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Sahebi K, Shahsavani F, Mehravar F, Hatam G, Alimi R, Radfar A, Bahreini MS, Pouryousef A, Teimouri A. In vitro and in vivo anti-parasitic activity of curcumin nanoemulsion on Leishmania major (MRHO/IR/75/ER). BMC Complement Med Ther 2024; 24:238. [PMID: 38890586 PMCID: PMC11184741 DOI: 10.1186/s12906-024-04522-1] [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: 11/23/2023] [Accepted: 05/27/2024] [Indexed: 06/20/2024] Open
Abstract
The present study aimed to assess the anti-leishmanial effects of curcumin nanoemulsion (CUR-NE) against Leishmania major (MRHO/IR/75/ER) in both in vitro and in vivo experiments. CUR-NE was successfully prepared via the spontaneous emulsification method. The in vitro effect of various concentrations of CUR-NE against L. major promastigotes was assessed using the flow cytometry method. In vivo experiments were carried out in BALB/c mice inoculated subcutaneously with 2 × 106 L. major promastigotes. Mice were treated with topical CUR-NE (2.5 mg/ml), intra-lesion injection of CUR-NE (2.5 mg/ml), topical CUR suspension (CUR-S, 2.5 mg/ml), topical NE without CUR (NE-no CUR), amphotericin B as the positive control group, and infected untreated mice as the negative control group. In vitro exposure of promastigotes to CUR-NE showed a dose-dependent anti-leishmanial effect, with a 67.52 ± 0.35% mortality rate at a concentration of 1250 µg/ml and an IC50 of 643.56 µg/ml. In vivo experiments showed that topical CUR-NE and CUR-S significantly decreased the mean lesion size in mice after four weeks from 4.73 ± 1.28 to 2.78 ± 1.28 mm and 4.45 ± 0.88 to 3.23 ± 0.59 mm, respectively (p = 0.001). Furthermore, CUR-NE significantly decreased the parasite load in treated mice compared with the negative control group (p = 0.001). Results from the current study demonstrated the promising activity of CUR-NE against L. major in both in vitro and in vivo experiments. Moreover, CUR-NE was more efficient than CUR-S in healing and reducing parasite burden in mouse models. Future studies should aim to identify molecular mechanisms as well as the pharmacologic and pharmacokinetic aspects of CUR-NE.
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Affiliation(s)
- Keivan Sahebi
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fatemeh Shahsavani
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fatemeh Mehravar
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Gholamreza Hatam
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Rasoul Alimi
- Department of Epidemiology and Biostatistics, School of Health, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran
| | - Amirhossein Radfar
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Saleh Bahreini
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ali Pouryousef
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Aref Teimouri
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
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Qin P, He C, Ye P, Li Q, Cai C, Li Y. PKCδ regulates the vascular biology in diabetic atherosclerosis. Cell Commun Signal 2023; 21:330. [PMID: 37974282 PMCID: PMC10652453 DOI: 10.1186/s12964-023-01361-4] [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: 06/25/2023] [Accepted: 10/20/2023] [Indexed: 11/19/2023] Open
Abstract
Diabetes mellitus, known for its complications, especially vascular complications, is becoming a globally serious social problem. Atherosclerosis has been recognized as a common vascular complication mechanism in diabetes. The diacylglycerol (DAG)-protein kinase C (PKC) pathway plays an important role in atherosclerosis. PKCs can be divided into three subgroups: conventional PKCs (cPKCs), novel PKCs (nPKCs), and atypical PKCs (aPKCs). The aim of this review is to provide a comprehensive overview of the role of the PKCδ pathway, an isoform of nPKC, in regulating the function of endothelial cells, vascular smooth muscle cells, and macrophages in diabetic atherosclerosis. In addition, potential therapeutic targets regarding the PKCδ pathway are summarized. Video Abstract.
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Affiliation(s)
- Peiliang Qin
- Department of Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Changhuai He
- Department of Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Pin Ye
- Department of Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Qin Li
- Department of Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Chuanqi Cai
- Department of Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Yiqing Li
- Department of Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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Song Y, Gou Y, Gao J, Chen D, Zhang H, Zhao W, Qian F, Xu A, Shen Y. Lomerizine attenuates LPS-induced acute lung injury by inhibiting the macrophage activation through reducing Ca 2+ influx. Front Pharmacol 2023; 14:1236469. [PMID: 37693893 PMCID: PMC10484514 DOI: 10.3389/fphar.2023.1236469] [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: 06/07/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023] Open
Abstract
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening lung diseases with high mortality rates, predominantly attributable to acute and severe pulmonary inflammation. Lomerizine (LMZ) is a calcium channel blocker previously used in preventing and treating migraine. Here, we found that LMZ inhibited inflammatory responses and lung pathological injury by reducing pulmonary edema, neutrophil infiltration and pro-inflammatory cytokine production in lipopolysaccharide (LPS)-induced ALI mice. In vitro experiments, upon treating with LMZ, the expression of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α was attenuated in macrophages. The phosphorylation of p38 MAPK, ERK1/2, JNK, and NF-κB p65 was inhibited after LMZ treatment. Furthermore, LPS-induced Ca2+ influx was reduced by treating with LMZ, which correlated with inhibition of pro-inflammatory cytokine production. And L-type Ca2+ channel agonist Bay K8644 (BK) could restore cytokine generation. In conclusion, our study demonstrated that LMZ alleviates LPS-induced ALI and is a potential agent for treating ALI/ARDS.
