RESUMEN
Melanoma is one of the most consequential skin cancer with a rising death incidences. Silent but belligerent nature of metastatic sprouting is the leading cause of melanoma related mortality. Invasion of metastatic cells and re-expression of E-Cadherin play the crucial role in the establishment of secondary tumor at distal sites. Thus, manipulation of tumor cell invasion in parallel to regulation of E-Cadherin expression can be considered as potential anti-metastatic strategy. Evidences suggested key role of reactive oxygen species associated ROCK activities in the modulation of metastatic invasion via F-actin stabilization. Here, we first-time report Decylubiquinone, a dietary Coenzyme Q10 analog, as an effective attenuator of pulmonary metastatic melanoma in C57BL/6 mice. Current study depicted detailed molecular interplay associated with Decylubiquinone mediated phosphorylation of ROCKII at Tyr722 along with reduced phosphorylation of ROCKII Ser1366 leading to suppression of Limk1/2-Cofilin-F-actin stabilization axis that finally restricted B16F10 melanoma cell invasion at metastatic site. Analysis further deciphered the role of HNF4α as its nuclear translocation modulated E-Cadherin expression, the effect of reactive oxygen species dependent ROCKII activity in secondarily colonized B16F10 melanoma cells at lungs. Thus unbosoming of related signal orchestra represented Decylubiquinone as a potential remedial agent against secondary lung melanoma.
Asunto(s)
Neoplasias Pulmonares , Melanoma Experimental , Melanoma , Ratones , Animales , Actinas , Especies Reactivas de Oxígeno , Línea Celular Tumoral , Ratones Endogámicos C57BL , Cadherinas/metabolismo , Melanoma/metabolismo , Pulmón/metabolismo , Neoplasias Pulmonares/metabolismo , Metástasis de la Neoplasia/patología , Melanoma Experimental/patología , Movimiento CelularRESUMEN
Rho-associated coiled-coil kinase (ROCK) inhibition decreases tumourogenic growth, proliferation and angiogenesis. Multifaceted evidences are there about the role of ROCK in cancer progression, but isoform specific analysis in secondary pulmonary melanoma is still unaddressed. This study explored the operating function of ROCK in the metastasis of B16F10 mice melanoma cell line. Inhibition by KD-025 indicated dual wielding role of ROCKII as it is associated with the regulation of MMP9 activity responsible for extra-cellular matrix (ECM) degradation as well as angiogenic invasion as an effect of Src-FAK-STAT3 interaction dependent VEGF switching. We found the assisting role of ROCKII, not ROCKI in nuclear localization of Smads that effectively increased MMP9 expression and activity (p < 0.01). This cleaved the protein components of ECM thereby played a crucial role in tissue remodeling at secondary site during establishment of metastatic tumour. ROCKII phosphorylation at Ser1366 as an activation of the same was imprinted essential for oncogenic molecular bagatelle leading to histo-architectural change of pulmonary tissue with extracellular matrix degradation as a consequence of invasion. Direct correlation of pROCKIISer1366 with MMP9 as well as VEGF expression in vivo studies cue to demonstrate the importance of pROCKIISer1366 inhibition in the context of angiogenesis, and metastasis suggesting ROCKII signaling as a possible target for the treatment of secondary lung cancer specially in metastatic melanoma.
