1
|
Fan W, Xu Y, He X, Luo P, Zhu J, Li J, Wang R, Yuan Q, Wu K, Hu W, Zhao Y, Xu S, Cheng X, Wang Y, Xu HE, Zhuang Y. Molecular basis for the activation of PAF receptor by PAF. Cell Rep 2024; 43:114422. [PMID: 38943642 DOI: 10.1016/j.celrep.2024.114422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/07/2024] [Accepted: 06/14/2024] [Indexed: 07/01/2024] Open
Abstract
Platelet-activating factor (PAF) is a potent phospholipid mediator crucial in multiple inflammatory and immune responses through binding and activating the PAF receptor (PAFR). However, drug development targeting the PAFR has been limited, partly due to an incomplete understanding of its activation mechanism. Here, we present a 2.9-Å structure of the PAF-bound PAFR-Gi complex. Structural and mutagenesis analyses unveil a specific binding mode of PAF, with the choline head forming cation-π interactions within PAFR hydrophobic pocket, while the alkyl tail penetrates deeply into an aromatic cleft between TM4 and TM5. Binding of PAF modulates conformational changes in key motifs of PAFR, triggering the outward movement of TM6, TM7, and helix 8 for G protein coupling. Molecular dynamics simulation suggests a membrane-side pathway for PAF entry into PAFR via the TM4-TM5 cavity. By providing molecular insights into PAFR signaling, this work contributes a foundation for developing therapeutic interventions targeting PAF signal axis.
Collapse
Affiliation(s)
- Wenjia Fan
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210046, China; The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Youwei Xu
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xinheng He
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ping Luo
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jingpeng Zhu
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Junrui Li
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Ruolan Wang
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingning Yuan
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; The Shanghai Advanced Electron Microscope Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Kai Wu
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; The Shanghai Advanced Electron Microscope Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Wen Hu
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; The Shanghai Advanced Electron Microscope Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yuxi Zhao
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210046, China; The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Shiqi Xu
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xi Cheng
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Wang
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
| | - H Eric Xu
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210046, China; The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Youwen Zhuang
- The State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; Medicinal Bioinformatics Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China.
| |
Collapse
|
2
|
Zhang Y, Jen FEC, Fox KL, Edwards JL, Jennings MP. The biosynthesis and role of phosphorylcholine in pathogenic and nonpathogenic bacteria. Trends Microbiol 2023; 31:692-706. [PMID: 36863982 PMCID: PMC10272106 DOI: 10.1016/j.tim.2023.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/18/2023] [Accepted: 01/23/2023] [Indexed: 03/03/2023]
Abstract
Phosphorylcholine (ChoP) can be found in all life forms. Although this molecule was first thought to be uncommon in bacteria, it is now appreciated that many bacteria express ChoP on their surface. ChoP is usually attached to a glycan structure, but in some cases, it is added as a post-translational modification to proteins. Recent findings have demonstrated the role of ChoP modification and phase variation (ON/OFF switching) in bacterial pathogenesis. However, the mechanisms of ChoP synthesis are still unclear in some bacteria. Here, we review the literature and examine the recent developments in ChoP-modified proteins and glycolipids and of ChoP biosynthetic pathways. We discuss how the well-studied Lic1 pathway exclusively mediates ChoP attachment to glycans but not to proteins. Finally, we provide a review of the role of ChoP in bacterial pathobiology and the role of ChoP in modulating the immune response.
Collapse
Affiliation(s)
- Yuan Zhang
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD 4222, Australia
| | - Freda E-C Jen
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD 4222, Australia
| | - Kate L Fox
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Jennifer L Edwards
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA; Department of Pediatrics, The Ohio State University, Columbus, OH 43210, USA
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD 4222, Australia.