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Affiliation(s)
- Yunduan Song
- Department of Respiratory and Critical Care Medicine, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
- Department of Clinical Laboratory, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yusen Gou
- Shanghai Frontiers Science Center of Drug Target Identification and Delivery, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Jiameng Gao
- Department of Respiratory and Critical Care Medicine, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
| | - Dongxin Chen
- Shanghai Frontiers Science Center of Drug Target Identification and Delivery, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Haibo Zhang
- Shanghai Frontiers Science Center of Drug Target Identification and Delivery, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Wenjuan Zhao
- Shanghai Frontiers Science Center of Drug Target Identification and Delivery, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Feng Qian
- Shanghai Frontiers Science Center of Drug Target Identification and Delivery, School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Ajing Xu
- Department of Clinical Pharmacy, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yao Shen
- Department of Respiratory and Critical Care Medicine, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
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Lin AJ, Joshi AU, Mukherjee R, Tompkins CA, Vijayan V, Mochly-Rosen D, Haileselassie B. δPKC-Mediated DRP1 Phosphorylation Impacts Macrophage Mitochondrial Function and Inflammatory Response to Endotoxin. Shock 2022; 57:435-443. [PMID: 34738957 PMCID: PMC8885892 DOI: 10.1097/shk.0000000000001885] [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] [Indexed: 11/25/2022]
Abstract
BACKGROUND Recent studies have demonstrated that alterations in mitochondrial dynamics can impact innate immune function. However, the upstream mechanisms that link mitochondrial dynamics to innate immune phenotypes have not been completely elucidated. This study asks if Protein Kinase C, subunit delta (δPKC)-mediated phosphorylation of dynamin-related protein 1 (Drp1), a key driver of mitochondrial fission, impacts macrophage pro-inflammatory response following bacterial-derived lipopolysaccharide (LPS) stimulation. METHODS Using RAW 264.7 cells, bone marrow-derived macrophages from C57BL/6J mice, as well as human monocyte-derived macrophages, we first characterized changes in δPKC-mediated phosphorylation of Drp1 following LPS stimulation. Next, using rationally designed peptides that inhibit δPKC activation (δV1-1) and δPKC-Drp1 interaction (ψDrp1), we determined whether δPKC-mediated phosphorylation of Drp1 impacts LPS-induced changes in mitochondrial morphology, mitochondrial function, and inflammatory response. RESULTS Our results demonstrated that δPKC-dependent Drp1 activation is associated with increased mitochondrial fission, impaired cellular respiration, and increased mitochondrial reactive oxygen species in LPS-treated macrophages. This is reversed using a rationally designed peptide that selectively inhibits δPKC phosphorylation of Drp1 (ψDrp1). Interestingly, limiting excessive mitochondrial fission using ψDrp1 reduced LPS-triggered pro-inflammatory response, including a decrease in NF-κB nuclear localization, decreased iNOS induction, and a reduction in pro-inflammatory cytokines (IL-1β, TNFα, IL-6). CONCLUSION These data suggest that inhibiting Drp1 phosphorylation by δPKC abates the excessive mitochondrial fragmentation and mitochondrial dysfunction that is seen following LPS treatment. Furthermore, these data suggest that limiting δPKC-dependent Drp1 activation decreases the pro-inflammatory response following LPS treatment. Altogether, δPKC-dependent Drp1 phosphorylation might be an upstream mechanistic link between alterations in mitochondrial dynamics and innate immune phenotypes, and may have therapeutic potential.
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Affiliation(s)
- Amanda J Lin
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Amit U Joshi
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Riddhita Mukherjee
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics Division of Critical Care Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Carly A Tompkins
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics Division of Critical Care Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Vijith Vijayan
- Department of Pediatrics Division of Critical Care Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Bereketeab Haileselassie
- Department of Pediatrics Division of Critical Care Medicine, Stanford University School of Medicine, Stanford, CA, USA
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Signal Transduction in Immune Cells and Protein Kinases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:133-149. [PMID: 33539014 DOI: 10.1007/978-3-030-49844-3_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Immune response relies upon several intracellular signaling events. Among the protein kinases involved in these pathways, members of the protein kinase C (PKC) family are prominent molecules because they have the capacity to acutely and reversibly modulate effector protein functions, controlling both spatial distribution and dynamic properties of the signals. Different PKC isoforms are involved in distinct signaling pathways, with selective functions in a cell-specific manner.In innate system, Toll-like receptor signaling is the main molecular event triggering effector functions. Various isoforms of PKC can be common to different TLRs, while some of them are specific for a certain type of TLR. Protein kinases involvement in innate immune cells are presented within the chapter emphasizing their coordination in many aspects of immune cell function and, as important players in immune regulation.In adaptive immunity T-cell receptor and B-cell receptor signaling are the main intracellular pathways involved in seminal immune specific cellular events. Activation through TCR and BCR can have common intracellular pathways while others can be specific for the type of receptor involved or for the specific function triggered. Various PKC isoforms involvement in TCR and BCR Intracellular signaling will be presented as positive and negative regulators of the immune response events triggered in adaptive immunity.
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Jung HJ, Kang JH, Pak S, Lee K, Seong JK, Oh SH. Detrimental Role of Nerve Injury-Induced Protein 1 in Myeloid Cells under Intestinal Inflammatory Conditions. Int J Mol Sci 2020; 21:ijms21020614. [PMID: 31963519 PMCID: PMC7013940 DOI: 10.3390/ijms21020614] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 12/24/2022] Open
Abstract
Nerve injury-induced protein 1 (Ninjurin1, Ninj1) is a cell-surface adhesion molecule that regulates cell migration and attachment. This study demonstrates the increase in Ninj1 protein expression during development of intestinal inflammation. Ninj1-deficient mice exhibited significantly attenuated bodyweight loss, shortening of colon length, intestinal inflammation, and lesser pathological lesions than wild-type mice. Although more severe inflammation and serious lesions are observed in wild-type mice than Ninj1-deficient mice, there were no changes in the numbers of infiltrating macrophages in the inflamed tissues obtained from WT and Ninj1-deficient mice. Ninj1 expression results in activation of macrophages, and these activated macrophages secrete more cytokines and chemokines than Ninj1-deficient macrophages. Moreover, mice with conditional deletion of Ninj1 in myeloid cells (Ninj1fl/fl; Lyz-Cre+) alleviated experimental colitis compared with wild-type mice. In summary, we propose that the Ninj1 in myeloid cells play a pivotal function in intestinal inflammatory conditions.
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Affiliation(s)
- Hyun Jin Jung
- Interdisciplinary Program in Cancer Biology, College of Medicine, Seoul National University, Seoul 03080, Korea;
- Korea Mouse Phenotyping Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Ju-Hee Kang
- College of Pharmacy, Gachon University, Incheon 21936, Korea
| | - Seongwon Pak
- Department of Biomedical Science, Hallym University, Chuncheon 24252, Korea
| | - Keunwook Lee
- Department of Biomedical Science, Hallym University, Chuncheon 24252, Korea
| | - Je Kyung Seong
- Interdisciplinary Program in Cancer Biology, College of Medicine, Seoul National University, Seoul 03080, Korea;
- Korea Mouse Phenotyping Center, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
- Laboratory of Developmental Biology and Genomics, Research Institute of Veterinary Science, BK21 Plus Program for Veterinary Science, Seoul National University, Seoul 08826, Korea
- Correspondence: (J.K.S.); (S.H.O.)
| | - Seung Hyun Oh
- College of Pharmacy, Gachon University, Incheon 21936, Korea
- Correspondence: (J.K.S.); (S.H.O.)