Asunto(s)
Neoplasias Pulmonares , Melanoma , Quinasas Asociadas a rho , Animales , Movimiento Celular/fisiología , Neoplasias Pulmonares/secundario , Metaloproteinasa 9 de la Matriz , Melanoma/patología , Ratones , Neovascularización Patológica , Proteínas Smad , Factor A de Crecimiento Endotelial Vascular , Quinasas Asociadas a rho/metabolismoRESUMEN
COVID-19 pandemic is still a major risk to human civilization. Besides the global immunization policy, more than five lac new cases are documented everyday. Some countries newly implement partial/complete nationwid lockdown to mitigate recurrent community spreading. To avoid the new modified stain of SARS-CoV-2 spreading, some countries imposed any restriction on the movement of the citizens within or outside the country. Effective economical point of care diagnostic and therapeutic strategy is vigorously required to mitigate viral spread. Besides struggling with repurposed medicines, new engineered materials with multiple unique efficacies and specific antiviral potency against SARS-CoV-2 infection may be fruitful to save more lives. Nanotechnology-based engineering strategy sophisticated medicine with specific, effective and nonhazardous delivery mechanism for available repurposed antivirals as well as remedial for associated diseases due to malfeasance in immuno-system e.g. hypercytokinaemia, acute respiratory distress syndrome. This review will talk about gloomy but critical areas for nanoscientists to intervene and will showcase about the different laboratory diagnostic, prognostic strategies and their mode of actions. In addition, we speak about SARS-CoV-2 pathophysiology, pathogenicity and host specific interation with special emphasis on altered immuno-system and also perceptualized, copious ways to design prophylactic nanomedicines and next-generation vaccines based on recent findings.
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COVID-19/terapia , Nanomedicina Teranóstica/métodos , Animales , Antivirales/administración & dosificación , Antivirales/uso terapéutico , COVID-19/diagnóstico , COVID-19/inmunología , COVID-19/patología , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/uso terapéutico , Sistemas de Liberación de Medicamentos/métodos , Humanos , Inmunización/métodos , Nanotecnología/métodos , Medicina de Precisión/métodos , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/inmunología , SARS-CoV-2/aislamiento & purificaciónRESUMEN
Bioactive components of dietary phytochemicals have been reported to possess antitumor activities. Evidences suggested key role of stress responsive p38MAPK in the induction of nutraceuticals mediated apoptosis in hepatocellular carcinoma (HCC). Current study demonstrated detailed molecular bagatelle associated with p38 MAPK mediated effective suppression of cell growth both in HepG2 and chemically induced liver carcinoma after S-allyl cysteine (SAC) treatment. SAC promoted p38MAPK activity responsible for p53 phosphorylation, its stabilization followed by nuclear translocation leading to induction in expression and oligomerization of Fas protein. Distinctive p38MAPK-p53 axis dependent Fas-FasL-FADD mediated caspase activities along with perturbed cell cycling became normalized with continuation of SAC treatment for another month to diethylnitrosamine induced liver carcinoma. Co-treatment with SB203580, the p38MAPK inhibitor, prevented pro-apoptotic effect of SAC by altering p53 phosphorylation and death inducing signaling complex conformation in HepG2 and induced HCC. Collectively study suggested significant contribution of p38MAPK-p53-DISC-Caspase pathway in the regulation of anti-neoplastic activity of SAC against HCC.
Asunto(s)
Antineoplásicos/farmacología , Cisteína/análogos & derivados , Neoplasias Hepáticas Experimentales/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Antineoplásicos/uso terapéutico , Caspasas/metabolismo , Cisteína/farmacología , Cisteína/uso terapéutico , Proteína Ligando Fas/metabolismo , Células Hep G2 , Humanos , Imidazoles/farmacología , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/enzimología , Neoplasias Hepáticas Experimentales/patología , Masculino , Ratones , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , Proteína p53 Supresora de Tumor/metabolismo , Receptor fas/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidoresRESUMEN
Andrographolide regimen in single or in combination with anticancer drugs is a promising new strategy to reverse chemoresistance in heaptocellular carcinoma. Apoptosis inducing factor (AIF) may regulate a complementary, cooperative or redundant pathway, along with caspase cascades. Despite these findings, mechanisms underlying caspase-dependent and-independent signaling pathways in andrographolide -induced apoptosis in cisplatin-resistant human hepatocellular carcinoma cell line (HepG2CR) remain unclear. Andrographolide treatment effectively reduced NF-κß nuclear localization by modulating protein kinase A- protein phosphatase 2 A- Iκß kinase (PKA/PP2 A/IKK) axis that in turn maintains initiator caspase8 activity. Lysosomal distribution of tBid stimulates cytosolic cathepsin B resulting accumulation of truncated-AIF with induction in scramblase mediated phosphatidylserine exposure in HepG2CR cells. Andrographolide treatment thereby switch on subG1 phase arrest by modulating cellular check points (cyclin A, B, cyclin dependent kinase-1) cueing to the apoptosis event. Collectively, this study suggested antineoplastic potential of andrographolide through PKA/PP2 A/IKK pathway in HepG2CR cells.
