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1.
J Exp Bot ; 75(8): 2545-2557, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38271585

RESUMO

Non-structural carbohydrates (NSCs) are building blocks for biomass and fuel metabolic processes. However, it remains unclear how tropical forests mobilize, export, and transport NSCs to cope with extreme droughts. We combined drought manipulation and ecosystem 13CO2 pulse-labeling in an enclosed rainforest at Biosphere 2, assessed changes in NSCs, and traced newly assimilated carbohydrates in plant species with diverse hydraulic traits and canopy positions. We show that drought caused a depletion of leaf starch reserves and slowed export and transport of newly assimilated carbohydrates below ground. Drought effects were more pronounced in conservative canopy trees with limited supply of new photosynthates and relatively constant water status than in those with continual photosynthetic supply and deteriorated water status. We provide experimental evidence that local utilization, export, and transport of newly assimilated carbon are closely coupled with plant water use in canopy trees. We highlight that these processes are critical for understanding and predicting tree resistance and ecosystem fluxes in tropical forest under drought.


Assuntos
Carbono , Floresta Úmida , Carbono/metabolismo , