Lipid flippase dysfunction as a therapeutic target for endosomal anomalies in Alzheimer's disease

Endosomal anomalies because of vesicular traffic impairment have been indicated as an early pathology of Alzheimer'vertical bar disease (AD). However, the mechanisms and therapeutic targets remain unclear. We previously reported thatbCTF, one of the pathogenic metabolites of APP, interacts with TMEM30A. TMEM30A constitutes a lipid flippase with P4-ATPase and regulates vesicular trafficking through the asymmetric distribution of phospholipids. Therefore, the alteration of lipid flippase activity in AD pathology has got attention. Herein, we showed that the interaction between beta CTF and TMEM30A suppresses the physiological formation and activity of lipid flippase in AD model cells, A7, and App(NLG-F/NLG-F) model mice. Furthermore, the T-RAP peptide derived from the beta CTF binding site of TMEM30A improved endosomal anomalies, which could be a result of the restored lipid flippase activity. Our results provide insights into the mechanisms of vesicular traffic impairment and suggest a therapeutic target for AD

Surgery-related disseminated intravascular coagulation predicts postoperative complications

Abstract Purpose The rate of postoperative morbidity, including infectious complications, is still high after major hepatobiliary pancreatic (HBP) surgery. Although surgery-related disseminated intravascular coagulation (DIC) occurs in some cases, its significance has not been elucidated in HBP surgery. This study aimed to evaluate the influence of surgery-related DIC on the complication severity after HBP surgery. Methods We analyzed the records of 100 patients with hepatectomy in two or more segments, hepatectomy with biliary tract reconstruction, and pancreaticoduodenectomy. The baseline characteristics and complications were compared between patients with and without surgery-related DIC on postoperative day 1 (POD1) after HBP surgery between 2010 and 2018. Complication severity was assessed using the Comprehensive Complication Index (CCI). Results The DIC group (surgery-related DIC on POD1) had predictive factors, such as larger bleeding volume and higher liver enzyme levels. The DIC group exhibited significantly elevated rates of surgical site infection, sepsis, prolonged intensive care unit stay, more frequent blood transfusions, and higher CCI. Furthermore, compared with and without adjustment of DIC, odds ratio (OR) of AST level and operation time for  the risk of high CCI decreased (OR of AST level: 1.25 to 1.19 and OR of operation time: 1.30 to 1.23) and the significant differences had vanished. Conclusions Surgery-related DIC on POD1 could be a partial mediator between AST level, operation time and higher CCI. The prevention or proper management of surgery-related DIC on POD1 can be an important target to reduce the severity of postoperative complications

Hepatic irradiation persistently eliminates liver resident NK cells

<div><p>Hepatic irradiation for the treatment of hepatobiliary malignancies often indirectly damages liver tissue and promotes the development of liver fibrosis. However, little is known concerning the effects of hepatic irradiation on the liver immune system, including natural killer (NK) cells. The aim of this study was therefore to investigate how hepatic irradiation influences the functions and characteristics of liver resident NK cells. An established murine hepatic irradiation model was used to examine the specific effects of hepatic irradiation on immune cell populations and metastasis. This analysis demonstrated that hepatic irradiation decreased the number of liver resident NK cells (DX5^–TRAIL⁺), but did not affect the total NK number or proportions of NK cells in the liver or spleen. This effect was correlated with the hepatic irradiation dose. Surprisingly, the liver resident NK population had not recovered by two months after hepatic irradiation. We also found that hepatic irradiation limited the cytotoxic effects of liver-derived lymphocytes against a mouse hepatoma cell line and promoted hepatic metastases in an <i>in vivo</i> model, although adoptive transfer of activated NK cells could alleviate metastatic growth. Finally, we demonstrated that hepatic irradiation disrupted the development of liver-resident NK cells, even after the adoptive transfer of precursor cells from the bone marrow, liver, and spleen, suggesting that irradiation had altered the developmental environment of the liver. In summary, our data demonstrated that hepatic irradiation abolished the DX5^–TRAIL⁺ liver-resident NK cell population and dampened antitumor activities in the liver for at least two months. Additionally, hepatic irradiation prevented differentiation of precursor cells into liver-resident NK cells.</p></div

Hepatic irradiation decreases the proportion of DX5^–TRAIL⁺ lrNK cells for up to two months.

<p>(A) The liver and splenic lymphocytes were stained with anti-NK1.1, anti-TCRβ, and PI. NK1.1⁺TCRβ⁻ NK cells were then gated for the analysis of other markers. NK cells were divided into DX5^–TRAIL⁺ lrNK cells and DX5⁺TRAIL⁻ cNK cells. (B) After hepatic irradiation, the lrNK cell population was significantly decreased, whereas the cNK cell population did not change, in livers irradiated with 10 Gy or 20 Gy when compared to sham-operation mice (n = 4). (C) The populations of DX5⁻TRAIL⁺ lrNK cells and DX5⁺ TRAIL⁻ cNK cells in the spleen did not change after hepatic irradiation in the 5 Gy, 10 Gy, and 20 Gy groups (n = 4). Data are expressed as the mean ± SD. Statistical differences were assessed using the nonparametric Mann-Whitney U test (*p < 0.05).</p

Hepatic irradiation increases hepatic metastasis and adoptive transfer of activated NK cells inhibits this effect.

