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1.
J Am Soc Nephrol ; 35(3): 281-298, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38200648

RESUMEN

SIGNIFICANCE STATEMENT: This study sheds light on the central role of adenine nucleotide translocase 2 (ANT2) in the pathogenesis of obesity-induced CKD. Our data demonstrate that ANT2 depletion in renal proximal tubule cells (RPTCs) leads to a shift in their primary metabolic program from fatty acid oxidation to aerobic glycolysis, resulting in mitochondrial protection, cellular survival, and preservation of renal function. These findings provide new insights into the underlying mechanisms of obesity-induced CKD and have the potential to be translated toward the development of targeted therapeutic strategies for this debilitating condition. BACKGROUND: The impairment in ATP production and transport in RPTCs has been linked to the pathogenesis of obesity-induced CKD. This condition is characterized by kidney dysfunction, inflammation, lipotoxicity, and fibrosis. In this study, we investigated the role of ANT2, which serves as the primary regulator of cellular ATP content in RPTCs, in the development of obesity-induced CKD. METHODS: We generated RPTC-specific ANT2 knockout ( RPTC-ANT2-/- ) mice, which were then subjected to a 24-week high-fat diet-feeding regimen. We conducted comprehensive assessment of renal morphology, function, and metabolic alterations of these mice. In addition, we used large-scale transcriptomics, proteomics, and metabolomics analyses to gain insights into the role of ANT2 in regulating mitochondrial function, RPTC physiology, and overall renal health. RESULTS: Our findings revealed that obese RPTC-ANT2-/- mice displayed preserved renal morphology and function, along with a notable absence of kidney lipotoxicity and fibrosis. The depletion of Ant2 in RPTCs led to a fundamental rewiring of their primary metabolic program. Specifically, these cells shifted from oxidizing fatty acids as their primary energy source to favoring aerobic glycolysis, a phenomenon mediated by the testis-selective Ant4. CONCLUSIONS: We propose a significant role for RPTC-Ant2 in the development of obesity-induced CKD. The nullification of RPTC-Ant2 triggers a cascade of cellular mechanisms, including mitochondrial protection, enhanced RPTC survival, and ultimately the preservation of kidney function. These findings shed new light on the complex metabolic pathways contributing to CKD development and suggest potential therapeutic targets for this condition.


Asunto(s)
Riñón , Insuficiencia Renal Crónica , Masculino , Animales , Ratones , Proteínas de Transporte de Membrana Mitocondrial , Fibrosis , Adenosina Trifosfato , Insuficiencia Renal Crónica/etiología
2.
J Cancer Educ ; 37(3): 709-716, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-32940883

RESUMEN

Rising incidence of cancer coupled with lack of structured oncology teaching in the undergraduate (UG) medical curriculum could be detrimental by generating unmet needs in the proper care of cancer patients in the future. To determine the orientation amongst undergraduate medical students regarding Oncology as a specialization and future career option, a cross-sectional, single institutional study was conducted amongst 950 undergraduate students by using an online survey over 2 months. The perception of the subject of Oncology as a career option and the opinion regarding the need for inclusion in the undergraduate curriculum were assessed. Students themselves or those with first-degree relatives as cancer survivors were excluded. A total of 317 responses (33.4%) met the inclusion criteria. Majority were MBBS students from semesters 6 to 9. Even though students ranked the future prospect of Oncology 7.5 on 10, only 6% of the respondents actually wanted to pursue it as a career option stating high mortality amongst cancer patients (63.6%) and emotional burnout (49.7%) as the primary limitations. On a brighter note, better job opportunity due to increasing global cancer incidence (61%) and opportunity for research (42.8%) were thought to be the promising features of the specialization. Majority (51.3%) wanted the inclusion of Oncology in the undergraduate curriculum. Due to limited exposure in the undergraduate curriculum, there is a lack of knowledge and interest regarding the scope of Oncology as a future career option. We therefore advocate revision of the undergraduate curriculum to include Oncology.


Asunto(s)
Educación de Pregrado en Medicina , Neoplasias , Estudiantes de Medicina , Estudios Transversales , Curriculum , Educación de Pregrado en Medicina/métodos , Humanos , Percepción , Estudiantes de Medicina/psicología , Encuestas y Cuestionarios
3.
Biochim Biophys Acta ; 1864(7): 773-86, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27041211

RESUMEN

BACKGROUND: Phosphopantetheine adenylyltransferase (PPAT) is a rate limiting enzyme which catalyzes the conversion of ATP and pantetheine to dephosphocoenzyme and pyrophosphate. The enzyme is allosteric in nature and regulated by Coenzyme A (CoA) through feedback inhibition. So far, several structures have been solved to decipher the catalytic mechanism of this enzyme. METHODS: To address catalytic and inhibitory mechanisms of PPAT, structural insights from single crystal X-ray diffraction method were primarily used, followed by biophysical and biochemical analysis. RESULTS: We have solved the structures of PPAT from Pseudomonas aeruginosa with its substrate analogue AMP-PNP and inhibitor CoA. For the first time, a co-crystal structure of PPAT with Acetyl-CoA (AcCoA) was determined. Enzymatic analysis was performed to decipher the catalytic, allosteric and inhibitory mechanisms involved in regulation of PPAT. Binding affinities of PPAT with its substrates and inhibitors were determined by SPR. CONCLUSION: Previous studies from Escherichia coli and Arabidopsis indicated the inhibitory activity of AcCoA. PPAT-AcCoA structure along with some biochemical methods established AcCoA as an inhibitor to PPAT and illustrated its inhibitory mechanism. Transition from catalytic to allosteric state involves formation of ternary complex. We have studied the structural features of the ternary complex of PPAT along with its product pyrophosphate and inhibitor CoA and validated it with other biophysical and biochemical methods. Extensive analysis of all these 3D structures indicates that changes in side chains R90 and D94 are responsible for transition between catalytic and allosteric inhibitory states. GENERAL SIGNIFICANCE: These enzymatic studies provide new insights into the allosteric mechanism of PPAT.


