Search

[Background and Aims] NAFLD is the most common hepatic pathology in western countries and no treatment is currently available. NAFLD is characterized by the aberrant hepatocellular accumulation of fatty acids in the form of lipid droplets (LDs). Recently, it was shown that liver LD degradation occurs through a process termed lipophagy, a form of autophagy. However, the molecular mechanisms governing liver lipophagy are elusive. Here, we aimed to ascertain the key molecular players that regulate hepatic lipophagy and their importance in NAFLD., [Approach and Results] We analyzed the formation and degradation of LD in vitro (fibroblasts and primary mouse hepatocytes), in vivo and ex vivo (mouse and human liver slices) and focused on the role of the autophagy master regulator mammalian target of rapamycin complex (mTORC) 1 and the LD coating protein perilipin (Plin) 3 in these processes. We show that the autophagy machinery is recruited to the LD on hepatic overload of oleic acid in all experimental settings. This led to activation of lipophagy, a process that was abolished by Plin3 knockdown using RNA interference. Furthermore, Plin3 directly interacted with the autophagy proteins focal adhesion interaction protein 200 KDa and autophagy-related 16L, suggesting that Plin3 functions as a docking protein or is involved in autophagosome formation to activate lipophagy. Finally, we show that mTORC1 phosphorylated Plin3 to promote LD degradation., [Conclusions] These results reveal that mTORC1 regulates liver lipophagy through a mechanism dependent on Plin3 phosphorylation. We propose that stimulating this pathway can enhance lipophagy in hepatocytes to help protect the liver from lipid-mediated toxicity, thus offering a therapeutic strategy in NAFLD., Supported by C0120R3166, C0245R4032, and BH182173 from Newcastle University. M. G.-M. is a Sara Borrell Postdoctoral fellow (CD18/00203) from the Ministerio de Ciencia, Innovación y Universidades (Spain). J. P. B. is funded by the Agencia Estatal de Investigación, grants PID2019-105699RB-I00/AEI/10.13039/501100011033 and RED2018-102576-T, Instituto de Salud Carlos III (CB16/10/00282), Junta de Castilla y León (Escalera de Excelencia CLU-2017-03), Ayudas Equipos Investigación Biomedicina 2017 Fundación BBVA, and Fundación Ramón Areces. V. I. K. acknowledges support from Biotechnology and Biological Sciences Research Council (BB/M023389/1, BB/R008167/1, BB

Building on theory suggesting that loneliness is distinct from living arrangements, social isolation, and perceived social support, we examined change in loneliness for older people at the onset of the COVID-19 pandemic. Analyzing 14-years of data with multilevel mixed-effects models, we found higher levels of loneliness among people living alone, people more socially isolated, and people with less perceived support. Gender affected changes in loneliness, controlling for social isolation, perceived support, living arrangements, age, education, income, health, and marital status. Women, whether living alone or with others, experienced increases in loneliness; women living alone reported the greatest increase in loneliness. Men living alone reported high levels of loneliness prior to the pandemic, but only a slight increase over time. These analyses, which demonstrate that loneliness changed at the onset of the pandemic as a function of gender and living arrangement identify older people most likely to benefit from intervention.

Cellular senescence is characterized by an irreversible cell cycle arrest as well as a pro-inflammatory phenotype, thought to contribute to aging and age-related diseases. Neutrophils have essential roles in inflammatory responses; however, in certain contexts their abundance is associated with a number of age-related diseases, including liver disease. The relationship between neutrophils and cellular senescence is not well understood. Here, we show that telomeres in non-immune cells are highly susceptible to oxidative damage caused by neighboring neutrophils. Neutrophils cause telomere dysfunction both in vitro and ex vivo in a ROS-dependent manner. In a mouse model of acute liver injury, depletion of neutrophils reduces telomere dysfunction and senescence. Finally, we show that senescent cells mediate the recruitment of neutrophils to the aged liver and propose that this may be a mechanism by which senescence spreads to surrounding cells. Our results suggest that interventions that counteract neutrophil-induced senescence may be beneficial during aging and age-related disease. publishedVersion

Correction to: Nature Metabolism https://doi.org/10.1038/s42255-020-00306-2, published online 9 November 2020. In the version of this article initially published, in the ×40 diseased human kidney images in Supplementary Fig. 1, the FSGS image duplicated the DN image. The error has been corrected in the HTML version of the article.

