title: Inhibition of metalloproteinase-9 secretion and gene expression by artemisinin derivatives.
abstract: Malaria remains one of the world's most common infectious diseases, being responsible for more deaths than any other communicable disease except tuberculosis. There is strong evidence that tumour necrosis factor α and interleukin-1β are important contributors to the systemic disease caused by the infection with Plasmodium falciparum. Circulating levels of TNFα are increased after infection, as a consequence of stimulation of monocyte-macrophages by infected red blood cells or parasite products, as shown in vitro for the malaria pigment haemozoin. TNFα in turn enhances the synthesis of metalloproteinase-9 in monocytes and macrophages. Metalloproteinase-9 acts on the extracellular matrix but also on non-traditional substrates, including precursors of inflammatory cytokines, which are proteolytically activated and contribute to the amplification of the inflammatory response. The aim of the present work was to establish whether artemisinin and its derivatives artemisone, artesunate and dihydroartemisinin possess immuno-modulatory properties. In particular, it is necessary to evaluate their effects on mRNA levels and secretion of MMP-9 by the human monocytic cell line (THP-1 cells) stimulated by hemozoin or TNFα. 5μM of each derivative, although not artemisinin itself, induced significantly inhibited TNFα production. Artesunate, artemisone and DHA antagonized haemozoin-induced MMP-9 secretion by 25%, 24% and 50%, respectively. mRNA levels were also depressed by 14%, 20% and 27%, respectively, thus reflecting in part the effect observed on protein production. The derivatives significantly inhibited both TNFα-induced MMP-9 secretion and mRNA levels to a greater extent than haemozoin itself. Both haemozoin and TNFα increased NF-κB driven transcription by 11 and 7.7 fold, respectively. Artesunate, artemisone and DHA inhibited haemozoin-induced NF-κB driven transcription by 28%, 34%, and 49%, respectively. Similarly the derivatives, but not artemisinin, prevented TNFα-induced NF-κB driven transcription by 47-51%. The study indicates that artemisinins may attenuate the inflammatory potential of monocytes in vivo. Thus, in addition to direct anti-parasitic activities, the beneficial clinical effects of artemisinins for the treatment of malaria include the apparent ability to attenuate the inflammatory response, thus limiting the risk of progression to the more severe form of the disease, including the onset of cerebral malaria.
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Magenta
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Sangiovanni
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milano, Italy. Electronic address: nicoletta.basilico@unimi.it.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Basilico
authors.affiliation: Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom 2520, South Africa; Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, PR China.
authors.forename: Richard K
authors.initials: RK
authors.lastname: Haynes
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Parapini
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Colombo
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Bosisio
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Taramelli
authors.affiliation: Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Dell'Agli
mesh_terms: D037621:Artemisinins / Q000494:pharmacology*; D000077332:Artesunate; D016207:Cytokines / Q000096:biosynthesis; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D018836:Inflammation Mediators / Q000494:pharmacology*; D016779:Malaria, Cerebral / Q000469:parasitology; D016778:Malaria, Falciparum / Q000469:parasitology; D020780:Matrix Metalloproteinase 9 / Q000235:genetics* / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects; D010963:Plasmodium falciparum / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D037621:Artemisinins; D016207:Cytokines; D018836:Inflammation Mediators; D012333:RNA, Messenger; D000077332:Artesunate; C039060:artenimol; C514498:artemisone; C031327:artemisinin; D020780:Matrix Metalloproteinase 9
keywords: Artemisinin derivatives; Haemozoin; Malaria; Metalloproteinase-9; NF-κB; Tumour necrosis factor alpha