The immunology of hepatocellular carcinoma.

In contrast to most other malignancies, hepatocellular carcinoma (HCC), which accounts for approximately 90% of primary liver cancers, arises almost exclusively in the setting of chronic inflammation. Irrespective of etiology, a typical sequence of chronic necroinflammation, compensatory liver regeneration, induction of liver fibrosis and subsequent cirrhosis often precedes hepatocarcinogenesis. The liver is a central immunomodulator that ensures organ and systemic protection while maintaining immunotolerance. Deregulation of this tightly controlled liver immunological network is a hallmark of chronic liver disease and HCC. Notably, immunotherapies have raised hope for the successful treatment of advanced HCC. Here we summarize the roles of specific immune cell subsets in chronic liver disease, with a focus on non-alcoholic steatohepatitis and HCC. We review new advances in immunotherapeutic approaches for the treatment of HCC and discuss the challenges posed by the immunotolerant hepatic environment and the dual roles of adaptive and innate immune cells in HCC.

Inhibition of LTßR signalling activates WNT-induced regeneration in lung.

Lymphotoxin ß-receptor (LTßR) signalling promotes lymphoid neogenesis and the development of tertiary lymphoid structures1,2, which are associated with severe chronic inflammatory diseases that span several organ systems3-6. How LTßR signalling drives chronic tissue damage particularly in the lung, the mechanism(s) that regulate this process, and whether LTßR blockade might be of therapeutic value have remained unclear. Here we demonstrate increased expression of LTßR ligands in adaptive and innate immune cells, enhanced non-canonical NF-κB signalling, and enriched LTßR target gene expression in lung epithelial cells from patients with smoking-associated chronic obstructive pulmonary disease (COPD) and from mice chronically exposed to cigarette smoke. Therapeutic inhibition of LTßR signalling in young and aged mice disrupted smoking-related inducible bronchus-associated lymphoid tissue, induced regeneration of lung tissue, and reverted airway fibrosis and systemic muscle wasting. Mechanistically, blockade of LTßR signalling dampened epithelial non-canonical activation of NF-κB, reduced TGFß signalling in airways, and induced regeneration by preventing epithelial cell death and activating WNT/ß-catenin signalling in alveolar epithelial progenitor cells. These findings suggest that inhibition of LTßR signalling represents a viable therapeutic option that combines prevention of tertiary lymphoid structures1 and inhibition of apoptosis with tissue-regenerative strategies.

Intestinal B cells license metabolic T-cell activation in NASH microbiota/antigen-independently and contribute to fibrosis by IgA-FcR signalling.

BACKGROUND & AIMS: The progression of non-alcoholic steatohepatitis (NASH) to fibrosis and hepatocellular carcinoma (HCC) is aggravated by auto-aggressive T cells. The gut-liver axis contributes to NASH, but the mechanisms involved and the consequences for NASH-induced fibrosis and liver cancer remain unknown. We investigated the role of gastrointestinal B cells in the development of NASH, fibrosis and NASH-induced HCC. METHODS: C57BL/6J wild-type (WT), B cell-deficient and different immunoglobulin-deficient or transgenic mice were fed distinct NASH-inducing diets or standard chow for 6 or 12 months, whereafter NASH, fibrosis, and NASH-induced HCC were assessed and analysed. Specific pathogen-free/germ-free WT and µMT mice (containing B cells only in the gastrointestinal tract) were fed a choline-deficient high-fat diet, and treated with an anti-CD20 antibody, whereafter NASH and fibrosis were assessed. Tissue biopsy samples from patients with simple steatosis, NASH and cirrhosis were analysed to correlate the secretion of immunoglobulins to clinicopathological features. Flow cytometry, immunohistochemistry and single-cell RNA-sequencing analysis were performed in liver and gastrointestinal tissue to characterise immune cells in mice and humans. RESULTS: Activated intestinal B cells were increased in mouse and human NASH samples and licensed metabolic T-cell activation to induce NASH independently of antigen specificity and gut microbiota. Genetic or therapeutic depletion of systemic or gastrointestinal B cells prevented or reverted NASH and liver fibrosis. IgA secretion was necessary for fibrosis induction by activating CD11b+CCR2+F4/80+CD11c-FCGR1+ hepatic myeloid cells through an IgA-FcR signalling axis. Similarly, patients with NASH had increased numbers of activated intestinal B cells; additionally, we observed a positive correlation between IgA levels and activated FcRg+ hepatic myeloid cells, as well the extent of liver fibrosis. CONCLUSIONS: Intestinal B cells and the IgA-FcR signalling axis represent potential therapeutic targets for the treatment of NASH. IMPACT AND IMPLICATIONS: There is currently no effective treatment for non-alcoholic steatohepatitis (NASH), which is associated with a substantial healthcare burden and is a growing risk factor for hepatocellular carcinoma (HCC). We have previously shown that NASH is an auto-aggressive condition aggravated, amongst others, by T cells. Therefore, we hypothesized that B cells might have a role in disease induction and progression. Our present work highlights that B cells have a dual role in NASH pathogenesis, being implicated in the activation of auto-aggressive T cells and the development of fibrosis via activation of monocyte-derived macrophages by secreted immunoglobulins (e.g., IgA). Furthermore, we show that the absence of B cells prevented HCC development. B cell-intrinsic signalling pathways, secreted immunoglobulins, and interactions of B cells with other immune cells are potential targets for combinatorial NASH therapies against inflammation and fibrosis.

