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Wang L, Sun X, Chen J, Li Y, He Y, Wei J, Shen Z, Yoshida S. Macropinocytic cups function as signal platforms for the mTORC2-AKT pathway to modulate LPS-induced cytokine expression in macrophages. J Leukoc Biol 2024:qiae074. [PMID: 38513294 DOI: 10.1093/jleuko/qiae074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 01/30/2024] [Accepted: 02/27/2024] [Indexed: 03/23/2024] Open
Abstract
Macropinocytosis is a large-scale endocytosis process that is primarily observed in phagocytes as part of their cellular function to ingest antigens. Once phagocytes encounter gram-negative bacteria, the receptor proteins identify lipopolysaccharides (LPSs), which trigger radical membrane ruffles that gradually change to cup-like structures. The open area of the cups closes to generate vesicles called macropinosomes. The target bacteria are isolated by the cups and engulfed by the cells as the cups close. In addition to its ingestion function, macropinocytosis also regulates the AKT pathway in macrophages. In the current study, we report that macropinocytic cups are critical for LPS-induced AKT phosphorylation (pAKT) and cytokine expression in macrophages. High-resolution scanning electron microscope (SEM) observations detailed the macropinocytic cup structures induced by LPS stimulation. Confocal microscopy revealed that AKT and the kinase molecule mTORC2 were localized in the cups. The biochemical analysis showed that macropinocytosis inhibition blocked LPS-induced pAKT. RNA-Seq, qPCR, and ELISA analyses revealed that the inhibition of macropinocytosis or the AKT pathway causes a decrease in the expression of pro-inflammatory cytokines IL-6 and IL-1α. Moreover, activation of the transcription factor NF-κB, which regulates the cytokine expression downstream of the AKT/IκB pathway, was hindered when macropinocytosis or AKT were inhibited. These results indicate that LPS-induced macropinocytic cups function as signal platforms for the AKT pathway to regulate the cytokine expression by modulating NF-κB activity in LPS-stimulated macrophages. Based on these findings, we propose that macropinocytosis may be a good therapeutic target for controlling cytokine expression.
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Affiliation(s)
- Li Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Life sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
| | - Xiaowei Sun
- State Key Laboratory of Medicinal Chemical Biology, College of Life sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
| | - Jianan Chen
- School of Medicine, Nankai University, Tianjin, China
- Organ Transplant Department, Tianjin First Central Hospital, School of Medicine, Nankai University, Tianjin, China
| | - Yanan Li
- State Key Laboratory of Medicinal Chemical Biology, College of Life sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
| | - Yuxin He
- State Key Laboratory of Medicinal Chemical Biology, College of Life sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
| | - Jinzi Wei
- State Key Laboratory of Medicinal Chemical Biology, College of Life sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
| | - Zhongyang Shen
- Organ Transplant Department, Tianjin First Central Hospital, School of Medicine, Nankai University, Tianjin, China
- Tianjin Key Laboratory for Organ Transplantation, Tianjin, China
- Research Institute of Transplant Medicine, Nankai University, Tianjin, China
| | - Sei Yoshida
- State Key Laboratory of Medicinal Chemical Biology, College of Life sciences, Frontiers Science Center for Cell Responses, Nankai University, Tianjin, China
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Masui K, Kato Y, Sawada T, Mischel PS, Shibata N. Molecular and Genetic Determinants of Glioma Cell Invasion. Int J Mol Sci 2017; 18:E2609. [PMID: 29207533 PMCID: PMC5751212 DOI: 10.3390/ijms18122609] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 11/27/2017] [Accepted: 12/02/2017] [Indexed: 12/21/2022] Open
Abstract
A diffusely invasive nature is a major obstacle in treating a malignant brain tumor, "diffuse glioma", which prevents neurooncologists from surgically removing the tumor cells even in combination with chemotherapy and radiation. Recently updated classification of diffuse gliomas based on distinct genetic and epigenetic features has culminated in a multilayered diagnostic approach to combine histologic phenotypes and molecular genotypes in an integrated diagnosis. However, it is still a work in progress to decipher how the genetic aberrations contribute to the aggressive nature of gliomas including their highly invasive capacity. Here we depict a set of recent discoveries involving molecular genetic determinants of the infiltrating nature of glioma cells, especially focusing on genetic mutations in receptor tyrosine kinase pathways and metabolic reprogramming downstream of common cancer mutations. The specific biology of glioma cell invasion provides an opportunity to explore the genotype-phenotype correlation in cancer and develop novel glioma-specific therapeutic strategies for this devastating disease.
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Affiliation(s)
- Kenta Masui
- Department of Pathology, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
| | - Yoichiro Kato
- Department of Pathology, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
| | - Tatsuo Sawada
- Department of Pathology, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
| | - Paul S Mischel
- Ludwig Institute for Cancer Research, University of California San Diego, La Jolla, CA 92093, USA.
| | - Noriyuki Shibata
- Department of Pathology, Tokyo Women's Medical University, Tokyo 162-8666, Japan.
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