Fibrosis is a common pathological feature of chronic disease. Deletion of the NF-κB subunit c-Rel limits fibrosis in multiple organs, although the mechanistic nature of this protection is unresolved. Using cell-specific gene-targeting manipulations in mice undergoing liver damage, we elucidate a critical role for c-Rel in controlling metabolic changes required for inflammatory and fibrogenic activities of hepatocytes and macrophages and identify Pfkfb3 as the key downstream metabolic mediator of this response. Independent deletions of Rel in hepatocytes or macrophages suppressed liver fibrosis induced by carbon tetrachloride, while combined deletion had an additive anti-fibrogenic effect. In transforming growth factor-β1-induced hepatocytes, c-Rel regulates expression of a pro-fibrogenic secretome comprising inflammatory molecules and connective tissue growth factor, the latter promoting collagen secretion from HMs. Macrophages lacking c-Rel fail to polarize to M1 or M2 states, explaining reduced fibrosis in RelΔLysM mice. Pharmacological inhibition of c-Rel attenuated multi-organ fibrosis in both murine and human fibrosis. In conclusion, activation of c-Rel/Pfkfb3 in damaged tissue instigates a paracrine signalling network among epithelial, myeloid and mesenchymal cells to stimulate fibrogenesis. Targeting the c-Rel-Pfkfb3 axis has potential for therapeutic applications in fibrotic disease. ispartof: NATURE METABOLISM vol:2 issue:11 ispartof: location:Germany status: published

Objective: Hypofractionated radiation therapy (HFRT) for early stage breast cancer is an established treatment option with equivalent cancer outcomes and better cosmetic results than standard fractionation. There is limited published information about expected skin changes of African-American breast cancer patients (pts) undergoing HFRT. While HFRT is not recommended for women with large breasts, the use of prone position may allow for homogeneous HFRT plans. We prospectively monitored and reported on skin changes in African-American pts who received HFRT for their breast cancer. Methods: A retrospective analysis at a single institution from 12/2012 to 08/2013 was performed to identify early stage breast cancer pts who underwent breast conservation surgery and received adjuvant whole-breast HFRT. An assessment form had been created to prospectively document weekly changes in radiation dermatitis (CTCAE V.4 Grade 0-4) and hyperpigmentation (none, faint, moderate, severe). Photographs of the treated area were collected before and at the end of treatment. Treatment planning guidelines were per RTOG 1005. Results: There were 15 African-American pts with Tis-T2N0M0 breast cancer who were treated with HFRT to a dose of 4256 cGy in 16 fractions (266 cGy per fraction) followed by a lumpectomy cavity boost of 1000-1250 cGy (250cGy per fraction). There were 12 (80%) pts with right-breast cancer and 6 (40%) who were treated in the prone position. The median age was 61 (36-70). The median body mass index (BMI) for the pts treated in the prone position (42.2 [36-54]) was greater than the median BMI for pts treated in the supine position (29.7 [26-43]). The median breast volume of the prone pts (2335cc [2163-3369]) was more than twice the median volume of supine pts (920cc [231-1459]). The median separation distance for prone and supine pts were 25.1cm (17.5-31.2) and 22.5cm (17.5- 31.8), respectively. Radiation dermatitis: None (6%), Grade 1 (60%), Grade 2 (34%), Grade 3 (none). Only three pts had desquamation:1 pt had dry, and two pts had both dry and minimal moist desquamation in the infra-mammary fold. Hyperpigmentation: none (6.5%), faint (40%), moderate (47%), severe (6.5%). The areas of severe hyperpigmentation correlated to areas of desquamation. The median DMax, mean heart dose, and ipsilateral lung V20Gy were 107.2% (105.2 – 109.9), 60 cGy (29 – 544), and 8.25% (0.0 – 23), respectively. Conclusion: African-American pts treated with HFRT experience minor skin toxicities with mostly Grade 1 dermatitis and moderate hyperpigmentation changes. Obese African-American pts can safely be treated with HFRT if they can be placed in the prone position. Some pts with a separation of > 25cm can be safely and effectively treated with HFRT. Citation Format: Arun G Paul, Amy Collins, Gregory Dyson, Neha Amin. Skin toxicities of obese African American breast cancer patients treated with hypofractionated radiation therapy [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-15-24.

