Flavone-resistant Leishmania donovani overexpresses LdMRP2 transporter in the parasite and activates host MRP2 on macrophages to circumvent the flavone-mediated cell death
Authors: Rupkatha Mukhopadhyay
Souvik Sengupta
Hemanta K Majumder
Sourav Saha
Syamal Roy
Sayan Chowdhury
Amartya Mishra
Journal: Journal of Biological Chemistry (2014)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Drug Resistance; Flavonoids; Infectious Diseases; Leishmania; Multidrug Transporters.
Affiliations: From the Molecular Parasitology Laboratory and., Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Jadavpur, Kolkata 700032, India and., 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., From the Molecular Parasitology Laboratory and .

Abstract:  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. 

Retracted: No

PubPeer comments:
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 #1 The manuscript and the figures were revised as per reviewersu2019 decision. Although we made our best to answer all the comments and modify our figures, it might be possible that due to updating of old figures with revised ones we overlooked the control b-Tubulin gel image. We accept it as unintentional human-error. The 9-lane gel was for the gene (MRP2) that have differential expression pattern; and the 8-lane gel showed no such statistically significant variation among the different groups and it would not alter the conclusion from the figure. We have done the experiment multiple times by RT-PCR (gel based) as well as Real-time PCR and flow cytometry analysis. The interpretation was similar from all the experiments done. , 
 #2 Thank you for your response. Will you be contacting the journal to correct the published figure? , 
 #1 Commenter Cucumaria Echinata suggests that there are really only 7 lanes in the loading control, as the 7th and 8th lanes are essentially copies. Here I have tried to highlight the similarity of those lanes by increasing image lightness; then increasing it again, so that the background texture is visible. ![file] ,