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1.
Rom J Ophthalmol ; 68(1): 53-56, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38617729

RESUMO

Objective: To describe acute calcareous corneal degeneration as a complication of chronic graft-versus-host disease. Materials and methods: Clinical case and review of the literature. Results: We presented a case of bilateral acute calcareous corneal degeneration in a patient with chronic graft-versus-host disease. Conclusions: Chronic graft-versus-host disease (cGVHD) occurs in 50-70% of bone marrow transplantation patients, the most frequent ocular complication being keratoconjunctivitis sicca (KCS). Calcareous corneal degeneration is a type of calcium deposition that can be secondary to chronic ocular inflammation or dry eye, but there are few cases reported of acute calcareous corneal degeneration and recurrent perforation in cGVHD. Abbreviations: GVHD = Chronic graft-versus-host disease, aGVHD = Acute graft-versus-host disease, cGVHD = Chronic graft-versus-host disease, KCS = Keratoconjunctivitis sicca, PKP = Penetrating keratoplasty, AMT = Amniotic membrane transplantation, PRGF = Plasma rich in growth factors, OD = Right eye, OS = Left eye.


Assuntos
Síndrome de Bronquiolite Obliterante , Distrofias Hereditárias da Córnea , Ceratoconjuntivite Seca , Humanos , Córnea , Ceratoplastia Penetrante , Inflamação
2.
Methods Mol Biol ; 2798: 1-9, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38587732

RESUMO

Total antioxidant capacity (TAC) is a reliable indicator of antioxidant content in animal and plant samples. The different experimental approaches available allow the determination of TAC using, as a reference, diverse compounds with recognized antioxidant capacities such as Trolox, ascorbic acid, gallic acid, or melatonin. A new portable device, named BRS (BQC redox system), is now commercially available that, through an electrochemical approach, allows the determination of TAC in a simple, fast, reproducible, and robust way. In this chapter, using this portable device, a comparative analysis of the TAC is assayed in different red, citrus, and Solanaceae fruits, several Allium species, and organs of different plant species, including Arabidopsis thaliana. The obtained results demonstrate the versatility of the BRS portable device.


Assuntos
Arabidopsis , Melatonina , Animais , Antioxidantes , Ácido Ascórbico , Ácido Gálico , Verduras
3.
Methods Mol Biol ; 2798: 213-221, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38587746

RESUMO

Catalase, a pivotal enzyme in plant antioxidative defense mechanisms, plays a crucial role in detoxifying hydrogen peroxide, a reactive oxygen species (ROS). In this chapter, a comparative analysis of catalase activity was conducted using two distinct methodologies: spectrophotometry and non-denaturing polyacrylamide gel electrophoresis (PAGE). The spectrophotometric approach allowed the quantification of catalase activity by measuring the breakdown rate of hydrogen peroxide, while native PAGE enabled the separation and visualization of catalase isozymes, based on their native molecular weight and charge characteristics, and specific staining assay. Both methods provide valuable insights into catalase activity, offering complementary information on the enzyme's functional diversity and distribution within different plant tissues. This study integrates different techniques, previously described, to comprehensively elucidate the role of catalase in plant metabolism. Furthermore, it provides the possibility of obtaining a holistic understanding of antioxidant defense mechanisms by considering both total activity and isoenzyme distribution of catalase enzyme.


Assuntos
Antioxidantes , Peróxido de Hidrogênio , Catalase , Eletroforese em Gel de Poliacrilamida Nativa , Espectrofotometria
4.
Methods Mol Biol ; 2798: 223-234, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38587747

RESUMO

At the cellular level, the generation of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), due to different abiotic or biotic stress, causes oxidative stress that induces an imbalance in the metabolism. Among the different H2O2-scavenging enzymatic antioxidants, ascorbate peroxidase (APX) is a heme-peroxidase that plays an important role in the ascorbate-glutathione pathway using ascorbate to reduce H2O2 to water. Using non-denaturing polyacrylamide gel electrophoresis (PAGE) in combination with a spectrophotometric assay for APX activity, the protocol allows identifying diverse APX isozymes present in different organs and plant species.


