Role of Efflux Pumps and Intracellular Thiols in Natural Antimony Resistant Isolates of Leishmania donovani

Rai, Smita; Bhaskar,; Goel, Sudhir K.; Dwivedi, Upendra N.; Sundar, Shyam; Goyal, Neena

doi:10.1371/journal.pone.0074862

Cited by 43 publications

(49 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…MRPA from Leishmania is one of the best-known ABC transporters implicated in antimony resistance through the sequestration of Sb III -thiol complexes within an intracellular organelle near the flagellar pocket and then expulsion from the parasite by exocytosis (3). The levels of antimony efflux obtained for LABCG2 are slightly higher than the ones observed for MRPA (35) but lower than those for other MDR pumps (36,37), suggesting similar mechanisms of action for MRPA and LABCG2. To the best of our III and pelleted at different time points.…”

Section: Resultsmentioning

confidence: 54%

The LABCG2 Transporter from the Protozoan Parasite Leishmania Is Involved in Antimony Resistance

Perea

Manzano

Castanys

et al. 2016

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Treatment for leishmaniasis, which is caused by Leishmania protozoan parasites, currently relies on a reduced arsenal of drugs. However, the significant increase in the incidence of drug therapeutic failure and the growing resistance to first-line drugs like antimonials in some areas of Northern India and Nepal limit the control of this parasitic disease. Understanding the molecular mechanisms of resistance in Leishmania is now a matter of urgency to optimize drugs used and to identify novel drug targets to block or reverse resistant mechanisms. Some members of the family of ATP-binding cassette (ABC) transporters in Leishmania have been associated with drug resistance. In this study, we have focused our interest to characterize LABCG2's involvement in drug resistance in Leishmania. Leishmania major parasites overexpressing the ABC protein transporter LABCG2 were generated in order to assess how LABCG2 is involved in drug resistance. Assays of susceptibility to different leishmanicidal agents were carried out. Analysis of the drug resistance profile revealed that Leishmania parasites overexpressing LABCG2 were resistant to antimony, as they demonstrated a reduced accumulation of Sb III due to an increase in drug efflux. Additionally, LABCG2 was able to transport thiols in the presence of Sb III . Biotinylation assays using parasites expressing LABCG2 fused with an N-terminal green fluorescent protein tag revealed that LABCG2 is partially localized in the plasma membrane; this supports data from previous studies which suggested that LABCG2 is localized in intracellular vesicles that fuse with the plasma membrane during exocytosis. In conclusion, Leishmania LABCG2 probably confers antimony resistance by sequestering metal-thiol conjugates within vesicles and through further exocytosis by means of the parasite's flagellar pocket.

show abstract

Section: Resultsmentioning

confidence: 54%

The LABCG2 Transporter from the Protozoan Parasite Leishmania Is Involved in Antimony Resistance

Perea

Manzano

Castanys

et al. 2016

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…The suggested mechanisms include decreased uptake, increased efflux/sequestration, and modulation of the unique parasite thiol metabolism (8,9). These studies also inferred that natural antimonial resistance is multifactorial and hence requires wider exploration.…”

mentioning

confidence: 94%

MAPK1 of Leishmania donovani Modulates Antimony Susceptibility by Downregulating P-Glycoprotein Efflux Pumps

Garg

Goyal

2015

Antimicrob Agents Chemother

Self Cite

View full text Add to dashboard Cite

Emergence of resistance to pentavalent antimonials has become a severe obstacle in the treatment of visceral leishmaniasis (VL) in the Indian subcontinent. Mitogen-activated protein kinases (MAPKs) are well-known mediators of signal transduction of eukaryotes, regulating important processes, like proliferation, differentiation, stress response, and apoptosis. In Leishmania, MAPK1 has been shown to be consistently downregulated in antimony-resistant field isolates, suggesting that it has a role in antimony resistance. The present work investigates the molecular mechanism of MAPK1 in antimony resistance in Leishmania donovani. The L. donovani MAPK1 (LdMAPK1) single-allele replacement mutants exhibited increased resistance to Sb(III) (5.57-fold) compared to wild-type promastigotes, while overexpressing parasites became much more susceptible to antimony. The LdMAPK1-mediated drug sensitivity was directly related to antimony-induced apoptotic death of the parasite, as was evidenced by a 4-to 5-fold decrease in cell death parameters in deletion mutants and a 2-to 3-fold increase in MAPK1-overexpressing cells. LdMAPK1-underexpressing parasites also exhibited increased P-glycoprotein (P-gp)-mediated efflux pump activity, while a significant decrease in pump activity was observed in overexpressing cells. This change in efflux pump activity was directly related to expression levels of P-gp in all cell lines. However, episomal complementation of the gene restored normal growth, drug sensitivity, P-gp expression, and efflux pump activity. The data indicate that LdMAPK1 negatively regulates the expression of P-glycoprotein-type efflux pumps in the parasite. The decrease in efflux pump activity with an increase in Ld-MAPK1 expression may result in increased antimony accumulation in the parasite, making it more vulnerable to the drug. L eishmania, a protozoan parasite, causes leishmaniasis, a group of diseases with clinical manifestations that range from selfhealing cutaneous and mucocutaneous skin ulcers to a fatal visceral form (visceral leishmaniasis [VL]). The disease imposes a significant burden of mortality and morbidity, affecting 12 million people in more than 88 countries in tropical and subtropical zones of the world (1). Since antileishmanial vaccines are still under development, control of the disease is dependent mostly on chemotherapy (2). However, the efficacy of Sb(V), the first-line treatment, is now threatened by the emergence of drug-resistant Leishmania parasites, as described in several regions of endemicity (3-5). During the last decade, several novel formulations of conventional antileishmanials, as well as new drugs, including the oral agent miltefosine, became available or were under investigation. However, their widespread use in poor countries is hindered by their high cost and also by concerns about toxicity and the emergence of resistance (6, 7). The present-day requirement in the treatment of leishmaniasis is to battle escalating lack of responsiveness to antimony, and hence, an urgent need exists...