Asunto(s)
Nucleotidiltransferasas/química , Pseudomonas aeruginosa/enzimología , Sitio Alostérico , Biocatálisis , Modelos Moleculares , Nucleotidiltransferasas/antagonistas & inhibidores , Estructura Cuaternaria de Proteína , Estructura Terciaria de Proteína
4.
Tumour Biol ; 39(5): 1010428317705759, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28466788

RESUMEN

Various epidemiological and preclinical studies have already established the cancer chemopreventive potential of vanadium-based compounds. In addition to its preventive efficacy, studies have also indicated the abilities of vanadium-based compounds to induce cell death selectively toward malignant cells. Therefore, the objective of the present investigation is to improve the therapeutic efficacy and toxicity profile of an alkylating agent, cyclophosphamide, by the concurrent use of an organovanadium complex, vanadium(III)-l-cysteine. In this study, vanadium(III)-l-cysteine (1 mg/kg body weight, per os) was administered alone as well as in combination with cyclophosphamide (25 mg/kg body weight, intraperitoneal) in concomitant and pretreatment schedule in mice bearing breast adenocarcinoma cells. The results showed that the combination treatment significantly decreased the tumor burden and enhanced survivability of tumor-bearing mice through generation of reactive oxygen species in tumor cells. These ultimately led to DNA damage, depolarization of mitochondrial membrane potential, and apoptosis in tumor cells. Further insight into the molecular pathway disclosed that the combination treatment caused upregulation of p53 and Bax and suppression of Bcl-2 followed by the activation of caspase cascade and poly (ADP-ribose) polymerase cleavage. Administration of vanadium(III)-l-cysteine also resulted in significant attenuation of peritoneal vasculature and sprouting of the blood vessels by decreasing the levels of vascular endothelial growth factor A and matrix metalloproteinase 9 in the ascites fluid of tumor-bearing mice. Furthermore, vanadium(III)-l-cysteine significantly attenuated cyclophosphamide-induced hematopoietic, hepatic, and genetic damages and provided additional survival advantages. Hence, this study suggested that vanadium(III)-l-cysteine may offer potential therapeutic benefit in combination with cyclophosphamide by augmenting anticancer efficacy and diminishing toxicity to the host.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Neoplasias de la Mama/tratamiento farmacológico , Complejos de Coordinación/administración & dosificación , Cisteína/análogos & derivados , Neoplasias Mamarias Animales/tratamiento farmacológico , Neovascularización Patológica/tratamiento farmacológico , Adenocarcinoma/patología , Animales , Apoptosis/efectos de los fármacos , Neoplasias de la Mama/patología , Línea Celular Tumoral , Ciclofosfamida/administración & dosificación , Cisteína/administración & dosificación , Daño del ADN/efectos de los fármacos , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Humanos , Neoplasias Mamarias Animales/patología , Ratones , Neovascularización Patológica/patología , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo
5.
Mol Cell Biochem ; 424(1-2): 13-33, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27696310

RESUMEN

Cyclophosphamide (CP) is one of the widely used anticancer agents; however, it has serious deleterious effects on normal host cells due to its nonspecific action. The essential trace element Selenium (Se) is suggested to have chemopreventive and chemotherapeutic efficacy and currently used in pharmaceutical formulations. Previous report had shown Nano-Se could protect CP-induced hepatotoxicity and genotoxicity in normal Swiss albino mice; however, its role in cancer management is still not clear. The aim of present study is to investigate the chemoprotective efficacy of Nano-Se against CP-induced toxicity as well as its chemoenhancing capability when used along with CP in Swiss albino mice against Ehrlich's ascites carcinoma (EAC) cells. CP was administered (25 mg/kg b.w., i.p.) and Nano-Se was given (2 mg Se/kg b.w., p.o.) in concomitant and pretreatment schedule. Increase levels of serum hepatic marker, hepatic lipid peroxidation, DNA damage, and chromosomal aberration in CP-treated mice were significantly (P < 0.05) reversed by Nano-Se. The lowered status of various antioxidant enzymes in tumor-bearing mice after CP treatment was also effectively increased by Nano-Se. Administration of Nano-Se along with CP caused a significant reduction in tumor volume, packed cell volume, viable tumor cell count, and increased the survivability of the tumor-bearing hosts. The results suggest that Nano-Se exhibits significant antitumor and antioxidant effects in EAC-bearing mice. The potential for Nano-Se to ameliorate the CP-evoked toxicity as well as to improve the chemotherapeutic effect could have beneficial implications for patients undergoing chemotherapy with CP.