Asunto(s)
Antineoplásicos/farmacología , Catepsina B/metabolismo , Cisplatino/farmacología , Diterpenos/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Proteínas de Transferencia de Fosfolípidos/metabolismo , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/metabolismoRESUMEN
Cancer cells often have faulty apoptotic pathways resulting in sustenance of survivability, tumour metastasis and resistance to anticancer drugs. Alternate strategies are sought to improve therapeutic efficacy and therefore HepG2 cells were treated with S-allyl-cysteine (SAC) and berberine (BER) to analyze their mechanistic impact upon necroptosis along with its interacting relationship to apoptosis. In the present study we observed that SAC and BER exposure reduced NFκß nuclear translocation through adenylate cyclase-cAMP-protein kinaseA axis and eventually evaded c-FLIP inhibition. Effective RIP1 k63-polyubiquitination and persistent MKK3/MKK6 expression during drug treatment potentiated caspase8 activity via p53-DISC conformation. Resultant tBid associated lysosomal protease mediated AIF truncation induced DNA fragmentation and persuaded effector caspase mediated scramblase activation resulting induction of necroptosis in parallel to apoptotic events. SAC+BER effectively reduced Rb-phosphorylation resulting insignificant nuclear E2F presence led to ending of cell proliferation. Therefore necroptosis augmented the drug response and may be targeted alongside cell proliferation inhibition in formation of efficient therapeutics against liver cancer.
Asunto(s)
Adenilil Ciclasas/genética , Berberina/farmacología , Cisteína/análogos & derivados , MAP Quinasa Quinasa 3/genética , MAP Quinasa Quinasa 6/genética , Transducción de Señal , Adenilil Ciclasas/metabolismo , Apoptosis/efectos de los fármacos , Factor Inductor de la Apoptosis/genética , Factor Inductor de la Apoptosis/metabolismo , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/genética , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/metabolismo , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/genética , Proteína Reguladora de Apoptosis Similar a CASP8 y FADD/metabolismo , Caspasa 8/genética , Caspasa 8/metabolismo , Línea Celular , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/genética , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Cisteína/farmacología , Fragmentación del ADN/efectos de los fármacos , Combinación de Medicamentos , Regulación de la Expresión Génica , Células Hep G2 , Humanos , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , MAP Quinasa Quinasa 3/metabolismo , MAP Quinasa Quinasa 6/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Necrosis/inducido químicamente , Necrosis/genética , Necrosis/metabolismo , Proteínas de Complejo Poro Nuclear/genética , Proteínas de Complejo Poro Nuclear/metabolismo , Transporte de Proteínas , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
BACKGROUND: Diethylnitrosamine (DEN) and carbon tetrachloride (CCl4) have been used as initiator and promoter respectively to establish an animal model for investigating molecular events appear to be involved in development of liver cancer. Use of herbal medicine in therapeutics to avoid the recurrence of hepatocarcinoma has already generated considerable interest among oncologists. In this context studies involving S-allyl-cysteine (SAC) and berberine have come up with promising results. Here we have determined the individual effect of SAC and berberine on the biomolecules associated with DEN+CCl4 induced hepatocarcinoma. Effective therapeutic value of combined treatment has also been estimated. METHODS: ROS accumulation was analyzed by FACS following DCFDA incubation. Bcl2-Bax and HDAC1-pMdm2 interaction were demonstrated by co-immunoprecipitation. Immunosorbent assay was performed to analyze PP2A and caspase3 activities. MMP was determined cytofluorimetrically by investigating JC-1 fluorescence. AnnexinV binding was demonstrated by labeling the cells with AnV-FITC followed by flow cytometry. RESULTS: CytochromeP4502E1 mediated bioactivation of DEN+CCl4 induced Akt dependent pMdm2-HDAC1 interaction that led to p53 deacetylation, probable cause of its degradation. In parallel, oxidative stress dependent Nrf2-HO1 activation increased Bcl2 expression which in turn stimulated cell proliferation. SAC in combination with berberine inhibited Akt mediated cell proliferation. Activation of PP2A as well as inhibition of JNK resulted in induction of apoptosis after 30 days of treatment. Extension of combined treatment reverted tissue physiology towards control. Co-treated group displayed normal tissue structure. CONCLUSION AND GENERAL SIGNIFICANCE: SAC and berberine mediated HDAC1/Akt inhibition implicates the efficacy of combined treatment in the amelioration of DEN+CCl4 induced hepatocarcinoma.
