bluuebunny/crossref_metadata_2025_split huggingface dataset:
Macrophage catabolism of aggregated lipoproteins using a novel extracellular compartment regulates lipid accumulation during atherosclerosis
Authors: Singh Rajesh K , Haka Abigail S , Barbosa‐Lorenzi Valeria C , Asmal Arky , Lund Frederik , Xiong Yuquan , Chin Harvey F , Grosheva Inna , Hla Timothy , Maxfield Frederick R 
Published: November 2023

Despite impressive advances in research, prevention, and treatment, atherosclerotic vascular disease remains the leading cause of death in the developed world. Mechanisms of cholesterol accumulation in the arteries have been studied intensively, but the in vivo contributions of different pathways leading to lipid accumulation and foam cell formation are not understood. In the arteries, low‐density lipoprotein (LDL) is aggregated and bound to the extracellular matrix. When such aggregated LDL is presented to macrophages, they form a novel acidic, hydrolytic compartment that is topologically extracellular, to which lysosomal enzymes are secreted. Using state‐of‐the‐art quantitative and high resolution microscopy techniques, characterization of compartment morphology reveals how macrophages use local actin polymerization to drive plasma membrane remodeling at the interface with aggregated LDL. This leads to sequestration of aggregated LDL into topologically convoluted structures that allow acidification, catabolism and internalization of LDL. Such compartments are observed in vivo in murine atherosclerotic plaque macrophages interacting with cholesterol rich deposits. We find that a TLR4/MyD88/Syk/PI3 kinase/Akt dependent signaling pathway in macrophages regulates the formation of such catabolic compartments. Consistent with this, deficiency of TLR4 in vivo can protect macrophages from lipid accumulation in murine atherosclerotic plaques. Herein, we provide compelling evidence for a novel form of catabolism that macrophages use to degrade aggregated LDL in vivo during atherosclerosis and this process leads to foam cell formation, cell death and promotes disease progression.Support or Funding InformationThe project described was supported by National Institutes of Health grants R37‐DK27083 and R01‐HL092234. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. R.K.S is an American Heart Association Stanley Stahl Postdoctoral Fellow (ID: 15POST22990022). V.C.B.L is supported by a fellowship from CNPq “Ciência sem Fronteiras” Brazilian program. H.F.C is a Merck Life Sciences Research Foundation Fellow. The authors declare no competing financial interests.
Novel function of tetraspanin‐interacting protein IGSF3 in the regulation of glycosphingolipid metabolism
Authors: Schweitzer Kelly , Justice Matthew J. , Bronova Irina , Leach Sonia M. , Berdyshev Evgeny V. , Petrache Irina 
Published: November 2023

RationaleWe have previously identified in a patient with severe emphysema with stable chromosomal translocation a disruption in the gene encoding for Immunoglobulin Superfamily, Member 3 (Igsf3) accompanied by low levels of this membrane‐anchored protein. We set out to identify the function of Igsf3, which is predicted to interact with other membrane proteins, tetraspanins. cDNA microarray analyses identified that loss of IGSF3 significantly altered gene expression in the glycosphingolipid (GSL) pathway. Since GLS interaction with tetraspanins at the plasma membrane (dubbed as glycosynapse microdomain) inhibits integrin‐mediated cell functions, we hypothesized that Igsf3 is required for the glycosynapse control of cell motility.MethodsTetraspanin‐enriched microdomains (TEMs) were isolated using density gradient‐ultracentrifugation from human bronchial airway epithelial cells (Beas2b) and from primary immortalized human lung lymphocytes isolated from the consenting subject. Beas2b were transduced or transfected with adenoviral‐ and mammalian‐ IGSF3 plasmid vectors; or with siRNA and lentiviral‐shRNA. GSL were measured by LC‐MS/MS and cell migration and proliferation were assessed by standard techniques.ResultsCo‐immunoprecipitation studies identified that within TEMs, Igsf3 colocalized with the tetraspanins CD9, CD81, CD82, and CD151, as well as with integrinb1 (Itgb1). As expected, when compared to other cellular fractions, TEMs were enriched in cholesterol, ceramides, and glycosylceramides (GC). IGSF3 knockdown significantly increased C16‐GC and C22‐GC (by 5.2‐ and 6.2‐ fold, respectively; p<0.0001), whereas IGSF3 overexpression tended to decrease glycosylceramide levels. Loss of Igsf3 by either siRNA or shRNA significantly delayed wound repair in a cell monolayer scratch assay (p<0.0001) and inhibited cell migration (p<0.03), but did not affect cell proliferation.ConclusionsIgsf3 controls glucosylceramide abundance in TEMs and is required for cell migration. While the mechanism by which Igsf3 regulates the GSL metabolism remains to be investigated, our results suggest that Igsf3 may be an important component of the glycosynapse with a functional role in cellular motility and injury repair.Support or Funding InformationWollowick Chair in Respiratory Research; Medresearch AEF_Schweitzer
Methionine restriction decreases fat mass in C57BL/6 mice via increasing endogenous hydrogen sulfide production
Authors: Wang Yanan , Zhang Jiahong , Guo Haitao , Yan Biao , Shi Yonghui , Le Guowei 
Published: November 2023