| |
Collapse
|
3
|
Medler TR, Blair TC, Alice AF, Dowdell AK, Piening BD, Crittenden MR, Gough MJ. Myeloid MyD88 restricts CD8 + T cell response to radiation therapy in pancreatic cancer. Sci Rep 2023; 13:8634. [PMID: 37244938 PMCID: PMC10224952 DOI: 10.1038/s41598-023-35834-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 05/24/2023] [Indexed: 05/29/2023] Open
Abstract
Radiation therapy induces immunogenic cell death in cancer cells, whereby released endogenous adjuvants are sensed by immune cells to direct adaptive immune responses. TLRs expressed on several immune subtypes recognize innate adjuvants to direct downstream inflammatory responses in part via the adapter protein MyD88. We generated Myd88 conditional knockout mice to interrogate its contribution to the immune response to radiation therapy in distinct immune populations in pancreatic cancer. Surprisingly, Myd88 deletion in Itgax (CD11c)-expressing dendritic cells had little discernable effects on response to RT in pancreatic cancer and elicited normal T cell responses using a prime/boost vaccination strategy. Myd88 deletion in Lck-expressing T cells resulted in similar or worsened responses to radiation therapy compared to wild-type mice and lacked antigen-specific CD8+ T cell responses from vaccination, similar to observations in Myd88-/- mice. Lyz2-specific loss of Myd88 in myeloid populations rendered tumors more susceptible to radiation therapy and elicited normal CD8+ T cell responses to vaccination. scRNAseq in Lyz2-Cre/Myd88fl/fl mice revealed gene signatures in macrophages and monocytes indicative of enhanced type I and II interferon responses, and improved responses to RT were dependent on CD8+ T cells and IFNAR1. Together, these data implicate MyD88 signaling in myeloid cells as a critical source of immunosuppression that hinders adaptive immune tumor control following radiation therapy.
Collapse
Affiliation(s)
- Terry R Medler
- Earle A. Chiles Research Institute, Providence Cancer Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, 4805 NE Glisan Street, Suite 2N100, Portland, OR, 97213, USA
| | - Tiffany C Blair
- Earle A. Chiles Research Institute, Providence Cancer Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, 4805 NE Glisan Street, Suite 2N100, Portland, OR, 97213, USA
| | - Alejandro F Alice
- Earle A. Chiles Research Institute, Providence Cancer Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, 4805 NE Glisan Street, Suite 2N100, Portland, OR, 97213, USA
| | - Alexa K Dowdell
- Earle A. Chiles Research Institute, Providence Cancer Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, 4805 NE Glisan Street, Suite 2N100, Portland, OR, 97213, USA
| | - Brian D Piening
- Earle A. Chiles Research Institute, Providence Cancer Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, 4805 NE Glisan Street, Suite 2N100, Portland, OR, 97213, USA
| | - Marka R Crittenden
- Earle A. Chiles Research Institute, Providence Cancer Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, 4805 NE Glisan Street, Suite 2N100, Portland, OR, 97213, USA
- The Oregon Clinic, Portland, OR, USA
| | - Michael J Gough
- Earle A. Chiles Research Institute, Providence Cancer Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, 4805 NE Glisan Street, Suite 2N100, Portland, OR, 97213, USA.
| |
Collapse
|
4
|
Pu Y, Zhu J, Xu J, Zhang S, Bao Y. Antitumor effect of a polysaccharide from Pseudostellaria heterophylla through reversing tumor-associated macrophages phenotype. Int J Biol Macromol 2022; 220:816-826. [PMID: 35988728 DOI: 10.1016/j.ijbiomac.2022.08.111] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/28/2022] [Accepted: 08/16/2022] [Indexed: 11/05/2022]
Abstract
Tumor-associated macrophages (TAMs), which are predominant tumor-infiltrating immune cells in the tumor microenvironment, participate in promoting the occurrence and metastasis of tumor cells. Reprogramming TAMs has become a promising immunotherapeutic approach for novel cancer treatments. In this study, a homogeneous polysaccharide (PHP-1) was obtained from Pseudostellaria heterophylla, and its antitumor and immunological activities, as well as the underlying molecular mechanisms were explored. These findings suggested that PHP-1 can switch M2 macrophages to the M1 type, thereby promoting tumor cell apoptosis in vitro. In addition, PHP-1 can modulate the TAMs phenotype, maintain the CD4+/CD8+ lymphocyte balance, and exert antitumor effects in H22 tumor-bearing mice. Mechanistically, PHP-1 is recognized by the TLR4 receptor, promotes Ca2+ release, and activates the NF-κB and MAPK signaling pathways to reset the M2-type macrophages. These findings indicate that PHP-1 from P. heterophylla can function as a tumor immunotherapeutic modulator.
