1
|
Conley HE, Brown CF, Westerman TL, Elfenbein JR, Sheats MK. MARCKS Inhibition Alters Bovine Neutrophil Responses to Salmonella Typhimurium. Biomedicines 2024; 12:442. [PMID: 38398044 PMCID: PMC10886653 DOI: 10.3390/biomedicines12020442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
Neutrophils are innate immune cells that respond quickly to sites of bacterial infection and play an essential role in host defense. Interestingly, some bacterial pathogens benefit from exuberant neutrophil inflammation. Salmonella is one such pathogen that can utilize the toxic mediators released by neutrophils to colonize the intestine and cause enterocolitis. Because neutrophils can aid gut colonization during Salmonella infection, neutrophils represent a potential host-directed therapeutic target. Myristoylated alanine-rich C-kinase substrate (MARCKS) is an actin-binding protein that plays an essential role in many neutrophil effector responses. We hypothesized that inhibition of MARCKS protein would alter bovine neutrophil responses to Salmonella Typhimurium (STm) ex vivo. We used a MARCKS inhibitor peptide to investigate the role of MARCKS in neutrophil responses to STm. This study demonstrates that MARCKS inhibition attenuated STm-induced neutrophil adhesion and chemotaxis. Interestingly, MARCKS inhibition also enhanced neutrophil phagocytosis and respiratory burst in response to STm. This is the first report describing the role of MARCKS protein in neutrophil antibacterial responses.
Collapse
Affiliation(s)
- Haleigh E Conley
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27607, USA
| | - Chalise F Brown
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
| | - Trina L Westerman
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Johanna R Elfenbein
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - M Katie Sheats
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27607, USA
| |
Collapse
|
2
|
Conley HE, Sheats MK. Targeting Neutrophil β 2-Integrins: A Review of Relevant Resources, Tools, and Methods. Biomolecules 2023; 13:892. [PMID: 37371473 DOI: 10.3390/biom13060892] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/15/2023] [Accepted: 05/23/2023] [Indexed: 06/29/2023] Open
Abstract
Neutrophils are important innate immune cells that respond during inflammation and infection. These migratory cells utilize β2-integrin cell surface receptors to move out of the vasculature into inflamed tissues and to perform various anti-inflammatory responses. Although critical for fighting off infection, neutrophil responses can also become dysregulated and contribute to disease pathophysiology. In order to limit neutrophil-mediated damage, investigators have focused on β2-integrins as potential therapeutic targets, but so far these strategies have failed in clinical trials. As the field continues to move forward, a better understanding of β2-integrin function and signaling will aid the design of future therapeutics. Here, we provide a detailed review of resources, tools, experimental methods, and in vivo models that have been and will continue to be utilized to investigate the vitally important cell surface receptors, neutrophil β2-integrins.
Collapse
Affiliation(s)
- Haleigh E Conley
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27607, USA
| | - M Katie Sheats
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27607, USA
| |
Collapse
|
3
|
Bayless RL, Sheats MK, Jones SL. Withaferin A Inhibits Neutrophil Adhesion, Migration, and Respiratory Burst and Promotes Timely Neutrophil Apoptosis. Front Vet Sci 2022; 9:900453. [PMID: 35782542 PMCID: PMC9247543 DOI: 10.3389/fvets.2022.900453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 05/24/2022] [Indexed: 01/25/2023] Open
Abstract
Neutrophils play a major role in many equine conditions, including equine asthma, laminitis, and intestinal ischemia and reperfusion injury, and therefore represent an attractive target for innovative therapeutic approaches. Novel strategies for reducing neutrophilic inflammation include modulation of neutrophil functions and lifespan. Withaferin A (WFA) is a phytochemical with well-established in vitro and in vivo anti-inflammatory properties, but its direct effects on neutrophils are largely unknown. We hypothesized that WFA would inhibit adhesion, migration, and respiratory burst by equine neutrophils and promote timely apoptosis of primed equine neutrophils. Consistent with this hypothesis, our data show that WFA causes a significant, concentration-dependent inhibition of equine neutrophil adhesion, migration, and respiratory burst in response to diverse stimuli. Further, WFA treatment increased apoptosis of equine neutrophils exposed to GM-CSF for 24 h. This pro-apoptotic effect of WFA was not observed in unprimed neutrophils, nor at the 2-h time point relevant to our functional neutrophil experiments. Our data demonstrate that WFA may reduce neutrophil-mediated inflammation through multiple mechanisms, including suppression of inflammatory responses and promotion of apoptosis. Additional research is needed to elucidate the molecular mechanisms for these effects and evaluate the potential clinical use of WFA in veterinary and human patients.