Asunto(s)
Carcinoma de Ehrlich/tratamiento farmacológico , Ciclofosfamida/farmacología , Nanopartículas del Metal/química , Selenio/farmacología , Animales , Carcinoma de Ehrlich/metabolismo , Carcinoma de Ehrlich/patología , Masculino , Ratones , Selenio/química
6.
Drug Chem Toxicol ; 40(3): 359-367, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27868436

RESUMEN

Cisplatin (CDDP) is one of the first-line anticancer drugs that has gained widespread use against various forms of human malignancies. But, the therapeutic outcome of CDDP therapy is limited due to its adverse effects including myelotoxicity and DNA damage which may lead to the subsequent risk of developing secondary cancer. Hence, in search of a suitable cytoprotectant, this study investigated the probable protective efficacy of an oxovanadium(IV) complex, namely oxovanadium(IV)-L-cysteine methyl ester complex (VC-IV) against CDDP-induced myelosuppression and genotoxic damage in the bone marrow cells of Swiss albino mice. CDDP was administered intraperitoneally (5 mg/kg b.w.) and VC-IV was administered orally (1 mg/kg b.w.) in concomitant and 7 d pretreatment schedule. Treatment with VC-IV in CDDP-treated mice significantly (p < 0.01) enhanced bone marrow cell proliferation and inhibited cell death in the bone marrow niche indicating improvement of CDDP-induced myelotoxicity. The organovanadium compound also significantly (p < 0.01) reduced the percentage of chromosomal aberrations, the frequency of micronuclei formation, and the extent of DNA damage. The observed chemoprotective effect of VC-IV was attributed to its anti-oxidant efficacy which significantly (p < 0.01) attenuated CDDP-induced generation of free radicals, and restored (p < 0.01) the levels of oxidized and reduced glutathione. Hence, VC-IV may serve as a promising candidate for future development to decrease the deleterious effects of CDDP in the bone marrow cells of cancer patients and associated secondary complications.


Asunto(s)
Antineoplásicos/toxicidad , Células de la Médula Ósea/efectos de los fármacos , Cisplatino/toxicidad , Daño del ADN/efectos de los fármacos , Compuestos Organometálicos/uso terapéutico , Sustancias Protectoras/uso terapéutico , Vanadatos/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Ensayo Cometa , Cisteína/análogos & derivados , Cisteína/química , Relación Dosis-Respuesta a Droga , Femenino , Ratones , Micronúcleos con Defecto Cromosómico/inducido químicamente , Pruebas de Micronúcleos , Compuestos Organometálicos/química , Sustancias Protectoras/química , Vanadatos/química
7.
Eur Biophys J ; 45(2): 113-28, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26463823

RESUMEN

Gram-negative bacteria like Yersinia, Pseudomonas, and Aeromonas need type III secretion system (T3SS) for their pathogenicity. V-antigen and its regulator are essential for functioning of T3SS. There is significant functional conservation amongst V-antigen and its regulator belonging to the Ysc family. In this study, we have structurally characterized the inter-genus complexes of V-antigen and its regulator. ConSurf analysis demonstrates that V-antigens belonging to the Ysc family show high structural identity predominantly confined to the two long helical regions. The regulator of V-antigen shows high conservation in its first intramolecular coiled-coil domain, responsible for interaction with V-antigen. ∆LcrG(1-70) localizes within the groove formed by long helices of LcrV, as observed in PcrV-∆PcrG(13-72) interaction. Inter-genus complexes of LcrV-PcrG and PcrV-LcrG exhibited elongated conformation and 1:1 heterodimeric state like the native complex of PcrV-PcrG and LcrV-LcrG. Both native and inter-genus complexes showed rigid tertiary structure, solvent-exposed hydrophobic patches, and cooperative melting behavior with high melting temperature. LcrV-PcrG and PcrV-LcrG showed nanomolar affinity of interaction, identical to PcrV-PcrG interaction, but stronger than LcrV-LcrG interaction. Calcium (a secretion blocker of T3SS) propels all the complexes towards a highly monodisperse form. Calcium and magnesium increase the helicity of the native and inter-genus complexes, and causes helix-helix stabilization. Stabilization of helices leads to a slight increase in the melting temperature by 1.5-2.0 °C. However, calcium does not alter the affinity of interaction of V-antigen and its regulator, emphasizing the effect of divalent of cations at the structural level without any regulatory implications. Therefore, the structural conservation of these inter-genus complexes could be the basis for their functional complementation.