Collapse
Affiliation(s)
- Youwei Pu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Junmo Zhu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Jie Xu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Sitong Zhang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Yixi Bao
- Department of Clinical Laboratory, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China.
| |
Collapse
|
5
|
Casais-E-Silva LL, da Cruz-Hofling MA, Teixeira CFP. The edematogenic effect of Micrurus lemniscatus venom is dependent on venom phospholipase A 2 activity and modulated by non-neurogenic factors. Toxicol Lett 2022; 369:12-21. [PMID: 35970279 DOI: 10.1016/j.toxlet.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 07/14/2022] [Accepted: 08/08/2022] [Indexed: 10/15/2022]
Abstract
Coral snakes mainly cause neurotoxic symptoms in human envenomation, but experimental studies have already demonstrated several pharmacological activities in addition to these effects. This investigation was carried out with the aim of evaluating (1) non-neurogenic mechanisms involved in the inflammatory response induced by Micrurus lemniscatus venom (MLV) in rat hind paws, (2) participation of PLA2 in this response, and (3) neutralizing efficiency of commercial anti-elapid antivenom on edema. MLV promoted a rapid, significant increase in vascular permeability, influx of leukocytes, and disorganization of collagen bundles, as demonstrated by histological analysis. Several pretreatments were applied to establish the involvement of inflammatory mediators in MLV-induced edema (5 µg/paw). Treatment of animals with chlorpromazine reduced MLV-induced edema, indicating participation of TNF-α. However, the inefficiency of other pharmacological treatments suggests that eicosanoids, leukotrienes, and nitric oxide have no role in this type of edema formation. In contrast, PAF negatively modulates this venom-induced effect. MLV was recognized by anti-elapid serum, but this antivenom did not neutralize edema formation. Chemical modification of MLV with p-bromophenacyl bromide abrogated the phospholipase activity and markedly reduced edema, demonstrating PLA2 participation in MLV-induced edema. In conclusion, the non-neurogenic inflammatory profile of MLV is characterized by TNF-α-mediated edema, participation of PLA2 activity, and down-regulation by PAF. MLV induces an influx of leukocytes and destruction of collagen fibers at the site of its injection.
Collapse
Affiliation(s)
- Luciana L Casais-E-Silva
- Laboratory of Neuroimmunoendocrinology and Toxinology, Department of Bioregulation, Institute of Health Sciences (ICS), Federal University of Bahia (UFBA), Salvador, BA, Brazil.
| | - Maria Alice da Cruz-Hofling
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | | |
Collapse
|
6
|
Silberberg E, Filep JG, Ariel A. Weathering the Storm: Harnessing the Resolution of Inflammation to Limit COVID-19 Pathogenesis. Front Immunol 2022; 13:863449. [PMID: 35615359 PMCID: PMC9124752 DOI: 10.3389/fimmu.2022.863449] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/22/2022] [Indexed: 12/13/2022] Open
Abstract
The resolution of inflammation is a temporally and spatially coordinated process that in its innate manifestations, primarily involves neutrophils and macrophages. The shutdown of infection or injury-induced acute inflammation requires termination of neutrophil accumulation within the affected sites, neutrophil demise, and clearance by phagocytes (efferocytosis), such as tissue-resident and monocyte-derived macrophages. This must be followed by macrophage reprogramming from the inflammatory to reparative and consequently resolution-promoting phenotypes and the production of resolution-promoting lipid and protein mediators that limit responses in various cell types and promote tissue repair and return to homeostatic architecture and function. Recent studies suggest that these events, and macrophage reprogramming to pro-resolving phenotypes in particular, are not only important in the acute setting, but might be paramount in limiting chronic inflammation, autoimmunity, and various uncontrolled cytokine-driven pathologies. The SARS-CoV-2 (COVID-19) pandemic has caused a worldwide health and economic crisis. Severe COVID-19 cases that lead to high morbidity are tightly associated with an exuberant cytokine storm that seems to trigger shock-like pathologies, leading to vascular and multiorgan failures. In other cases, the cytokine storm can lead to diffuse alveolar damage that results in acute respiratory distress syndrome (ARDS) and lung failure. Here, we address recent advances on effectors in the resolution of inflammation and discuss how pro-resolution mechanisms with particular emphasis on macrophage reprogramming, might be harnessed to limit the universal COVID-19 health threat.
