Effect Of Chloroquine Treatment Research Articles

Chloroquine disrupts zinc storage granules in primary Malpighian tubule cells of Drosophila melanogaster.

Contrasting reports exist in the literature regarding the effect of chloroquine treatment on cellular zinc uptake or secretion. Here, we tested the effect of chloroquine administration in the Drosophila model organism. We show that larvae grown on a diet supplemented with 2.5mg/ml chloroquine lose up to 50% of their stored zinc and around 10% of their total potassium content. This defect in chloroquine-treated animals correlates with the appearance of abnormal autophagolysosomes in the principal cells of the Malpighian tubules, where zinc storage granules reside. We further show that the reported increase of Fluozin-3 fluorescence following treatment of cells with 300 μM chloroquine for 1 h may not reflect increased zinc accumulation, since a similar treatment in Madin-Darby canine kidney cells results in a 36% decrease in their total zinc content. Thus, chloroquine should not be considered a zinc ionophore. Zinc supplementation plus chloroquine treatment restored zinc content both in vivo and in vitro, without correcting autophagic or other ionic alterations, notably in potassium, associated with the chloroquine treatment. We suggest that chloroquine or hydroxychloroquine administration to patients could reduce intracellular zinc storage pools and be part of the drug's mechanism of action.

Melatonin mitigates Chloroquine-induced defects in porcine immature Sertoli cells

Chloroquine (CQ) could function as a lysosomotropic agent to inhibit the endolysosomal trafficking in the autophagy pathway, and is widely used on malarial, tumor and recently COVID-19. However, the effect of CQ treatment on porcine immature Sertoli cells (iSCs) remains unclear. Here we showed that CQ could reduce iSC viability in a dose-dependent manner. CQ treatment (20 μM) on iSCs for 36h could elevate oxidative stress, damage mitochondrial function and promote apoptosis, which could be partially rescued by melatonin (MT) (10 nM). Transcriptome profiling identified 1611 differentially expressed genes (DEGs) (776 up- and 835 down-regulated) (20 μM CQ vs. DMSO), mainly involved in MAPK cascade, cell proliferation/apoptosis, HIF-1, PI3K-Akt and lysosome signaling pathways. In contrast, only 467 (224 up- and 243 down-regulated) DEGs (CQ + MT vs. DMSO) could be found after MT (10 nM) addition, enriched in cell cycle, regulation of apoptotic process, lysosome and reproduction pathways. Therefore, the partial rescue effects of MT on CQ treatment were confirmed by multiple assays (cell viability, ROS level, mitochondrial function, apoptosis, and mRNA levels of selected genes). Collectively, CQ treatment could impair porcine iSC viability by deranging the signaling pathways related to apoptosis and autophagy, which could be partially rescued by MT supplementation.

Effect of chloroquine treatment on cardiac function as well as cardiac atrial natriuretic peptide level in Bcl-2-associated athanogene (BAG) 3 transgenic mice

Effect of chloroquine treatment on cardiac function as well as cardiac atrial natriuretic peptide level in Bcl-2-associated athanogene (BAG) 3 transgenic mice

Holographic analysis on deformation and restoration of malaria-infected red blood cells by antimalarial drug.

Malaria parasites induce morphological, biochemical, and mechanical changes in red blood cells (RBCs). Mechanical variations are closely related to the deformability of individual RBCs. The deformation of various RBCs, including healthy and malaria-infected RBCs (iRBCs), can be directly observed through quantitative phase imaging (QPI). The effects of chloroquine treatment on the mechanical property variation of iRBCs were investigated using time-resolved holographic QPI of single live cells on a millisecond time scale. The deformabilities of healthy RBCs, iRBCs, and drug-treated iRBCs were compared, and the effect of chloroquine on iRBC restoration was experimentally examined. The present results are beneficial to elucidate the dynamic characteristics of iRBCs and the effect of the antimalarial drug on iRBCs.

