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1.
Proc Natl Acad Sci U S A ; 117(45): 28212-28220, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33106431

RESUMO

Somatic mutations are major genetic contributors to cancers and many other age-related diseases. Many disease-causing somatic mutations can initiate clonal growth prior to the appearance of any disease symptoms, yet experimental models that can be used to examine clonal abnormalities are limited. We describe a mosaic analysis system with Cre or Tomato (MASCOT) for tracking mutant cells and demonstrate its utility for modeling clonal hematopoiesis. MASCOT can be induced to constitutively express either Cre-GFP or Tomato for lineage tracing of a mutant and a reference group of cells simultaneously. We conducted mosaic analysis to assess functions of the Id3 and/or Tet2 gene in hematopoietic cell development and clonal hematopoiesis. Using Tomato-positive cells as a reference population, we demonstrated the high sensitivity of this system for detecting cell-intrinsic phenotypes during short-term or long-term tracking of hematopoietic cells. Long-term tracking of Tet2 mutant or Tet2/Id3 double-mutant cells in our MASCOT model revealed a dynamic shift from myeloid expansion to lymphoid expansion and subsequent development of lymphoma. This work demonstrates the utility of the MASCOT method in mosaic analysis of single or combined mutations, making the system suitable for modeling somatic mutations identified in humans.


Assuntos
Integrases/genética , Modelos Genéticos , Mutação/genética , Solanum lycopersicum/genética , Animais , Hematopoiese Clonal/genética , Técnicas Genéticas , Linfoma/genética , Camundongos , Camundongos Transgênicos , Mosaicismo , Análise de Sequência de DNA
2.
Toxicol Appl Pharmacol ; 456: 116267, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36240863

RESUMO

Organophosphates (OPs) are ubiquitous environmental contaminants, widely used as pesticides in agricultural fields. In addition, they serve as flame-retardants, plasticizers, antifoaming or antiwear agents in lacquers, hydraulic fluids, and floor polishing agents. Therefore, world-wide and massive application of these compounds have increased the risk of unintentional exposure to non-targets including the human beings. OPs are neurotoxic agents as they inhibit the activity of acetylcholinesterase at synaptic cleft. Moreover, they can fuel cardiovascular issues in the form of myocardities, cardiac oedema, arrhythmia, systolic malfunction, infarction, and altered electrophysiology. Such pathological outcomes might increase the severity of cardiovascular diseases which are the leading cause of mortality in the developing world. Coronavirus disease-19 (COVID-19) is the ongoing global health emergency caused by SARS-CoV-2 infection. Similar to OPs, SARS-CoV-2 disrupts cytokine homeostasis, redox-balance, and angiotensin-II/AT1R axis to promote cardiovascular injuries. Therefore, during the current pandemic milieu, unintentional exposure to OPs through several environmental sources could escalate cardiac maladies in patients with COVID-19.


Assuntos
COVID-19 , Doenças Cardiovasculares , Humanos , Sistema Renina-Angiotensina/fisiologia , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2 , Organofosfatos , Acetilcolinesterase , Peptidil Dipeptidase A/metabolismo , Inflamação/induzido quimicamente , Doenças Cardiovasculares/induzido quimicamente , Estresse Oxidativo
3.
J Immunol ; 198(8): 3136-3148, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28258199