Assuntos
Antioxidantes , Peróxido de Hidrogênio , Ascorbato Peroxidases , Eletroforese em Gel de Poliacrilamida Nativa , Ácido Ascórbico
5.
Eur Arch Otorhinolaryngol ; 281(5): 2739-2742, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38453713

RESUMO

PURPOSE: To investigate the clinical manifestations, management and outcomes of Leishmania lesions in the ear-nose-throat (ENT) region, and its relationship with tumor necrosis factor (TNF)-α blocking drugs. METHODS: Single-center retrospective observational study. Patients diagnosed with cutaneous and mucosal leishmaniasis in the otorhinolaryngologic area at a tertiary referral center over a period of 8 years. RESULTS: Three cases of Leishmania lesions in the ear and two in the nose were encountered at our institution. All patients were under treatment with TNF-α blocking drugs. Diagnosis was challenging, and it was important to have a clinical suspicion in order to use accurate detection techniques. All patients received systemic treatment and achieved a complete resolution of the lesions. CONCLUSIONS: With the increasing use of biologic treatments like TNF-α blockers, this type of infection will be increasingly frequent in endemic areas and also worldwide. It is important to include leishmaniasis in the differential diagnosis of inflammatory/infectious lesions in the ENT region.


Assuntos
Leishmaniose Cutânea , Leishmaniose , Otolaringologia , Humanos , Fator de Necrose Tumoral alfa , Leishmaniose/diagnóstico , Leishmaniose/tratamento farmacológico , Pele , Estudos Retrospectivos , Leishmaniose Cutânea/terapia
6.
Cancers (Basel) ; 16(6)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38539479

RESUMO

Immune checkpoint inhibitors have been proposed as the standard treatment for different stages of non-small-cell lung cancer in multiple indications. Not all patients benefit from these treatments, however, and certain patients develop immune-related adverse events. Although the search for predictors of response to these drugs is a major field of research, these issues have yet to be resolved. It has been postulated that microbiota could play a relevant role in conditioning the response to cancer treatments; however, the human factor of intestinal permeability also needs to be considered as it is closely related to the regulation of host-microbiota interaction. In this article, we analyzed the possible relationship between the response to immune checkpoint inhibitors and the onset of immune-related adverse events, gut microbiota status, and intestinal membrane permeability. In a pioneering step, we also measured short-chain fatty acid content in feces. Although the correlation analyses failed to identify predictive biomarkers, even when all variables were integrated, our patients' microbial gut ecosystems were rich and diverse, and the intestinal barrier's integrity was preserved. These results add new knowledge on the composition of microbiota and its correlation with barrier permeability and short-chain fatty acids and suggest that more studies are required before these potential biomarkers can be incorporated into the clinical management of patients via immune checkpoint inhibitor treatment.

7.
World J Oncol ; 15(2): 223-238, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38545481

RESUMO

Background: Immune checkpoint inhibitors (ICIs) have been proposed as the standard first-line and subsequent treatment for metastatic non-small cell lung cancer (NSCLC). This study analyzed whether patients with good lung immune prognostic index (LIPI) have a better response to ICIs and the relationship between immune-related adverse events (irAEs) and response in clinical practice. Methods: This was an observational, retrospective, single-center study. Patients with stage IV NSCLC between 2016 and 2021 were included in the study. Toxicity was assessed according to The Common Terminology Criteria for Adverse Events. Response assessment was performed according to RECIST 2.0 and immuno-related criteria. Descriptive and survival analyses were conducted. Degree of toxicity and response to treatment (based on treatment and histology) were assessed. LIPI and response were assessed. LIPI included dNLR (absolute neutrophil count/(white blood cell count - absolute neutrophil count)) ≥ 3 and lactate dehydrogenase (LDH) greater than the upper limit of normal. Patients were stratified into good (G), intermediate (I), and poor (P) prognostic groups. Results: A total of 168 patients were included (130 men and 38 women, mean age 64.3 years). ICI use in the first- or second-line treatment was 65% and 35%, respectively. Fifteen (9%) patients showed complete response (CR), 50 (30%) showed partial response (PR), 39 (22%) had stable disease (SD), 45 (28%) had progressive disease (PD), and 19 (11%) were not evaluated (NE). Patients with good prognostic LIPI (dNLR < 3 and normal LDH levels) showed a better response. Progression-free survival (PFS) was 19 months in G, 6 months in I, and 2 months in P. Overall survival (OS) was 27 months in G, 8 months in I, and 3 months in P. One hundred fourteen patients died (56% G, 76% I, 93% P). Patients with adenocarcinoma were 116 (77 with irAEs G1-4 (13 CR, 31 PR, 21 SD, eight PD, and four NE)), and without were 39 (three PR, six SD, 21 PD, and nine NE). Fifty-two patients had squamous carcinoma (27 with irAEs G1-4 (two CR, 12 PR, nine SD, and four PD)), and 25 did not (four PR, three SD, 12 PD, and six NE)). IrAEs appearance was observed in longer PFS (19 vs. 2 months) and OS (27 vs. 4 months; P < 0.0001). Conclusions: LIPI was a positive predictor of response to ICI. The presence of irAEs is associated with a better immune response. In contrast, the absence of toxicity predicted a worse prognosis.