Asunto(s)
Antígenos Bacterianos/química , Proteínas Bacterianas/química , Calcio/química , Magnesio/química , Proteínas Citotóxicas Formadoras de Poros/química , Secuencia de Aminoácidos , Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Calcio/farmacología , Magnesio/farmacología , Datos de Secuencia Molecular , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Unión Proteica , Estabilidad Proteica/efectos de los fármacos , Estructura Terciaria de Proteína
8.
Mutagenesis ; 30(4): 509-17, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25778689

RESUMEN

Cisplatin (CDDP) is one of the first-line anticancer drugs indicated for use against various form of human malignancies; but, the therapeutic outcome of CDDP chemotherapy is limited due to the development of myelosuppression and genotoxicity which may lead to secondary cancer. Induction of oxidative stress in normal host cells is thought to be responsible for these adverse effects. Therefore, in search of a potential chemoprotectant, an oraganovanadium compound, viz., vanadium(III)-l-cysteine (VC-III) was evaluated against CDDP-induced clastogenicity and cytotoxicity in bone marrow cells of Swiss albino mice. CDDP was administered intraperitoneally (5mg/kg body weight [b.w.]) and VC-III was given by oral gavage (1mg/kg b.w.) in concomitant and pretreatment schedule. The results showed that VC-III administration significantly (P < 0.001) enhanced cell proliferation and inhibited apoptosis in the bone marrow niche indicating recovery of CDDP-induced myelosuppression. VC-III also significantly (P < 0.001) decreased the percentage of chromosomal aberrations, the frequency of micronuclei formation and the extent of DNA damage. The observed antigenotoxic and cytoprotective effect of VC-III was attributed to its attenuation of free radicals status and restoration of oxidised and reduced glutathione levels. These results suggest that VC-III is a potential candidate for future development as a chemoprotective agent against chemotherapy-associated primary and secondary complications.


Asunto(s)
Células de la Médula Ósea/efectos de los fármacos , Enfermedades de la Médula Ósea/prevención & control , Aberraciones Cromosómicas/efectos de los fármacos , Cisplatino/toxicidad , Cisteína/química , Compuestos Organometálicos/uso terapéutico , Vanadatos/química , Animales , Antineoplásicos/toxicidad , Células de la Médula Ósea/patología , Enfermedades de la Médula Ósea/inducido químicamente , Aberraciones Cromosómicas/inducido químicamente , Daño del ADN/efectos de los fármacos , Femenino , Humanos , Ratones , Estrés Oxidativo/efectos de los fármacos
9.
Mol Cell Biochem ; 405(1-2): 243-56, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25920447

RESUMEN

Chemotherapy is an integral part of modern day treatment regimen but anticancer drugs fail to demarcate between cancerous and normal cells thereby causing severe form of systemic toxicity. Among which pulmonary toxicity is a dreadful complication developed in cancer patients upon cyclophosphamide (CP) therapy. Oxidative stress, fibrosis, and apoptosis are the major patho-mechanisms involved in CP-induced pulmonary toxicity. In the present study, we have synthesized Nano-Se, nanotechnology-based new form of elemental selenium which has significantly lower toxicity and acceptable bioavailability. In order to meet the need of effective drugs against CP-induced adverse effects, nano selenium (Nano-Se) was tested for its possible protective efficacy on CP-induced pulmonary toxicity and bone marrow toxicity. CP intoxication resulted in structural and functional lung impairment which was revealed by massive histopathological changes. Lung injury was associated with oxidative stress/lipid peroxidation as evident by increased in reactive oxygen species, nitric oxide level, and malondialdehyde (MDA) formation with decreased in level of antioxidants such as reduced glutathione, glutathione-S-transferase, glutathione peroxidase, superoxide dismutase, and catalase. Furthermore, CP at a dose of 25 mg/kg b.w. increased pulmonary DNA damage ('comet tail') and triggered DNA fragmentation and apoptosis in mouse bone marrow cells. On the other hand, Nano-Se at a dose of 2 mg Se/kg b.w., significantly inhibited CP-induced DNA damage in bronchoalveolar lavage cells, and decreased the apoptosis and percentage of DNA fragmentation in bone marrow cells and also antagonized the reduction of the activities of antioxidant enzymes and the increase level of MDA. Thus, our results suggest that Nano-Se in pre- and co-administration may serve as a promising preventive strategy against CP-induced pulmonary toxicity.


Asunto(s)
Ciclofosfamida/farmacología , Daño del ADN/efectos de los fármacos , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/tratamiento farmacológico , Nanopartículas/administración & dosificación , Estrés Oxidativo/efectos de los fármacos , Selenio/farmacología , Animales , Antioxidantes/metabolismo , Apoptosis/efectos de los fármacos , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Lavado Broncoalveolar/métodos , Femenino , Peroxidación de Lípido/efectos de los fármacos , Lesión Pulmonar/metabolismo , Malondialdehído/metabolismo , Ratones , Nanotecnología/métodos , Óxido Nítrico/metabolismo , Especies Reactivas de Oxígeno/metabolismo
10.
Pharm Biol ; 53(4): 524-32, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25471377