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Yi L, Wu Q, Chen N, Song G, Wang C, Zou Q, Zhang Z. Valproate Plays a Protective Role against Migraine by Inhibiting Protein Kinase C Signalling in Nitroglycerin-treated Mice. Basic Clin Pharmacol Toxicol 2017; 122:310-316. [PMID: 28990289 DOI: 10.1111/bcpt.12915] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/26/2017] [Indexed: 12/23/2022]
Abstract
Migraine is a common disease with a high morbidity. Valproate (VP) is used as an anti-epilepsy drug in clinic. This study aimed to investigate the role of VP in nitroglycerin (NTG)-induced migraine using a mouse model. NTG was employed by intraperitoneal injection to induce a migraine model in mice. The NTG administration caused mouse head discomforts, decreased tolerance to cold or hot stimulation and increased content of nitric oxide, calcitonin gene-related peptide and neuropeptide Y in serum, which were ameliorated by intraperitoneal injection of VP. The levels of two inflammatory factors, interleukin (IL)-1β and inducible nitric oxide synthase, in dura mater were increased by NTG treatment, while the increase was attenuated by application of VP. In addition, the phosphorylation levels of protein kinase C (PKC) α, γ, δ and ε were increased by NTG and decreased by VP. However, their total expression at the transcriptional and translational levels did not change significantly. Two substrates of PKC, cAMP-response element binding protein 1 and signal transducer and activator of transcription 1 were also phosphorylated by NTG application, and the phosphorylation level was attenuated by VP, consistent with the change of PKC informs. Together, we demonstrated that VP prevented damage due to migraine by inhibiting PKC signalling in NTG-injected mice, which may provide a basis for investigating the clinical treatment of migraine.
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Affiliation(s)
- Lian Yi
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Qiong Wu
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Nan Chen
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Ge Song
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Chao Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Qiaoge Zou
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Zhongling Zhang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
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Galeotti N. Hypericum perforatum (St John's wort) beyond depression: A therapeutic perspective for pain conditions. JOURNAL OF ETHNOPHARMACOLOGY 2017; 200:136-146. [PMID: 28216196 DOI: 10.1016/j.jep.2017.02.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/30/2017] [Accepted: 02/10/2017] [Indexed: 06/06/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Hypericum perforatum L. (Hypericaceae), popularly called St. John's wort (SJW), has a rich historical background being one of the oldest used and most extensively investigated medicinal herbs. Many bioactivities and applications of SJW are listed in popular and in scientific literature, including antibacterial, antiviral, anti-inflammatory. In the last three decades many studies focused on the antidepressant activity of SJW extracts. However, several studies in recent years also described the antinociceptive and analgesic properties of SJW that validate the traditional uses of the plant in pain conditions. AIM OF THE REVIEW This review provides up-to-date information on the traditional uses, pre-clinical and clinical evidence on the pain relieving activity of SJW and its active ingredients, and focuses on the possible exploitation of this plant for the management of pain. MATERIALS AND METHODS Historical ethnobotanical publications from 1597 were reviewed for finding local and traditional uses. The relevant data on the preclinical and clinical effects of SJW were searched using various databases such as PubMed, Science Direct, Scopus, and Google Scholar. Plant taxonomy was validated by the database Plantlist.org. RESULTS Preclinical animal studies demonstrated the ability of low doses of SJW dry extracts (0.3% hypericins; 3-5% hyperforins) to induce antinociception, to relieve from acute and chronic hyperalgesic states and to augment opioid analgesia. Clinical studies (homeopathic remedies, dry extracts) highlighted dental pain conditions as a promising SJW application. In vivo and in vitro studies showed that the main components responsible for the pain relieving activity are hyperforin and hypericin. SJW analgesia appears at low doses (5-100mg/kg), minimizing the risk of herbal-drug interactions produced by hyperforin, a potent inducer of CYP enzymes. CONCLUSION Preclinical studies indicate a potential use of SJW in medical pain management. However, clinical research in this field is still scarce and the few studies available on chronic pain produced negative results. Prospective randomized controlled clinical trials performed at low doses are needed to validate its potential efficacy in humans.
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Affiliation(s)
- Nicoletta Galeotti
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology, University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy.
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Eason RJ, Bell KS, Marshall FA, Rodgers DT, Pineda MA, Steiger CN, Al-Riyami L, Harnett W, Harnett MM. The helminth product, ES-62 modulates dendritic cell responses by inducing the selective autophagolysosomal degradation of TLR-transducers, as exemplified by PKCδ. Sci Rep 2016; 6:37276. [PMID: 27869138 PMCID: PMC5116678 DOI: 10.1038/srep37276] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/27/2016] [Indexed: 12/25/2022] Open
Abstract
We have previously shown that ES-62, a phosphorylcholine (PC)-containing glycoprotein secreted by the parasitic filarial nematode Acanthocheilonema viteae targets dendritic cell (DC) responses, specifically by suppressing TLR4 signalling to inhibit Th1/Th17-driven inflammation. We have now investigated the molecular mechanisms underpinning such immunomodulation and show here that ES-62-mediated downregulation of protein kinase C-δ (PKC-δ), a TLR4-associated signalling mediator required for full activation of LPS-driven pro-inflammatory responses, is associated with induction of a low level of autophagic flux, as evidenced by upregulation and trafficking of p62 and LC3 and their consequent autophagolysosomal degradation. By contrast, the classical TLR4 ligand LPS, strongly upregulates p62 and LC3 expression but under such canonical TLR4 signalling this upregulation appears to reflect a block in autophagic flux, with these elements predominantly degraded in a proteasomal manner. These data are consistent with autophagic flux acting to homeostatically suppress proinflammatory DC responses and indeed, blocking of PKC-δ degradation by the autophagolysosomal inhibitors, E64d plus pepstatin A, results in abrogation of the ES-62-mediated suppression of LPS-driven release of IL-6, IL-12p70 and TNF-α by DCs. Thus, by harnessing this homeostatic regulatory mechanism, ES-62 can protect against aberrant inflammation, either to promote parasite survival or serendipitously, exhibit therapeutic potential in inflammatory disease.