RESUMO

Inhibitor of DNA binding (Id) proteins, including Id1-4, are transcriptional regulators involved in promoting cell proliferation and survival in various cell types. Although upregulation of Id proteins is associated with a broad spectrum of tumors, recent studies have identified that Id3 plays a tumor-suppressor role in the development of Burkitt's lymphoma in humans and hepatosplenic T cell lymphomas in mice. In this article, we report rapid lymphoma development in Id2/Id3 double-knockout mice that is caused by unchecked expansion of invariant NKT (iNKT) cells or a unique subset of innate-like CD1d-independent T cells. These populations began to expand in neonatal mice and, upon malignant transformation, resulted in mortality between 3 and 11 mo of age. The malignant cells also gave rise to lymphomas upon transfer to Rag-deficient and wild-type hosts, reaffirming their inherent tumorigenic potential. Microarray analysis revealed a significantly modified program in these neonatal iNKT cells that ultimately led to their malignant transformation. The lymphoma cells demonstrated chromosome instability along with upregulation of several signaling pathways, including the cytokine-cytokine receptor interaction pathway, which can promote their expansion and migration. Dysregulation of genes with reported driver mutations and the NF-κB pathway were found to be shared between Id2/Id3 double-knockout lymphomas and human NKT tumors. Our work identifies a distinct premalignant state and multiple tumorigenic pathways caused by loss of function of Id2 and Id3. Thus, conditional deletion of Id2 and Id3 in developing T cells establishes a unique animal model for iNKT and relevant innate-like lymphomas.


Assuntos
Proteína 2 Inibidora de Diferenciação/imunologia , Proteínas Inibidoras de Diferenciação/imunologia , Linfoma/imunologia , Células T Matadoras Naturais/imunologia , Subpopulações de Linfócitos T/imunologia , Transferência Adotiva , Animais , Separação Celular , Transformação Celular Neoplásica/imunologia , Transformação Celular Neoplásica/metabolismo , Modelos Animais de Doenças , Citometria de Fluxo , Humanos , Linfoma/patologia , Camundongos , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase
4.
Environ Monit Assess ; 189(11): 557, 2017 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-29030761

RESUMO

Various organisms are adversely affected when subjected to chronic fluoride exposure. This highly electronegative ion present in several insecticide formulations is found to be lethal to target pests. In the present study, Drosophila melanogaster is treated with sub-lethal concentrations of a diamide insecticide formulation, Flubendiamide. Chronic exposure to the diamide (0.5-100 µg/mL) was found to be responsible for increase in fluoride ion concentration in larval as well as adult body fluid. Interestingly, 100 µg/mL Flubendiamide exposure resulted in 107 and 298% increase in fluoride ion concentration whereas only 23 and 52% of Flubendiamide concentration increase in larval and adult body fluid, respectively. Further, in this study, selected life cycle parameters like larval duration, pupal duration and emergence time showed minimal changes, whereas percentage of emergence and fecundity revealed significant treatment-associated variation. It can be noted that nearly 79% reduction in fecundity was observed with 100 µg/mL Flubendiamide exposure. The variations in these parameters indicate probable involvement of fluoride ion in detectable alterations in the biology of the non-target model insect, D. melanogaster. Furthermore, the outcomes of life cycle study suggest change in resource allocation pattern in the treated flies. The altered resource allocation might have been sufficient to resist changes in selective life cycle parameters, but it could not defend the changes in fecundity. The significant alterations indicate a definite trade-off pattern, where the treated individuals happen to compromise. Thus, survival is apparently taking an upper hand in comparison to reproductive ability in response to Flubendiamide exposure. Graphical abstract The figure demonstrates increase in Fluoride and Flubendiamide concentrations in Drosophila melanogaster after chronic sub-lethal exposure to Flubendiamide. Treatment-induced alterations in larval and pupal duration, reduction in fecundity and alteration in male-female ratio is also observed.


Assuntos
Benzamidas/toxicidade , Drosophila melanogaster/fisiologia , Inseticidas/toxicidade , Sulfonas/toxicidade , Animais , Drosophila melanogaster/efeitos dos fármacos , Monitoramento Ambiental , Feminino , Fertilidade , Fluoretos , Larva/efeitos dos fármacos , Masculino , Fosfatos , Pupa , Reprodução/efeitos dos fármacos
5.
Crit Rev Immunol ; 35(1): 33-48, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25746046