CCL2 in the Tumor Microenvironment.

The C-C motif chemokine ligand 2 (CCL2) is a crucial mediator of immune cell recruitment during microbial infections and tissue damage. CCL2 is also frequently overexpressed in cancer cells and other cells in the tumor microenvironment, and a large body of evidence indicates that high CCL2 levels are associated with more aggressive malignancies, a higher probability of metastasis, and poorer outcomes in a wide range of cancers. CCL2 plays a role in recruiting tumor-associated macrophages (TAMs), which adopt a pro-tumorigenic phenotype and support cancer cell survival, facilitate tumor cell invasion, and promote angiogenesis. CCL2 also has direct, TAM-independent effects on tumor cells and the tumor microenvironment, including recruitment of other myeloid subsets and non-myeloid cells, maintaining an immunosuppressive environment, stimulating tumor cell growth and motility, and promoting angiogenesis. CCL2 also plays important roles in the metastatic cascade, such as creating a pre-metastatic niche in distant organs and promoting tumor cell extravasation across endothelia. Due to its many roles in tumorigenesis and metastatic processes, the CCL2-CCR2 signaling axis is currently being pursued as a potential therapeutic target for cancer.

A dual role for hepatocyte-intrinsic canonical NF-κB signaling in virus control.

BACKGROUND & AIMS: Hepatic innate immune control of viral infections has largely been attributed to Kupffer cells, the liver-resident macrophages. However, hepatocytes, the parenchymal cells of the liver, also possess potent immunological functions in addition to their known metabolic functions. Owing to their abundance in the liver and known immunological functions, we aimed to investigate the direct antiviral mechanisms employed by hepatocytes. METHODS: Using lymphocytic choriomeningitis virus (LCMV) as a model of liver infection, we first assessed the role of myeloid cells by depletion prior to infection. We investigated the role of hepatocyte-intrinsic innate immune signaling by infecting mice lacking canonical NF-κB signaling (IkkßΔHep) specifically in hepatocytes. In addition, mice lacking hepatocyte-specific interferon-α/ß signaling-(IfnarΔHep), or interferon-α/ß signaling in myeloid cells-(IfnarΔMyel) were infected. RESULTS: Here, we demonstrate that LCMV activates NF-κB signaling in hepatocytes. LCMV-triggered NF-κB activation in hepatocytes did not depend on Kupffer cells or TNFR1 signaling but rather on Toll-like receptor signaling. LCMV-infected IkkßΔHep livers displayed strongly elevated viral titers due to LCMV accumulation within hepatocytes, reduced interferon-stimulated gene (ISG) expression, delayed intrahepatic immune cell influx and delayed intrahepatic LCMV-specific CD8+ T cell responses. Notably, viral clearance and ISG expression were also reduced in LCMV-infected primary hepatocytes lacking IKKß, demonstrating a hepatocyte-intrinsic effect. Similar to livers of IkkßΔHep mice, enhanced hepatocytic LCMV accumulation was observed in livers of IfnarΔHep mice, whereas IfnarΔMyel mice were able to control LCMV infection. Hepatocytic NF-κB signaling was also required for efficient ISG induction in HDV-infected dHepaRG cells and interferon-α/ß-mediated inhibition of HBV replication in vitro. CONCLUSIONS: Together, these data show that hepatocyte-intrinsic NF-κB is a vital amplifier of interferon-α/ß signaling, which is pivotal for strong early ISG responses, immune cell infiltration and hepatic viral clearance. LAY SUMMARY: Innate immune cells have been ascribed a primary role in controlling viral clearance upon hepatic infections. We identified a novel dual role for NF-κB signaling in infected hepatocytes which was crucial for maximizing interferon responses and initiating adaptive immunity, thereby efficiently controlling hepatic virus replication.