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Affiliation(s)
- Russell J. Eason
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
| | - Kara S. Bell
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | - Fraser A. Marshall
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
| | - David T. Rodgers
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
| | - Miguel A. Pineda
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
| | - Christina N. Steiger
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
| | - Lamyaa Al-Riyami
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | - William Harnett
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | - Margaret M. Harnett
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
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Gordon R, Singh N, Lawana V, Ghosh A, Harischandra DS, Jin H, Hogan C, Sarkar S, Rokad D, Panicker N, Anantharam V, Kanthasamy AG, Kanthasamy A. Protein kinase Cδ upregulation in microglia drives neuroinflammatory responses and dopaminergic neurodegeneration in experimental models of Parkinson's disease. Neurobiol Dis 2016; 93:96-114. [PMID: 27151770 DOI: 10.1016/j.nbd.2016.04.008] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/22/2016] [Accepted: 04/29/2016] [Indexed: 02/06/2023] Open
Abstract
Chronic microglial activation has been linked to the progressive degeneration of the nigrostriatal dopaminergic neurons evidenced in Parkinson's disease (PD) pathogenesis. The exact etiology of PD remains poorly understood. Although both oxidative stress and neuroinflammation are identified as co-contributors in PD pathogenesis, signaling mechanisms underlying neurodegenerative processes have yet to be defined. Indeed, we recently identified that protein kinase C delta (PKCδ) activation is critical for induction of dopaminergic neuronal loss in response to neurotoxic stressors. However, it remains to be defined whether PKCδ activation contributes to immune signaling events driving microglial neurotoxicity. In the present study, we systematically investigated whether PKCδ contributes to the heightened microglial activation response following exposure to major proinflammatory stressors, including α-synuclein, tumor necrosis factor α (TNFα), and lipopolysaccharide (LPS). We report that exposure to the aforementioned inflammatory stressors dramatically upregulated PKCδ with a concomitant increase in its kinase activity and nuclear translocation in both BV-2 microglial cells and primary microglia. Importantly, we also observed a marked upregulation of PKCδ in the microglia of the ventral midbrain region of PD patients when compared to age-matched controls, suggesting a role for microglial PKCδ in neurodegenerative processes. Further, shRNA-mediated knockdown and genetic ablation of PKCδ in primary microglia blunted the microglial proinflammatory response elicited by the inflammogens, including ROS generation, nitric oxide production, and proinflammatory cytokine and chemokine release. Importantly, we found that PKCδ activated NFκB, a key mediator of inflammatory signaling events, after challenge with inflammatory stressors, and that transactivation of NFκB led to translocation of the p65 subunit to the nucleus, IκBα degradation and phosphorylation of p65 at Ser536. Furthermore, both genetic ablation and siRNA-mediated knockdown of PKCδ attenuated NFκB activation, suggesting that PKCδ regulates NFκB activation subsequent to microglial exposure to inflammatory stimuli. To further investigate the pivotal role of PKCδ in microglial activation in vivo, we utilized pre-clinical models of PD. We found that PKCδ deficiency attenuated the proinflammatory response in the mouse substantia nigra, reduced locomotor deficits and recovered mice from sickness behavior in an LPS-induced neuroinflammation model of PD. Likewise, we found that PKCδ knockout mice treated with MPTP displayed a dampened microglial inflammatory response. Moreover, PKCδ knockout mice exhibited reduced susceptibility to the neurotoxin-induced dopaminergic neurodegeneration and associated motor impairments. Taken together, our studies propose a pivotal role for PKCδ in PD pathology, whereby sustained PKCδ activation drives sustained microglial inflammatory responses and concomitant dopaminergic neurotoxicity consequently leading to neurobehavioral deficits. We conclude that inhibiting PKCδ activation may represent a novel therapeutic strategy in PD treatment.
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Affiliation(s)
- Richard Gordon
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Neeraj Singh
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Vivek Lawana
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Anamitra Ghosh
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Dilshan S Harischandra
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Huajun Jin
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Colleen Hogan
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Souvarish Sarkar
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Dharmin Rokad
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Nikhil Panicker
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Vellareddy Anantharam
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Anumantha G Kanthasamy
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Arthi Kanthasamy
- Parkinson Disorders Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA.
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Leppänen T, Tuominen RK, Moilanen E. Protein kinase C and its inhibitors in the regulation of inflammation: inducible nitric oxide synthase as an example. Basic Clin Pharmacol Toxicol 2013; 114:37-43. [PMID: 24107256 DOI: 10.1111/bcpt.12139] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 09/13/2013] [Indexed: 01/19/2023]
Abstract
Protein kinase C (PKC) is a family of ten isoenzymes that play a crucial role in cellular signal transduction. Studies with PKC knockout animals have revealed that many of the isoenzymes are involved in cell growth, proliferation and differentiation. Several PKC isoenzymes have also been shown to be important mediators in inflammation and immunity, particularly in lymphocyte responses. However, less is known about the role of PKC in the regulation of the expression of inflammatory genes. In inflammatory processes, nitric oxide is primarily produced by inducible nitric oxide synthase (iNOS) in inflammatory cells, such as macrophages. In innate immunity, nitric oxide functions as an effector molecule towards the infectious organisms. Increased levels of nitric oxide are also produced by inflammatory and tissue cells in inflammatory diseases, such as asthma and arthritis. In this MiniReview, the role of PKC isoenzymes in the pathogenesis and as a potential drug target in inflammation will be discussed presenting iNOS as an example of an inflammatory gene regulated by the pleiotropic PKC signalling pathway.