Collapse
Affiliation(s)
- Rosemary L Bayless
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| | - M Katie Sheats
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| | - Samuel L Jones
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States.,Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| |
Collapse
|
4
|
Stonex T, Salmon JH, Adler KB, Gilger BC. Peptide Inhibitors of MARCKS Suppress Endotoxin Induced Uveitis in Rats. J Ocul Pharmacol Ther 2022; 38:223-231. [PMID: 35385320 PMCID: PMC9048183 DOI: 10.1089/jop.2021.0114] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Purpose: To determine if inhibition of Myristoylated Alanine Rich C Kinase Substrate (MARCKS) protein, using novel MARCKS inhibitor peptides, will reduce the severity of endotoxin-induced uveitis (EIU) in rats. Methods: EIU was induced in Lewis rats using subcutaneous administration of lipopolysaccharide. In the first phase of the study, 3 different novel MARCKS inhibitor peptides that mimic the N-terminal region of MARCKS (BIO-11006, or lower molecular weight analogs BIO-91201 or BIO-91202; Biomarck Pharmaceuticals, Ltd., Newtown, PA) were administered intravitreally (IVT) at 50 and 100 μM. In the second phase, BIO-91201 was administered IVT at 10, 50, and 100 μM and topically at the 100 μM concentration. The efficacy of MARCKS inhibitor peptides was assessed by clinical examination using slit lamp biomicroscopy, optical coherence tomography (OCT) anterior chamber cell counts, histopathology, and aqueous humor cytokine analysis. Results: Clinical scores were significantly reduced 24 h following uveitis induction in the first phase of the study in the following treatment groups: BIO-11006 50 μM IVT and 100 μM IVT, BIO-91201 50 μM IVT, and BIO-91202 100 μM IVT (P < 0.05). OCT anterior chamber cell counts were significantly reduced in the first phase of the study in all treatment groups (P < 0.001). OCT anterior chamber cell counts and histopathology scores were significantly reduced in the second phase of the study in the BIO-91201 50 μM IVT group (P < 0.05). No effect was seen with topical administration. Conclusion: MARCKS inhibitor peptides were effective in reducing the severity of ocular inflammation and cellular influx in EIU.
Collapse
Affiliation(s)
- Tara Stonex
- Department of Clinical Science, North Carolina State University, Raleigh, North Carolina, USA
| | - Jacklyn H Salmon
- Department of Clinical Science, North Carolina State University, Raleigh, North Carolina, USA
| | - Kenneth B Adler
- Department of Molecular Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Brian C Gilger
- Department of Clinical Science, North Carolina State University, Raleigh, North Carolina, USA.,Department of Ophthalmology, University of North Carolina, Chapel Hill, North Carolina, USA
| |
Collapse
|
5
|
Gaurav R, Mikuls TR, Thiele GM, Nelson AJ, Niu M, Guda C, Eudy JD, Barry AE, Wyatt TA, Romberger DJ, Duryee MJ, England BR, Poole JA. High-throughput analysis of lung immune cells in a combined murine model of agriculture dust-triggered airway inflammation with rheumatoid arthritis. PLoS One 2021; 16:e0240707. [PMID: 33577605 PMCID: PMC7880471 DOI: 10.1371/journal.pone.0240707] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/18/2020] [Indexed: 01/10/2023] Open
Abstract
Rheumatoid arthritis (RA)-associated lung disease is a leading cause of mortality in RA, yet the mechanisms linking lung disease and RA remain unknown. Using an established murine model of RA-associated lung disease combining collagen-induced arthritis (CIA) with organic dust extract (ODE)-induced airway inflammation, differences among lung immune cell populations were analyzed by single cell RNA-sequencing. Additionally, four lung myeloid-derived immune cell populations including macrophages, monocytes/macrophages, monocytes, and neutrophils were isolated by fluorescence cell sorting and gene expression was determined by NanoString analysis. Unsupervised clustering revealed 14 discrete clusters among Sham, CIA, ODE, and CIA+ODE treatment groups: 3 neutrophils (inflammatory, resident/transitional, autoreactive/suppressor), 5 macrophages (airspace, differentiating/recruited, recruited, resident/interstitial, and proliferative airspace), 2 T-cells (differentiating and effector), and a single cluster each of inflammatory monocytes, dendritic cells, B-cells and natural killer cells. Inflammatory monocytes, autoreactive/suppressor neutrophils, and recruited/differentiating macrophages were predominant with arthritis induction (CIA and CIA+ODE). By specific lung cell isolation, several interferon-related and autoimmune genes were disproportionately expressed among CIA and CIA+ODE (e.g. Oasl1, Oas2, Ifit3, Gbp2, Ifi44, and Zbp1), corresponding to RA and RA-associated lung disease. Monocytic myeloid-derived suppressor cells were reduced, while complement genes (e.g. C1s1 and Cfb) were uniquely increased in CIA+ODE mice across cell populations. Recruited and inflammatory macrophages/monocytes and neutrophils expressing interferon-, autoimmune-, and complement-related genes might contribute towards pro-fibrotic inflammatory lung responses following airborne biohazard exposures in setting of autoimmune arthritis and could be predictive and/or targeted to reduce disease burden.
