Flavone-resistant Leishmania donovani overexpresses LdMRP2 transporter in the parasite and activates host MRP2 on macrophages to circumvent the flavone-mediated cell death.
In parasites, ATP-binding cassette (ABC) transporters represent an important family of proteins related to drug resistance and other biological activities. Resistance of leishmanial parasites to therapeutic drugs continues to escalate in developing countries, and in many instances, it is due to overexpressed ABC efflux pumps. Progressively adapted baicalein (BLN)-resistant parasites (pB(25)R) show overexpression of a novel ABC transporter, which was classified as ABCC2 or Leishmania donovani multidrug resistance protein 2 (LdMRP2). The protein is primarily localized in the flagellar pocket region and in internal vesicles. Overexpressed LdABCC2 confers substantial BLN resistance to the parasites by rapid drug efflux. The BLN-resistant promastigotes when transformed into amastigotes in macrophage cells cannot be cured by treatment of macrophages with BLN. Amastigote resistance is concomitant with the overexpression of macrophage MRP2 transporter. Reporter analysis and site-directed mutagenesis assays demonstrated that antioxidant response element 1 is activated upon infection. The expression of this phase II detoxifying gene is regulated by NFE2-related factor 2 (Nrf2)-mediated antioxidant response element activation. In view of the fact that the signaling pathway of phosphoinositol 3-kinase controls microfilament rearrangement and translocation of actin-associated proteins, the current study correlates with the intricate pathway of phosphoinositol 3-kinase-mediated nuclear translocation of Nrf2, which activates MRP2 expression in macrophages upon infection by the parasites. In contrast, phalloidin, an agent that prevents depolymerization of actin filaments, inhibits Nrf2 translocation and Mrp2 gene activation by pB(25)R infection. Taken together, these results provide insight into the mechanisms by which resistant clinical isolates of L. donovani induce intracellular events relevant to drug resistance.
From the Molecular Parasitology Laboratory and.
Sayan
S
Chowdhury
Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Jadavpur, Kolkata 700032, India and.
Rupkatha
R
Mukhopadhyay
From the Molecular Parasitology Laboratory and.
Sourav
S
Saha
From the Molecular Parasitology Laboratory and.
Amartya
A
Mishra
Laboratory of Molecular Biology, Department of Physical Chemistry, Indian Association for the Cultivation of Sciences, 2A and 2B Raja S. C. Mullick Road, Kolkata 700032, India.
Souvik
S
Sengupta
Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Jadavpur, Kolkata 700032, India and.
Syamal
S
Roy
From the Molecular Parasitology Laboratory and hkmajumder@iicb.res.in.
Hemanta K
HK
Majumder
D000818:Animals; D001483:Base Sequence; D016923:Cell Death / Q000187:drug effects*; D002460:Cell Line; D017931:DNA Primers; D024202:Electrophoretic Mobility Shift Assay; D047309:Flavones / Q000494:pharmacology*; D007893:Leishmania donovani / Q000187:drug effects* / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D051379:Mice; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D047309:Flavones; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins
Drug Resistance; Flavonoids; Infectious Diseases; Leishmania; Multidrug Transporters