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Affiliation(s)
- Tiina Leppänen
- The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
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PKC-Dependent Signaling Pathways within PAG and Thalamus Contribute to the Nitric Oxide-Induced Nociceptive Behavior. ISRN PAIN 2013; 2013:471378. [PMID: 27335876 PMCID: PMC4893404 DOI: 10.1155/2013/471378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 07/08/2013] [Indexed: 01/24/2023]
Abstract
Nitric oxide (NO) is an important molecule involved in nociceptive processing in the central nervous system. The release of NO within the spinal cord has long been implicated in the mechanisms underlying exaggerated pain sensitivity, and administration of NO donors can induce hyperalgesia. To elucidate the supraspinal mechanism responsible for NO-induced nociceptive hypersensitivity, we investigated the modulation of protein kinase C (PKC) and downstream effectors following treatment with the NO donors nitroglycerin and sodium nitroprusside. Both compounds induced a prolonged cold allodynia and heat hyperalgesia, increased levels of c-Fos and IL-1β, and activated NF-κB within periaqueductal grey matter and thalamus. Simultaneously, an increased expression and phosphorylation of PKC γ and ε were detected. To clarify the cellular mechanism involved in the NO-induced hypernociception, we examined the expression of transcription factors that act as PKC downstream effectors. A dramatic hyperphosphorylation of CREB and STAT1 was observed. The i.c.v. administration of the PKC blocker calphostin C prevented the NO-induced hypernociception, the hyperphosphorylation of CREB and STAT1, and partially reduced NF-κB activation. Conversely, the increase of IL-1β was unmodified by calphostin C. These results suggest the relevance of cerebral PKC-mediated CREB and STAT1 activation in the NO donor-induced nociceptive behavior.
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Galeotti N, Ghelardini C. Reversal of NO-induced nociceptive hypersensitivity by St. John's wort and hypericin: NF-κB, CREB and STAT1 as molecular targets. Psychopharmacology (Berl) 2013; 227:149-63. [PMID: 23254377 DOI: 10.1007/s00213-012-2950-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 12/03/2012] [Indexed: 12/19/2022]
Abstract
RATIONALE Hypericum perforatum, popularly called St. John's wort (SJW), is a medicinal plant mainly used as antidepressant with a favorable safety profile than standard antidepressants. Some studies have also documented other SJW bioactivities, including pain modulation. OBJECTIVES The aim of this study was to demonstrate the capability of SJW to relieve nitric oxide (NO)-induced nociceptive hypersensitivity and identify the effective component. METHODS Nociceptive hypersensitivity induced by administration of the NO donors nitroglycerin (GTN) and sodium nitroprusside (SNP) was assessed by cold and hot plate tests. The cellular pathways and molecular targets involved were investigated by Western blotting. RESULTS GTN and SNP produced a prolonged allodynia and hyperalgesia in mice. A single oral administration of low doses of an SJW dried extract or purified hypericin reversed the NO donor-induced nociceptive behavior whereas hyperforin and flavoinoids were ineffective. Investigating into the cellular pathways involved, an increased CREB and STAT1 phosphorylation, and activation of NF-κB were detected within PAG and thalamus following NO donors' administration. These cellular events were prevented by SJW or hypericin. Since hypericin showed PKC blocking properties, a role of PKC as an upstream modulator of these transcription factors was hypothesized. NO donors increased expression and phosphorylation of protein kinase C (PKC) γ and ε isoforms, molecular events prevented by SJW or hypericin. CONCLUSIONS SJW reversed NO-induced nociceptive hypersensitivity through the blockade of a supraspinal signaling pathway involving a PKC-dependent CREB, STAT1 and NF-κB activation due to presence of hypericin. These data indicate SJW/hypericin as a therapeutic perspective for pain treatment.
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Affiliation(s)
- Nicoletta Galeotti
- Department of Preclinical and Clinical Pharmacology, Viale G. Pieraccini 6, 50139, Florence, Italy.
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Galeotti N, Ghelardini C. Inhibition of the PKCγ-ε pathway relieves from meningeal nociception in an animal model: an innovative perspective for migraine therapy? Neurotherapeutics 2013; 10:329-39. [PMID: 23055050 PMCID: PMC3625380 DOI: 10.1007/s13311-012-0151-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
There is convincing evidence that nitric oxide (NO) may be a causative factor in the pathogenesis of migraine. We investigated the consequences of NO donors' administration on meningeal processes related to the development of migraine pain in an animal model of meningeal nociception. The administration in mice of the NO donors nitroglycerin (GTN) and sodium nitroprusside (SNP) produced a delayed meningeal upregulation of interleukin-1ß and inducible NO synthase. A thermal allodynia and hyperalgesia devoid of side effects was produced 1 to 4 h after administration. To clarify the cellular pathways modulated by GTN and SNP, we examined the expression of cellular factors involved in pain modulation, such as protein kinase C (PKC) and its downstream effectors. Western blotting experiments showed an upregulation and increased phosphorylation of PKCγ and PKCε within dura mater after NO donors' administration. A dramatic PKC-dependent increase of the phosphorylation of cyclic AMP response element binding protein (CREB) and signal transducer and activator of transcription (STAT)-1 was observed, along with an activation of the nuclear factor-κB (NF-κB) pathway, as reflected by a reduction of the inhibitory protein-κ-Bα (IκBα). Furthermore, the PKC blocker, Calphostin C, prevented the GTN and SNP-induced pain hypersensitivity. These results suggest the relevance of the PKC-mediated pathway in the induction of meningeal nociception and might help clarify the etiopathology of migraines. We can suggest PKC as a new target for migraine pain.
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Affiliation(s)
- Nicoletta Galeotti
- Department of Preclinical and Clinical Pharmacology, Viale G. Pieraccini 6, Florence, 50139, Italy.
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Leppänen T, Korhonen R, Laavola M, Nieminen R, Tuominen RK, Moilanen E. Down-regulation of protein kinase Cδ inhibits inducible nitric oxide synthase expression through IRF1. PLoS One 2013; 8:e52741. [PMID: 23326354 PMCID: PMC3541401 DOI: 10.1371/journal.pone.0052741] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 11/21/2012] [Indexed: 12/15/2022] Open
Abstract
In inflammation, pro-inflammatory cytokines and bacterial products induce the production of high amounts of NO by inducible nitric oxide synthase (iNOS) in inflammatory and tissue cells. NO is an effector molecule in innate immunity, and it also has regulatory and pro-inflammatory/destructive effects in the inflammatory process. Protein kinase Cδ (PKCδ) is an important signaling protein regulating B lymphocyte functions, but less is known about its effects in innate immunity and inflammatory gene expression. In the present study we investigated the role of PKCδ in the regulation of iNOS expression in inflammatory conditions. NO production and iNOS expression were induced by LPS or a combination of cytokines IFNγ, IL-1β, and TNFα. Down-regulation of PKCδ by siRNA and inhibition of PKCδ by rottlerin suppressed NO production and iNOS expression in activated macrophages and fibroblasts. PKCδ directed siRNA and inhibition of PKCδ by rottlerin suppressed also the expression of transcription factor IRF1, possibly through inhibition of STAT1 activation. Accordingly, down-regulation of IRF1 by siRNA reduced iNOS expression in response to inflammatory stimuli. In addition, inhibition of PKCδ showed anti-inflammatory effects in carrageenan induced paw inflammation in mice as did iNOS inhibitor L-NIL. These results suggest that inhibitors of PKCδ have anti-inflammatory effects in disease states complicated by enhanced NO production through iNOS pathway.