Collapse
Affiliation(s)
- Rohit Gaurav
- Division of Allergy and Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
- * E-mail:
| | - Ted R. Mikuls
- Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, NE, United States of America
- Division of Rheumatology & Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Geoffrey M. Thiele
- Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, NE, United States of America
- Division of Rheumatology & Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Amy J. Nelson
- Division of Allergy and Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Meng Niu
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Chittibabu Guda
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - James D. Eudy
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Austin E. Barry
- Division of Allergy and Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Todd A. Wyatt
- Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, NE, United States of America
- Division of Pulmonary, Critical Care & Sleep, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
- Department of Environmental, Agricultural & Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE, United States of America
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Debra J. Romberger
- Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, NE, United States of America
- Division of Pulmonary, Critical Care & Sleep, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Michael J. Duryee
- Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, NE, United States of America
- Division of Rheumatology & Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Bryant R. England
- Veterans Affairs Nebraska-Western Iowa Health Care System, Research Service, Omaha, NE, United States of America
- Division of Rheumatology & Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Jill A. Poole
- Division of Allergy and Immunology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, United States of America
| |
Collapse
|
6
|
Sheats MK, Yin Q, Fang S, Park J, Crews AL, Parikh I, Dickson B, Adler KB. MARCKS and Lung Disease. Am J Respir Cell Mol Biol 2019; 60:16-27. [PMID: 30339463 DOI: 10.1165/rcmb.2018-0285tr] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
MARCKS (myristoylated alanine-rich C kinase substrate) is a prominent PKC substrate expressed in all eukaryotic cells. It is known to bind to and cross-link actin filaments, to serve as a bridge between Ca2+/calmodulin and PKC signaling, and to sequester the signaling molecule phosphatidylinositol 4,5-bisphosphate in the plasma membrane. Since the mid-1980s, this evolutionarily conserved and ubiquitously expressed protein has been associated with regulating cellular events that require dynamic actin reorganization, including cellular adhesion, migration, and exocytosis. More recently, translational studies have implicated MARCKS in the pathophysiology of a number of airway diseases, including chronic obstructive pulmonary disease, asthma, lung cancer, and acute lung injury/acute respiratory distress syndrome. This article summarizes the structure and cellular function of MARCKS (also including MARCKS family proteins and MARCKSL1 [MARCKS-like protein 1]). Evidence for MARCKS's role in several lung diseases is discussed, as are the technological innovations that took MARCKS-targeting strategies from theoretical to therapeutic. Descriptions and updates derived from ongoing clinical trials that are investigating inhalation of a MARCKS-targeting peptide as therapy for patients with chronic bronchitis, lung cancer, and ARDS are provided.