8.
Arch Dis Child ; 109(2): 144-151, 2024 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-37940361

RESUMO

BACKGROUND AND OBJECTIVES: Antimicrobial stewardship programmes (ASPs) have resulted in antimicrobial consumption (AMC) reduction and quality of prescription (QOP) improvement. However, evidence of ASP impact in paediatrics is still limited. This study aims to assess a paediatric ASP long-term outcomes. METHODS: A quality improvement study assessed by a interrupted time series analysis was conducted in a paediatric tertiary hospital. QOP expressed as proportion of adequate prescriptions, AMC measured by defined daily dose incidence per 1000 occupied bed days, incidence density of bloodstream infections (BSIs) and its related all-cause crude death rate (CDR) were compared between pre (from January 2013 to December 2015) and post (from January 2016 to December 2019) ASP activities intensification, which included a dedicated paediatric infectious diseases physician to actively perform educational interviews with prescribers. RESULTS: Inappropriate prescribing showed a significant downward shift associated to the intervention with a -51.4% (-61.2% to -41.8%) reduction with respect to the expected values. Overall AMC showed no trend change after the intervention. For neonatology a28.8% (-36.8% to -20.9%) reduction was observed. Overall anti-pseudomonal cephalosporin use showed a -51.2% (-57.0% to -45.4%) reduction. Decreasing trends were observed for carbapenem use, with a quarterly per cent change (QPC) of -2.4% (-4.3% to -0.4%) and BSI-related CDR (QPC=-3.6%; -5.4% to -1.7%) through the study period. Healthcare-associated multi-drug-resistant BSI remained stable (QPC=2.1; -0.6 to 4.9). CONCLUSIONS: Intensification of counselling educational activities within an ASP suggests to improve QOP and to partially reduce AMC in paediatric patients. The decreasing trends in mortality remained unchanged.


Assuntos
Anti-Infecciosos , Gestão de Antimicrobianos , Humanos , Criança , Antibacterianos/uso terapêutico , Gestão de Antimicrobianos/métodos , Melhoria de Qualidade , Anti-Infecciosos/uso terapêutico , Carbapenêmicos
9.
Int J Pharm ; 651: 123743, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38151103

RESUMO

HYPOTHESIS: The stabilization and isolation to dryness of drug nanoparticles has always been a challenge for nano-medicine production. In the past, the use of montmorillonite (MMT) clay carrier particles to adsorb drug nanoparticles and maintain their high surface area to volume ratio after isolation to dryness has proven to be effective. We hypothesise that the distribution of hydrophilic and hydrophobic patches on the clay's surface as well as its porosity/roughness, hinder the agglomeration of the drug nanoparticles to the extent that they retain their high surface area to volume ratio and display fast dissolution profiles. EXPERIMENTS: In this work, the distribution of hydrophobicity and hydrophilicity, and the porosity/roughness, of the surface of selected silica carrier particles were varied and the impact of these variations on drug nanoparticle attachment to the carrier particle and subsequent dissolution profiles was studied. FINDINGS: The fastest dissolution profiles at the highest drug nanoparticle loadings were obtained with a periodic mesoporous organosilane carrier particle which had a homogeneous distribution of hydrophobic and hydrophilic surface properties. Carrier particles with rough/porous surfaces and a combination of hydrophobic and hydrophilic patches resulted in nanocomposite powders with faster dissolution behaviour than carrier particles with predominantly either a hydrophobic or hydrophilic surface, or with non-porous/smoother surfaces.