Dietary methionine restriction (MR) increases lifespan, reduces adiposity in diverse organisms. However, the mechanisms underlying the healthy benefits of adiposity reduction remain largely unknown. This study aimed to investigate the effects of MR on the activity of the transsulfuration pathway (TSP) enzyme cystathionine γ‐lyase (CGL), hydrogen sulfide (H2S) production, and lipid metabolism in high‐fat diet mice. C57BL/6 mice were fed a high fat diet (HFD) containing either 0.86% methionine (CF) or 0.17% methionine (MR). In the 23th week, lipid profiles, the activity of CGL and the level of H2S in liver were determined. The mRNA level of CGL and the relactive genes (FAS, ACC‐1, SREBP1c, CYP7A1, CPT1 and PPARα) expression of lipid metabolism in mice liver were assayed by real‐time PCR. The protein level of CGL was measured by western blot. We found that compared with CF group, MR significantly decreased the level of triglyceride and cholesterol in mice plasma. The fat synthesis genes (FAS, ACC‐1 and SREBP1c) of MR group were down‐regulated and the fatty acid oxidation genes (CYP7A1, CPT1 and PPARα) were increased. And we found MR significantly increased mRNA and protein expression of CGL, and increased H2S production in mice liver. We concluded that MR can attenuate high‐fat diet‐induced adiposity possibly through increasing endogenous H2S production.Support or Funding InformationThis research was supported by program of “Collaborative innovation center of food safety and quality control in Jiangsu Province”, the National Natural Science Foundation of China (No. 31571841), State Key Laboratory of Food Science and Technology of Jiangnan University in China (SKLF‐ZZB‐201609), and China Postdoctoral Science Foundation (2015M571669).
Angiopoietin‐like 4 Directs Uptake of Dietary Fat Away From Adipose During Fasting
Authors: Cushing Emily Malcolm , Davies Brandon 
Published: November 2023

Misregulation of lipid metabolism has been implicated in numerous disease states including metabolic syndrome, diabetes mellitus, and atherosclerosis. Angiopoietin‐like 4 (ANGPTL4) is a fasting‐induced inhibitor of lipoprotein lipase (LPL) and regulator of plasma triglyceride metabolism. ANGPTL4 is expressed most highly in adipose tissue and liver, but is also expressed in several other tissues including heart and skeletal muscle, and is also present in the plasma. We used gene expression assays in combination with triglyceride clearance and lipase activity assays to examine the kinetics of Angptl4 induction in various tissues during a fasting time course and the effects of global ANGPTL4 deficiency on triglyceride uptake in mice. Angptl4 was strongly induced early in fasting (within 2 to 4 hours), and this induction was not attributable to circadian rhythms. Consistent with previous reports we found that plasma triglyceride levels in Angptl4–/− mice were lower than wild‐type littermate controls, but interestingly, this was only the case in the fasted state. Using chylomicrons containing 3H‐labeled triglycerides we found that Angptl4–/− mice deliver more triglycerides to adipose tissue than wild‐type mice. Again, this difference was only apparent in the fasted state as Angptl4–/− mice showed no significant differences in uptake compared to wild‐type mice in the refed state. Our data support a model where Angptl4 is induced early in fasting and acts locally to divert uptake of fatty acids and triglycerides away from adipose tissues and toward triglyceride‐fueled tissues such as heart and skeletal muscle.Support or Funding Information1R01HL130146‐01A1, NIH/NHLBI (Davies) 06/01/16–03/31/21
A new anti‐atherogenic strategy
Authors: Ma Chuanrui , Zhang Wenwen , Duan Yajun , Chen Yuanli , Han Jihong 
Published: November 2023