RESUMO

Natural killer T (NKT) cells are αß T cells that express a semi-invariant T-cell receptor (TCR) along with natural killer (NK) cell markers and have an innate cell-like ability to produce a myriad of cytokines very quickly upon antigen exposure and subsequent activation. These cells are diverted from conventional single positive (SP) T-cell fate at the double positive (DP) stage, where TCR-mediated recognition of a lipid antigen presented on a CD1d molecule promotes their selection into the NKT lineage. Although many key regulatory molecules have been shown to play important roles in the development of NKT cells, the mechanism of lineage specification and acquisition of effector functions in these cells still remain to be fully addressed. In this review, we specifically discuss the role of a family of class-I helix-loop-helix proteins known as E proteins, and their antagonists Id proteins in NKT celldevelopment. Recent work has shown that these proteins play key roles in invariant NKT (iNKT) development, from the invariant TCR rearrangement to terminal differentiation and maturation. Elucidating these roles provides an opportunity to uncover the transcriptional network that separates NKT cells from concurrently developed conventional αß T cells.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteína 1 Inibidora de Diferenciação/metabolismo , Células T Matadoras Naturais/imunologia , Linfócitos T/imunologia , Animais , Antígenos CD1d/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular , Linhagem da Célula , Humanos , Imunidade Inata , Proteína 1 Inibidora de Diferenciação/genética
6.
Toxicol Ind Health ; 31(12): 1341-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23847017

RESUMO

The study explored variations in the life cycle parameters in Drosophila melanogaster as a function of treatment with fluorinated insecticide, cryolite. Some of the life cycle parameters considered in this study were larval duration, pupal duration, and percentage of adult fly emergence in D. melanogaster of Oregon R strain. Freshly hatched first instar larvae were transferred to different dietary concentrations of the test chemical (5, 10, 15, 20, 40, 60, 80, 100, 150, and 200 ppm). Larval duration, pupal duration, and the emergence of flies of both treated and control groups were recorded. Results obtained show a significant (p < 0.001-0.05) change in the mentioned parameters in the treated flies when compared with the controls. Interestingly, the percentage emergence of flies shows a decreasing trend along with increase in treatment concentration and almost no detectable emergence is observed in 200 ppm treatment category until the 20th day of experiment. Thus, the study indicates insecticide-induced variation in duration of different life stages and thereby suggests an effect of the fluorinated insecticide on the biology of a nontarget organism like Drosophila.


Assuntos
Drosophila melanogaster/efeitos dos fármacos , Inseticidas , Estágios do Ciclo de Vida/efeitos dos fármacos , Fluoreto de Sódio , Animais , Drosophila melanogaster/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Concentração Osmolar , Pupa/efeitos dos fármacos , Pupa/crescimento & desenvolvimento , Fatores de Tempo
7.
Toxicol Ind Health ; 29(3): 276-85, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22301816

RESUMO

Widely used fungicides and pesticides are known to have profound effect on several nontarget organisms, which is a cause of concern. The present study aims to demonstrate the effect of a fungicide, Thiovit(®) Jet on the structure of epidermal microtrichia (trichome) of the dorsal thorax in Drosophila melanogaster. External morphology and structural variations of thoracic appendages have been extensively studied using scanning electron microscope from flies treated with different concentrations of Thiovit Jet (20, 30, 40 or 200 µg/ml). Similar to the effect of other fungicides like captan and captafol which are reported to produce somatic mutations in the same organism, the present study successfully demonstrates variation in the trichome/microtrichia structure of the dorsal thorax of D. melanogaster. Structural variations were observed to be associated with different concentrations of Thiovit Jet (30, 40 and 200 µg/ml), but the maximum notable change was found with 40 µg/ml treatment. The gross abnormality in the trichome structure may be due to mutation in proteins associated with normal cuticular deposition.


Assuntos
Drosophila melanogaster/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Animais , Drosophila melanogaster/anatomia & histologia , Microscopia Eletrônica de Varredura
8.
Front Immunol ; 14: 1188738, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37483636

RESUMO

V(D)J recombination of antigen receptor loci is a highly developmentally regulated process. During T lymphocyte development, recombination of the Tcra gene occurs in CD4+CD8+ double positive (DP) thymocytes and requires the Tcra enhancer (Eα). E proteins are known regulators of DP thymocyte development and have three identified binding sites in Eα. To understand the contribution of E proteins to Eα function, mutants lacking one or two of the respective binding sites were generated. The double-binding site mutant displayed a partial block at the positive selection stage of αß T cell development. Further investigation revealed loss of germline transcription within the Tcra locus at the Jα array, along with dysregulated primary and impaired secondary Vα-Jα rearrangement. Eα E protein binding increases Tcra locus accessibility and regulates TCRα recombination, thus directly promoting Tcra repertoire diversity.