Collapse
Affiliation(s)
- Esther Silberberg
- Department of Biology and Human Biology, University of Haifa, Haifa, Israel
| | - János G. Filep
- Department of Pathology and Cell Biology, University of Montreal, Montreal, QC, Canada
- Research Center, Maisonneuve-Rosemont Hospital, Montreal, QC, Canada
- *Correspondence: Amiram Ariel, ; János G. Filep,
| | - Amiram Ariel
- Department of Biology and Human Biology, University of Haifa, Haifa, Israel
- *Correspondence: Amiram Ariel, ; János G. Filep,
| |
Collapse
|
7
|
Zheng LW, Wang WC, Mao XZ, Luo YH, Tong ZY, Li D. TNF-α regulates the early development of avascular necrosis of the femoral head by mediating osteoblast autophagy and apoptosis via the p38 MAPK/NF-κB signaling pathway. Cell Biol Int 2020; 44:1881-1889. [PMID: 32437045 DOI: 10.1002/cbin.11394] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 04/23/2020] [Accepted: 05/18/2020] [Indexed: 01/16/2023]
Abstract
Previous studies have shown that the tumor necrosis factor-α (TNF-α) levels in serum and bone tissues formed in avascular necrosis of femoral head (ANFH) patients were higher than those of normal individuals, indicating TNF-α might play a role in the pathogenesis of ANFH. However, the underlying mechanisms remain unclear. Hematoxylin and eosin staining was performed to show the pathological changes of ANFH bone tissues. TNF-α expression in normal and ANFH tissues was examined by quantitative real-time polymerase chain reaction and western blot analyses. Osteoblast autophagy and apoptosis, as well as signaling pathways activation, were measured by their corresponding marker proteins. Osteoblast proliferation, autophagy, and apoptosis were evaluated using cell counting kit-8, transmission electron microscopy, and flow cytometry. The structures of bone tissues of ANFH were obviously damaged. TNF-α expression was significantly upregulated in ANFH bone tissues compared to normal tissues. Autophagy and apoptosis were remarkably promoted, and p38 mitogen-activated protein kinase (MAPK)/nuclear factor-κB (NF-κB) signaling pathways were markedly activated in ANFH. Suppression of the p38 MAPK/NF-κB pathway significantly attenuated the TNF-α-induced autophagy, however, enhanced the TNF-α-induced apoptosis in osteoblasts. Increased TNF-α in ANFH regulated osteoblast autophagy and apoptosis by p38 MAPK/NF-κB signaling pathways, blocking the pathway by inhibitors exacerbated TNF-α-induced apoptosis through impairing autophagy flux.
Collapse
Affiliation(s)
- Li-Wen Zheng
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wan-Chun Wang
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xin-Zhan Mao
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yong-Heng Luo
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhong-Yi Tong
- Department of Pathology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ding Li
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| |
Collapse
|
8
|
Niu X, Lin X, Chen X, Xu S, Huang Z, Tang Q. Long-wave Ultraviolet Ray Promotes Inflammation in Keloid-derived Fibroblasts by Activating P38-NFκB1 Signaling Pathway. J Burn Care Res 2020; 41:1231-1239. [PMID: 32433772 DOI: 10.1093/jbcr/iraa075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
One of the main mechanisms of keloid formation is the persistent chronic inflammation, which initiates the activation of keloid-derived fibroblasts (KFs) and boosts the production of extracellular matrix. Meanwhile, 95% of the ultraviolet rays that reach the earth are long-wave ultraviolet (UVA). However, the effect of UVA on keloids is currently unclear. The objective of our research is to investigate UVA's impact on keloids. Cell viability assay, migration assay, and cell cycle analysis were conducted. UVA's impacts on gene expressions were detected by real-time quantitative polymerase chain reaction, western blot analysis, enzyme-linked immunosorbent assay, and immunofluorescence. Our results indicated that UVA inhibited the proliferation and migration of KFs. In addition, after UVA irradiation, the expressions of matrix metallopeptidase 1 and matrix metallopeptidase 2 markedly increased in KFs. Moreover, the expression of α-smooth muscle actin and collagen I decreased. Furthermore, KFs with UVA irradiation secreted more interleukin-6 and interleukin-8 in the culture medium. And it was confirmed that the protein expressions of inflammation-related factors, including P38, CK2A, NFκB1, and P65, increased observably in KFs with UVA irradiation. The protein expression of IKBα, also known as NFκB inhibitor α, decreased. All these observations suggested that UVA irradiation could inhibit cellular activity and collagen production in KFs while promoting inflammation by activating P38-NFκB1 signal pathway.