Collapse
Affiliation(s)
| | - Qi Yin
- 2 Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina; and
| | - Shijing Fang
- 2 Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina; and
| | - Joungjoa Park
- 2 Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina; and
| | - Anne L Crews
- 2 Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina; and
| | - Indu Parikh
- 3 BioMarck Pharmaceuticals, Durham, North Carolina
| | | | - Kenneth B Adler
- 2 Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina; and
| |
Collapse
|
7
|
Westerman TL, Bogomolnaya L, Andrews-Polymenis HL, Sheats MK, Elfenbein JR. The Salmonella type-3 secretion system-1 and flagellar motility influence the neutrophil respiratory burst. PLoS One 2018; 13:e0203698. [PMID: 30204776 PMCID: PMC6133356 DOI: 10.1371/journal.pone.0203698] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 08/24/2018] [Indexed: 11/28/2022] Open
Abstract
Neutrophils are innate immune response cells designed to kill invading microorganisms. One of the mechanisms neutrophils use to kill bacteria is generation of damaging reactive oxygen species (ROS) via the respiratory burst. However, during enteric salmonellosis, neutrophil-derived ROS actually facilitates Salmonella expansion and survival in the gut. This seeming paradox led us to hypothesize that Salmonella may possess mechanisms to influence the neutrophil respiratory burst. In this work, we used an in vitro Salmonella-neutrophil co-culture model to examine the impact of enteric infection relevant virulence factors on the respiratory burst of human neutrophils. We report that neutrophils primed with granulocyte-macrophage colony stimulating factor and suspended in serum containing complement produce a robust respiratory burst when stimulated with viable STm. The magnitude of the respiratory burst increases when STm are grown under conditions to induce the expression of the type-3 secretion system-1. STm mutants lacking the type-3 secretion system-1 induce less neutrophil ROS than the virulent WT. In addition, we demonstrate that flagellar motility is a significant agonist of the neutrophil respiratory burst. Together our data demonstrate that both the type-3 secretion system-1 and flagellar motility, which are established virulence factors in enteric salmonellosis, also appear to directly influence the magnitude of the neutrophil respiratory burst in response to STm in vitro.
Collapse
Affiliation(s)
- Trina L. Westerman
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States of America
| | - Lydia Bogomolnaya
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Bryan, TX, United States of America
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Helene L. Andrews-Polymenis
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Bryan, TX, United States of America
| | - M. Katherine Sheats
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States of America
| | - Johanna R. Elfenbein
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States of America
| |
Collapse
|
8
|
El Amri M, Fitzgerald U, Schlosser G. MARCKS and MARCKS-like proteins in development and regeneration. J Biomed Sci 2018; 25:43. [PMID: 29788979 PMCID: PMC5964646 DOI: 10.1186/s12929-018-0445-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/07/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Myristoylated Alanine-Rich C-kinase Substrate (MARCKS) and MARCKS-like protein 1 (MARCKSL1) have a wide range of functions, ranging from roles in embryonic development to adult brain plasticity and the inflammatory response. Recently, both proteins have also been identified as important players in regeneration. Upon phosphorylation by protein kinase C (PKC) or calcium-dependent calmodulin-binding, MARCKS and MARCKSL1 translocate from the membrane into the cytosol, modulating cytoskeletal actin dynamics and vesicular trafficking and activating various signal transduction pathways. As a consequence, the two proteins are involved in the regulation of cell migration, secretion, proliferation and differentiation in many different tissues. MAIN BODY Throughout vertebrate development, MARCKS and MARCKSL1 are widely expressed in tissues derived from all germ layers, with particularly strong expression in the nervous system. They have been implicated in the regulation of gastrulation, myogenesis, brain development, and other developmental processes. Mice carrying loss of function mutations in either Marcks or Marcksl1 genes die shortly after birth due to multiple deficiencies including detrimental neural tube closure defects. In adult vertebrates, MARCKS and MARCKL1 continue to be important for multiple regenerative processes including peripheral nerve, appendage, and tail regeneration, making them promising targets for regenerative medicine. CONCLUSION This review briefly summarizes the molecular interactions and cellular functions of MARCKS and MARCKSL1 proteins and outlines their vital roles in development and regeneration.