RESUMEN

CONTEXT: The widely used antineoplastic drug cyclophosphamide causes pulmonary toxicity by inducing oxidative stress. Selenium, a dietary micronutrient, has been found to protect various organs from oxidative injuries. OBJECTIVE: This study was designed to investigate the protective efficacy of an organoselenium compound 2-(5-selenocyanato-pentyl)-benzo[de]isoquinoline 1,3-dione against cyclophosphamide-induced pulmonary toxicity in Swiss albino mice. MATERIALS AND METHODS: Cyclophosphamide (25 mg/kg b.w.) was administered intraperitoneally for 10 d and the organoselenium compound (3 mg/kg b.w.) was given by oral gavage in concomitant and pretreatment schedules. Various biochemical parameters related to oxidative stress and antioxidant enzymes along with histology of lungs were evaluated to assess the effect of the test compound. RESULTS: The oral LD50 of the test compound was more than 1000 mg/kg b.w. in Swiss albino mice. The test compound substantially ameliorated cyclophosphamide-induced pulmonary injury by reducing the levels of reactive oxygen species, reactive nitrogen species, and lipid peroxidation, respectively, by 14.88, 18.54, and 21.10% in concomitant treatment schedule and by 23.89, 35.73, and 30.76% in the pretreatment schedule as well as by restoring the level of reduced glutathione and activities of glutathione-S-transferase, superoxide dismutase, catalase, and glutathione peroxidase, respectively, by 36.88, 42.43, 38.0, 35.0, and 34.06% in the concomitant treatment schedule and by 66.02, 59.29, 57.23, 71.59, and 57.22% in the pretreatment schedule. The test compound also attenuated cyclophosphamide-induced histological alterations of lung tissue. DISCUSSION AND CONCLUSION: The test compound emerged as an efficient antioxidant protecting lungs tissue from cyclophosphamide-induced injury.


Asunto(s)
Antineoplásicos Alquilantes/toxicidad , Antioxidantes/uso terapéutico , Ciclofosfamida/toxicidad , Lesión Pulmonar/prevención & control , Pulmón/efectos de los fármacos , Naftalimidas/uso terapéutico , Compuestos de Organoselenio/uso terapéutico , Animales , Antioxidantes/toxicidad , Femenino , Dosificación Letal Mediana , Pulmón/enzimología , Pulmón/patología , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/metabolismo , Lesión Pulmonar/patología , Ratones , Estructura Molecular , Naftalimidas/toxicidad , Compuestos de Organoselenio/toxicidad , Especies Reactivas de Oxígeno/metabolismo
11.
Proteins ; 82(12): 3273-85, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25116453

RESUMEN

Pseudomonas aeruginosa, a Gram-negative pathogen uses a specialized set of Type III secretion system (T3SS) translocator proteins to establish virulence in the host cell. An understanding of the factors that govern translocation by the translocator protein-chaperone complex is thus of immense importance. In this work, experimental and computational techniques were used to probe into the structure of the major translocator protein PopB from P. aeruginosa and to identify the important regions involved in functioning of the translocator protein. This study reveals that the binding sites of the common chaperone PcrH, needed for maintenance of the translocator PopB within the bacterial cytoplasm, which are primarily localized within the N-terminal domain. However, disordered and flexible residues located both at the N- and C-terminal domains are also observed to be involved in association with the chaperone. This intrinsic disorderliness of the terminal domains is conserved for all the major T3SS translocator proteins and is functionally important to maintain the intrinsically disordered state of the translocators. Our experimental and computational analyses suggest that a "disorder-to-order" transition of PopB protein might take place upon PcrH binding. The long helical coiled-coil part of PopB protein perhaps helps in pore formation while the flexible apical region is involved in chaperone interaction. Thus, our computational model of translocator protein PopB and its binding analyses provide crucial functional insights into the T3SS translocation mechanism.


Asunto(s)
Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Modelos Moleculares , Chaperonas Moleculares/metabolismo , Pseudomonas aeruginosa/metabolismo , Secuencia de Aminoácidos , Antígenos Bacterianos/química , Antígenos Bacterianos/genética , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Sistemas de Secreción Bacterianos , Sitios de Unión , Biología Computacional , Secuencia Conservada , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Mutación , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/metabolismo , Dominios y Motivos de Interacción de Proteínas , Replegamiento Proteico , Pseudomonas aeruginosa/patogenicidad , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Eliminación de Secuencia , Homología de Secuencia de Aminoácido , Propiedades de Superficie
12.
BMC Struct Biol ; 14: 5, 2014 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-24460624