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Affiliation(s)
- Tiina Leppänen
- The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - Riku Korhonen
- The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - Mirka Laavola
- The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - Riina Nieminen
- The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - Raimo K. Tuominen
- The Division of Pharmacology and Toxicology, University of Helsinki Faculty of Pharmacy, Helsinki, Finland
| | - Eeva Moilanen
- The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
- * E-mail:
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Chakraborty R, Bhatt KH, Sodhi A. High mobility group box 1 protein synergizes with lipopolysaccharide and peptidoglycan for nitric oxide production in mouse peritoneal macrophages in vitro. Mol Immunol 2012. [PMID: 23201852 DOI: 10.1016/j.molimm.2012.10.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Extracellular high mobility group box 1 (HMGB1) protein and nitric oxide (NO) has been credited with multiple inflammatory functions using in vivo and in vitro systems. Therefore, delineating their regulation may be an important therapeutic strategy for the treatment of sepsis. In the present study, it is demonstrated that recombinant HMGB1 (rHMGB1) synergizes with sub threshold concentration of TLR2 agonist (PGN; 1 μg/ml) as well as with TLR4 agonist (LPS; 1 ng/ml) to induce NO release in mouse peritoneal macrophages. The enhanced iNOS expression was also observed at the transcription and translational level. Co-incubation of macrophages with rHMGB1 with either PGN or LPS showed enhanced expression of TLR2, TLR4 and RAGE. TLR2, TLR4 or RAGE knockdown macrophages effectively inhibited the rHMGB1+PGN or LPS induced NO synergy. It was further observed that the JNK MAPK inhibitor SP600125 attenuated the PGN+rHMGB1 induced iNOS/NO synergy whereas p38 MAPK inhibitor SB908912 inhibited iNOS/NO synergy induced by LPS+rHMGB1. It was also observed that the activation of NF-κB is essential for the synergy as the pharmacological inhibition or siRNA knockdown of NF-κB (cRel) significantly reduced the rHMGB1+PGN or rHMGB1+LPS induced enhanced iNOS/NO expression. Altogether, the data suggests that the co-incubation of macrophages with rHMGB1 with either LPS or PGN induces the synergistic effect on iNOS expression and NO release by the upregulation of surface receptors (TLR2, TLR4 and RAGE) which in turn amplifies the MAPKs (p38 and JNK) and NF-κB activation and results in enhanced iNOS expression and NO production.
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Mehta HV, Jones PH, Weiss JP, Okeoma CM. IFN-α and lipopolysaccharide upregulate APOBEC3 mRNA through different signaling pathways. THE JOURNAL OF IMMUNOLOGY 2012; 189:4088-103. [PMID: 22972924 DOI: 10.4049/jimmunol.1200777] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
APOBEC3 (A3) proteins are virus-restriction factors that provide intrinsic immunity against infections by viruses like HIV-1 and mouse mammary tumor virus. A3 proteins are inducible by inflammatory stimuli, such as LPS and IFN-α, via mechanisms that are not fully defined. Using genetic and pharmacological studies on C57BL/6 mice and cells, we show that IFN-α and LPS induce A3 via different pathways, independently of each other. IFN-α positively regulates mouse APOBEC3 (mA3) mRNA expression through IFN-αR/PKC/STAT1 and negatively regulates mA3 mRNA expression via IFN-αR/MAPKs-signaling pathways. Interestingly, LPS shows some variation in its regulatory behavior. Although LPS-mediated positive regulation of mA3 mRNA occurs through TLR4/TRIF/IRF3/PKC, it negatively modulates mA3 mRNA via TLR4/MyD88/MAPK-signaling pathways. Additional studies on human peripheral blood mononuclear cells reveal that PKC differentially regulates IFN-α and LPS induction of human A3A, A3F, and A3G mRNA expression. In summary, we identified important signaling targets downstream of IFN-αR and TLR4 that mediate A3 mRNA induction by both LPS and IFN-α. Our results provide new insights into the signaling targets that could be manipulated to enhance the intracellular store of A3 and potentially enhance A3 antiviral function in the host.
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Affiliation(s)
- Harshini V Mehta
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Bhatt KH, Sodhi A, Chakraborty R. Peptidoglycan induced expression of peroxisome proliferator-activated receptor γ in mouse peritoneal macrophages: role of ERK and JNK MAP kinases. Cytokine 2012; 60:778-86. [PMID: 22925536 DOI: 10.1016/j.cyto.2012.07.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 07/07/2012] [Accepted: 07/29/2012] [Indexed: 01/28/2023]
Abstract
The peroxisome proliferator-activated receptor (PPAR) γ plays an important role in macrophage inflammatory homeostasis. Here we investigate the cross talk between PPARγ and TLR2 signaling pathway in mouse peritoneal macrophages. Real time RT-PCR and immunoblot analysis revealed that peptidoglycan (PGN) treatment of macrophages leads to biphasic effect on PPARγ expression i.e. an early upregulation and a late suppression. Inhibition of ERK MAP kinase by PD98059 abolished the early and rapid induction of PPARγ, while the inhibition of JNK MAP kinase by SP600125 nullifies the late inhibitory effect on the PPARγ expression in a dose-dependent manner. Furthermore, PPARγ knockdown macrophages showed enhanced NF-κB activity after PGN treatment. PGN treatment also enhances PPARγ interaction with p65 as observed by immunoprecipitation. This interaction may inhibit NF-κB (p65) activity as increased nuclear localization of p65 was observed in PPARγ knockdown macrophages after PGN treatment. PPARγ knockdown also increased the PGN-induced inflammatory cytokines (TNF-α, IL-1β, IL-12p40) production. Thus, our observations suggest that PGN induces PPARγ expression which is regulated by MAPKs activation and this enhanced PPARγ in turn attenuate NF-κB activity probably via enhancing p65 nuclear export. These results provide insight into how these pathways could be modulated in inflammatory diseases.