Background Pancreatic cancer cells exist in a hypoxic microenvironment containing numerous factors that impact tumor survival, proliferation, and metastasis. MicroRNAs (miRs) are differentially expressed in cancer but also altered by hypoxia. We hypothesized that hypoxia could induce expression of miR-21, an oncomir in pancreatic cancer cells. Materials and methods We examined how hypoxia regulates miR-21 expression in pancreatic cancer cell lines (BxPC-3, AsPC-1) by stem-loop RT-PCR. Chromatin immunoprecipitation assays were used to study how hypoxia alters hypoxia-inducible factor (HIF)-1α binding to the hypoxia response element of miR-21. BxPC-3 and AsPC-1 cells were transfected with a constitutively stable HIF-1α subunit or vector control (pcDNA3.1) to determine the influence of miR-21 in normoxia. The effect of mature miR-21 sense and antisense oligonucleotides on proliferation and apoptosis in hypoxic and normoxic conditions was assessed via WST-1 assay and flow cytometry. Results MiR-21 levels increased in all cell lines grown in hypoxic conditions versus normoxia, whereas siRNA targeting HIF-1α reduced miR-21 expression. Hypoxic conditions resulted in direct binding of HIF-1α to the predicted binding site in miR-21. Transfection with a constitutively stable HIF-1α expression plasmid in normoxia resulted in upregulated miR-21, similar to that seen in hypoxia. Cells transfected with antisense constructs targeting miR-21 had reduced proliferation and increased apoptosis in normoxia, whereas miR-21 overexpression abrogated hypoxia-associated reductions in proliferation. Conclusions MiR-21 is induced by hypoxia in pancreatic cancer cells via HIF-1α upregulation. MiR-21 overexpression allows cells to avoid apoptosis in a hypoxic microenvironment. Inhibition of miR-21 expression may increase cellular susceptibility to hypoxia in pancreatic cancer.

Cancers of the bile duct and the pancreas are virtually indistinguishable using conventional histopathological and clinical characteristics. We sought to use microRNA (miR) profiling to differentiate these two cancers.RNA was harvested from the tumors of patients undergoing curative resection for cholangiocarcinoma or pancreatic adenocarcinoma and compared with adjacent normal bile duct or pancreas, respectively. There were 31 pairs of cholangiocarcinoma with matched tumor and adjacent bile duct and nine pairs of pancreatic cancer with matched tumor and adjacent uninvolved pancreas that had sufficient quantity of RNA that were included in the final analysis. Differential microRNA expression profiles were determined using the nCounter System from nanoString Technologies (Seattle, WA,USA).A total of 41 differentially expressed miRs were identified in cholangiocarcinoma (25 overexpressed, 16 underexpressed) and 52 differentially expressed miRs were found in pancreatic adenocarcinoma (30 overexpressed, 22 underexpressed) relative to adjacent normal tissue. Of these two profiles, 15 miRs were commonly dysregulated between tumor types. Also, eight miRs were similarly overexpressed or underexpressed in cholangiocarcinoma and pancreatic adenocarcinoma, whereas the other seven miRs had inverse expression levels.Cholangiocarcinoma has a distinct miR profile from pancreatic adenocarcinoma. Discrimination between these two tumor types may be possible with as few as seven miRs.

Osteopontin (OPN) is a secreted protein of the extracellular matrix. It has been used as a marker for tumor aggressiveness and correlated with clinical outcomes in several solid tumors, such as liver, lung, and breast. We determined the OPN expression and its influence on survival in patients with resected pancreatic adenocarcinoma.Tissue microarrays were constructed from 245 resected pancreatic adenocarcinomas. Immunohistochemical staining for OPN was undertaken and compared to normal pancreas (n = 12). OPN expression was then correlated with patient demographics, tumor size, grade, node, and margin status. Survival curves were created by the Kaplan-Meier method and compared by log rank analysis.In total, 181 (74 %) of pancreatic adenocarcinoma tissues expressed OPN compared to 7 (58 %) of normal controls (p = 0.004). Expression was observed predominantly in the cytoplasm of the tumor cells. The median and 2 year overall survival was longer when OPN was expressed (17.1 vs. 11.6 months, and 38 vs. 24 %, respectively, p = 0.04). Multivariate analysis showed OPN expression and T stage to be independent predictors of overall survival, while other histopathologic factors such as tumor grade, tumor size, and nodal status were not.These results suggest that the presence of OPN expression in pancreatic adenocarcinoma may have a protective effect independent of tumor stage. This emphasizes the importance of the interaction between pancreatic cancer cells and their stromal elements.

