scholarly journals Autophagy Induced by Palmitic Acid: a Brake in NAFLD Neutrophils

2021 ◽  
Author(s):  
Zhicheng Peng ◽  
Heyuan Wang ◽  
Alan Y. Hsu ◽  
Xiliang Du ◽  
Yuchen Yang ◽  
...  
Keyword(s):  
Palmitic Acid ◽  
Metabolic Diseases ◽  
Ex Vivo ◽  
Neutrophil Function ◽  
List Type ◽  
Nonalcoholic Fatty Liver ◽  
Blood Constituents ◽  
Key Points ◽  
Ethanol Toxicity

AbstractInnate immune suppression and high blood fatty acid levels are the pathological basis of multiple metabolic diseases. Neutrophil vacuolation is an indicator of the immune status of patients, which is associated with autophagy-dependent granule degradation. Vacuolated neutrophils are observed in ethanol toxicity and septicemia patients due to the changes in their blood constituents, but how about the neutrophils in nonalcoholic fatty liver disease (NAFLD) patient is unknown. Here, we confirmed that an adhesion deficiency and an increased autophagy level existed in NAFLD neutrophils, and the three neutrophil granule subunits, namely, the azurophil granules, specific granules and gelatinase granules, could be engulfed by autophagosomes for degradation, and these autophagy-triggered granule degradation events were associated with vacuolation in palmitic acid (PA)-treated and NAFLD neutrophils. Concordantly, the adhesion-associated molecules CD11a, CD11b, CD18 and Rap1 on the three granule subunits were degraded during PA induced autophagy. Moreover, the cytosolic CD11a, CD11b, CD18 and Rap1 were targeted by Hsc70 and then delivered to lysosomal-like granules for degradation. Notably, in vitro and ex vivo, PA induced autophagy by inhibiting the p-PKCα/PKD2 pathway. Overall, we showed that high blood PA level inhibited the p-PKCα/PKD2 pathway to induce NAFLD neutrophil autophagy, which promoted the degradation of CD11a, CD11b, CD18 and Rap1 and further decreased the adhesion of neutrophils, thereby impairing the neutrophil function of NAFLD patients. This theory provides a new therapeutic strategy to improve the immune deficiency in NAFLD patients.Visual AbstractKey PointsVacuolation and adhesion deficiency of NAFLD neutrophils are associated with autophagy-dependent granule degradationPA inhibits p-PKCα/PKD2 to induce autophagy, which induces the degradation of CD11a, CD11b, CD18 and Rap1 and decreases neutrophil adhesion

scholarly journals Kruppel-like factor 4 regulates neutrophil activation

2017 ◽  
Vol 1 (11) ◽  
pp. 662-668 ◽  
Author(s):  
Yuyan Shen ◽  
Hong Hong ◽  
Panjamaporn Sangwung ◽  
Stephanie Lapping ◽  
Lalitha Nayak ◽  
...  
Keyword(s):  
Crucial Role ◽  
Neutrophil Function ◽  
Neutrophil Activation ◽  
Key Points

Key Points KLF4 deficiency impairs neutrophil function in vitro and in vivo. This is the first demonstration that KLF4 plays a crucial role in neutrophils.

Antisense-based RNA therapy of factor V deficiency: in vitro and ex vivo rescue of a F5 deep-intronic splicing mutation

Blood ◽  
2013 ◽  
Vol 122 (23) ◽  
pp. 3825-3831 ◽  
Author(s):  
Francesca Nuzzo ◽  
Claudia Radu ◽  
Marco Baralle ◽  
Luca Spiezia ◽  
Tilman M. Hackeng ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Factor V ◽  
Splicing Mutation ◽  
Splicing Defect ◽  
Factor V Deficiency ◽  
Key Points ◽  
Life Threatening

Key Points Homozygosity for the F5 c.1296+268A>G splicing mutation causes life-threatening factor V deficiency. Mutation-specific antisense molecules can correct this splicing defect and restore factor V synthesis in the patient’s megakaryocytes.

scholarly journals Direct anabolic three carbon metabolism via propionate to a six carbon metabolite occurs in human heart and in vivo across mouse tissues

2019 ◽  
Author(s):  
Mary T. Doan ◽  
Michael D. Neinast ◽  
Erika L Varner ◽  
Kenneth Bedi ◽  
David Bartee ◽  
...  
Keyword(s):  
Human Heart ◽  
Ex Vivo ◽  
Tibialis Anterior Muscle ◽  
Whole Body ◽  
List Type ◽  
Isotope Tracing ◽  
Brown Adipose ◽  
Mouse Tissues