Assuntos
Receptores de Antígenos de Linfócitos T alfa-beta , Timócitos , Ligação Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Recombinação V(D)J/genética , Fatores de Transcrição/genética , Elementos Facilitadores Genéticos
9.
J Clin Invest ; 133(12)2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37317970

RESUMO

While the rapid advancement of immunotherapies has revolutionized cancer treatment, only a small fraction of patients derive clinical benefit. Eradication of large, established tumors appears to depend on engaging and activating both innate and adaptive immune system components to mount a rigorous and comprehensive immune response. Identifying such agents is a high unmet medical need, because they are sparse in the therapeutic landscape of cancer treatment. Here, we report that IL-36 cytokine can engage both innate and adaptive immunity to remodel an immune-suppressive tumor microenvironment (TME) and mediate potent antitumor immune responses via signaling in host hematopoietic cells. Mechanistically, IL-36 signaling modulates neutrophils in a cell-intrinsic manner to greatly enhance not only their ability to directly kill tumor cells but also promote T and NK cell responses. Thus, while poor prognostic outcomes are typically associated with neutrophil enrichment in the TME, our results highlight the pleiotropic effects of IL-36 and its therapeutic potential to modify tumor-infiltrating neutrophils into potent effector cells and engage both the innate and adaptive immune system to achieve durable antitumor responses in solid tumors.


Assuntos
Imunidade Adaptativa , Neutrófilos , Humanos , Citocinas , Terapia de Imunossupressão , Imunoterapia
10.
Asian J Psychiatr ; 76: 103133, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35551878

RESUMO

BACKGROUND: Attention Deficit/ Hyperactivity Disorder (ADHD) is one of the most common neurodevelopmental psychiatric disorders of childhood. Treatment of ADHD includes medications and Behavioural interventions. Neurofeedback, a type of biofeedback, has been found to be useful in ADHD. It helps patients to control their brain waves consciously. However, it is not yet conclusive if it is efficacious in comparison to behavioural management training and medication. AIM: To compare the efficacy of neurofeedback training, behaviour management including attention enhancement training and medication in children with ADHD. METHOD: Ninety children between 6 and 12 years with ADHD were taken and randomly divided into 3 treatment groups equally- neurofeedback, behaviour management and medication (methylphenidate). Conners 3-P Short Scale was applied for baseline assessment. The respective interventions were given and follow up was done at the end of 3 months by using Conners 3-P Short scale to assess the improvement in the symptoms. There were 6 dropouts, the final sample size was 84. RESULTS: The medication group showed the greatest reduction of symptoms in inattention, hyperactivity, executive functioning domain (core symptoms of ADHD). No statistically significant difference was observed between Neurofeedback and Behaviour Management in these domains. Learning problems improved in all three groups, neurofeedback being the most effective followed by medication. Both Neurofeedback and Medication groups showed similar effect which was higher than the Behavioural Management group in Peer Relation. CONCLUSION: Improvement in core ADHD symptoms have been observed with all 3 interventions with medication showing the greatest improvement Neurofeedback has been superior for learning problems. Thus, Neurofeedback can be an independent or combined intervention tool for children with ADHD in outpatient department of Psychiatry.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Metilfenidato , Neurorretroalimentação , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Criança , Seguimentos , Humanos , Metilfenidato/uso terapêutico , Resultado do Tratamento
11.
Nat Commun ; 13(1): 5901, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-36202870