The effect of chloroquine treatment in malignant astrocytomas on prognosis

To investigate the adjuvant role of the antimutagenic agent chloroquine in the treatment of patients with malignant astrocytomas (MAs). Materials and methods: Clinical research was conducted at the Neurosurgery Clinic of the Erciyes University School of Medicine, from September 2003 to April 2007, on 37 patients diagnosed with MA after tumor resection subsequent to craniotomy. Chloroquine treatment was started on a daily dose of 150 mg, additional to the patients' radiotherapy and chemotherapy protocol, and was continued throughout the 43-month surveillance period. A control group was formed of 81 patients with MA after the craniotomy. Results: While the mean survival time of the patients who were treated with chloroquine was found to be 15 months, during the observation period 7 of these patients (18.9%) were alive throughout. In the control group, 20 patients (35.1%) were alive throughout the observation period and their mean survival time was 17 months. There were no statistical differences between the control and chloroquine groups (P > 0.05). Conclusion: The chloroquine treatment was not been found to be effective for the medical treatment of MAs.

Chloroquine treatment reduces the number of cutaneous HLA-DR+ and CD1a+ cells in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that can be exacerbated by exposure to ultraviolet radiation (UVR). The number and phenotype of antigen presenting cells in the skin play a role in cutaneous immune response generation. Although antimalarials are widely used in SLE treatment, their mode of action is not completely elucidated. The aim of our study was to determine the effect of chloroquine treatment on HLA-DR+ and CD1a+ cell number in locally irradiated (three minimal erythema doses of UVB) and normal appearing skin in SLE patients and healthy subjects. A significantly higher number of HLA-DR+ and CD1a+ cells were found in both locations in SLE patients compared with controls. Following three months of daily chloroquine treatment (250 mg), the HLA-DR+ and CD1a+ cell counts were significantly reduced in both irradiated and unirradiated sites of SLE patients, although still higher than in controls. Chloroquine treatment reduces the number of antigen presenting cells in the skin of SLE patients, and this effect may explain the antimalarials beneficial immunoregulatory and anti-inflammatory properties.

The effect of chloroquine treatment on the infectivity of Plasmodium chabaudi gametocytes

The antimalarial drug chloroquine has been reported to increase the infectivity of the forms of blood-stage malaria parasites (gametocytes) that are capable of infecting mosquito vectors. This effect has been demonstrated convincingly in the short term (12 h post treatment), although several authors have suggested infectivity enhancement a week or more after treatment. We carried out experiments to investigate the effects of chloroquine on the longer-term infectivity of gametocytes of the rodent malaria parasite, Plasmodium chabaudi, to Anopheles stephensi mosquitoes. Gametocytes of chloroquine-treated infections were significantly more infectious than untreated infections 6 and 7 days post-treatment, although not on days 8 and 9. However, this effect was most likely the result of a reduction in infectivity in untreated infections, caused by immune activity which was not so pronounced in chloroquine-treated infections. Gametocytaemia (gametocytes per r.b.c.) showed a strong positive and linear relationship with infectivity. Infectivity was not influenced by either asexual parasitaemia, asexual density or anaemia. Parsimonious interpretations of the effect of chloroquine on gametocyte infectivity are discussed.

Effects of Chloroquine Treatment on Antioxidant Enzymes in Rat Liver and Kidney

The effect of chloroquine (CHQ) administration on antioxidant enzymes in rat liver and kidney was studied. Male Sprague–Dawley rats were administered 20 mg/kg CHQ once a week for 4 weeks (chronic treatment) or a single dose at 10 or 20 mg/kg (acute treatment). Antioxidant enzyme activities were determined in cytosolic fractions of liver and kidney, whereas reduced glutathione (GSH) and malondialdehyde (MDA) were determined in tissue samples. Results indicate minimal effects of acute CHQ treatment, whereas chronic treatment with CHQ differentially affected antioxidant enzymes in the two organs. Superoxide dismutase activity was increased nearly twofold, while activities of selenium glutathione peroxidase (GPX), catalase, and NAD (P) H: quinone oxidoreductase were decreased in livers of CHQ-treated rats compared to controls. No significant effects of CHQ on glutathione reductase, GSH, and MDA levels were seen in the liver. Fewer effects of CHQ were observed in the kidney where a decrease in GPX activity and an increase in MDA levels was seen. Lowering of antioxidant enzymes activities in the liver by CHQ could render the organ more susceptible to subsequent oxidative stress; while increased MDA production after CHQ treatment in the kidney indicate that the organ is being subjected to oxidative stress. This could have implications for prolonged chloroquine intake. Copyright © 1996 Elsevier Science Inc.