AbstractAnabolic metabolism of carbon in mammals is mediated via the one and two carbon carriers S-adenosyl methionine and acetyl-coenzyme A (acetyl-CoA). In contrast, anabolic metabolism using three carbon units via propionate is not thought to occur. Mammals are primarily thought to oxidize the 3-carbon short chain fatty acid propionate by shunting propionyl-CoA to succinyl-CoA for entry into the TCA cycle. We found that this may not be absolute and that in mammals one non-oxidative fate of two units of propionyl-CoA is to condense to a six-carbon trans-2-methyl-2-pentenoyl-CoA (2M2PE-CoA). We confirmed this pathway using purified protein extracts provided limited substrates and confirmed the product with a synthetic standard. In whole-body in vivo stable isotope tracing with infusion of 13C-labeled valine achieving steady state, 2M2PE-CoA formed via propionyl-CoA in multiple murine tissues including heart, kidney, and to a lesser degree in brown adipose tissue, liver, and tibialis anterior muscle. Using ex vivo isotope tracing, we found that 2M2PE-CoA formed in human myocardial tissue incubated with propionate to a limited extent. While the complete enzymology of this pathway remains to be elucidated, these results confirm the in vivo existence of at least one anabolic three to six carbon reaction conserved in humans and mice that utilizes three carbons via propionate.Highlights- Synthesis and confirmation of structure 2-methyl-2-pentenoyl-CoA- In vivo fate of valine across organs includes formation of a 6-carbon metabolite from propionyl-CoA- Ex vivo metabolism of propionate in the human heart includes direct anabolism to a 6-carbon product- In both cases, this reaction occurred at physiologically relevant concentrations of propionate and valine- In vitro this pathway requires propionyl-CoA and NADH/NADPH as substrates

scholarly journals CyTOF reveals phenotypically-distinct human blood neutrophil populations differentially correlated with melanoma stage

2019 ◽  
Author(s):  
Yanfang Peipei Zhu ◽  
Tobias Eggert ◽  
Daniel J. Araujo ◽  
Pandurangan Vijayanand ◽  
Christian H. Ottensmeier ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Disease Stage ◽  
Positive Trend ◽  
List Type ◽  
Functional Evaluation ◽  
Blood Neutrophil ◽  
Key Points ◽  
Treatment Naïve ◽  
Melanoma Patients

ABSTRACTUnderstanding neutrophil heterogeneity and its relationship to disease progression has become a recent focus of cancer research. Indeed, several studies have identified neutrophil subpopulations associated with pro- or anti-tumoral functions. However, this work has been hindered by the lack of widely-accepted markers with which to define neutrophil subpopulations. To identify markers of neutrophil heterogeneity in cancer, we utilized single-cell cytometry by time-of-flight (CyTOF) coupled with high-dimensional analysis on blood samples from treatment-naïve, melanoma patients. Our efforts allowed us to identify 7 blood-neutrophil clusters, including 2 previously identified individual populations. Interrogation of these neutrophil subpopulations revealed a positive trend between specific clusters and disease stage. Finally, we recapitulated these 7 blood-neutrophil populations via flow cytometry and found that they exhibit diverse capacities for phagocytosis and reactive oxygen species (ROS) production in vitro. In summary, our data provide a refined consensus on neutrophil-heterogeneity markers, enabling a prospective functional evaluation in patients with solid tumors.KEY POINTSCyTOF analysis reveals 7 blood neutrophil clusters correlating with melanoma stage in treatment-naïve patients.Neutrophil clusters by unbiased-calling are recapitulated by flow cytometry and harbor diverse phagocytic and ROS-producing capacities.

mTOR inhibition by metformin impacts monosodium urate crystal–induced inflammation and cell death in gout: a prelude to a new add-on therapy?