RESUMO

Production of a functional peripheral T cell compartment typically involves massive expansion of the bone marrow progenitors that seed the thymus. There are two main phases of expansion during T cell development, following T lineage commitment of double-negative (DN) 2 cells and after successful rearrangement and selection for functional TCRß chains in DN3 thymocytes, which promotes the transition of DN4 cells to the DP stage. The signals driving the expansion of DN2 thymocytes are well studied. However, factors regulating the proliferation and survival of DN4 cells remain poorly understood. Here, we uncover an unexpected link between the transcription factor Zfp335 and control of cGAS/STING-dependent cell death in post-ß-selection DN4 thymocytes. Zfp335 controls survival by sustaining expression of Ankle2, which suppresses cGAS/STING-dependent cell death. Together, this study identifies Zfp335 as a key transcription factor regulating the survival of proliferating post-ß-selection thymocytes and demonstrates a key role for the cGAS/STING pathway in driving apoptosis of developing T cells.


Assuntos
Apoptose , Proteínas de Membrana/metabolismo , Timócitos , Animais , Apoptose/genética , Diferenciação Celular , Camundongos , Camundongos Endogâmicos C57BL , Nucleotidiltransferases , Timócitos/metabolismo , Timo/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Food Chem Toxicol ; 149: 112007, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33493637

RESUMO

Consistent gathering of immunotoxic substances on earth is a serious global issue affecting people under pathogenic stress. Organophosphates are among such hazardous compounds that are ubiquitous in nature. They fuel oxidative stress to impair antiviral immune response in living entities. Aside, organophosphates promote cytokine burst and pyroptosis in broncho-alveolar chambers leading to severe respiratory ailments. At present, we witness COVID-19 outbreak caused by SARS-CoV-2. Infection triggers cytokine storm coupled with inflammatory manifestations and pulmonary disorders in patients. Since organophosphate-exposure promotes necroinflammation and respiratory troubles hence during current pandemic situation, additional exposure to such chemicals can exacerbate inflammatory outcome and pulmonary maladies in patients, or pre-exposure to organophosphates might turn-out to be a risk factor for compromised immunity. Fortunately, antioxidants alleviate organophosphate-induced immunosuppression and hence under co-exposure circumstances, dietary intake of antioxidants would be beneficial to boost immunity against SARS-CoV-2 infection.


Assuntos
COVID-19 , Exposição Ambiental/efeitos adversos , Imunidade/efeitos dos fármacos , Inflamação/etiologia , Organofosfatos/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , SARS-CoV-2/patogenicidade , Animais , Antioxidantes/uso terapêutico , COVID-19/imunologia , COVID-19/virologia , Síndrome da Liberação de Citocina , Citocinas/metabolismo , Humanos , Inflamação/metabolismo , Inflamação/prevenção & controle , Pandemias , Praguicidas/efeitos adversos , Piroptose , Doenças Respiratórias/etiologia , Virulência/efeitos dos fármacos
13.
Reprod Biol ; 21(4): 100559, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34547545

RESUMO

COVID-19 is the ongoing health emergency affecting individuals of all ages around the globe. Initially, the infection was reported to affect pulmonary structures. However, recent studies have delineated the impacts of COVID-19 on the reproductive system of both men and women. Hence, the present review aims to shed light on the distribution of SARS-CoV-2 entry factors in various reproductive organs. In addition, impacts of COVID-19 mediators like disrupted renin angiotensin system, oxidative stress, cytokine storm, fever, and the mental stress on reproductive physiology have also been discussed. For the present study, various keywords were used to search literature on PubMed, ScienceDirect, and Google Scholar databases. Articles were screened for relevancy and were studied in detail for qualitative synthesis of the review. Through our literature review, we found a multitude of effects of COVID-19 mediators on reproductive systems. Studies reported expression of receptors like ACE-2, TMPRSS2, and CD147 in the testes, epididymis, prostrate, seminal vesicles, and ovarian follicles. These proteins are known to serve as major SARS-CoV-2 entry factors. The expression of lysosomal cathepsins (CTSB/CTSL) and/ neuropilin-1 (NRP-1) are also evident in the testes, epididymis, seminal vesicles, fallopian tube, cervix, and endometrium. The binding of viral spike protein with ACE-2 was found to alter the renin-angiotensin cascade, which could invite additional infertility problems. Furthermore, COVID-19 mediated cytokine storm, oxidative stress, and elevated body temperature could be detrimental to gametogenesis, steroidogenesis, and reproductive cycles in patients. Finally, social isolation, confinement, and job insecurities have fueled mental stress and frustration that might promote glucocorticoid-mediated subnormal sperm quality in men and higher risk of miscarriage in women. Hence, the influence of COVID-19 on the alteration of reproductive health and fertility is quite apparent.