Assuntos
Portadores de Fármacos , Nanopartículas , Portadores de Fármacos/química , Argila , Solubilidade , Nanopartículas/química , Dióxido de Silício/química , Propriedades de Superfície , Tamanho da Partícula
10.
Rom J Ophthalmol ; 67(3): 305-308, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37876503

RESUMO

Objective: Description of melphalan's toxicity in retinoblastoma treatment. Methods: Clinical case report. Results: We presented a case of unilateral retinoblastoma with vitreous seeding at diagnosis, in which the use of intravitreal melphalan produced many adverse reactions. Conclusions: Vitreous seedings have been one of the most important challenges in retinoblastoma treatment. Intravitreal melphalan has achieved the regression of vitreous seedings in a large percentage of cases. It is a safe treatment; however, it can produce toxicity, even with the standard dose of 20-30 µg, which has been poorly documented. Exhaustive follow-up of patients is recommended for an early diagnosis of possible adverse effects. Abbreviations: OS = left eye, RI = magnetic resonance imaging, OCT = optical coherence tomography.


Assuntos
Neoplasias da Retina , Retinoblastoma , Humanos , Retinoblastoma/diagnóstico , Retinoblastoma/tratamento farmacológico , Melfalan/efeitos adversos , Neoplasias da Retina/diagnóstico , Neoplasias da Retina/tratamento farmacológico , Antineoplásicos Alquilantes/efeitos adversos , Estudos Retrospectivos , Corpo Vítreo , Injeções Intravítreas , Inoculação de Neoplasia
11.
Curr Biol ; 33(20): 4446-4457.e5, 2023 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-37751744

RESUMO

Chromosomal instability (CIN), an increased rate of changes in chromosome structure and number, is observed in most sporadic human carcinomas with high metastatic activity. Here, we use a Drosophila epithelial model to show that DNA damage, as a result of the production of lagging chromosomes during mitosis and aneuploidy-induced replicative stress, contributes to CIN-induced invasiveness. We unravel a sub-lethal role of effector caspases in invasiveness by enhancing CIN-induced DNA damage and identify the JAK/STAT signaling pathway as an activator of apoptotic caspases through transcriptional induction of pro-apoptotic genes. We provide evidence that an autocrine feedforward amplification loop mediated by Upd3-a cytokine with homology to interleukin-6 and a ligand of the JAK/STAT signaling pathway-contributes to amplifying the activation levels of the apoptotic pathway in migrating cells, thus promoting CIN-induced invasiveness. This work sheds new light on the chromosome-signature-independent effects of CIN in metastasis.


Assuntos
Caspases , Dano ao DNA , Humanos , Caspases/genética , Aneuploidia , Mitose , Instabilidade Cromossômica
13.
Mol Cancer ; 22(1): 127, 2023 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-37559050

RESUMO

BACKGROUND: Approximately 15% of adult GIST patients harbor tumors that are wild-type for KIT and PDGFRα genes (KP-wtGIST). These tumors usually have SDH deficiencies, exhibit a more indolent behavior and are resistant to imatinib. Underlying oncogenic mechanisms in KP-wtGIST include overexpression of HIF1α high IGFR signaling through the MAPK pathway or BRAF activating mutation, among others. As regorafenib inhibits these signaling pathways, it was hypothesized that it could be more active as upfront therapy in advanced KP-wtGIST. METHODS: Adult patients with advanced KP-wtGIST after central confirmation by NGS, naïve of systemic treatment for advanced disease, were included in this international phase II trial. Eligible patients received regorafenib 160 mg per day for 21 days every 28 days. The primary endpoint was disease control rate (DCR), according to RECIST 1.1 at 12 weeks by central radiological assessment. RESULTS: From May 2016 to October 2020, 30 patients were identified as KP-wtGIST by Sanger sequencing and 16 were confirmed by central molecular screening with NGS. Finally, 15 were enrolled and received regorafenib. The study was prematurely closed due to the low accrual worsened by COVID outbreak. The DCR at 12 weeks was 86.7% by central assessment. A subset of 60% experienced some tumor shrinkage, with partial responses and stabilization observed in 13% and 87% respectively, by central assessment. SDH-deficient GIST showed better clinical outcome than other KP-wtGIST. CONCLUSIONS: Regorafenib activity in KP-wtGIST compares favorably with other tyrosine kinase inhibitors, especially in the SDH-deficient GIST subset and it should be taken into consideration as upfront therapy of advanced KP-wtGIST. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02638766.


Assuntos
Antineoplásicos , Tumores do Estroma Gastrointestinal , Sarcoma , Adulto , Humanos , Antineoplásicos/uso terapêutico , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/genética , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-kit/genética , Sarcoma/tratamento farmacológico
14.
Plants (Basel) ; 12(13)2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37447106

RESUMO

As pest management options, such as nematicides, become more restrictive, developing rootstocks resistant to the citrus nematode is fundamental for citrus production. This study provides an updated methodology to screen for citrus nematode resistance in rootstock-breeding programs. We developed a novel method to extract female citrus nematodes from roots that is suitable for molecular work and a real-time-PCR-based nematode quantification method for Tylenchulus semipenetrans. These procedures allow scaling up screening to high-throughput workflows, increasing the chances of finding rootstock candidates that combine all the desired traits. Our results contribute to the growing literature supporting quantification of nematodes with molecular methods.