The progress on the selective liver X receptor β (LXRβ) modulators, which can reduce atherosclerosis without activation of lipogenesis, is limited. Metformin, a medicine for diabetes treatment, activates AMPKα to enhance energy metabolism. In this study, we investigate if metformin can enhance T0901317 (LXR ligand)‐inhibited atherosclerosis while eliminating T0901317‐activated hypertriglyceridemia. We randomly divided the proatherogenic apoE deficient (apoE−/−) mice into 4 groups (15 mice/group), and fed them a high‐fat diet (HFD), HFD containing T0901317 [1 mg/kg bodayweight/day (mpk)], metformin (100 mpk), or combined T0901317 and metformin, respectively for 16 weeks. After treatment, we collected mouse aorta and liver samples, and determined atherosclerotic lesions and liver steatosis, respectively. We found that T0901317 alone inhibited en face and aortic root sinus lesions, and the inhibition was enhanced by co‐treatment with metformin. The co‐treatment of T0901317 and metformin also enhanced lesion stability by increasing collagen content in lesion caps while reducing necrotic cores and calcification within lesions. Macrophage/foam cell formation and accumulation were inhibited by the co‐treatment which can be attributed by the LXR‐activated ABCA1/ABCG1 expression. T0901317 induced a severe fatty liver and hyperglyceridemia which was substantially blocked by metformin. Mechanistically, metformin had little effect on T0901317‐induced hepatic LXRα/β expression. However, it selectively reduced T0901317‐mediated LXRα (the main transcription factor controlling lipogenesis) but not LXRβ, nuclear translocation. Thereby, metformin blocked expression of T0901317‐induced lipogenic genes, SREBP1c, FASN and ACC, while increased ACC phosphorylation. Moreover, metformin favored energy dissipation process by inducing ATGL, HSL, PPARα and CAT and inhibiting DGAT1 expression. Furthermore, we used AMPKα knockout HepG2 cells to determine the effect of metformin relied on AMPKα expression. Taken together, our study demonstrates that addition of metformin to T0901317 not only enhances T0901317‐inhibited atherosclerosis, but also blocks T0901317‐induced severe hepatic lipid accumulation, fatty liver and hypertriglyceridemia, which suggests that the co‐treatment of metformin and T0901317 may function as a safe and novel therapy for atherosclerosis treatment.Support or Funding InformationThe National Science Foundation of China Grants 81473204 to J Han and 81573427 to Y Duan
Multifaceted Role of Glycan interactions on Clathrin‐Independent Endocytosis of MHC1 and CD59
Authors: Mathew Mohit Philip , Donaldson Julie G. 
Published: November 2023

Glycosylation is an often overlooked post‐translational modification that is unique in its complexity and variety. In fact, altered glycosylation is a hallmark of cancer. Although these changes have been viewed as passive by‐products of cancer metabolism (with efforts primarily directed at their use as biomarkers for detection), more recent results have shown that these glycans can serve important functional roles. The role that glycan interactions can play in clathrin‐independent endocytosis (CIE) is an area of increasing interest in particular because CIE is a form of endocytosis which, unlike clathrin mediated endocytosis (CME), does not have well defined canonical machinery. As a result, studying the role glycans can play in this setting could help elucidate some of the regulatory and molecular mechanisms that govern these trafficking pathways.In this study we show that the perturbation of global cellular glycosylation patterns by metabolic flux modulation affects clathrin independent endocytosis. Interestingly, these changes in glycosylation appear to have certain cargo‐specific effects. For example, treatment of cells with N‐Acetyl Glucosamine (that corresponds to an increase in production of branched glycans) leads to an increase in major histocompatibility complex Class I (MHCI) internalization while at the same time mediating a decrease in endocytosis of CD59, a GPI‐anchored protein.In order to better understand the mechanism behind these glycosylation mediated effects we focused on the role of Galectin 3. Galectin3 is a galactose binding pentameric lectin that is produced in the cytoplasm of cells, is secreted and binds to glycans on the surface of the cell. The multivalent binding potential of galectin 3 makes it unique from other galectins and essential in forming the galectin lattice which can be a major determinant of membrane characteristics. We found that knocking‐down the expression of Galectin 3 led to a decrease in MHCI uptake and an increase in CD59 uptake. Whereas, the inhibition of all glycan‐galectin interactions by lactose treatment inhibits the uptake of both CIE cargo. Our results suggest that glycans play a role in CIE that is quite nuanced, with each cargo affected in a specific manner and different galectins having possibly competing effects. These treatments did not affect the uptake of transferrin, a CME cargo protein, further suggesting a CIE specific role for glycosylation.These findings are interesting for a couple of reasons: 1) The elucidation of the role glycans play in CIE could lead to a more complete understanding of how these still mysterious pathways are regulated and 2) This could open a window into how altered glycosylation can alter the progress of cancer via the CIE pathway.
MODE‐K Cells as a Model to Study the Gut Epithelial Response: An Outside‐in and Inside‐out Approach
Authors: Crockett Erica K. , Washburn Karley F. , Graef Jennifer L. , Lucas Edralin A. , Smith Brenda J. 
Published: November 2023