Sulfated N-linked oligosaccharides affect secretion but are not essential for the transport, proteolytic processing, and sorting of lysosomal enzymes in Dictyostelium discoideum.

Although previous studies have indicated that N-linked oligosaccharides on lysosomal enzymes in Dictyostelium discoideum are extensively phosphorylated and sulfated, the role of these modifications in the sorting and function of these enzymes remains to be determined. We have used radiolabel pulse-chase, subcellular fractionation, and immunofluorescence microscopy to analyze the transport, processing, secretion, and sorting of two lysosomal enzymes in a mutant, HL244, which is almost completely defective in sulfation. [3H]Mannose-labeled N-linked oligosaccharides were released from immunoprecipitated alpha-mannosidase and beta-glucosidase of HL244 by digestion with peptide: N-glycosidase. The size, Man9-10GlcNAc2, and processing of the neutral species were similar to that found in the wild type, but the anionic oligosaccharides were less charged than those from the wild-type enzymes. All of the negative charges on the oligosaccharides for HL244 were due to the presence of 1, 2, or 3 phosphodiesters and not to sulfate esters. The rate of proteolytic processing of precursor forms of alpha-mannosidase and beta-glucosidase to mature forms in HL244 was identical to wild type. The precursor polypeptides in the mutant and the wild type were membrane associated until being processed to mature forms; therefore, sulfated sugars are not essential for this association. Furthermore, the rate of transport of alpha-mannosidase and beta-glucosidase from the endoplasmic reticulum to the Golgi complex was normal in the mutant as determined by the rate at which the newly synthesized proteins became resistant to the enzyme, endo-beta-N-acetylglucosaminidase H. There was no increase in the percentage of newly synthesized mutant precursors which escaped sorting and were secreted, and the intracellularly retained lysosomal enzymes were properly localized to lysosomes as determined by fractionation of cell organelles on Percoll gradients and immunofluorescence microscopy. However, the mutant secreted lysosomally localized mature forms of the enzymes at 2-fold lower rates than wild-type cells during both growth and during starvation conditions that stimulate secretion. Furthermore, the mutant was more resistant to the effects of chloroquine treatment which results in the missorting and oversecretion of lysosomal enzymes. Together, these results suggest that sulfation of N-linked oligosaccharides is not essential for the transport, processing, or sorting of lysosomal enzymes in D. discoideum, but these modified oligosaccharides may function in the secretion of mature forms of the enzymes from lysosomes.

A study of HLA (Bg) on red cells and platelets by immunoblotting with monoclonal antibodies

HLA class I antigens (Bg) on red cells (RBCs) are expressed by some normal donors and by many patients with systemic lupus erythematosus (SLE). To identify the membrane components previously detected by hemagglutination with HLA class I-specific monoclonal antibodies (MoAbs), RBC membrane preparations were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotted with the HLA class I MoAbs. Two components were obtained that reacted with the MoAbs: a heavy chain of 45 kDa and a light chain termed beta2-microglobulin (beta2-M) of 11 kDa. The effect of chloroquine and acid elution in stripping HLA antigens is shown to be due to the removal of beta2-M, as only that component was detected in eluates from reactive RBCs. Neither antibody elution method affected the heavy chain expression assessed by immunoblotting. It is concluded that HLA class I antigens on RBCs are integral membrane components of the type normally found and wisely distributed on many nucleated cells. Platelets, which have stronger HLA class I antigen expression, were also studied, and their membrane preparations yielded heavy chain and beta2-M molecules; the effect of chloroquine treatment was harder to assess than that of acid elution, owing to the sensitivity with which both components are detected in immunoblotting. In eluates obtained from acid treatment only beta2-M is detected.