RESUMEN

BACKGROUND: PcrV is a hydrophilic translocator of type three secretion system (TTSS) and a structural component of the functional translocon. C-terminal helix of PcrV is essential for its oligomerization at the needle tip. Conformational changes within PcrV regulate the effector translocation. PcrG is a cytoplasmic regulator of TTSS and forms a high affinity complex with PcrV. C-terminal residues of PcrG control the effector secretion. RESULT: Both PcrV and PcrG-PcrV complex exhibit elongated conformation like their close homologs LcrV and LcrG-LcrV complex. The homology model of PcrV depicts a dumbbell shaped structure with N and C-terminal globular domains. The grip of the dumbbell is formed by two long helices (helix-7 and 12), which show high level of conservation both structurally and evolutionary. PcrG specifically protects a region of PcrV extending from helix-12 to helix-7, and encompassing the C-terminal globular domain. This fragment ∆PcrV(128-294) interacts with PcrG with high affinity, comparable to the wild type interaction. Deletion of N-terminal globular domain leads to the oligomerization of PcrV, but PcrG restores the monomeric state of PcrV by forming a heterodimeric complex. The N-terminal globular domain (∆PcrV(1-127)) does not interact with PcrG but maintains its monomeric state. Interaction affinities of various domains of PcrV with PcrG illustrates that helix-12 is the key mediator of PcrG-PcrV interaction, supported by helix-7. Bioinformatic analysis and study with our deletion mutant ∆PcrG(13-72) revealed that the first predicted intramolecular coiled-coil domain of PcrG contains the PcrV interaction site. However, 12 N-terminal amino acids of PcrG play an indirect role in PcrG-PcrV interaction, as their deletion causes 40-fold reduction in binding affinity and changes the kinetic parameters of interaction. ∆PcrG(13-72) fits within the groove formed between the two globular domains of PcrV, through hydrophobic interaction. CONCLUSION: PcrG interacts with PcrV through its intramolecular coiled-coil region and masks the domains responsible for oligomerization of PcrV at the needle tip. Also, PcrG could restore the monomeric state of oligomeric PcrV. Therefore, PcrG prevents the premature oligomerization of PcrV and maintains its functional state within the bacterial cytoplasm, which is a pre-requisite for formation of the functional translocon.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Pseudomonas aeruginosa/metabolismo , Sistemas de Secreción Bacterianos , Sitios de Unión , Dicroismo Circular , Evolución Molecular , Modelos Moleculares , Simulación del Acoplamiento Molecular , Conformación Proteica , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , Estructura Secundaria de Proteína , Homología de Secuencia de Aminoácido
13.
J Biol Inorg Chem ; 19(6): 981-96, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24777843

RESUMEN

Vanadium is an essential micronutrient for living systems and has antioxidant and genoprotective property. In the present study, the protective role of an organovanadium compound vanadium(III)-L-cysteine (VC-III) was evaluated against hepatotoxicity and genotoxicity induced by cyclophosphamide (CP) (25 mg/kg b.w., i.p.) in Swiss albino mice. Treatment with VC-III (1 mg/kg b.w., p.o.) mitigated CP-induced hepatic injury as indicated by reduction in activities of alanine transaminase, aspartate transaminase, alkaline phosphatase by 1.57-, 1.58- and 1.32-fold in concomitant treatment schedule and by 1.83-, 1.77- and 1.45-fold in pretreatment schedule, respectively, and confirmed by histopathological evidences. Parallel to these changes, VC-III ameliorated CP-induced oxidative stress in liver by 1.46-, 1.26-, 1.32- and 1.42-fold in concomitant treatment group and by 1.95-, 1.40-, 1.46- and 1.73-fold in pretreatment group at the level of H2O2, superoxide, nitric oxide and lipid peroxidation, respectively. VC-III also enhanced activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and glutathione (reduced) level in mice liver by 1.46-, 1.37-, 1.29-, 1.44- and 1.45-fold in concomitant treatment schedule and by 1.64-, 1.65-, 1.42-, 1.49- and 1.57-fold in pretreatment schedule, respectively. In addition, the organovanadium compound could efficiently attenuate CP-induced chromosomal aberrations, DNA fragmentation and apoptosis in bone marrow cells and DNA damage in lymphocytes by 1.49-, 1.43-, 1.48- and 1.59-fold in concomitant treatment group and by 1.76-, 1.92-, 1.99- and 2.15-fold in pretreatment group, respectively. Thus, the present study showed that VC-III could exert protection against CP-induced hepatotoxicity and genotoxicity.


Asunto(s)
Aberraciones Cromosómicas/efectos de los fármacos , Ciclofosfamida/antagonistas & inhibidores , Cisteína/química , Hígado/efectos de los fármacos , Compuestos Organometálicos/química , Compuestos Organometálicos/farmacología , Vanadio/química , Animales , Aberraciones Cromosómicas/inducido químicamente , Ciclofosfamida/administración & dosificación , Ciclofosfamida/toxicidad , Citoprotección/efectos de los fármacos , Daño del ADN , Femenino , Hígado/lesiones , Hígado/metabolismo , Ratones , Mutágenos/administración & dosificación , Mutágenos/toxicidad , Compuestos Organometálicos/síntesis química
14.
Obstet Gynecol Sci ; 67(1): 67-75, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37817413

RESUMEN

OBJECTIVE: To analyze tumour response and toxicity with respect to cumulative radiotherapy dose to target and organs at risk (OARs) with computed tomography (CT)-based image guided adaptive brachytherapy planning for locally advanced carcinoma cervix. METHODS: Patients were treated with two-dimensional concurrent chemoradiotherapy to whole pelvis followed by intracavitary brachytherapy (ICBT) with dose prescription to point 'A'. CT image-based delineation of high-risk clinical target volume (HR-CTV), urinary bladder, rectum and sigmoid colon was done with generation of dose-volume histogram (DVH) data and optimization of doses to target and OARs. Follow up assessments were done for response of disease and toxicity with generation of data for statistical analysis. RESULTS: One hundred thirty-six patients were enrolled in the study. Delineated volume of HR-CTV ranged from 20.9 to 37.1 mL, with median value of 30.2 mL. The equivalent dose in 2 Gy per fraction (EQD2) for point 'A' ranged from 71.31 to 79.75 Gy with median value of 75.1 Gy and EQD2 HR-CTV D90 ranged from 71.9 to 89.7 Gy with median value of 85.1 Gy. 69.2% of patients showed complete response and after median follow-up of 25 months, 50 patients remained disease free, of whom, 74.0% had received ≥85 Gy to HR-CTV D90 versus 26.0% receiving <85 Gy to HR-CTV D90. CONCLUSION: s Amidst the unavailability of magnetic resonance imaging facilities in low middle income countries, incorporation of CT-image based treatment planning into routine practice for ICBT provides the scope to delineate volumes of target and OARs and to generate DVH data, which can prove to be a better surrogate for disease response and toxicity.