Collapse
Affiliation(s)
- Xingtang Niu
- Department of Plastic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Xunxun Lin
- Department of Plastic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Xiaoqian Chen
- General Committee Office, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shuqia Xu
- Department of Plastic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Zhipeng Huang
- Department of Plastic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Qing Tang
- Department of Plastic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| |
Collapse
|
9
|
Wahid HH, Chin PY, Sharkey DJ, Diener KR, Hutchinson MR, Rice KC, Moldenhauer LM, Robertson SA. Toll-Like Receptor-4 Antagonist (+)-Naltrexone Protects Against Carbamyl-Platelet Activating Factor (cPAF)-Induced Preterm Labor in Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:1030-1045. [PMID: 32084361 DOI: 10.1016/j.ajpath.2020.01.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/24/2019] [Accepted: 01/17/2020] [Indexed: 02/06/2023]
Abstract
Spontaneous preterm labor is frequently caused by an inflammatory response in the gestational tissues elicited by either infectious or sterile agents. In sterile preterm labor, the key regulators of inflammation are not identified, but platelet-activating factor (PAF) is implicated as a potential rate-limiting effector agent. Since Toll-like receptor (TLR)-4 can amplify PAF signaling, we evaluated whether TLR4 contributes to inflammation and fetal loss in a mouse model of PAF-induced sterile preterm labor, and whether a small-molecule TLR4 inhibitor, (+)-naltrexone, can mitigate adverse PAF-induced effects. The administration of carbamyl (c)-PAF caused preterm labor and fetal loss in wild-type mice but not in TLR4-deficient mice. Treatment with (+)-naltrexone prevented preterm delivery and alleviated fetal demise in utero elicited after cPAF administered by i.p. or intrauterine routes. Pups born after cPAF and (+)-naltrexone treatment exhibited comparable rates of postnatal survival and growth to carrier-treated controls. (+)-Naltrexone suppressed the cPAF-induced expression of inflammatory cytokine genes Il1b, Il6, and Il10 in the decidua; Il6, Il12b, and Il10 in the myometrium; and Il1b and Il6 in the placenta. These data demonstrate that the TLR4 antagonist (+)-naltrexone inhibits the inflammatory cascade induced by cPAF, preventing preterm birth and perinatal death. The inhibition of TLR4 signaling warrants further investigation as a candidate strategy for fetal protection and delay of preterm birth elicited by sterile stimuli.
Collapse
Affiliation(s)
- Hanan H Wahid
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Peck Yin Chin
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - David J Sharkey
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Kerrilyn R Diener
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia; School of Pharmacy and Medical Science, University of South Australia, Adelaide, South Australia, Australia
| | - Mark R Hutchinson
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia; Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Adelaide, South Australia, Australia
| | - Kenner C Rice
- Drug Design and Synthesis Section, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, Maryland
| | - Lachlan M Moldenhauer
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Sarah A Robertson
- Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia.