The toxicity of antiprion antibodies is mediated by the flexible tail of the prion protein.

Prion infections cause lethal neurodegeneration. This process requires the cellular prion protein (PrP(C); ref. 1), which contains a globular domain hinged to a long amino-proximal flexible tail. Here we describe rapid neurotoxicity in mice and cerebellar organotypic cultured slices exposed to ligands targeting the α1 and α3 helices of the PrP(C) globular domain. Ligands included seven distinct monoclonal antibodies, monovalent Fab1 fragments and recombinant single-chain variable fragment miniantibodies. Similar to prion infections, the toxicity of globular domain ligands required neuronal PrP(C), was exacerbated by PrP(C) overexpression, was associated with calpain activation and was antagonized by calpain inhibitors. Neurodegeneration was accompanied by a burst of reactive oxygen species, and was suppressed by antioxidants. Furthermore, genetic ablation of the superoxide-producing enzyme NOX2 (also known as CYBB) protected mice from globular domain ligand toxicity. We also found that neurotoxicity was prevented by deletions of the octapeptide repeats within the flexible tail. These deletions did not appreciably compromise globular domain antibody binding, suggesting that the flexible tail is required to transmit toxic signals that originate from the globular domain and trigger oxidative stress and calpain activation. Supporting this view, various octapeptide ligands were not only innocuous to both cerebellar organotypic cultured slices and mice, but also prevented the toxicity of globular domain ligands while not interfering with their binding. We conclude that PrP(C) consists of two functionally distinct modules, with the globular domain and the flexible tail exerting regulatory and executive functions, respectively. Octapeptide ligands also prolonged the life of mice expressing the toxic PrP(C) mutant, PrP(Δ94-134), indicating that the flexible tail mediates toxicity in two distinct PrP(C)-related conditions. Flexible tail-mediated toxicity may conceivably play a role in further prion pathologies, such as familial Creutzfeldt-Jakob disease in humans bearing supernumerary octapeptides.

Correction: Prion infections and anti-PrP antibodies trigger converging neurotoxic pathways.

[This corrects the article DOI: 10.1371/journal.ppat.1004662.].

Prion infections and anti-PrP antibodies trigger converging neurotoxic pathways.

Prions induce lethal neurodegeneration and consist of PrPSc, an aggregated conformer of the cellular prion protein PrPC. Antibody-derived ligands to the globular domain of PrPC (collectively termed GDL) are also neurotoxic. Here we show that GDL and prion infections activate the same pathways. Firstly, both GDL and prion infection of cerebellar organotypic cultured slices (COCS) induced the production of reactive oxygen species (ROS). Accordingly, ROS scavenging, which counteracts GDL toxicity in vitro and in vivo, prolonged the lifespan of prion-infected mice and protected prion-infected COCS from neurodegeneration. Instead, neither glutamate receptor antagonists nor inhibitors of endoplasmic reticulum calcium channels abolished neurotoxicity in either model. Secondly, antibodies against the flexible tail (FT) of PrPC reduced neurotoxicity in both GDL-exposed and prion-infected COCS, suggesting that the FT executes toxicity in both paradigms. Thirdly, the PERK pathway of the unfolded protein response was activated in both models. Finally, 80% of transcriptionally downregulated genes overlapped between prion-infected and GDL-treated COCS. We conclude that GDL mimic the interaction of PrPSc with PrPC, thereby triggering the downstream events characteristic of prion infection.

Canonical NF-κB signaling in hepatocytes acts as a tumor-suppressor in hepatitis B virus surface antigen-driven hepatocellular carcinoma by controlling the unfolded protein response.