2019 ◽  
Vol 78 (5) ◽  
pp. 663-671 ◽  
Author(s):  
Nadia Vazirpanah ◽  
Andrea Ottria ◽  
Maarten van der Linden ◽  
Catharina G K Wichers ◽  
Mark Schuiveling ◽  
...  
Keyword(s):  
Cell Death ◽  
Immune Cells ◽  
Metabolic Diseases ◽  
Ex Vivo ◽  
Mtor Pathway ◽  
Monosodium Urate ◽  
Mtor Inhibition ◽  
Msu Crystals

ObjectiveGout is the most common inflammatory arthritis worldwide, and patients experience a heavy burden of cardiovascular and metabolic diseases. The inflammation is caused by the deposition of monosodium urate (MSU) crystals in tissues, especially in the joints, triggering immune cells to mount an inflammatory reaction. Recently, it was shown that MSU crystals can induce mechanistic target of rapamycin (mTOR) signalling in monocytes encountering these crystals in vitro. The mTOR pathway is strongly implicated in cardiovascular and metabolic disease. We hypothesised that inhibiting this pathway in gout might be a novel avenue of treatment in these patients, targeting both inflammation and comorbidities.Methods We used a translational approach starting from ex vivo to in vitro and back to in vivo.ResultsWe show that ex vivo immune cells from patients with gout exhibit higher expression of the mTOR pathway, which we can mimic in vitro by stimulating healthy immune cells (B lymphocytes, monocytes, T lymphocytes) with MSU crystals. Monocytes are the most prominent mTOR expressers. By using live imaging, we demonstrate that monocytes, on encountering MSU crystals, initiate cell death and release a wide array of proinflammatory cytokines. By inhibiting mTOR signalling with metformin or rapamycin, a reduction of cell death and release of inflammatory mediators was observed. Consistent with this, we show that patients with gout who are treated with the mTOR inhibitor metformin have a lower frequency of gout attacks.ConclusionsWe propose mTOR inhibition as a novel therapeutic target of interest in gout treatment.

Dysfunction of the PI3 kinase/Rap1/integrin αIIbβ3 pathway underlies ex vivo platelet hypoactivity in essential thrombocythemia

Blood ◽  
2013 ◽  
Vol 121 (7) ◽  
pp. 1209-1219 ◽  
Author(s):  
Samantha F. Moore ◽  
Roger W. Hunter ◽  
Matthew T. Harper ◽  
Joshua S. Savage ◽  
Samreen Siddiq ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Signaling Pathway ◽  
Essential Thrombocythemia ◽  
Clinical Observation ◽  
Ex Vivo ◽  
Pi3 Kinase ◽  
Integrin Αiibβ3 ◽  
Key Points

Key Points Platelets from essential thrombocythemia patients have an intrinsic impairment in the P13kinase/Rap1/integrin αIIbβ3 signaling pathway. This explains the clinical observation that in vitro platelet aggregation is impaired in patients with essential thrombocythemia.

scholarly journals A T-cell–directed chimeric antigen receptor for the selective treatment of T-cell malignancies

Blood ◽  
2015 ◽  
Vol 126 (8) ◽  
pp. 983-992 ◽  
Author(s):  
Maksim Mamonkin ◽  
Rayne H. Rouce ◽  
Haruko Tashiro ◽  
Malcolm K. Brenner
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
Selective Treatment ◽  
Key Points ◽  
Car T ◽  
Control Disease ◽  
T Cell Malignancies ◽  
And Control

Key Points T cells transduced with a CD5 CAR demonstrate limited and transient fratricide and expand ex vivo. CD5 CAR T cells eliminate T-ALL blasts in vitro and control disease progression in xenograft T-ALL mouse models.

scholarly journals LXRα Phosphorylation in Cardiometabolic Disease: Insight From Mouse Models

Endocrinology ◽  
2020 ◽  
Vol 161 (7) ◽  
Author(s):  
Maud Voisin ◽  
Matthew C Gage ◽  
Natalia Becares ◽  
Elina Shrestha ◽  
Edward A Fisher ◽  
...  
Keyword(s):  
Nuclear Receptors ◽  
Posttranslational Modifications ◽  
Physiological Response ◽  
Metabolic Diseases ◽  
Cardiometabolic Disease ◽  
Nonalcoholic Fatty Liver ◽  
Environmental Signals ◽  
Powerful Means ◽  
And Function