Quantitation of platelet antigens after chloroquine treatment

The effect of chloroquine treatment on the expression of various platelet antigens was studied. For this purpose, the binding of several human platelet-reactive antibodies (polyspecific HLA antibodies; platelet-specific PlA1, PlA2, Baka antibodies; platelet autoantibodies) and of murine monoclonal antibodies specific for epitopes on the glycoprotein (Gp) complexes IIb/IIIa or Ib/IX were quantitated by means of a competitive enzyme-linked immunoassay (CELIA) using fresh and stored chloroquine-treated platelets. We found that HLA antigens were substantially removed from platelets following chloroquine treatment (confirming earlier results) while platelet-specific antigens on the Gp complex IIb/IIIa were but little affected. Epitopes on the Gp complex Ib/IX did not show any alteration. Storage of chloroquine-treated panel platelets known to interfere with immunofluorescence had no effect on quantitative IgG determinations by CELIA. We conclude that chloroquine treatment of platelets is practicable for platelet antibody analysis, but exerts its effect unspecifically and requires cautious interpretation.

Biochemical and ultrastructural effects of chloroquine on horseradish peroxidase uptake and lysosomal enzyme activities in innervated and denervated mouse skeletal muscle

The effects of chloroquine treatment on horseradish peroxidase (HRP) uptake and lysosomal enzyme activities in innervated and denervated mouse skeletal muscle have been studied using biochemical, histochemical and ultrastructural techniques. Chloroquine treatment caused a large (59–101%) increase in the activity of cathepsin D in both innervated and denervated muscle. The activity of N-acetyl-β- d-glucosaminidase also increased slightly in denervated muscle. No effect was observed on acid phosphatase activity. The in vivo uptake of HRP in innervated and denervated muscle was unaffected by chloroquine treatment. The results show that the activities of certain lysosomal enzymes may increase in skeletal muscle without an increase in endocytic activity. This is discussed in comparison to what is seen in denervated and dystrophic muscle. Histochemical and ultrastructural studies showed the HRP uptake to occur segmentally in denervated muscle fibres from untreated as well as chloroquine-treated animals. Ultrastructurally the peroxidase-positive phagosomes occurring in these segments were found to contain increased levels of undegraded material after chloroquine treatment suggesting that these phagosomes are of a lysosomal nature and also participate in autophagic processes.

Effect of chloroquine treatment on the different phospholipid species of rat liver lysosomes.

The lysosomal phospholipids of rat liver were determined after treatment of the animals with chloroquine for varying periods up to 15 days. During this period, all the measured phospholipids increased. After two weeks of treatment the absolute level of each phospholipid had increased 3 to 6-fold, with the exception of bis(monoacylglycero)phosphate which was increased 25-fold, accounting for one third of the total phospholipids. The fatty acid pattern not only differed between the classes of lipids; it changed during treatment within every lipid class. In addition to other changes, the polyenoic fatty acids of the main glycerophospholipids were markedly reduced between the 3rd and 14th day of chloroquine treatment: to one half in phosphatidylcholine, to about one tenth in phosphatidylethanolamine, and to one quarter in phosphatidylinositol. However, the polyenoic fatty acid content of bis(monoacylglycero)phosphate was doubled, reaching 76% of the total at the end of treatment. Whereas docosahexaenoic acid was not detected in this acidic phospholipid in the first 3 days of treatment, it was present to the extent of 55% of the total fatty acids after 15 days of chloroquine application;

Studies on T and B lymphocytes in the peripheral blood of discoid lupus erythematosus patients with and without chloroquine treatment

The proportions of T-B cells of peripheral lymphocytes in DLE patients as well as the effect of chloroquine treatment on T cell count were studied. In DLE, both the active and the total rosette-forming cell counts decreased, whereas the B cell count did not differ from normal values. Long-term chloroquine administration causes a further reduction in T cell count.