Assuntos
COVID-19/complicações , Infertilidade Feminina/virologia , Infertilidade Masculina/virologia , Complicações Infecciosas na Gravidez/virologia , SARS-CoV-2 , Adulto , Feminino , Humanos , Masculino , Gravidez
14.
Curr Res Toxicol ; 2: 411-423, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34917955

RESUMO

Rotenone is a broad-spectrum pesticide employed in various agricultural practices all over the world. Human beings are exposed to this chemical through oral, nasal, and dermal routes. Inhalation of rotenone exposes bio-molecular components of lungs to this chemical. Biophysical activity of lungs is precisely regulated by pulmonary surfactant to facilitate gaseous exchange. Surfactant proteins (SPs) are the fundamental components of pulmonary surfactant. SPs like SP-A and SP-D have antimicrobial activities providing a crucial first line of defense against infections in lungs whereas SP-B and SP-C are mainly involved in respiratory cycle and reduction of surface tension at air-water interface. In this study, molecular docking analysis using AutoDock Vina has been conducted to investigate binding potential of rotenone with the four SPs. Results indicate that, rotenone can bind with carbohydrate recognition domain (CRD) of SP-A, N-, and C- terminal peptide of SP-B, SP-C, and CRD of SP-D at multiples sites via several interaction mediators such as H bonds, C-H bonds, alkyl bonds, pi-pi stacked, Van der Waals interaction, and other. Such interactions of rotenone with SPs can disrupt biophysical and anti-microbial functions of SPs in lungs that may invite respiratory ailments and pathogenic infections.

15.
Environ Toxicol Pharmacol ; 74: 103308, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31816565

RESUMO

Based on several adverse reports of pesticides on reproductive efficiency of various organisms, studies on "reproductive toxicity" have gained importance. Fecundity, reflecting reproductive success of any organism, is governed by several factors from female and male reproductive systems. This present study explored morphological and biochemical alterations in the male reproductive system of a non-target model organism, Drosophila melanogaster following chronic sub-lethal exposure (1st instar larvae differentially exposed to 1-6 µg/mL until adulthood) to the organophosphate (OP) pesticide, acephate (chronic LC50 8.71 µg/mL). This study demonstrates altered testis structure, decreased germ cell viability and gross body weight, increased activities of oxidative stress marker lipid peroxidase (LPO), and the endogenous antioxidant enzyme catalase (CAT)in addition with altered expression of reproductive marker proteins like vitellogenin and mitoferrin in acephate-exposed flies when compared to control counterparts. Altered reproductive behavior, indicated by a significant decline in the number of mating pairs, validates the adverse effect of chronic acephate exposure on male reproduction in the non-target insect model D. melanogaster.


Assuntos
Drosophila melanogaster , Genitália Masculina/efeitos dos fármacos , Organofosfatos/toxicidade , Animais , Antioxidantes , Catalase/metabolismo , Fertilidade , Inseticidas , Masculino , Modelos Biológicos
16.
Neuroendocrinology ; 89(2): 140-51, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18818486