The gut epithelium serves as a barrier between the intestinal lumen and immune cells residing in gut‐associated lymphoid tissues. These epithelial cells are required to respond to stimuli from the outside‐in (e.g., microbiome and dietary components), as well as from the inside‐out (e.g., cytokines and growth mediators). This study evaluated the utility of a gut epithelial cell model and its response to inside‐out (tumor necrosis factor; TNF‐α) or outside‐in (E. coli lipopolysaccharide; LPS) immune challenges. Experiments were designed to evaluate alterations in cell viability, proliferation, and gene expression using the MODE‐K cell line which was derived from the small intestine of C3H/HeJ mice. For all experiments, MODE‐K cells were grown at 37°C with 5% CO2/95% humidified air in RPMI GlutMAX media supplemented with 10% FBS, 1% HEPES, 1% NEAA, 1% sodium pyruvate, and 0.1% β‐mercaptoethanol. Cell viability and proliferation were assessed using trypan blue exclusion and MTT assays at 12, 24, and 48 hours. Doses of TNF‐α and LPS were selected based on MTT results and cell viability (≥90%). MODE‐K cells were cultured in 12‐well plates and treated with TNF‐α (0, 0.1 or 1.0 ng/mL) or LPS (0, 0.1, 1.0, or 10 ug/mL). Cells were harvested after 2 or 6 hours and total RNA was extracted, followed by qRT‐PCR using Cyclo as the invariant control. Both doses TNF‐α up‐regulated (p<0.05) the relative abundance of interleukin‐6 (Il6), a pro‐inflammatory cytokine, at 2 hrs, whereas only the higher dose of TNF‐α up‐regulated Il6 at 6 hrs. The relative abundance of Tgfb, a cytokine involved in T‐cell differentiation, was elevated with the 1.0 TNF‐α dose at 2 hrs, but not by 6 hrs. The gene expression of the anti‐inflammatory cytokines, interleukin‐10 (Il10) and ‐4 (Il4), was not detectable at either time point. Expression of toll‐like receptor 4 (Tlr4), a pattern recognition receptor, was suppressed (p<0.05) at 2 hrs with all doses of TNF‐α and LPS. This response was normalized by 6 hrs, with the exception of the 1.0 TNF‐α treatment. All doses of LPS, representing the outside‐in stimulus, up‐regulated Il6 at both time points. Likewise, all doses of LPS up‐regulated Tnfa (p<0.05) at 2 hrs, while only the two highest doses increased (p<0.05) Tgfb. No alterations in these responses were observed after 6 hrs. These findings demonstrate that the MODE‐K cells respond to the pro‐inflammatory cytokine, TNF‐α, from the gut mucosa, as well as endotoxins present in the intestinal lumen (i.e., LPS), demonstrating the importance of both the mucosal immune system and the microbiome in initiating epithelial cell signaling. This cell culture model can potentially serve as a system to study the gut epithelial cells' in‐side out and outside‐in responses and to understand the modulating effects of dietary bioactive components.Support or Funding InformationOklahoma Center for the Advancement of Science and Technology (HR14‐126)
Prenatal food and micronutrient interventions in rural Bangladesh remain cost‐effective when assessing both favorable and unfavorable outcomes: Cost‐effectiveness analysis of the MINIMat trial on under five‐mortality and stunting.
Authors: Svefors Pernilla , Selling Katarina Ekholm , Shaheen Rubina Ekholm , Persson Lars Åke Ekholm , Lindholm Lars 
Published: November 2023