UNLABELLED: Chronic hepatitis B virus (HBV) infection remains the most common risk factor for hepatocellular carcinoma (HCC). Efficient suppression of HBV viremia and necroinflammation as a result of nucleos(t)ide analogue treatment is able to reduce HCC incidence; nevertheless, hepatocarcinogenesis can occur in the absence of active hepatitis, correlating with high HBV surface antigen (HBsAg) levels. Nuclear factor κB (NF-κB) is a central player in chronic inflammation and HCC development. However, in the absence of severe chronic inflammation, the role of NF-κB signaling in HCC development remains elusive. As a model of hepatocarcinogenesis driven by accumulation of HBV envelope polypeptides, HBsAg transgenic mice, which show no HBV-specific immune response, were crossed to animals with hepatocyte-specific inhibition of canonical NF-κB signaling. We detected prolonged, severe endoplasmic reticulum stress already at 20 weeks of age in NF-κB-deficient hepatocytes of HBsAg-expressing mice. The unfolded protein response regulator binding immunoglobulin protein/78-kDa glucose-regulated protein was down-regulated, activating transcription factor 6, and eIF2α were activated with subsequent overexpression of CCAAT/enhancer binding protein homologous protein. Notably, immune cell infiltrates and liver transaminases were unchanged. However, as a result of this increased cellular stress, insufficient hepatocyte proliferation due to G1 /S-phase cell cycle arrest with overexpression of p27 and emergence of ductular reactions was detected. This culminated in increased DNA damage already at 20 weeks of age and finally led to 100% HCC incidence due to NF-κB inhibition. CONCLUSION: The role of canonical NF-κB signaling in HCC development depends on the mode of liver damage; in the case of HBsAg-driven hepatocarcinogenesis, NF-κB in hepatocytes acts as a critical tumor suppressor by augmenting the endoplasmic reticulum stress response.

The direct and indirect roles of HBV in liver cancer: prospective markers for HCC screening and potential therapeutic targets.

Chronic hepatitis B virus (HBV) infection remains the number one risk factor for hepatocellular carcinoma (HCC), accounting for more than 600 000 deaths/year. Despite highly effective antiviral treatment options, chronic hepatitis B (CHB), subsequent end-stage liver disease and HCC development remain a major challenge worldwide. In CHB, liver damage is mainly caused by the influx of immune cells and destruction of infected hepatocytes, causing necro-inflammation. Treatment with nucleoside/nucleotide analogues can effectively suppress HBV replication in patients with CHB and thus decrease the risk for HCC development. Nevertheless, the risk of HCC in treated patients showing sufficient suppression of HBV DNA replication is significantly higher than in patients with inactive CHB, regardless of the presence of baseline liver cirrhosis, suggesting direct, long-lasting, predisposing effects of HBV. Direct oncogenic effects of HBV include integration in the host genome, leading to deletions, cis/trans-activation, translocations, the production of fusion transcripts and generalized genomic instability, as well as pleiotropic effects of viral transcripts (HBsAg and HBx). Analysis of these viral factors in active surveillance may allow early identification of high-risk patients, and their integration into a molecular classification of HCC subtypes might help in the development of novel therapeutic approaches.

Lymphotoxin, but not TNF, is required for prion invasion of lymph nodes.

Neuroinvasion and subsequent destruction of the central nervous system by prions are typically preceded by a colonization phase in lymphoid organs. An important compartment harboring prions in lymphoid tissue is the follicular dendritic cell (FDC), which requires both tumor necrosis factor receptor 1 (TNFR1) and lymphotoxin ß receptor (LTßR) signaling for maintenance. However, prions are still detected in TNFR1⁻/⁻ lymph nodes despite the absence of mature FDCs. Here we show that TNFR1-independent prion accumulation in lymph nodes depends on LTßR signaling. Loss of LTßR signaling, but not of TNFR1, was concurrent with the dedifferentiation of high endothelial venules (HEVs) required for lymphocyte entry into lymph nodes. Using luminescent conjugated polymers for histochemical PrP(Sc) detection, we identified PrP(Sc) deposits associated with HEVs in TNFR1⁻/⁻ lymph nodes. Hence, prions may enter lymph nodes by HEVs and accumulate or replicate in the absence of mature FDCs.

Challenging Tumor Heterogeneity with HER2, p16 and Somatostatin Receptor 2 Expression in a Case of EBV-Associated Lymphoepithelial Carcinoma of the Salivary Gland.