Collapse
Affiliation(s)
- Mohamed El Amri
- Centre for Research in Medical Devices (CÚRAM), National University of Ireland, Galway, Biomedical Sciences Building, Newcastle Road, Galway, Ireland
| | - Una Fitzgerald
- Galway Neuroscience Centre, School of Natural Sciences, Biomedical Sciences Building, National University of Ireland, Newcastle Road, Galway, Ireland
| | - Gerhard Schlosser
- Centre for Research in Medical Devices (CÚRAM), National University of Ireland, Galway, Biomedical Sciences Building, Newcastle Road, Galway, Ireland. .,School of Natural Sciences and Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Biomedical Sciences Building, Newcastle Road, Galway, Ireland.
| |
Collapse
|
9
|
Brudvig JJ, Cain JT, Schmidt-Grimminger GG, Stumpo DJ, Roux KJ, Blackshear PJ, Weimer JM. MARCKS Is Necessary for Netrin-DCC Signaling and Corpus Callosum Formation. Mol Neurobiol 2018; 55:8388-8402. [PMID: 29546593 DOI: 10.1007/s12035-018-0990-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/06/2018] [Indexed: 11/24/2022]
Abstract
Axons of the corpus callosum (CC), the white matter tract that connects the left and right hemispheres of the brain, receive instruction from a number of chemoattractant and chemorepulsant cues during their initial navigation towards and across the midline. While it has long been known that the CC is malformed in the absence of Myristoylated alanine-rich C-kinase substrate (MARCKS), evidence for a direct role of MARCKS in axon navigation has been lacking. Here, we show that MARCKS is necessary for Netrin-1 (NTN1) signaling through the DCC receptor, which is critical for axon guidance decisions. Marcks null (Marcks-/-) neurons fail to respond to exogenous NTN1 and are deficient in markers of DCC activation. Without MARCKS, the subcellular distributions of two critical mediators of NTN1-DCC signaling, the tyrosine kinases PTK2 and SRC, are disrupted. Together, this work establishes a novel role for MARCKS in axon dynamics and highlights the necessity of MARCKS as an organizer of DCC signaling at the membrane.
Collapse
Affiliation(s)
- J J Brudvig
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD, 57104, USA.,Basic Biomedical Sciences, University of South Dakota Sanford School of Medicine, Vermillion, SD, 57069, USA
| | - J T Cain
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD, 57104, USA
| | | | - D J Stumpo
- Signal Transduction Laboratory, National Institute of Environmental Health Science, Research Triangle Park, NC, 27709, USA
| | - K J Roux
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD, 57104, USA.,Department of Pediatrics, University of South Dakota, Sioux Falls, SD, 57105, USA
| | - P J Blackshear
- Signal Transduction Laboratory, National Institute of Environmental Health Science, Research Triangle Park, NC, 27709, USA
| | - J M Weimer
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD, 57104, USA. .,Department of Pediatrics, University of South Dakota, Sioux Falls, SD, 57105, USA.
| |
Collapse
|
10
|
Anderson SL, Singh B. Equine neutrophils and their role in ischemia reperfusion injury and lung inflammation. Cell Tissue Res 2018; 371:639-648. [PMID: 29335779 DOI: 10.1007/s00441-017-2770-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 12/07/2017] [Indexed: 01/06/2023]
Abstract
Horses are susceptible to a multitude of inflammatory conditions that are characterized by a strong neutrophilic response. Here, we review basic equine neutrophil biology and explore the role of neutrophils in inflammatory conditions with emphasis on intestinal ischemia and reperfusion injury and lung inflammation. In addition, unique aspects of equine neutrophil biology have been highlighted. Neutrophils comprise the highest proportion of circulating white blood cells in equine blood. The concentration of circulating equine neutrophils is a primary indicator of systemic inflammation. Additionally, equine neutrophils exposed to various stimulants develop "toxic" changes characterized as cytoplasmic basophilia, presence of Döhle bodies, cytoplasmic vacuolation and toxic granulation. In contrast to human neutrophils, equine neutrophils fail to undergo chemotaxis in response to the peptide N-formyl-methionyl-leucyl-phenylalanine and are dependent on the addition of arachidonic acid due to reduced activity of phospholipase A2 to synthesize leukotrienes as part of the arachidonic acid pathway. Understanding the biologic function of neutrophils in horses is integral to developing methods to modulate inflammation associated with ischemia reperfusion injury and lung disease.