<p>(A) Representative histopathological findings of liver specimens (stained with H&E). Specimens are shown from the control group (left), hepatic irradiated group (middle), and the group that received irradiation followed by NK cell transplantation (right). Arrows indicate metastatic tumors. (B) Seven days before splenic injection of Hepa1-6, mice underwent hepatic irradiation using single-fraction doses of 10 Gy or did not undergo hepatic irradiation as the control group and were injected with tumor cells on Day 0. On Day 3, the hepatic irradiation + NK inoculation group (n = 5) received an intravenous injection of 5 × 10⁵ liver NK cells, whereas control group (n = 5) and the hepatic irradiation group (n = 7) received medium alone. The proliferation of hepatoma cells was promoted but the adoptive transfer of activated liver NK cells inhibited liver metastasis. Data are represented as the mean ± SD. Statistical differences were assessed using unpaired Student’s <i>t</i>-test (* p < 0.05 for control vs. hepatic irradiation; ** p < 0.05 for hepatic irradiation vs. hepatic irradiation + NK inoculation mice).</p

DX5^–TRAIL⁺ NK cells were generated from non-T, non-NK precursors (CD3⁻NK1.1⁻ cells) isolated from liver lymphocytes, splenic lymphocytes, and BM cells in control mice, but not from mice that received liver irradiation.

<p>(A) Liver lymphocytes of RAG-2γ(c) knockout mice were stained with anti-NK1.1, anti-TCRβ, and PI. Representative flow panels show the percentages of NK1.1⁺TCRβ− fractionation among the live lymphocyte population in the liver. (B) Representative flow cytometry plots of DX5^–TRAIL⁺ lrNK cells isolated from the liver in CD3^–NK1.1^– liver lymphocyte-administered (upper), CD3^–NK1.1^– splenic lymphocyte-administered (middle), and CD3^–NK1.1^– BM lymphocyte-administered (lower) mice, gated on the total NK1.1⁺ TCRβ⁻ cell population (n = 5). (C) Representative flow cytometry plots of DX5^–TRAIL⁺ lrNK cells isolated from the liver in CD3^–NK1.1^– liver lymphocyte-administered (upper), CD3^–NK1.1^– splenic lymphocyte-administered (middle), and CD3^–NK1.1^– BM lymphocyte-administered (lower) mice that received hepatic irradiation, gated on the total NK1.1⁺ TCRβ⁻ cell population (n = 5). (D) The proportion of DX5^- TRAIL⁺ NK cells in control mice was significantly higher than that in mice with hepatic irradiation in the CD3^–NK1.1^– liver lymphocyte-administered group (left), CD3^–NK1.1^– splenic lymphocyte-administered group (middle), and CD3^–NK1.1^– BM lymphocyte-administered group (right). Data are presented as the mean ± SD. Statistical differences were assessed using unpaired Student’s <i>t</i>-test (* p < 0.05 for control vs. hepatic irradiation mice).</p

Time course analysis of liver and splenic lymphocytes.

<p>Liver and splenic lymphocytes were isolated from control or hepatic irradiated B6 mice. (A) Liver and splenic lymphocytes were stained with anti-NK1.1, anti-TCRβ, and PI. Representative flow panels show the percentages of NK1.1⁺TCRβ⁻ NK cells, NK1.1⁺TCRβ⁺ NK1⁺-like T cells, and NK1.1⁻TCRβ⁺ T cells among the live lymphocyte population in the liver. (B) The overall proportions of NK cells, NK1⁺-like T cells, and T cells among the live lymphocyte population in the liver and spleen did not change in the 2 months after hepatic irradiation (n = 4). Data are expressed as the mean ± SD. Statistical differences were assessed using the nonparametric Mann-Whitney U test.</p

Hepatic irradiation decreases the cytotoxic activities of liver lymphocytes.

<p>The cytotoxicity of liver lymphocytes after hepatic irradiation using single-fraction doses of 10 Gy was decreased at both one (left) and two (right) months after irradiation. Freshly isolated liver lymphocytes after sham operation were used as the control. Data are expressed as the mean ± SD. (n = 4 mice per group). Statistical differences were assessed using ANOVA (*p < 0.05).</p

Impact of a new liver immune status index among patients with hepatocellular carcinoma after initial hepatectomy

Abstract Aim The anti‐tumor effects of natural killer (NK) cells vary among individuals. Tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) expressed on liver NK cells is a marker of anti‐tumor cytotoxicity against hepatocellular carcinoma (HCC) in immune cell therapy. This study aimed to develop a liver immune status index (LISI) that predicts low TRAIL expression and validates its ability to predict recurrence after initial hepatectomy for primary HCC. Methods A functional analysis of liver NK cells co‐cultured with interleukin‐2 for 3 days was performed of 40 liver transplant donors. The LISI, which predicted low TRAIL expression (25% quartile: <33%) in liver NK cells, was calculated using multiple logistic regression analysis. Next, 586 initial hepatectomy cases were analyzed based on the LISI. Results Our model was based on the Fibrosis‐4 index+0.1 (odds ratio [OR], 1.33), body mass index (OR, 0.61), and albumin levels+0.1 (OR, 0.54). The area under the receiver operating characteristic curve (AUC) of the LISI for low TRAIL expression was 0.89. Stratification of the recurrence rates (RR) revealed that LISI was an independent predictive factor of RR (moderate risk: hazard ratio, 1.44; high risk: hazard ratio, 3.02). The AUC was similar for the LISI, albumin–indocyanine green evaluation grade, albumin–bilirubin score, and geriatric nutritional risk index for predicting RR. Among the vascular invasion cases, the LISI was more useful than the other indexes. Conclusion Our model facilitates the prediction of RR in high‐risk patients by providing LISI to predict the anti‐tumor effects of NK cells