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Affiliation(s)
- Kunal H Bhatt
- School of Biotechnology, Faculty of Science, Banaras Hindu University, Varanasi 221 005, India
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Chakraborty R, Bhatt KH, Sodhi A. Ultraviolet B induces high mobility group box 1 release from mouse peritoneal macrophages in vitro via caspase-1 mediated secretion pathway. Immunobiology 2012; 218:135-44. [PMID: 22398161 DOI: 10.1016/j.imbio.2012.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 01/30/2012] [Accepted: 02/07/2012] [Indexed: 01/13/2023]
Abstract
High mobility group box 1 (HMGB1) protein is a unique non histone nuclear protein that acts extracellularly as a mediator of delayed inflammation. Sub lethal dose of UVB triggers the release of cytokines from macrophages (MΦs). Adding to the panoply of UVB induced cytokines; it is reported that UVB induces HMGB1 release from mouse peritoneal MΦs in time and partially dose dependent manner, independent of TNF-α. UVB also enhanced the transcription of HMGB1 gene and expression of cellular protein, which influences its subsequent release. HMGB1 is secreted by an unconventional secretion pathway of unknown mechanism. Caspase-1 has been shown to function as a general regulator of stress induced unconventional secretion for a number of cytokines. In the present study, we have observed that pharmacological inhibitors specific for caspase-1 (ZVAD and YVAD) abrogated UVB induced HMGB1 release from MΦs. This effect was most likely mediated via physical interaction between HMGB1 and active caspase-1 (p10 and p20) as demonstrated by immunoprecipitation. In addition, it was found that HMGB1 and active caspase-1 p20 release depends on UVB mediated enhancement of intracellular Ca(2+). Thus our data suggests that optimal dose of UVB (50 mJ/cm(2)) induces HMGB1 upregulation and active release from mouse peritoneal MΦs which is mediated by caspase-1 in a Ca(2+) dependent manner.
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Affiliation(s)
- Rituparna Chakraborty
- School of Biotechnology, Faculty of Science, Banaras Hindu University, Varanasi 221005, India
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20
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Koh YH, Tamizhselvi R, Moochhala S, Bian JS, Bhatia M. Role of protein kinase C in caerulein induced expression of substance P and neurokinin-1-receptors in murine pancreatic acinar cells. J Cell Mol Med 2012; 15:2139-49. [PMID: 20973912 PMCID: PMC4394224 DOI: 10.1111/j.1582-4934.2010.01205.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Substance P (SP) is involved in the pathophysiology of acute pancreatitis (AP) via binding to its high-affinity receptor, neurokinin-1-receptor (NK1R). An up-regulation of SP and NK1R expression was observed in experimental AP and in caerulein-stimulated pancreatic acinar cells. However, the mechanisms that lead to this up-regulation are not fully understood. In this study, we showed the role of protein kinase C (PKC) in caerulein-induced SP and NK1R production in isolated mouse pancreatic acinar cells. Caerulein (10(-7) M) stimulation rapidly activated the conventional PKC-α and novel PKC-δ as observed by the phosphorylation of these molecules. Pre-treatment of pancreatic acinar cells with Gö6976 (1-10 nM) and rottlerin (1-10 μM) inhibited PKC-α and PKC-δ phosphorylation, respectively, but not the other way round. At these concentrations used, PKC-α and PKC-δ inhibition reversed the caerulein-induced up-regulation of SP and NK1R, indicating an important role of PKCs in the modulation of SP and NK1R expression. Further experiments looking into signalling mechanisms showed that treatment of pancreatic acinar cells with both Gö6976 and rottlerin inhibited the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). Inhibition of PKC-α or PKC-δ also affected caerulein-induced transcription factor activation, as represented by nuclear factor-κB and AP-1 DNA-binding activity. The findings in this study suggested that PKC is upstream of the mitogen-activated protein kinases and transcription factors, which then lead to the up-regulation of SP/NK1R expression in caerulein-treated mouse pancreatic acinar cells.
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Affiliation(s)
- Yung-Hua Koh
- Department of Pharmacology, National University of Singapore, Singapore
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Dalloneau E, Lopes Pereira P, Brault V, Nabel EG, Hérault Y. Prmt2 Regulates the Lipopolysaccharide-Induced Responses in Lungs and Macrophages. THE JOURNAL OF IMMUNOLOGY 2011; 187:4826-34. [DOI: 10.4049/jimmunol.1101087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Loegering DJ, Lennartz MR. Protein kinase C and toll-like receptor signaling. Enzyme Res 2011; 2011:537821. [PMID: 21876792 PMCID: PMC3162977 DOI: 10.4061/2011/537821] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 05/31/2011] [Indexed: 11/20/2022] Open
Abstract
Protein kinase C (PKC) is a family of kinases that are implicated in a plethora of diseases, including cancer and cardiovascular disease. PKC isoforms can have different, and sometimes opposing, effects in these disease states. Toll-like receptors (TLRs) are a family of pattern recognition receptors that bind pathogens and stimulate the secretion of cytokines. It has long been known that PKC inhibitors reduce LPS-stimulated cytokine secretion by macrophages, linking PKC activation to TLR signaling. Recent studies have shown that PKC-α, -δ, -ε, and -ζ are directly involved in multiple steps in TLR pathways. They associate with the TLR or proximal components of the receptor complex. These isoforms are also involved in the downstream activation of MAPK, RhoA, TAK1, and NF-κB. Thus, PKC activation is intimately involved in TLR signaling and the innate immune response.