15.
PLoS One ; 19(3): e0298527, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38466701

RESUMEN

Lung cancer is one of the leading causes of cancer-related deaths worldwide. To reduce the mortality rate, early detection and proper treatment should be ensured. Computer-aided diagnosis methods analyze different modalities of medical images to increase diagnostic precision. In this paper, we propose an ensemble model, called the Mitscherlich function-based Ensemble Network (MENet), which combines the prediction probabilities obtained from three deep learning models, namely Xception, InceptionResNetV2, and MobileNetV2, to improve the accuracy of a lung cancer prediction model. The ensemble approach is based on the Mitscherlich function, which produces a fuzzy rank to combine the outputs of the said base classifiers. The proposed method is trained and tested on the two publicly available lung cancer datasets, namely Iraq-Oncology Teaching Hospital/National Center for Cancer Diseases (IQ-OTH/NCCD) and LIDC-IDRI, both of these are computed tomography (CT) scan datasets. The obtained results in terms of some standard metrics show that the proposed method performs better than state-of-the-art methods. The codes for the proposed work are available at https://github.com/SuryaMajumder/MENet.


Asunto(s)
Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Diagnóstico por Computador/métodos , Irak
16.
medRxiv ; 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38798603

RESUMEN

Hermansky-Pudlak syndrome (HPS) is a group of rare genetic disorders, with several subtypes leading to fatal adult-onset pulmonary fibrosis (PF) and no effective treatment. Circulating biomarkers detecting early PF have not been identified. We investigated whether endocannabinoids could serve as blood biomarkers of PF in HPS. We measured endocannabinoids in the serum of HPS, IPF, and healthy human subjects and in a mouse model of HPSPF. Pulmonary function tests (PFT) were correlated with endocannabinoid measurements. In a pale ear mouse model of bleomycin-induced HPSPF, serum endocannabinoid levels were measured with and without treatment with zevaquenabant (MRI-1867), a peripheral CB1R and iNOS antagonist. In three separate cohorts, circulating anandamide levels were increased in HPS-1 patients with or without PF, compared to healthy volunteers. This increase was not observed in IPF patients or in HPS-3 patients, who do not have PF. Circulating anandamide (AEA) levels were negatively correlated with PFT. Furthermore, a longitudinal study over the course of 5-14 years with HPS-1 patients indicated that circulating AEA levels begin to increase with the fibrotic lung process even at the subclinical stages of HPSPF. In pale ear mice with bleomycin-induced HpsPF, serum AEA levels were significantly increased in the earliest stages of PF and remained elevated at a later fibrotic stage. Zevaquenabant treatment reduced the increased AEA levels and attenuated progression in bleomycin-induced HpsPF. Circulating AEA may be a prognostic blood biomarker for PF in HPS-1 patients. Further studies are indicated to evaluate endocannabinoids as potential surrogate biomarkers in progressive fibrotic lung diseases.

17.
Indian J Cancer ; 60(3): 337-344, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36861704

RESUMEN

Introduction: Management of brain metastases (BM) is witnessing marked advancement worldwide and modern technologies with better outcomes are gradually being adopted in developing countries. However, data regarding current practice in this field is lacking from the Indian subcontinent prompting us to plan the current study. Materials and Methods: A retrospective, single institutional audit was performed on 112 patients with solid tumors metastasizing to the brain treated over the last 4 years at a tertiary care center in eastern India, of which 79 were ultimately evaluable. Demography, patterns of incidence, and overall survival (OS) were determined. Results: The prevalence of BM was 5.65% among all patients with solid tumors. The median age was 55 years with a slight male preponderance. Lung followed by breast were the most common primary subsites. Multiple BM (54%), left-sided (61%), and frontal lobe lesions (54%) were the more common. Metachronous BM was found in 76% of patients. All patients received whole brain radiation therapy (WBRT). The median OS for the entire cohort was 7 months (95% confidence interval [CI]: 4 - 19 months). The median OS for lung and breast primaries were 6.5 and 8 months and for recursive partitioning analysis (RPA) classes I, II, and III the OS were 11.5, 7, and 3 months, respectively. Median OS did not differ by number of or other sites of metastases. Conclusions: The outcomes from our series about BM from solid tumors in patients from eastern Indian are in congruence to those available in the literature. Patients with BM are still largely treated with WBRT in resource-limited settings.