15.
Antioxidants (Basel) ; 12(7)2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37507999

RESUMO

Cancer is considered one of the main causes of human death worldwide, being characterized by an alteration of the oxidative metabolism. Many natural compounds from plant origin with anti-tumor attributes have been described. Among them, capsaicin, which is the molecule responsible for the pungency in hot pepper fruits, has been reported to show antioxidant, anti-inflammatory, and analgesic activities, as well as anti-proliferative properties against cancer. Thus, in this work, the potential anti-proliferative activity of pepper (Capsicum annuum L.) fruits from diverse varieties with different capsaicin contents (California < Piquillo < Padrón < Alegría riojana) against several tumor cell lines (lung, melanoma, hepatoma, colon, breast, pancreas, and prostate) has been investigated. The results showed that the capsaicin content in pepper fruits did not correspond with their anti-proliferative activity against tumor cell lines. By contrast, the greatest activity was promoted by the pepper tissues which contained the lowest capsaicin amount. This indicates that other compounds different from capsaicin have this anti-tumor potentiality in pepper fruits. Based on this, green fruits from the Alegría riojana variety, which has negligible capsaicin levels, was used to study the effect on the oxidative and redox metabolism of tumor cell lines from liver (Hep-G2) and pancreas (MIA PaCa-2). Different parameters from both lines treated with crude pepper fruit extracts were determined including protein nitration and protein S-nitrosation (two post-translational modifications (PTMs) promoted by nitric oxide), the antioxidant capacity, as well as the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX), among others. In addition, the activity of the NADPH-generating enzymes glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), and NADP-isocitrate dehydrogenase (NADP-ICDH) was followed. Our data revealed that the treatment of both cell lines with pepper fruit extracts altered their antioxidant capacity, enhanced their catalase activity, and considerably reduced the activity of the NADPH-generating enzymes. As a consequence, less H2O2 and NADPH seem to be available to cells, thus avoiding cell proliferation and possibly triggering cell death in both cell lines.

16.
World J Psychiatry ; 13(4): 182-190, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37123096

RESUMO

BACKGROUND: Physical exercise is an underutilized tool for the management of mental disorders. New technologies have made a breakthrough in health care, and one of its possible applications (apps) could be that of customizing exercise programs for special populations, such as patients with mental disorders. However, the app of the so-called e-health to mental health care is still limited. AIM: To know the efficacy of apps to promote physical activity in patients with mental disorders. METHODS: We conducted a systematic review of the PubMed and Embase databases with the aim of exploring the use of new technologies for the enhancement of physical exercise in patients with a psychiatric illness. Following the selection process, 10 articles were included in the review. RESULTS: The most commonly used devices in this type of intervention are wearable devices and web platforms. Good results in terms of effectiveness and acceptability were obtained in most of the studies. CONCLUSION: Our findings suggest that the use of new technologies in mental health represents a feasible strategy with great potential in clinical practice.

17.
J Exp Bot ; 74(20): 6349-6368, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37157899

RESUMO

S-Nitrosoglutathione plays a central role in nitric oxide (NO) homeostasis, and S-nitrosoglutathione reductase (GSNOR) regulates the cellular levels of S-nitrosoglutathione across kingdoms. Here, we investigated the role of endogenous NO in shaping shoot architecture and controlling fruit set and growth in tomato (Solanum lycopersicum). SlGSNOR silencing promoted shoot side branching and led to reduced fruit size, negatively impacting fruit yield. Greatly intensified in slgsnor knockout plants, these phenotypical changes were virtually unaffected by SlGSNOR overexpression. Silencing or knocking out of SlGSNOR intensified protein tyrosine nitration and S-nitrosation and led to aberrant auxin production and signaling in leaf primordia and fruit-setting ovaries, besides restricting the shoot basipetal polar auxin transport stream. SlGSNOR deficiency triggered extensive transcriptional reprogramming at early fruit development, reducing pericarp cell proliferation due to restrictions on auxin, gibberellin, and cytokinin production and signaling. Abnormal chloroplast development and carbon metabolism were also detected in early-developing NO-overaccumulating fruits, possibly limiting energy supply and building blocks for fruit growth. These findings provide new insights into the mechanisms by which endogenous NO fine-tunes the delicate hormonal network controlling shoot architecture, fruit set, and post-anthesis fruit development, emphasizing the relevance of NO-auxin interaction for plant development and productivity.