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Affiliation(s)
- Daniel J Loegering
- Center for Cardiovascular Sciences, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, USA
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Wen J, Ribeiro R, Zhang Y. Specific PKC isoforms regulate LPS-stimulated iNOS induction in murine microglial cells. J Neuroinflammation 2011; 8:38. [PMID: 21510893 PMCID: PMC3110130 DOI: 10.1186/1742-2094-8-38] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Accepted: 04/21/2011] [Indexed: 12/22/2022] Open
Abstract
Background Excessive production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) in reactive microglia is a major contributor to initiation/exacerbation of inflammatory and degenerative neurological diseases. Previous studies have indicated that activation of protein kinase C (PKC) can lead to iNOS induction. Because of the existence of various PKC isoforms and the ambiguous specificity of PKC inhibitors, it is unclear whether all PKC isoforms or a specific subset are involved in the expression of iNOS by reactive microglia. In this study, we employed molecular approaches to characterize the role of each specific PKC isoform in the regulation of iNOS expression in murine microglia. Methods Induction of iNOS in response to bacterial endotoxin lipopolysaccharide (LPS) was measured in BV-2 murine microglia treated with class-specific PKC inhibitors, or transfected with siRNA to silence specific PKC isoforms. iNOS expression and MAPK phosphorylation were evaluated by western blot. The role of NF-κB in activated microglia was examined by determining NF-κB transcriptional response element- (TRE-) driven, promoter-mediated luciferase activity. Results Murine microglia expressed high levels of nPKCs, and expressed relatively low levels of cPKCs and aPKCs. All PKC inhibitors attenuated induction of iNOS in LPS-activated microglia. Knockdown of PKC δ and PKC β attenuated ERK1/2 and p38 phosphorylation, respectively, and blocked NF-κB activation that leads to the expression of iNOS in reactive microglia. Conclusions Our results identify PKC δ and β as the major PKC isoforms regulating iNOS expression in reactive microglia. The signaling pathways mediated by PKC involve phosphorylation of distinct MAPKs and activation of NF-κB. These results may help in the design of novel and selective PKC inhibitors for the treatment of many inflammatory and neurological diseases in which production of NO plays a pathogenic role.
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Affiliation(s)
- Jie Wen
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
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Role of mitogen-activated protein kinases in peptidoglycan-induced expression of inducible nitric oxide synthase and nitric oxide in mouse peritoneal macrophages: extracellular signal-related kinase, a negative regulator. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:994-1001. [PMID: 21450974 DOI: 10.1128/cvi.00541-10] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The expression of inducible nitric oxide synthase (iNOS) and the production of nitric oxide (NO) are important host defense mechanisms against pathogens in mononuclear phagocytes. The objectives of this study were to examine the roles of mitogen-activated protein kinases (MAPKs) and transcription factors (nuclear factor-κB [NF-κB] and activating protein 1 [AP-1]) in peptidoglycan (PGN)-induced iNOS expression and NO production in macrophages. PGN is a cell wall component of Gram-positive bacteria that stimulates inflammatory responses both ex vivo and in vivo. PGN stimulates the activation of all three classes of MAPKs, extracellular signal-related kinase (ERK), c-Jun N-terminal kinase (JNK), and p38(mapk) in macrophages, albeit with differential activation kinetics. Using a selective inhibitor of JNK (SP600125) and JNK1/2 small interfering RNA (siRNA) knocked-down macrophages, it was observed that PGN-induced iNOS and NO expression is significantly inhibited. This suggested that JNK MAPK plays an essential role in PGN-induced iNOS expression and NO production. In contrast, inhibition of the ERK pathway using PD98059 dose dependently enhanced PGN-induced iNOS expression and NO production. PGN-induced ERK activation was attenuated in ERK1/2 siRNA knocked-down macrophages; however, NO and iNOS expression were significantly enhanced. An electrophoretic mobility shift assay showed that SP600125 inhibited PGN-induced NF-κB and AP-1 activation, whereas inhibition of the ERK pathway enhanced NF-κB activation, but with no effect on AP-1. These results indicate that the JNK MAPK positively regulate PGN-induced iNOS and NO expression by activating NF-κB and AP-1 transcription factors, whereas the ERK pathway plays a negative regulatory role via affecting NF-κB activity.
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Intrinsic nitric oxide-stimulatory activity of lipoteichoic acids from different Gram-positive bacteria. Nitric Oxide 2010; 23:300-10. [DOI: 10.1016/j.niox.2010.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 08/24/2010] [Accepted: 09/08/2010] [Indexed: 11/16/2022]
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Abstract
Obesity is a major problem worldwide that increases risk for a wide range of diseases, including diabetes and heart disease. As such, it is increasingly important to understand how excess adiposity can perturb normal metabolic functions. It is now clear that this disruption involves not only pathways controlling lipid and glucose homeostasis but also integration of metabolic and immune response pathways. Under conditions of nutritional excess, this integration can result in a metabolically driven, low-grade, chronic inflammatory state, referred to as "metaflammation," that targets metabolically critical organs and tissues to adversely affect systemic homeostasis. Endoplasmic reticulum dysfunction is another important feature of chronic metabolic disease that is also linked to both metabolic and immune regulation. A thorough understanding of how these pathways intersect to maintain metabolic homeostasis, as well as how this integration is altered under conditions of nutrient excess, is important to fully understand, and subsequently treat, chronic metabolic diseases.
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Affiliation(s)
- Sarah Hummasti
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, MA, USA
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Gupta SC, Sundaram C, Reuter S, Aggarwal BB. Inhibiting NF-κB activation by small molecules as a therapeutic strategy. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:775-87. [PMID: 20493977 DOI: 10.1016/j.bbagrm.2010.05.004] [Citation(s) in RCA: 575] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 05/08/2010] [Indexed: 12/21/2022]
Abstract
Because nuclear factor-κB (NF-κB) is a ubiquitously expressed proinflammatory transcription factor that regulates the expression of over 500 genes involved in cellular transformation, survival, proliferation, invasion, angiogenesis, metastasis, and inflammation, the NF-κB signaling pathway has become a potential target for pharmacological intervention. A wide variety of agents can activate NF-κB through canonical and noncanonical pathways. Canonical pathway involves various steps including the phosphorylation, ubiquitination, and degradation of the inhibitor of NF-κB (IκBα), which leads to the nuclear translocation of the p50-p65 subunits of NF-κB followed by p65 phosphorylation, acetylation and methylation, DNA binding, and gene transcription. Thus, agents that can inhibit protein kinases, protein phosphatases, proteasomes, ubiquitination, acetylation, methylation, and DNA binding steps have been identified as NF-κB inhibitors. Because of the critical role of NF-κB in cancer and various chronic diseases, numerous inhibitors of NF-κB have been identified. In this review, however, we describe only small molecules that suppress NF-κB activation, and the mechanism by which they block this pathway.
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Affiliation(s)
- Subash C Gupta
- Cytokine Research Laboratory, Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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