Collapse
Affiliation(s)
- Stacy L Anderson
- College of Veterinary Medicine, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, TN, 37752, USA.
| | - Baljit Singh
- College of Veterinary Medicine, University of Calgary, Calgary, Alberta, T2N 4Z6, Canada
| |
Collapse
|
11
|
Martin EM, Till RL, Sheats MK, Jones SL. Misoprostol Inhibits Equine Neutrophil Adhesion, Migration, and Respiratory Burst in an In Vitro Model of Inflammation. Front Vet Sci 2017; 4:159. [PMID: 29034248 PMCID: PMC5626936 DOI: 10.3389/fvets.2017.00159] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/12/2017] [Indexed: 01/08/2023] Open
Abstract
In many equine inflammatory disease states, neutrophil activities, such as adhesion, migration, and reactive oxygen species (ROS) production become dysregulated. Dysregulated neutrophil activation causes tissue damage in horses with asthma, colitis, laminitis, and gastric glandular disease. Non-steroidal anti-inflammatory drugs do not adequately inhibit neutrophil inflammatory functions and can lead to dangerous adverse effects. Therefore, novel therapies that target mechanisms of neutrophil-mediated tissue damage are needed. One potential neutrophil-targeting therapeutic is the PGE1 analog, misoprostol. Misoprostol is a gastroprotectant that induces intracellular formation of the secondary messenger molecule cyclic AMP (cAMP), which has been shown to have anti-inflammatory effects on neutrophils. Misoprostol is currently used in horses to treat NSAID-induced gastrointestinal injury; however, its effects on equine neutrophils have not been determined. We hypothesized that treatment of equine neutrophils with misoprostol would inhibit equine neutrophil adhesion, migration, and ROS production, in vitro. We tested this hypothesis using isolated equine peripheral blood neutrophils collected from 12 healthy adult teaching/research horses of mixed breed and gender. The effect of misoprostol treatment on adhesion, migration, and respiratory burst of equine neutrophils was evaluated via fluorescence-based adhesion and chemotaxis assays, and luminol-enhanced chemiluminescence, respectively. Neutrophils were pretreated with varying concentrations of misoprostol, vehicle, or appropriate functional inhibitory controls prior to stimulation with LTB4, CXCL8, PAF, lipopolysaccharide (LPS) or immune complex (IC). This study revealed that misoprostol pretreatment significantly inhibited LTB4-induced adhesion, LTB4-, CXCL8-, and PAF-induced chemotaxis, and LPS-, IC-, and PMA-induced ROS production in a concentration-dependent manner. This data indicate that misoprostol-targeting of E-prostanoid (EP) receptors potently inhibits equine neutrophil effector functions in vitro. Additional studies are indicated to further elucidate the role of EP receptors in regulating neutrophil function. Overall, our results suggest misoprostol may hold promise as a novel anti-inflammatory therapeutic in the horse.
Collapse
Affiliation(s)
- Emily Medlin Martin
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Rebecca Louise Till
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Mary Katherine Sheats
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States.,College of Veterinary Medicine, Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| | - Samuel L Jones
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States.,College of Veterinary Medicine, Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States
| |
Collapse
|
12
|
Yin Q, Fang S, Park J, Crews AL, Parikh I, Adler KB. An Inhaled Inhibitor of Myristoylated Alanine-Rich C Kinase Substrate Reverses LPS-Induced Acute Lung Injury in Mice. Am J Respir Cell Mol Biol 2017; 55:617-622. [PMID: 27556883 DOI: 10.1165/rcmb.2016-0236rc] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Intratracheal instillation of bacterial LPS is a well-established model of acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS). Because the myristoylated alanine-rich C kinase substrate (MARCKS) protein is involved in neutrophil migration and proinflammatory cytokine production, we examined whether an aerosolized peptide that inhibits MARCKS function could attenuate LPS-induced lung injury in mice. The peptide, BIO-11006, was delivered at 50 μM via inhalation either just before intratracheal instillation of 5 μg of LPS into Balb/C mice, or 4, 12, 24, or 36 hours after LPS instillation. Effects of BIO-11006 were evaluated via analysis of mouse disease-related behavior, lung histology, bronchoalveolar lavage fluid total protein, neutrophil counts and percentages, cytokine (KC [CXCl1, mouse IL-8 equivalent] and TNF-α) expression, and activation of NF-κB in lung tissue. Treatment with aerosolized BIO-11006 at 0, 4, 12, 24, and even 36 hours after LPS instillation reversed the disease process: mouse behavior returned to normal after two treatments 12 hours apart with the inhaled peptide after LPS injury, whereas control LPS-instilled animals treated with PBS only remained moribund. Histological appearance of inflammation, bronchoalveolar lavage fluid protein levels, leukocyte and neutrophil numbers, KC and TNF-α gene and protein expression, and NF-κB activation were all significantly attenuated by inhaled BIO-11006 at all time points. These results implicate MARCKS protein in the pathogenesis of ALI/ARDS and suggest that MARCKS-inhibitory peptide(s), delivered by inhalation, could represent a new and potent therapeutic treatment for ALI/ARDS, even if administered well after the disease process has begun.