BackgroundFew studies analyze the cost‐effectiveness of nutrition interventions in low‐income countries, possibly deterring large‐scale implementation. Nutrition interventions may have favorable as well as unfavorable effects. The Maternal and Infant Nutrition Interventions in Matlab (MINIMat) with early prenatal food and micronutrient supplementation reduced infant mortality and were reported to be very cost‐effective. However, the multiple micronutrients (MMS) resulted in an increased risk of stunted growth in infancy and early childhood. This unfavorable outcome was not included in the previous cost‐effectiveness analysis. The aim of this study is to evaluate whether the MINIMat interventions remain cost‐effective in view of both favorable (decreased under‐five year mortality) and unfavorable (increased stunting) outcomes.MethodPregnant women in rural Bangladesh, where food insecurity still is prevalent, were randomized to early (E) or usual (U) invitation to food supplementation and daily doses of 30 mg, or 60 mg iron with 400 μgm of folic acid, or MMS with 15 micronutrients including 30 mg iron and 400 μgm of folic acid. E reduced stunting at 4.5 years compared with U, MMS compared with Fe60 increased stunting at 4.5 years while the combination EMMS reduced infant mortality compared with UFe60. The outcome measure used was disability adjusted life years (DALY), a measure of overall disease burden that combines years of life lost due to premature mortality (under five‐year mortality) and years lived with disability (stunting). Incremental cost effectiveness ratios were calculated using cost data from already published studies.ResultsBy incrementing UFe60F to EMMS, one DALY could be averted at a cost of US$26.ConclusionWhen both favorable and unfavorable outcomes were included in the analysis early prenatal food and multiple micronutrient interventions remained highly cost effective and seem to be meaningful from a public health perspective.
FEASIBILITY OF INTEGRATING CALCIUM AND IRON‐FOLIC ACID SUPPLEMENTATION TO PREVENT PREECLAMPSIA AND ANEMIA IN PREGNANCY IN PRIMARY HEALTHCARE FACILITIES IN KENYA
Authors: Omotayo Moshood Olanrewaju , Dickin Katherine , Pelletier David , Martin Stephanie , Kung'u Jacqueline , Stoltzfus Rebecca 
Published: November 2023

BackgroundCalcium (Ca) supplementation to prevent preeclampsia can save maternal and newborn lives, but there are no program models for integration into existing antenatal care (ANC) platforms. Many countries have existing antenatal iron supplementation programs, however feasibility of integrating Ca supplementation has not been examined.MethodsWe used a program impact pathway model to guide design of integrated Ca and iron‐folic acid (IFA) supplementation in Kenya. We provided healthcare providers with job aids (posters and counseling cards), trained them on counseling techniques and supplementation guidelines, and developed behavior change materials for pregnant women (calendar and poster). We allocated health facilities to prescribe either 1.0 or 1.5 g/d Ca, with standard IFA. We collected implementation data from 16 facilities and 990 women through record review, spot‐checks and exit interviews and carried out descriptive analyses. We also modeled effects of supplementation on percentage of the population meeting recommended daily allowance (RDA).ResultsSupplements and job aids were available during 90% of facility spot‐check episodes; calendar availability was lower (78%). Over 98% of clients received Ca and IFA supplements, but only 76% received enough Ca supplements to last between ANC visits. Among clients that still had pills by return date, adherence was 77% and 83% for the IFA and Ca regimen, respectively. In the most conservative modeling scenario, over 75% of participants were estimated to meet the RDA, when 1.5 g/d of Ca supplements was prescribed. Only 54% were estimated to meet the RDA when 1.0 g/d was prescribed.ConclusionThis study illustrates a systematic approach for integrating Ca supplementation into primary health care and demonstrates that such integration is feasible when contextual bottlenecks are addressed. Policy makers and program planners should pay attention to supply chain, healthcare worker dispensing behaviour, and appropriateness of regimen for their settings.Support or Funding InformationFunding for this research was provided by the Micronutrient Initiative