Asunto(s)
Neoplasias Encefálicas , Radiocirugia , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Centros de Atención Terciaria , Estudios Retrospectivos , Incidencia , Irradiación Craneana , Neoplasias Encefálicas/epidemiología , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/patología , Encéfalo/patología , Resultado del Tratamiento
18.
Artículo en Inglés | MEDLINE | ID: mdl-36597505

RESUMEN

YspD is a hydrophilic translocator forming the platform for assemblage of functional translocon. Exposure to the extra-cellular milieu makes YspD a potential therapeutic target. DoGSiteScorer predicted best druggable pocket (P0) within YspD, encompassing predominantly the C-terminal helical bundles and the long helices-9 & 5. COACH metaserver also identified ligand binding residues within the aforementioned druggable pocket mapping to helix-9. Amino acids of helix-9 are involved in oligomerization of YspD. Interaction of helix-9 and parts of C-terminal of YspD with hydrophobic translocator protein (YspB), is essential for translocation of bacterial effectors to initiate an infection. Helices-9 & 5 form an intramolecular coiled-coil structure, required for protein-protein interaction. Targeting intramolecular coiled-coil and parts of C-terminal would be important for functional inactivation of YspD. Solvent exposed surface in YspD, particularly in P0, enhances its accessibility to ligands. Nine small molecular inhibitors of TIIISS were identified and retrieved from ZINC15 database (drug-library) as putative drug candidates. Molecular docking of potential ligands with P0 was done using SwissDock server and Achilles Blind Docking server. Considering the "Significance" threshold of binding score and region of interaction, Salicylidene Acyl Hydrazide derivatives (INP0400) and Phenoxyacetamide derivative (MBX1641) were found to bind effectively with YspD. These potential ligands interact with functional domains of YspD including parts of C-terminal and the intramolecular coiled-coil, which may affect the oligomerization of YspD and disrupt the interaction of YspD with YspB, inhibiting formation of functional translocon. The identified small molecular antimicrobial ligands of YspD could be tested in vivo to attenuate Y. enterocolitica infection by deregulation of Ysa-Ysp TIIISS. Supplementary Information: The online version contains supplementary material available at 10.1007/s40011-022-01443-2.

19.
Asian Pac J Cancer Prev ; 24(7): 2543-2550, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37505789

RESUMEN

BACKGROUND: To evaluate dosimetry between CT based radiation planning and PET-CT based radiation planning. MATERIAL & METHODS: Histologically proven 40 cases of locally advanced non-small cell carcinoma of lung were accrued for the prospective study. Contrast enhanced planning CT images and PET images were acquired. Target volume delineation, organs of interest & radiation planning were performed in Eclipse V 14.5 followed by dosimetric comparison among GTV, PTV and OARs. A p-value of <0.05 was considered significant. RESULTS: The mean of GTV were 141.18 ± 119.76 cc in CT and 115.54 ± 91.02 cc in PET-CT based and the difference was statistically significant (p=0.03). The mean of CTV were 313.91 ± 180.87 cc in CT and 260.81 ± 148.83 cc in PET-CT based and the difference was statistically significant (p=0.03). The contralateral lung mean dose was statistically very significant (p<0.01) among both the 3D-CRT plans which were 8.49 Gy in CECT based planning and 9.53 Gy in PET CT based planning. The heart mean dose was also statistically significant (p=0.03) among the plans which were 17.90 Gy in CECT based planning and 17.06 Gy in PET CT based planning. Mann-Whitney U test showed the CT based PTV D90 was 58.20 Gy vs 57.58 Gy in PET CT based planning (p=0.02). PTV V95 were also comparable in both of the plans (p=0.02). CONCLUSIONS: GTV measured using PET-CT, may be greater or lesser than the CECT-based GTV. PET-CT-based contouring is more accurate for identifying tumour margins and new lymph node volumes.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Carcinoma de Pulmón de Células no Pequeñas/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones , Estudios Prospectivos , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/patología , Electrones , Planificación de la Radioterapia Asistida por Computador/métodos , Tomografía de Emisión de Positrones/métodos , Tomografía Computarizada por Rayos X/métodos , Dosificación Radioterapéutica , Fluorodesoxiglucosa F18
20.
Adv Sci (Weinh) ; 10(16): e2207454, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37038090

RESUMEN

Pulmonary fibrosis (PF) is a heterogeneous disease with a poor prognosis. Therefore, identifying additional therapeutic modalities is required to improve outcome. However, the lack of biomarkers of disease progression hampers the preclinical to clinical translational process. Here, this work assesses and identifies progressive alterations in pulmonary function, transcriptomics, and metabolomics in the mouse lung at 7, 14, 21, and 28 days after a single dose of oropharyngeal bleomycin. By integrating multi-omics data, this work identifies two central gene subnetworks associated with multiple critical pathological changes in transcriptomics and metabolomics as well as pulmonary function. This work presents a multi-omics-based framework to establish a translational link between the bleomycin-induced PF model in mice and human idiopathic pulmonary fibrosis to identify druggable targets and test therapeutic candidates. This work also indicates peripheral cannabinoid receptor 1 (CB1 R) antagonism as a rational therapeutic target for clinical translation in PF. Mouse Lung Fibrosis Atlas can be accessed freely at https://niaaa.nih.gov/mouselungfibrosisatlas.


Asunto(s)
Fibrosis Pulmonar Idiopática , Multiómica , Humanos , Ratones , Animales , Pulmón/patología , Fibrosis Pulmonar Idiopática/genética , Fibrosis Pulmonar Idiopática/patología , Bleomicina , Metabolómica
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