RESUMO

BACKGROUND: Imbalance in thyroid hormone concentrations has been linked with profound neurobehavioral alterations in the adult. Peripheral hypothyroidism is associated with a phenomenon of central thyroid hormone homeostasis in adult rat. This central homeostasis mechanism could be maintained by adrenergic interplay due to close physiological association between sympathetic nervous system activity and thyroid hormones. The central homeostasis is characterized by increased cerebrocortical synaptosomal T(3) content, deiodinase type II (DII) activity, and cAMP content. METHODS: We injected specific alpha- and beta-adrenergic receptor (AR) agonists and antagonists along with an anti-thyroid drug to find out any AR-mediated action on central homeostasis. RESULTS: The alpha(2)-AR agonist did not alter the onset of central homeostasis, but prolonged its duration. Similar prolongation was observed with alpha(2)-AR antagonist and beta-AR agonist, but these compounds amplified the normal anti-thyroid drug-induced rise in cerebrocortical T(3) content on the day of onset of central homeostasis. Injections of the beta-AR antagonist did not cause any perturbations. All these observations have been supported by parallel changes in cerebrocortical DII activity, cAMP and [Ca(2+)](i) content. CONCLUSION: There emerges a close correlation between cerebral T(3) content, DII activity, cAMP and [Ca(2+)](i) content that are regulated by the AR system. Thus, thyroid hormone homeostasis in the adult mammalian brain is maintained primarily by the beta-adrenergic pathway along with an unexpected pharmacological involvement of the alpha-ARs.


Assuntos
Adrenérgicos/farmacologia , Córtex Cerebral/metabolismo , Homeostase/efeitos dos fármacos , Tiroxina/metabolismo , Tri-Iodotironina/metabolismo , Adrenérgicos/administração & dosagem , Animais , Antitireóideos/administração & dosagem , Antitireóideos/farmacologia , Cálcio/metabolismo , Córtex Cerebral/efeitos dos fármacos , Combinação de Medicamentos , Iodeto Peroxidase/metabolismo , Masculino , Propiltiouracila/administração & dosagem , Propiltiouracila/farmacologia , Ratos , Ratos Sprague-Dawley , Sinaptossomos/metabolismo , Tiroxina/efeitos dos fármacos , Tri-Iodotironina/efeitos dos fármacos , Iodotironina Desiodinase Tipo II
17.
J Exp Med ; 216(8): 1749-1761, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31201207

RESUMO

Preselection thymocytes are normally retained in the thymic cortex, but the mechanisms responsible remain incompletely understood. We now report that deletion of genes encoding the E-protein transcription factors E2A and HEB disorders chemokine receptor expression on developing thymocytes to allow escape of preselection TCR-CD8+ thymocytes into the periphery. We document that CXCR4 expression normally anchors preselection thymocytes to the thymic cortex via interaction with its ligand CXCL12 on cortical thymic epithelial cells, and that disruption of CXCR4-CXCL12 engagements release preselection thymocytes from the thymic cortex. We further document that CXCR4 expression must be extinguished by TCR-mediated positive selection signals to allow migration of TCR-signaled thymocytes out of the thymic cortex into the medulla. Thus, E-protein transcription factors regulate the ordered expression pattern of chemokine receptors on developing thymocytes, and the interaction of the chemokine receptor CXCR4 with its ligand adheres TCR-unsignaled preselection thymocytes to the thymic cortex.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Receptores CXCR4/metabolismo , Timócitos/metabolismo , Timo/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Antígenos CD8/metabolismo , Diferenciação Celular/genética , Quimiocina CXCL12/metabolismo , Células Epiteliais/metabolismo , Humanos , Linfopoese/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores CXCR4/genética , Transdução de Sinais/genética
18.
Front Med ; 12(4): 374-386, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30043222

RESUMO

A family of transcription factors known as Id proteins, or inhibitor of DNA binding and differentiation, is capable of regulating cell proliferation, survival and differentiation, and is often upregulated in multiple types of tumors. Due to their ability to promote self-renewal, Id proteins have been considered as oncogenes, and potential therapeutic targets in cancer models. On the contrary, certain Id proteins are reported to act as tumor suppressors in the development of Burkitt's lymphoma in humans, and hepatosplenic and innate-like T cell lymphomas in mice. The contexts and mechanisms by which Id proteins can serve in such contradictory roles to determine tumor outcomes are still not well understood. In this review, we explore the roles of Id proteins in lymphocyte development and tumorigenesis, particularly with respect to inhibition of their canonical DNA binding partners known as E proteins. Transcriptional regulation by E proteins, and their antagonism by Id proteins, act as gatekeepers to ensure appropriate lymphocyte development at key checkpoints. We re-examine the derailment of these regulatory mechanisms in lymphocytes that facilitate tumor development. These mechanistic insights can allow better appreciation of the context-dependent roles of Id proteins in cancers and improve considerations for therapy.