| |
Collapse
|
10
|
Duncan RS, Rohowetz L, Vogt A, Koulen P. Repeat exposure to polyinosinic:polycytidylic acid induces TLR3 expression via JAK-STAT signaling and synergistically potentiates NFκB-RelA signaling in ARPE-19 cells. Cell Signal 2019; 66:109494. [PMID: 31809875 DOI: 10.1016/j.cellsig.2019.109494] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/11/2019] [Accepted: 12/02/2019] [Indexed: 01/05/2023]
Abstract
Dry age-related macular degeneration (AMD), accounting for approximately 90% of AMD cases, is characterized by photoreceptor death, retinal pigment epithelium (RPE) dysfunction and, ultimately, geographic atrophy - the localized death of RPE leading to loss of the center of the visual field. The pathological etiology of AMD is multifactorial, but innate immune signaling and inflammation are involved in early stages of the disease. Although numerous single-nucleotide polymorphisms in innate immune genes are associated with dry AMD, no single gene appears to cause dry AMD. Here, we hypothesized that activation of TLR3 potentiates expression of TLR3 itself and the NFκB-p65 (RelA) subunit as part of pro-inflammatory RPE signaling. Furthermore, we hypothesized that TLR3 activation can 'prime' cells to future RelA stimulation, leading to enhanced, persistent RelA expression and signaling following a second TLR3 activation. We used the human RPE-derived cell line ARPE-19 as a model system for RPE signaling and measured NFκB expression and activity in response to TLR3 stimulation with its ligand, polyinosinic:polycytidylic acid (pI:C). Activation of TLR3 with pI:C led to increased TLR3 and RelA expression that was sustained for at least 24 h. Cells exposed for a second time to pI:C after an initial pI:C exposure displayed elevated RelA expression and RelA nuclear translocation above the level generated by individual primary or secondary exposures alone. Such an elevated response could also not be generated by a single application of higher concentrations of the agonist pI:C. Additionally, we determined the mechanism for TLR3 mediated TLR3 and RelA expression by using inhibitors of canonical TLR3-TBK1-IKKε and JAK-STAT signaling pathways. These data suggest that initial exposure of ARPE-19 cells to pI:C upregulates TLR3 and RelA signaling, leading to potentiated and persistent RelA signaling potentially generated by a positive feedback loop that may cause exacerbated inflammation in AMD. Furthermore, inhibition of JAK-STAT signaling may be a possible therapeutic treatment to prevent induction of TLR3 expression subsequent to pI:C exposure. Our results identify possible therapeutic targets to reduce the TLR3 positive feedback loop and subsequent overproduction of pro-inflammatory cytokines in RPE cells.
Collapse
Affiliation(s)
- R Scott Duncan
- Vision Research Center, Department of Ophthalmology, School of Medicine, University of Missouri - Kansas City, 2411 Holmes St., Kansas City, MO 64108, United States of America.
| | - Landon Rohowetz
- Vision Research Center, Department of Ophthalmology, School of Medicine, University of Missouri - Kansas City, 2411 Holmes St., Kansas City, MO 64108, United States of America
| | - Alex Vogt
- Vision Research Center, Department of Ophthalmology, School of Medicine, University of Missouri - Kansas City, 2411 Holmes St., Kansas City, MO 64108, United States of America
| | - Peter Koulen
- Vision Research Center, Department of Ophthalmology, School of Medicine, University of Missouri - Kansas City, 2411 Holmes St., Kansas City, MO 64108, United States of America; Department of Biomedical Sciences, School of Medicine, University of Missouri - Kansas City, 2411 Holmes St., Kansas City, MO 64108, United States of America
| |
Collapse
|
11
|
Long H, Zhong G, Wang C, Zhang J, Zhang Y, Luo J, Shi S. TREM2 Attenuates Aβ1-42-Mediated Neuroinflammation in BV-2 Cells by Downregulating TLR Signaling. Neurochem Res 2019; 44:1830-1839. [PMID: 31134514 DOI: 10.1007/s11064-019-02817-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 05/12/2019] [Accepted: 05/16/2019] [Indexed: 11/30/2022]
Abstract
The pathogenesis of late-onset Alzheimer's disease (LOAD) mainly involves abnormal accumulation of extracellular β-amyloid (Aβ) and the consequent neurotoxic effects. The triggering receptor expressed on myeloid cells 2 (TREM2) gene is associated with the pathogenesis of LOAD and plays important roles in mediating the phagocytosis of Aβ by microglia and regulating inflammation in central nervous system. However, the exact mechanisms of these processes have not yet been clarified. In this study, we investigated the mechanism by which TREM2 regulates neuroinflammation and promotes Aβ1-42 clearance by BV-2 cells and further elucidated the underlying molecular mechanisms. We either silenced or overexpressed TREM2 in BV-2 cells and evaluated the cell viability, Aβ1-42 content, and expression of inflammatory markers (IL-1β, IL-6, and TNF-α). TREM2 overexpression up-regulated cell activity, promoted clearance of Aβ1-42 by BV-2 cells, and down-regulated expression of the inflammatory factors. In addition, TREM2 overexpression downregulation the expression of the TLR family (TLR2, TLR4 and TLR6) in BV-2 cells. Moreover, LPS, as an agonist of the TLR family, up-regulated the expression of inflammatory cytokines (IL-1β, TNF-α, and IL-6) in BV-2 cells overexpressing TREM2. In conclusion, TREM2 promoted clearance of Aβ1-42 by BV-2 cells and restored BV-2 cell viability from Aβ1-42-mediated neuroinflammation by downregulating TLRs. These findings suggest that TREM2 may be a target for LOAD therapy.