Assuntos
Reguladores de Crescimento de Plantas , Solanum lycopersicum , Reguladores de Crescimento de Plantas/metabolismo , Oxirredutases/metabolismo , Solanum lycopersicum/genética , Frutas/metabolismo , S-Nitrosoglutationa/metabolismo , Ácidos Indolacéticos/metabolismo , Homeostase , Óxido Nítrico/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
18.
Int J Mol Sci ; 24(9)2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37175829

RESUMO

The uncoupling protein UCP2 is a mitochondrial carrier for which transport activity remains controversial. The physiological contexts in which UCP2 is expressed have led to the assumption that, like UCP1, it uncouples oxidative phosphorylation and thereby reduces the generation of reactive oxygen species. Other reports have involved UCP2 in the Warburg effect, and results showing that UCP2 catalyzes the export of matrix C4 metabolites to facilitate glutamine utilization suggest that the carrier could be involved in the metabolic adaptations required for cell proliferation. We have examined the role of UCP2 in the energy metabolism of the lung adenocarcinoma cell line A549 and show that UCP2 silencing decreased the basal rate of respiration, although this inhibition was not compensated by an increase in glycolysis. Silencing did not lead to either changes in proton leakage, as determined by the rate of respiration in the absence of ATP synthesis, or changes in the rate of formation of reactive oxygen species. The decrease in energy metabolism did not alter the cellular energy charge. The decreased cell proliferation observed in UCP2-silenced cells would explain the reduced cellular ATP demand. We conclude that UCP2 does not operate as an uncoupling protein, whereas our results are consistent with its activity as a C4-metabolite carrier involved in the metabolic adaptations of proliferating cells.


Assuntos
Metabolismo Energético , Canais Iônicos , Neoplasias Pulmonares , Proteína Desacopladora 2 , Humanos , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Trifosfato de Adenosina/metabolismo , Linhagem Celular , Canais Iônicos/genética , Canais Iônicos/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Proteínas de Desacoplamento Mitocondrial/metabolismo , Neoplasias , Espécies Reativas de Oxigênio/metabolismo , Proteína Desacopladora 2/genética , Proteína Desacopladora 2/metabolismo
19.
Front Cell Dev Biol ; 11: 1147610, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37181752

RESUMO

In eutherian mammals, hundreds of programmed DNA double-strand breaks (DSBs) are generated at the onset of meiosis. The DNA damage response is then triggered. Although the dynamics of this response is well studied in eutherian mammals, recent findings have revealed different patterns of DNA damage signaling and repair in marsupial mammals. To better characterize these differences, here we analyzed synapsis and the chromosomal distribution of meiotic DSBs markers in three different marsupial species (Thylamys elegans, Dromiciops gliorides, and Macropus eugenii) that represent South American and Australian Orders. Our results revealed inter-specific differences in the chromosomal distribution of DNA damage and repair proteins, which were associated with differing synapsis patterns. In the American species T. elegans and D. gliroides, chromosomal ends were conspicuously polarized in a bouquet configuration and synapsis progressed exclusively from the telomeres towards interstitial regions. This was accompanied by sparse H2AX phosphorylation, mainly accumulating at chromosomal ends. Accordingly, RAD51 and RPA were mainly localized at chromosomal ends throughout prophase I in both American marsupials, likely resulting in reduced recombination rates at interstitial positions. In sharp contrast, synapsis initiated at both interstitial and distal chromosomal regions in the Australian representative M. eugenii, the bouquet polarization was incomplete and ephemeral, γH2AX had a broad nuclear distribution, and RAD51 and RPA foci displayed an even chromosomal distribution. Given the basal evolutionary position of T. elegans, it is likely that the meiotic features reported in this species represent an ancestral pattern in marsupials and that a shift in the meiotic program occurred after the split of D. gliroides and the Australian marsupial clade. Our results open intriguing questions about the regulation and homeostasis of meiotic DSBs in marsupials. The low recombination rates observed at the interstitial chromosomal regions in American marsupials can result in the formation of large linkage groups, thus having an impact in the evolution of their genomes.

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