasatinib. The results demonstrate that sensitivity to dasatinib was associated with a progenitor subtype. Dasatinib was effective at inducing cell cycle arrest and apoptosis in ''progenitor-like'' cell lines but not in resistant lines. Conclusion: These findings suggest that cell line models maintain the molecular background of HCC and that subtype may be important for selecting patients for response to novel therapies. In addition, it highlights a potential role for Src family signaling in this progenitor subtype of HCC.