BACKGROUND: Lymphoepithelial carcinoma of the salivary glands (LECSG) is a rare disease in the Western hemisphere that is typically associated with an EBV infection. The molecular mechanisms of LECSG tumorigenesis are poorly understood. RESULTS: Here we report a case of EBV-associated LECSG with an unusual immunophenotype. The tumor exhibited bi-morphic histological features with a mutually exclusive expression of HER2 and p16. The p16-positive domain of the tumor immunohistochemically co-expressed late membrane protein 1 (LMP-1), while the HER2 positive domain did not. Both tumor regions expressed SSTR2. METHODS: In situ hybridization confirmed the EBV origin of the tumor while extensive immunohistochemical characterization and the recently established RNA-based next generation sequencing panel ("SalvGlandDx" panel) did not reveal evidence for another salivary gland neoplasm. No HPV co-infection was detected by in situ hybridization or PCR-based screenings and no ERBB2 gene amplification was detected by fluorescence in situ hybridization. CONCLUSION: These findings suggest tumor heterogeneity and lack of genomic aberrations in EBV-associated LECSGs. The heterogenous and unusual immunohistochemical features explain the diagnostic difficulties and simultaneously extend the immunophenotype spectrum of this tumor entity.

The contribution of activated astrocytes to Aß production: implications for Alzheimer's disease pathogenesis.

BACKGROUND: ß-Amyloid (Aß) plays a central role in Alzheimer's disease (AD) pathogenesis. Neurons are major sources of Aß in the brain. However, astrocytes outnumber neurons by at least five-fold. Thus, even a small level of astrocytic Aß production could make a significant contribution to Aß burden in AD. Moreover, activated astrocytes may increase Aß generation. ß-Site APP cleaving enzyme 1 (BACE1) cleavage of amyloid precursor protein (APP) initiates Aß production. Here, we explored whether pro-inflammatory cytokines or Aß42 would increase astrocytic levels of BACE1, APP, and ß-secretase processing, implying a feed-forward mechanism of astrocytic Aß production. METHODS: Mouse primary astrocytes were treated with combinations of LPS, TNF-α, IFN-γ, and IL-1ß and analyzed by immunoblot and ELISA for endogenous BACE1, APP, and secreted Aß40 levels. Inhibition of JAK and iNOS signaling in TNF-α+IFN-γ-stimulated astrocytes was also analyzed. In addition, C57BL/6J or Tg2576 mouse astrocytes were treated with oligomeric or fibrillar Aß42 and analyzed by immunoblot for levels of BACE1, APP, and APPsßsw. Astrocytic BACE1 and APP mRNA levels were measured by TaqMan RT-PCR. RESULTS: TNF-α+IFN-γ stimulation significantly increased levels of astrocytic BACE1, APP, and secreted Aß40. BACE1 and APP elevations were post-transcriptional at early time-points, but became transcriptional with longer TNF-α+IFN-γ treatment. Despite a ~4-fold increase in astrocytic BACE1 protein level following TNF-α+IFN-γ stimulation, BACE1 mRNA level was significantly decreased suggesting a post-transcriptional mechanism. Inhibition of iNOS and JAK did not reduce TNF-α+IFN-γ-stimulated elevation of astrocytic BACE1, APP, and Aß40, except that JAK inhibition blocked the APP increase. Finally, oligomeric and fibrillar Aß42 dramatically increased levels of astrocytic BACE1, APP, and APPsßsw through transcriptional mechanisms, at least in part. CONCLUSIONS: Cytokines including TNF-α+IFN-γ increase levels of endogenous BACE1, APP, and Aß and stimulate amyloidogenic APP processing in astrocytes. Oligomeric and fibrillar Aß42 also increase levels of astrocytic BACE1, APP, and ß-secretase processing. Together, our results suggest a cytokine- and Aß42-driven feed-forward mechanism that promotes astrocytic Aß production. Given that astrocytes greatly outnumber neurons, activated astrocytes may represent significant sources of Aß during neuroinflammation in AD.

Outcome of Everolimus-Based Therapy in Hormone-Receptor-Positive Metastatic Breast Cancer Patients After Progression on Palbociclib.

