Review
Cell Biology
Maria C. Tanzer
Summary: Efferocytosis is the process of phagocytes removing dead or dying cells, which is considered anti-inflammatory. However, it can induce inflammatory signaling pathways under certain conditions. The mechanisms and molecules involved in this response are not well understood. This article discusses the influence of dead cell cargo, ingestion type, and digestion efficiency on phagocyte programming in disease contexts, presents recent findings, identifies knowledge gaps, and proposes experimental approaches to fill them.
FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY
(2023)
Review
Cell Biology
Tamas Roeszer
Summary: The safe removal of apoptotic cells by macrophages is crucial for tissue health, but in the case of adipocyte apoptosis, the clearance process can lead to inflammation and metabolic diseases. Metabolites released by apoptotic cells and produced by macrophages during digestion of apoptotic cells control macrophage immune functions.
Article
Endocrinology & Metabolism
Patrick B. Ampomah, Bishuang Cai, Santosh R. Sukka, Brennan D. Gerlach, Arif Yurdagul, Xiaobo Wang, George Kuriakose, Lancia N. F. Darville, Yan Sun, Simone Sidoli, John M. Koomen, Alan R. Tall, Ira Tabas
Summary: This study demonstrates that methionine derived from apoptotic cells taken up by macrophages during efferocytosis plays a role in mediating tissue resolution by providing a substrate for DNA methylation and repressing the expression of the ERK1/2 phosphatase Dusp4, leading to activation of ERK1/2 and the expression of pro-resolving mediators.
Article
Cell Biology
Hongxue Shi, Xiaobo Wang, Fang Li, Brennan D. Gerlach, Arif Yurdagul, Mary P. Moore, Sharon Zeldin, Hanrui Zhang, Bishuang Cai, Ze Zheng, Luca Valenti, Ira Tabas
Summary: Impaired clearance of necroptotic hepatocytes (necHCs) by liver macrophages due to up-regulation of the CD47-SIRP alpha axis contributes to fibrotic nonalcoholic steatohepatitis (NASH). Therapeutic blockade of the CD47-SIRP alpha axis may decrease the accumulation of necHCs in NASH liver and dampen the progression of hepatic fibrosis.
SCIENCE TRANSLATIONAL MEDICINE
(2022)
Review
Critical Care Medicine
Yutian Li, Qianqian Li, Guo-Chang Fan
Summary: Macrophages are crucial for cardiac development, homeostasis, and healing, playing a vital role in clearing dying cells and cellular debris through efferocytosis. Understanding macrophage efferocytosis provides valuable insights on cardiac health and offers new therapeutic strategies for patients with heart failure.
Review
Immunology
Kevin Schneider, Sanja Arandjelovic
Summary: Rheumatoid arthritis (RA) is a chronic inflammatory disease that affects about 1% of the human population. It is characterized by joint swelling and bone erosion, causing disability and even death. Immune dysregulation, including circulating autoantibodies and inflammatory mediators, plays an important role in the development of RA. Studies have shown that inducing cell death through apoptosis can reduce the severity of the disease. Apoptotic cells are cleared by phagocytes through a process called efferocytosis, which has anti-inflammatory properties. Dysfunctions in efferocytosis have been linked to autoimmune diseases, while administration of apoptotic cells in RA models effectively inhibits inflammation. However, the signaling pathways and clearance mediators involved in RA are still not well understood.
IMMUNOLOGICAL REVIEWS
(2023)
Article
Immunology
Yonggang Ma, Scott S. Kemp, Xiaoyuan Yang, Mack H. Wu, Sarah Y. Yuan
Summary: Phagocytosis and clearance of dying cells by macrophages, known as efferocytosis, play crucial roles in maintaining homeostasis and promoting tissue repair. Defects in efferocytosis are implicated in various inflammatory and autoimmune diseases. This review highlights the signaling and metabolic processes of macrophage efferocytosis, its importance in tissue homeostasis and repair, and the mechanisms underlying efferocytotic abnormalities in disease or injury conditions. Potential molecular targets for enhanced efferocytosis in animal models of disease are also discussed.