Collapse
Affiliation(s)
- Huiping Long
- Department of Neurology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Gang Zhong
- Guangxi Medical University, Nanning, Guangxi, China
| | - Chengzhi Wang
- Department of Neurology, The Third Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jian Zhang
- Department of Neurology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Yueling Zhang
- Department of Neurology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jinglian Luo
- Department of Neurology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Shengliang Shi
- Department of Neurology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.
| |
Collapse
|
12
|
Ginkgolide B enhances gemcitabine sensitivity in pancreatic cancer cell lines via inhibiting PAFR/NF-кB pathway. Biomed Pharmacother 2019; 109:563-572. [DOI: 10.1016/j.biopha.2018.10.084] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/14/2018] [Accepted: 10/14/2018] [Indexed: 12/15/2022] Open
|
13
|
Romer E, Thyagarajan A, Krishnamurthy S, Rapp CM, Liu L, Fahy K, Awoyemi A, Sahu RP. Systemic Platelet-Activating Factor-Receptor Agonism Enhances Non-Melanoma Skin Cancer Growth. Int J Mol Sci 2018; 19:ijms19103109. [PMID: 30314274 PMCID: PMC6212876 DOI: 10.3390/ijms19103109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/01/2018] [Accepted: 10/04/2018] [Indexed: 12/27/2022] Open
Abstract
Platelet-activating factor-receptor (PAF-R) agonists are pleiotropic lipid factors that influence multiple biological processes, including the induction and resolution of inflammation as well as immunosuppression. PAF-R agonists have been shown to modulate tumorigenesis and/or tumor growth in various skin cancer models by suppressing either cutaneous inflammation and/or anti-tumoral adaptive immunity. We have previously shown that a chronic systemic PAF-R agonist administration of mice enhances the growth of subcutaneously implanted melanoma tumors. Conversely, chronic topical applications of a PAF-R agonist suppressed non-melanoma skin cancer (NMSC) in a topical chemical carcinogenesis model (dimethylbenz[a]anthracene/phorbol 12-myristate 13-acetate (DMBA/PMA)) in-part via anti-inflammatory effects. These results indicate that the context of PAF-R agonist exposure via either chronic cutaneous or systemic administration, result in seemingly disparate effects on tumor promotion. To further dissect the contextual role of PAF-R agonism on tumorigenesis, we chronically administered systemic PAF-R agonist, carbamoyl-PAF (CPAF) to mice under a cutaneous chemical carcinogenesis protocol, recently characterized to initiate both NMSC and melanocytic nevus formation that can progress to malignant melanoma. Our results showed that while systemic CPAF did not modulate melanocytic nevus formation, it enhanced the growth of NMSC tumors.
Collapse
Affiliation(s)
- Eric Romer
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University; Dayton, OH 45435, USA.
| | - Anita Thyagarajan
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University; Dayton, OH 45435, USA.
| | - Smita Krishnamurthy
- Department of Pathology and Dermatology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA.
| | - Christine M Rapp
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University; Dayton, OH 45435, USA.
| | - Langni Liu
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University; Dayton, OH 45435, USA.
| | - Katherine Fahy
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University; Dayton, OH 45435, USA.
| | - Azeezat Awoyemi
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University; Dayton, OH 45435, USA.
| | - Ravi P Sahu
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University; Dayton, OH 45435, USA.
| |
Collapse
|
14
|
Chammas R, de Sousa Andrade LN, Jancar S. Oncogenic effects of PAFR ligands produced in tumours upon chemotherapy and radiotherapy. Nat Rev Cancer 2017; 17:253. [PMID: 28280268 DOI: 10.1038/nrc.2017.15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Roger Chammas
- Instituto do Câncer do Estado de São Paulo, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | | | - Sonia Jancar
- Instituto de Ciências Biomédicas da Universidade de São Paulo, São Paulo, Brazil
| |
Collapse
|