Collapse
Affiliation(s)
- Qi Yin
- 1 Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina; and
| | - Shijing Fang
- 1 Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina; and
| | | | - Anne L Crews
- 1 Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina; and
| | - Indu Parikh
- 2 Biomarck Pharmaceuticals, Incorporated, Durham, North Carolina
| | - Kenneth B Adler
- 1 Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, North Carolina; and
| |
Collapse
|
13
|
In Vitro Neutrophil Migration Requires Protein Kinase C-Delta (δ-PKC)-Mediated Myristoylated Alanine-Rich C-Kinase Substrate (MARCKS) Phosphorylation. Inflammation 2016; 38:1126-41. [PMID: 25515270 DOI: 10.1007/s10753-014-0078-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Dysregulated release of neutrophil reactive oxygen species and proteolytic enzymes contributes to both acute and chronic inflammatory diseases. Therefore, molecular regulators of these processes are potential targets for new anti-inflammatory therapies. We have shown previously that myristoylated alanine-rich C-kinase substrate (MARCKS), a well-known actin binding protein and protein kinase C (PKC) substrate, is a key regulator of neutrophil functions. In the current study, we investigate the role of PKC-mediated MARCKS phosphorylation in neutrophil migration and adhesion in vitro. We report that treatment of human neutrophils with the δ-PKC inhibitor rottlerin significantly attenuates f-Met-Leu-Phe (fMLF)-induced MARCKS phosphorylation (IC50=5.709 μM), adhesion (IC50=8.4 μM), and migration (IC50=6.7 μM), while α-, β-, and ζ-PKC inhibitors had no significant effect. We conclude that δ-PKC-mediated MARCKS phosphorylation is essential for human neutrophil migration and adhesion in vitro. These results implicate δ-PKC-mediated MARCKS phosphorylation as a key step in the inflammatory response of neutrophils.
Collapse
|
14
|
Non-Cationic Proteins Are Associated with HIV Neutralizing Activity in Genital Secretions of Female Sex Workers. PLoS One 2015; 10:e0130404. [PMID: 26090884 PMCID: PMC4475052 DOI: 10.1371/journal.pone.0130404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/20/2015] [Indexed: 11/20/2022] Open
Abstract
Objective Cationic proteins found in cervicovaginal secretions (CVS) are known to contribute to the early antiviral immune response against HIV-infection in vitro. We here aimed to define additional antiviral factors that are over-expressed in CVS from female sex workers at high risk of infection. Methods CVS were collected from Kenyan HIV-seronegative (n = 34) and HIV-seropositive (n = 12) female sex workers, and were compared with those from HIV-seronegative low-risk women (n = 12). The highly exposed seronegative (HESN) sex workers were further divided into those with less (n = 22) or more (n = 12) than three years of documented sex work. Cationic protein-depleted CVS were assessed for HIV-neutralizing activity by a PBMC-based HIV-neutralizing assay, and then characterized by proteomics. Results HIV neutralizing activity was detected in all unprocessed CVS, however only CVS from the female sex worker groups maintained its HIV neutralizing activity after cationic protein-depletion. Differentially abundant proteins were identified in the cationic protein-depleted secretions including 26, 42, and 11 in the HESN>3yr, HESN<3yr, and HIV-positive groups, respectively. Gene ontology placed these proteins into functional categories including proteolysis, oxidation-reduction, and epidermal development. The proteins identified in this study include proteins previously associated with the HESN phenotype in other cohorts as well as novel proteins not yet associated with anti-HIV activities. Conclusion While cationic proteins appear to contribute to the majority of the intrinsic HIV neutralizing activity in the CVS of low-risk women, a broader range of non-cationic proteins were associated with HIV neutralizing activity in HESN and HIV-positive female sex workers. These results indicate that novel protein factors found in CVS of women with high-risk sexual practices may have inherent antiviral activity, or are involved in other aspects of anti-HIV host defense, and warrant further exploration into their mode of action.
Collapse
|