BACKGROUND: Despite the approval of mTOR inhibitor everolimus and CDK4/6 inhibitors in the management of hormone-receptor-positive HER2 non-amplified metastatic breast cancer (HR+ HER2-MBC), the optimal sequence of therapy is unclear. There are no clinical data on efficacy of everolimus in HR+ HER2-MBC after cancer progresses on CDK4/6 inhibitors. OBJECTIVE: The objective of this study is to find the efficacy of everolimus in HR+ HER2-MBC after they progress on a CDK4/6 inhibitor palbociclib. METHODS: This is a retrospective, 2-institute review of HR+ HER2-MBC from Jan 2015 to March 2018 treated with everolimus after progression on palbociclib. Primary end point was median progression-free survival (PFS), secondary end points objective response rate (ORR), clinical benefit ratio (CBR), and overall survival (OS). RESULTS: Out of 41 women with median age 61 years (33, 87) enrolled, 66% had received adjuvant systemic therapy, 61% had visceral disease, and 95% had prior nonsteroidal aromatase inhibitors. About 83% women had 3 or more chemotherapy or hormonal therapies prior to everolimus. Kaplan-Meier estimates showed a median PFS of 4.2 months (95% confidence interval [CI]: 3.2-6.2). The median OS was 18.7 months (95% CI 9.5 to not reached). Objective response rate and CBR were both 17.1%. CONCLUSION: Everolimus was associated with modest PFS and ORR in HR+ HER2-MBCs postprogression on palbociclib.

A Reading-Writing Assignment Based on Popular Literature To Enhance Learning about Microbiology.

In order to stimulate engagement in microbiology, a reading-writing assignment based on a narrative popular science book was created for a one-semester introductory microbiology course. In order to encourage critical thinking, students were required to formulate a question related to the book to research and report on. Active learning was supported by guidance and feedback at each stage of the assignment. The assignment components were graded according to a rubric based on the learning outcomes: reading comprehension, question formulation, literature research, synthesis, and written communication. Median scores for the assignment components indicated that students successfully demonstrated the learning outcomes. A question was included on the final examination, asking students to summarize their most important learning from the assignment. Qualitative analysis of the exam answers revealed a wide variety of lessons learned about the practical applications of microbiology. On average, students scored better on the assignment and the assignment-related exam question than on the final exam. There was no significant correlation between a student's performance on the final exam and their performance on either of the assignment-related assessments, suggesting that the assignment benefited students regardless of their exam-taking capability. According to surveys administered at the end of the introductory microbiology course and again when students were enrolled in a senior microbiology course, a strong majority of students found the reading-writing assignment to be engaging and informative. This assignment may be modified in various ways in order to suit the needs of other courses.

Age-Related Gliosis Promotes Central Nervous System Lymphoma through CCL19-Mediated Tumor Cell Retention.

How lymphoma cells (LCs) invade the brain during the development of central nervous system lymphoma (CNSL) is unclear. We found that NF-κB-induced gliosis promotes CNSL in immunocompetent mice. Gliosis elevated cell-adhesion molecules, which increased LCs in the brain but was insufficient to induce CNSL. Astrocyte-derived CCL19 was required for gliosis-induced CNSL. Deleting CCL19 in mice or CCR7 from LCs abrogated CNSL development. Two-photon microscopy revealed LCs transiently entering normal brain parenchyma. Astrocytic CCL19 enhanced parenchymal CNS retention of LCs, thereby promoting CNSL formation. Aged, gliotic wild-type mice were more susceptible to forming CNSL than young wild-type mice, and astrocytic CCL19 was observed in both human gliosis and CNSL. Therefore, CCL19-CCR7 interactions may underlie an increased age-related risk for CNSL.

Platelet GPIbα is a mediator and potential interventional target for NASH and subsequent liver cancer.

Non-alcoholic fatty liver disease ranges from steatosis to non-alcoholic steatohepatitis (NASH), potentially progressing to cirrhosis and hepatocellular carcinoma (HCC). Here, we show that platelet number, platelet activation and platelet aggregation are increased in NASH but not in steatosis or insulin resistance. Antiplatelet therapy (APT; aspirin/clopidogrel, ticagrelor) but not nonsteroidal anti-inflammatory drug (NSAID) treatment with sulindac prevented NASH and subsequent HCC development. Intravital microscopy showed that liver colonization by platelets depended primarily on Kupffer cells at early and late stages of NASH, involving hyaluronan-CD44 binding. APT reduced intrahepatic platelet accumulation and the frequency of platelet-immune cell interaction, thereby limiting hepatic immune cell trafficking. Consequently, intrahepatic cytokine and chemokine release, macrovesicular steatosis and liver damage were attenuated. Platelet cargo, platelet adhesion and platelet activation but not platelet aggregation were identified as pivotal for NASH and subsequent hepatocarcinogenesis. In particular, platelet-derived GPIbα proved critical for development of NASH and subsequent HCC, independent of its reported cognate ligands vWF, P-selectin or Mac-1, offering a potential target against NASH.