Abstract Posttranslational modifications, such as phosphorylation, are a powerful means by which the activity and function of nuclear receptors such as LXRα can be altered. However, despite the established importance of nuclear receptors in maintaining metabolic homeostasis, our understanding of how phosphorylation affects metabolic diseases is limited. The physiological consequences of LXRα phosphorylation have, until recently, been studied only in vitro or nonspecifically in animal models by pharmacologically or genetically altering the enzymes enhancing or inhibiting these modifications. Here we review recent reports on the physiological consequences of modifying LXRα phosphorylation at serine 196 (S196) in cardiometabolic disease, including nonalcoholic fatty liver disease, atherosclerosis, and obesity. A unifying theme from these studies is that LXRα S196 phosphorylation rewires the LXR-modulated transcriptome, which in turn alters physiological response to environmental signals, and that this is largely distinct from the LXR-ligand–dependent action.

scholarly journals Leptin's Role in Lipodystrophic and Nonlipodystrophic Insulin-Resistant and Diabetic Individuals

2013 ◽  
Vol 34 (3) ◽  
pp. 377-412 ◽  
Author(s):  
Hyun-Seuk Moon ◽  
Maria Dalamaga ◽  
Sang-Yong Kim ◽  
Stergios A. Polyzos ◽  
Ole-Petter Hamnvik ◽  
...  
Keyword(s):  
Highly Active Antiretroviral Therapy ◽  
Energy Homeostasis ◽  
Ex Vivo ◽  
Immune Functions ◽  
Open Label ◽  
Nonalcoholic Fatty Liver ◽  
Insulin Resistant ◽  
Leptin Deficiency

Abstract Leptin is an adipocyte-secreted hormone that has been proposed to regulate energy homeostasis as well as metabolic, reproductive, neuroendocrine, and immune functions. In the context of open-label uncontrolled studies, leptin administration has demonstrated insulin-sensitizing effects in patients with congenital lipodystrophy associated with relative leptin deficiency. Leptin administration has also been shown to decrease central fat mass and improve insulin sensitivity and fasting insulin and glucose levels in HIV-infected patients with highly active antiretroviral therapy (HAART)-induced lipodystrophy, insulin resistance, and leptin deficiency. On the contrary, the effects of leptin treatment in leptin-replete or hyperleptinemic obese individuals with glucose intolerance and diabetes mellitus have been minimal or null, presumably due to leptin tolerance or resistance that impairs leptin action. Similarly, experimental evidence suggests a null or a possibly adverse role of leptin treatment in nonlipodystrophic patients with nonalcoholic fatty liver disease. In this review, we present a description of leptin biology and signaling; we summarize leptin's contribution to glucose metabolism in animals and humans in vitro, ex vivo, and in vivo; and we provide insights into the emerging clinical applications and therapeutic uses of leptin in humans with lipodystrophy and/or diabetes.

scholarly journals Interaction of RSC chromatin remodelling complex with nucleosomes is modulated by H3 K14 acetylation and H2B SUMOylation in vivo

2020 ◽  
Author(s):  
Neha Jain ◽  
Davide Tamborrini ◽  
Brian Evans ◽  
Shereen Chaudhry ◽  
Bryan J. Wilkins ◽  
...  
Keyword(s):  
Histone Variants ◽  
Chromatin Remodelling ◽  
List Type ◽  
Atpase Subunit ◽  
Chromatin Remodelling Complex ◽  
Key Points ◽  
Target Sites ◽  
Nucleosome Binding

AbstractChromatin remodelling complexes are multi-subunit nucleosome translocases that reorganize chromatin in the context of DNA replication, repair and transcription. A key question is how these complexes find their target sites on chromatin. Here, we use genetically encoded photo-crosslinker amino acids to map the footprint of Sth1, the catalytic subunit of the RSC (remodels the structure of chromatin) complex, on the nucleosome in living yeast. We find that the interaction of the Sth1 bromodomain with the H3 tail depends on K14 acetylation by Gcn5. This modification does not recruit RSC to chromatin but mediates its interaction with neighbouring nucleosomes. We observe a preference of RSC for H2B SUMOylated nucleosomes in vivo and show that this modification moderately enhances RSC binding to nucleosomes in vitro. Furthermore, RSC is not ejected from chromatin in mitosis, but its mode of nucleosome binding differs between interphase and mitosis. In sum, our in vivo analyses show that RSC recruitment to specific chromatin targets involves multiple histone modifications most likely in combination with other components such as histone variants and transcription factors.Key PointsIn vivo photo-crosslinking reveals the footprint of the ATPase subunit of RSC on the nucleosome.RSC binds to H3 K14ac nucleosomes via the C-terminal bromodomain of its ATPase-subunit Sth1.RSC preferentially localizes to H2B-SUMOylated nucleosomes.

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