Asunto(s)
Antineoplásicos/farmacología , Berberina/farmacología , Tetracloruro de Carbono/toxicidad , Carcinoma Hepatocelular/prevención & control , Cisteína/análogos & derivados , Dietilnitrosamina/toxicidad , Neoplasias Hepáticas/prevención & control , Alquilantes/toxicidad , Animales , Apoptosis/efectos de los fármacos , Western Blotting , Carcinoma Hepatocelular/inducido químicamente , Carcinoma Hepatocelular/metabolismo , Caspasa 3/metabolismo , Células Cultivadas , Cisteína/farmacología , Citocromo P-450 CYP2E1/metabolismo , Citocromos c/metabolismo , Citometría de Flujo , Hepatocitos/citología , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Histona Desacetilasa 1/metabolismo , Técnicas para Inmunoenzimas , Inmunoprecipitación , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/metabolismo , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Proteínas de Transporte de Membrana Mitocondrial , Poro de Transición de la Permeabilidad Mitocondrial , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
BACKGROUND: Chronic lead (Pb(2+)) exposure leads to the reduced lifespan of erythrocytes. Oxidative stress and K(+) loss accelerate Fas translocation into lipid raft microdomains inducing Fas mediated death signaling in these erythrocytes. Pathophysiological-based therapeutic strategies to combat against erythrocyte death were evaluated using garlic-derived organosulfur compounds like diallyl disulfide (DADS), S allyl cysteine (SAC) and imidazole based Gardos channel inhibitor clotrimazole (CLT). METHODS: Morphological alterations in erythrocytes were evaluated using scanning electron microscopy. Events associated with erythrocyte death were evaluated using radio labeled probes, flow cytometry and activity gel assay. Mass spectrometry was used for detection of GSH-4-hydroxy-trans-2-nonenal (HNE) adducts. Fas redistribution into the lipid rafts was studied using immunoblotting technique and confocal microscopy. RESULTS: Combination of SAC and CLT was better than DADS and CLT combination and monotherapy with these agents in prolonging the survival of erythrocytes during chronic Pb(2+) exposure. Combination therapy with SAC and CLT prevented redistribution of Fas into the lipid rafts of the plasma membrane and downregulated Fas-dependent death events in erythrocytes of mice exposed to Pb(2+). CONCLUSION AND GENERAL SIGNIFICANCE: Ceramide generation was a critical component of Fas receptor-induced apoptosis, since inhibition of acid sphingomyelinase (aSMase) interfered with Fas-induced apoptosis during Pb(2+) exposure. Combination therapy with SAC and CLT downregulated apoptotic events in erythrocytes by antagonizing oxidative stress and Gardos channel that led to suppression of ceramide-initiated Fas aggregation in lipid rafts. Hence, combination therapy with SAC and CLT may be a potential therapeutic option for enhancing the lifespan of erythrocytes during Pb(2+) toxicity.