Assuntos
Carcinogênese/metabolismo , Proteína 1 Inibidora de Diferenciação/metabolismo , Linfócitos/fisiologia , Proteínas Supressoras de Tumor/metabolismo , Fenômenos Fisiológicos Celulares , Fatores de Transcrição
19.
Invert Neurosci ; 18(2): 6, 2018 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-29700671

RESUMO

Flubendiamide is widely used in agricultural fields to exterminate a broad spectrum of pests (lepidopteran insects) by disrupting their muscle function. The main objective of this study was to find the effects of flubendiamide on a non-target organism, Drosophila melanogaster (dipteran insect). In the present study, different sub-lethal concentrations of Flubendiamide caused a significant (P < 0.05) decrease in acetylcholinesterase activity and increase in cytochrome P450 activity in adult D. melanogaster. Phototaxis and climbing behaviours were found to significantly (P < 0.05) alter in exposed flies. The observed alteration in phototaxis and climbing behaviours were not restricted to P generation, but were found to be transmitted to subsequent generations (F1 and F2 generation) that had never been directly exposed to the test chemical during their life time. It is only their predecessors (P generation) who have been affronted with different concentrations of Flubendiamide. Humans and Drosophilids share almost 60% genomic similarity and 75% disease gene resemblance. Moreover, most of the circuits governing the behaviours studied involve the inhibition and excitation of neurotransmitters, which are conserved in humans and flies. Thus, the present findings suggest that chronic flubendiamide exposure might induce alteration in neurotransmission leading to discrepancy in the behavioural responses (vision and flight) in other beneficial insects and insect-dependent organisms.


Assuntos
Benzamidas/farmacologia , Locomoção/efeitos dos fármacos , Sulfonas/farmacologia , Visão Ocular/efeitos dos fármacos , Acetilcolinesterase/metabolismo , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Relação Dose-Resposta a Droga , Drosophila melanogaster/efeitos dos fármacos , Fototaxia/efeitos dos fármacos
20.
Chemosphere ; 209: 220-231, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29936113

RESUMO

Reactive oxygen species (ROS) is known to be associated with the process of aging and other health hazards. Organisms are compelled to compromise with body homeostasis when exposed to toxic substances. In the present study sodium fluoride (NaF) exposure (10-100 µgmL-1) to Drosophila melanogaster in the parental (P) generation leads to increase in adult mortality and alteration in male-female ratio in the P and F1 (1st Filial) generation. Post-treatment alterations in selected behavioral traits (crawling, embedding and climbing) were observed in larvae and adults. Altered behavioral pattern was found to be associated with reduced mitochondrial activity and decreased number of viable brain cells in treated individuals. Interestingly, higher cholinesterase activities in treated males in comparison to females demonstrate a definite sex bias in NaF-induced response. Hyper-activation of antioxidant enzyme like catalase and reduced superoxide dismutase (SOD) and glutathione-s-transferase (GST) activity indicate a shift in the oxidative status after fluoride exposure. Additionally, increase in lipid peroxidation suggests enhancement in ROS which is further validated through increment in protein carbonyl content. Hence, the observations of the present study propose behavioral alterations resulting from increased ROS after chronic exposure to sub-lethal concentrations of NaF in D. melanogaster.


Assuntos
Comportamento Animal/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Fluoretos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Animais , Drosophila melanogaster/metabolismo , Feminino , Masculino , Fatores Sexuais , Fluoreto de Sódio/toxicidade
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