IMMUNOLOGY LETTERS
(2023)
Article
Biochemistry & Molecular Biology
Narsa M. Reddy, Chandra Mohan Tamatam, Ankireddy Aparna, Sekhar P. Reddy
Summary: Recognition and clearance of apoptotic cells by phagocytes, mediated primarily by macrophages, are crucial for lung inflammatory responses and tissue repair. The Nrf2 transcription factor plays a critical role in this process. This study found that Nrf2 deficiency impairs the ability of macrophages to clear apoptotic neutrophils, and activating Nrf2 may accelerate the clearance of apoptotic cells after oxidant injury.
Article
Multidisciplinary Sciences
Luciane Costa Dalboni, Anuska Marcelino Alvares Saraiva, Fabiana Toshie de Camargo Konno, Elizabeth Cristina Perez, Jessica Feliciana Codeceira, Diva Denelle Spadacci-Morena, Maria Anete Lallo
Summary: This study found that pre-incubation of macrophages with apoptotic cells and subsequent challenge with Encephalitozoon cuniculi microsporidia increased phagocytosis and promoted pathogen multiplication. Additionally, efferocytosis of apoptotic cells and pathogen challenge decreased macrophage viability and led to the polarization of macrophages to an M2 profile, facilitating pathogen development.
Editorial Material
Biology
Isabel Stoetzel, Eva Kiermaier
Summary: The centrosome plays a crucial role in determining which branches extending from the body of microglia will successfully engulf and clear away dead neurons.
Review
Chemistry, Multidisciplinary
Xuefei Zhou, Xiangrui Liu, Leaf Huang
Summary: Macrophages, important in tumor immunity, can engulf tumor cells and present antigens; tumor cells evade macrophage phagocytosis through anti-phagocytic molecules, while macrophages' efferocytosis of apoptotic cells promotes tumor immune escape; blocking anti-phagocytic signals or inhibiting tumor efferocytosis is a potential strategy for cancer immunotherapy.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Cardiac & Cardiovascular Systems
Bhupesh Singla, Hui-Ping Lin, WonMo Ahn, Jiean Xu, Qian Ma, Moses Sghayyer, Kunzhe Dong, Mary Cherian-Shaw, Jiliang Zhou, Yuqing Huo, Joseph White, Gabor Csanyi
Summary: This study demonstrates the potential of targeting SIRP alpha in atherosclerosis and highlights the importance of cell-specific CD47 inhibition as a future therapeutic strategy. Results show that loss of SIRP alpha signaling in macrophages can stimulate efferocytosis and attenuate arterial wall inflammation, while loss of myeloid cell CD47 can impair cholesterol efflux and promote cellular inflammation in atherosclerotic vessels. Comprehensive blood cell analysis also revealed differences in haemoglobin and erythrocyte levels between Cd47(-/-) mice compared to wild-type and Sirpa(mut/mut) mice.
CARDIOVASCULAR RESEARCH
(2022)
Article
Zoology
Jamie Bojko, Krista A. McCoy, April M. H. Blakeslee
Summary: This study describes a new bacterial pathogen (Mellornella promiscua) discovered in mud crabs on the North Carolina coastline, USA. The bacterium infects the hepatopancreas of the crab host and is often found in co-infection with a rhizocephalan barnacle. The circular genome of the bacterium encodes 939 genes and shows phylogenetic similarity to Anaplasmataceae family.
JOURNAL OF INVERTEBRATE PATHOLOGY
(2022)
Review
Cell Biology
Diane Patricia Vig Lebo, Kimberly McCall
Summary: During oogenesis in Drosophila, the survival and development of egg chambers rely on a delicate balance between the oocytes and their nurse cells, with the sacrifice of the nurse cells' lives for the maturation of the oocytes. The phagocytic stretch follicle cells play a crucial role in inducing the non-autonomous cell death of the nurse cells to support oocyte development.
Article
Agronomy
Anna Maria Gajda, Ewa Danuta Mazur, Andrzej Marcin Bober, Michal Czopowicz
Summary: Research findings indicate that N. ceranae is more pathogenic to A. mellifera than N. apis, and the course of type C nosemosis is more severe, resulting in shorter lifespans for bees. The presence of BQCV exacerbates the disease, making it even more dangerous for bees.