Asunto(s)
Clotrimazol/farmacología , Cisteína/análogos & derivados , Eritrocitos/efectos de los fármacos , Intoxicación por Plomo/sangre , Receptor fas/metabolismo , Animales , Apoptosis , Cisteína/farmacología , Regulación hacia Abajo/efectos de los fármacos , Eritrocitos/metabolismo , Eritrocitos/patología , Femenino , Plomo/toxicidad , Intoxicación por Plomo/patología , Espectrometría de Masas , Ratones , Ratones Endogámicos BALB C , Especies Reactivas de Oxígeno , Transducción de SeñalRESUMEN
BACKGROUND: Evidence in the literature suggests that down-regulation of nitric oxide (NO) is associated with the pathophysiological conditions during visceral leishmaniasis (VL). Here we have investigated the mechanism that leads to the down regulation of systemic NO in the infected condition. Moreover, we have determined whether down regulation of NO is associated with increased generation of reactive oxygen species (ROS) during this disease. Therapeutic strategy targeting signaling molecules of these events was evaluated. METHODS: Plasma protein-nitrotyrosine was examined by ELISA kit. Generation of superoxides and peroxynitrites was investigated by flow cytometry. NO bioavailability in endothelial cells was evaluated using DAF-2DA fluorescence. Ceramide contents were evaluated using FACS analysis, HPTLC and HPLC. RESULTS: L. donovani infected reticulo-endothelial cells regulated the activity of eNOS and NAD(P)H oxidase in the endothelial cells through the generation of intercellular messenger, ceramide. Activation of SMases played an important role in the generation of ceramide in animals during chronic infection. These events led to generation of ROS within endothelial cells. Modulation of redox status of plasma and accumulation of ROS in endothelial cells were critically involved in the regulation of NO bioavailability in plasma of the infected animal. Endothelial dysfunction and decline of NO were resulted from an increased production of superoxide where upregulation of eNOS expression appeared as an ineffective compensatory event. Inhibition of ceramide generation increased NO bioavailability, prevented endothelial dysfunction and concomitant oxidative stress. CONCLUSION AND GENERAL SIGNIFICANCE: Decreased NO bioavailability and endothelial dysfunction were the downstream of ceramide signaling cascade. ROS accumulation promoted peroxynitrite generation and reduced NO bioavailability. Inhibition of ceramide generation may be a potential therapeutic option in preventing the co-morbidity associated with VL.
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Endotelio Vascular/fisiopatología , Homeostasis/fisiología , Leishmaniasis Visceral/fisiopatología , Animales , Western Blotting , Células Cultivadas , Ceramidas/sangre , Ceramidas/metabolismo , Cricetinae , Endotelio Vascular/citología , Endotelio Vascular/metabolismo , Citometría de Flujo , Glutatión/sangre , Disulfuro de Glutatión/sangre , Interacciones Huésped-Parásitos , Macrófagos del Hígado/metabolismo , Macrófagos del Hígado/parasitología , Leishmania donovani/fisiología , Leishmaniasis Visceral/sangre , Leishmaniasis Visceral/parasitología , Masculino , Mesocricetus , NADPH Oxidasas/metabolismo , Óxido Nítrico/sangre , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Oxidación-Reducción , Oxidorreductasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Esfingomielina Fosfodiesterasa/metabolismo , Superóxidos/metabolismo , Factores de TiempoRESUMEN
Long treatment regime with d-penicillamine is needed before it can exert clinically meaningful benefits in the treatment of copper toxicosis. The consequence of long-term d-penicillamine treatment is associated with numerous side effects. The limitations of d-penicillamine monotherapy prompted us to search for more effective treatment strategies that could decrease the duration of d-penicillamine therapy. The present study was designed to evaluate the therapeutic potential of d-penicillamine in combination with another hepatoprotective drug, andrographolide in treatment of copper toxicosis in rats. d-penicillamine treatment led to the excretion of copper through urine. Addition of andrographolide to d-penicillamine regime appeared to increase protection of liver by increasing the biliary excretion of copper and reduction in cholestatic injury. The early removal of the causative agent copper during combination treatment was the most effective therapeutic intervention that contributed to the early rectification of fibrosis in liver. Combination treatment reduced Kupffer cells accumulation and TNFα production in liver of copper exposed rats. In particular, andrographolide mediated the anti-inflammatory effect by inhibiting the cytokine production. However, another possible mechanism of cytoprotection of andrographolide was decreasing mitochondrial production of superoxide anions that resulted in better restoration of mitochondrial dysfunction during combination therapy than monotherapy. Furthermore, ROS inhibition by combination regimen resulted in significant decline in activation of caspase cascade. Inhibition of caspases attenuated apoptosis of hepatocytes, induced by chronic copper exposure. In summary, this study suggested that added benefit of combination treatment over use of either agent alone in alleviating the hepatotoxicity and fibrosis associated with copper toxicosis.