Beta-site amyloid precursor protein cleaving enzyme 1 levels become elevated in neurons around amyloid plaques: implications for Alzheimer's disease pathogenesis.

Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) (beta-secretase) initiates generation of beta-amyloid (Abeta), which plays an early role in Alzheimer's disease (AD). BACE1 levels are increased in postmortem AD brain, suggesting BACE1 elevation promotes Abeta production and AD. Alternatively, the BACE1 increase may be an epiphenomenon of late-stage AD. To distinguish between these possibilities, we analyzed BACE1 elevation using a highly specific BACE1 antibody, BACE-Cat1, made in BACE1-/- mice, which mount a robust anti-BACE1 immune response. Previous BACE1 immunohistochemical studies lack consistent results because typical BACE1 antibodies produce nonspecific background, but BACE-Cat1 immunolabels BACE1 only. BACE1 elevation was recapitulated in two amyloid precursor protein (APP) transgenic mouse lines. 5XFAD mice form amyloid plaques at young ages and exhibit neuron loss. In contrast, Tg2576 form plaques at a more advanced age and do not show cell death. These two mouse lines allow differentiation between early Abeta-induced events and late phenomena related to neuron death. BACE1 levels became elevated in parallel with amyloid burden in each APP transgenic, starting early in 5XFAD and late in Tg2576. The increase in BACE1 protein occurred without any change in BACE1 mRNA level, indicating a posttranscriptional mechanism. In APP transgenic and AD brains, high BACE1 levels were observed in an annulus around Abeta42-positive plaque cores and colocalized with neuronal proteins. These results demonstrate that amyloid plaques induce BACE1 in surrounding neurons at early stages of pathology before neuron death occurs. We conclude that BACE1 elevation is most likely triggered by the amyloid pathway and may drive a positive-feedback loop in AD.

Efficacy of Palbociclib Combinations in Hormone Receptor-Positive Metastatic Breast Cancer Patients After Prior Everolimus Treatment.

PURPOSE: Outcome data on hormone receptor positive (HR+), human epidermal growth factor receptor 2 (HER2) nonamplified (HER2-) metastatic breast cancer (MBC) treated with palbociclib after treatment with everolimus are lacking. The PALOMA-3 trial, showing benefit of palbociclib plus fulvestrant compared to fulvestrant alone in HR+HER2- MBC after progression while receiving endocrine therapy excluded women previously treated with everolimus. The objective of this study was to examine outcomes of HR+HER2- MBC with prior exposure to everolimus while receiving palbociclib-based therapy. PATIENTS AND METHODS: A retrospective, single-institute review was conducted of HR+HER2- MBC from January 2014 to November 2016 in patients treated with palbociclib after prior treatment with everolimus. Progression-free survival (PFS) was defined as the time from initiation of palbociclib to the date of progression as determined by the treating physician based on radiologic, biochemical, and/or clinical criteria. Response rates were determined on the basis of available radiologic data. Objective response rate (ORR) was defined as the rate of any complete or partial responses; clinical benefit rate (CBR) was the rate of complete response, partial response, or stable disease for at least 24 weeks. RESULTS: Twenty-three patients with a mean (range) age of 68 (42-81) years were identified. Kaplan-Meier estimate showed median PFS of 2.9 months (95% confidence interval, 2.1-4.2); ORR was 0 of 23 and CBR was 4 (17.4%) of 23. In the PALOMA-3 trial, median PFS, ORR, and CBR of palbociclib cohort were 9.5 months (95% confidence interval, 9.2-11.0), 19%, and 67%, respectively. CONCLUSION: There is a limited clinical activity of palbociclib combinations after progression with everolimus combination therapy. Further studies are necessary to confirm these findings.