Pancreatic stellate cells (PSC) are a subset of pancreatic cancer-associated fibroblasts. These cells provide prosurvival signals to tumors; however, little is known regarding their interactions with immune cells within the tumor microenvironment. We hypothesized that factors produced by human PSC could enhance myeloid-derived suppressor cell (MDSC) differentiation and function, which promotes an immunosuppressive microenvironment. Primary PSC cell lines (n = 7) were generated from human specimens and phenotypically confirmed via expression of vimentin, α-smooth muscle actin (α-SMA), and glial fibrillary acidic protein (GFAP). Luminex analysis indicated that PSC but not human fetal primary pancreatic fibroblast cells (HPF; negative controls) produced MDSC-promoting cytokines [interleukin (IL-6), VEGF, macrophage colony-stimulating factor (M-CSF) ] and chemokines (SDF-1, MCP-1). Culture of peripheral blood mononuclear cells [peripheral blood mononuclear cell (PBMC), n = 3 donors] with PSC supernatants or IL-6/granulocyte macrophage colony-stimulating factor (GM-CSF; positive control) for 7 days promoted PBMC differentiation into an MDSC (CD11b+CD33+) phenotype and a subpopulation of polymorphonuclear CD11b+CD33+CD15+ cells. The resulting CD11b+CD33+ cells functionally suppressed autologous T-lymphocyte proliferation. In contrast, supernatants from HPF did not induce an MDSC phenotype in PBMCs. Culture of normal PBMCs with PSC supernatants led to STAT3 but not STAT1 or STAT5 phosphorylation. IL-6 was an important mediator as its neutralization inhibited PSC supernatant-mediated STAT3 phosphorylation and MDSC differentiation. Finally, the FLLL32 STAT3 inhibitor abrogated PSC supernatant-mediated MDSC differentiation, PSC viability, and reduced autocrine IL-6 production indicating these processes are STAT3 dependent. These results identify a novel role for PSC in driving immune escape in pancreatic cancer and extend the evidence that STAT3 acts as a driver of stromal immunosuppression to enhance its interest as a therapeutic target. Cancer Res; 73(10); 3007–18. ©2013 AACR.

Background MicroRNAs (miRNAs) are small non‐coding genes which become dysregulated in cancer and may predict survival. The role of miRNAs in outcomes in cholangiocarcinoma (CC) has not been reported. Methods RNA was extracted from 32 resected CCs along with adjacent uninvolved bile duct epithelium. A total of 43 miRNAs were quantified using NanoString™. Clinicopathologic characteristics and outcomes were captured and compared. Overall survival curves were created using the Kaplan–Meier method; factors, including miRNA expression, were compared by log‐rank, chi‐squared or Cox regression analyses. Results Absolute expression of each miRNA was compared with overall survival after excluding perioperative deaths ( n = 3). One upregulated (miR‐151‐3p; P = 0.003) and one downregulated (miR‐126; P = 0.023) miRNA in resected CC relative to adjacent normal bile duct epithelium correlated with survival on univariate analysis. Clinical factors and these miRNAs were compared. Dysregulated miR‐151‐3p and miR‐126, respectively, were the only factors that correlated with improved overall survival [41.5 months vs. 12.3 months ( P = 0.002) and 21.9 months vs. 15.1 months ( P = 0.02), respectively]. In eight patients, both miRNAs were dysregulated. In the remainder, only one or neither showed dysregulation. Concomitant dysregulation correlated with the best overall survival (58.7 months vs. 15.1 months; P n = 8); clinicopathologic factors in these groups were otherwise similar. conclusions In resected CC, the concomitant dysregulation of both miR‐151‐3p and miR‐126 was the factor related to the greatest improvement in overall survival. Further analysis of the targets of these miRNAs may yield potential therapeutic targets or prognostic biomarkers.