Asunto(s)
Antiinflamatorios/uso terapéutico , Cobre/toxicidad , Diterpenos/uso terapéutico , Cirrosis Hepática/tratamiento farmacológico , Hígado/efectos de los fármacos , Penicilamina/uso terapéutico , Alanina Transaminasa/metabolismo , Animales , Apoptosis , Biomarcadores/metabolismo , Caspasas/metabolismo , Cobre/metabolismo , Quimioterapia Combinada , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática/metabolismo , Masculino , Mitocondrias/efectos de los fármacos , Estrés Oxidativo , Piruvato Quinasa/metabolismo , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismoRESUMEN
BACKGROUND: Nitric oxide (NO) plays a vital role in maintaining the survivability of circulating erythrocytes. Here we have investigated whether NO depletion associated with visceral leishmaniasis (VL) is responsible for the reduced survival of erythrocytes observed during the disease. METHODS: Infected hamsters were treated with standard anti-leishmanial sodium stibogluconate (SAG) and NO donor isosorbide dinitrate (ISD). Erythrophagocytosis by macrophages was determined by labelling the cells with FITC followed by flow cytometry. Aggregation of band3 was estimated from band3 associated EMA fluorescence. Caspase 3 activity was measured using immunosorbent assay kit. Phosphatidylserine (PS) externalization and cell shrinkage were determined using annexin V. Aminophspholipid translocase and scramblase activities were measured following NBD-PS and NBD-PC internalization, respectively. RESULTS: Impairment of both synthesis and uptake of NO resulted in decreased bioavailability of this signaling molecule in erythrocytes in VL. NO level was replenished after simultaneous treatment with ISD and SAG. Combination treatment decreased red cell apoptosis in infected animals by deactivating caspase 3 through s-nitrosylation. Drug treatment prevented infection-mediated ATP depletion and altered calcium homeostasis in erythrocytes. Improved metabolic environment effectively amended dysregulation of aminophospholipid translocase and scramblase, which in turn reduced cell shrinkage, and exposure of phosphatidylserine on the cell surface under the diseased condition. CONCLUSION AND GENERAL SIGNIFICANCE: In this study, we have identified NO depletion to be an important factor in promoting premature hemolysis with the progress of leishmanial infection. The study implicates NO to be a possible target for future drug development towards the promotion of erythrocyte survival in VL.
Asunto(s)
Eritrocitos/metabolismo , Leishmania donovani , Leishmaniasis Visceral/metabolismo , Óxido Nítrico/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Proteína 1 de Intercambio de Anión de Eritrocito/metabolismo , Gluconato de Sodio Antimonio/farmacología , Antiprotozoarios/farmacología , Calcio/metabolismo , Caspasa 3/metabolismo , Supervivencia Celular/efectos de los fármacos , Cricetinae , Eritrocitos/parasitología , Hemólisis/efectos de los fármacos , Humanos , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/parasitología , Macrófagos/metabolismo , Macrófagos/parasitología , Masculino , Mesocricetus , Fagocitosis/efectos de los fármacos , Transducción de Señal/efectos de los fármacosRESUMEN
In visceral leishmaniasis (VL), oxidative assault on erythrocytes perturbs their cellular environment and makes them vulnerable to premature hemolysis. In this study, we assessed the contribution of oxidation-induced modifications of hemoglobin and membrane protein band 3 in the reduced survival of red cells in VL. Oxidative transformation of oxyhemoglobin to hemichrome enhanced its interaction with erythrocyte membrane in the infected animals. Association between denatured globin and band 3 contributed to the formation of insoluble copolymer of macromolecular dimension. Disulfide bonding appeared to be necessary in the making of high molecular weight aggregates during copolymerization. Hemichrome induced clustering of band 3 promoted generation of epitopes on erythrocyte cell surface. This provided a signal favoring immunologic recognition of redistributed band 3 by autologous IgG followed by erythrophagocytosis. An eventual outcome of the sequence of events pointed to early removal of affected red cells from circulation during the disease.