show abstract

“…[12][13][14][15] The multidrug resistance (MDR1) gene expresses a transmembrane efflux pump (the P-glycoprotein molecule, Pgp 170 [16][17][18] ), which appears to play a key role in the phenomenon of drug resistance. 15,18 Control of the disease relies principally on chemotherapy, both in patients and dogs, 19 and antimony has been the main drug to combat the disease in the last 65 years. Antimony-resistant Leishmania strains have been reported from many endemic areas, worldwide, reaching epidemic proportions in the state of Bihar, India 20,21 and the phenomenon appears to be intensifying and geographically spreading.…”

Section: Introductionmentioning

confidence: 99%

“…15,18 This pump is effective for a diverse group of lipophilic compounds [15][16][17] and the higher the number of the Pgp 170 molecules on the cell membrane, the greater the ability of the isolate to expel the compound from its body. 14,18,[22][23][24] Our aim was to evaluate the MDR1 expression of Leishmania in Greece and Cyprus and present it geographically to assess the distribution of drug resistance and give the clinicians the knowledge required for effective treatment, which will safeguard against the expansion of this phenomenon.…”

Section: Introductionmentioning

confidence: 99%

Geographical Distribution of MDR1 Expression in Leishmania Isolates, from Greece and Cyprus, Measured by the Rhodamine-123 Efflux Potential of the Isolates, Using Flow Cytometry

Tsirigotakis

Christodoulou

Ntais

et al. 2016

The American Society of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

Abstract. Leishmaniasis, a neglected vector-borne disease caused by the protozoan parasite Leishmania, is encountered in 98 countries causing serious concerns to public health. The most alarming is the development of parasite drug resistance, a phenomenon increasingly encountered in the field rendering chemotherapy ineffective. Although resistance to drugs is a complex phenomenon, the rate of efflux of the fluorescent dye Rhodamine-123 from the parasite body, using flow cytometry, is an indication of the isolate's ability to efflux the drug, thus avoiding death. The rate of efflux measured 275 Leishmania strains, isolated from patients and dogs from Greece and Cyprus, was measured and mapped to study the geographical distribution of the multidrug resistance (MDR) gene expression as an indication of the drug resistance of the parasite. The map showed that out of the seven prefectures, where dogs presented high efflux rates, five also had patients with high efflux rates. In one, out of the 59 prefectures studied, the highest number of isolates with efflux slope α > 1, in both human and dog isolates, was found; a fact which may suggest that spread of drug resistance is taking place. The virulence of the Leishmania strains, assessed after infecting human macrophages of the THP-1 cell line, fluctuated from 1% to 59.3% with only 2.5% of the isolates showing infectivity > 50%. The most virulent strains were isolated from Attica and Crete.

show abstract

Role of Efflux Pumps and Intracellular Thiols in Natural Antimony Resistant Isolates of Leishmania donovani

Cited by 43 publications

References 78 publications

The LABCG2 Transporter from the Protozoan Parasite Leishmania Is Involved in Antimony Resistance

The LABCG2 Transporter from the Protozoan Parasite Leishmania Is Involved in Antimony Resistance

MAPK1 of Leishmania donovani Modulates Antimony Susceptibility by Downregulating P-Glycoprotein Efflux Pumps

Geographical Distribution of MDR1 Expression in Leishmania Isolates, from Greece and Cyprus, Measured by the Rhodamine-123 Efflux Potential of the Isolates, Using Flow Cytometry

Contact Info

Product

Resources

About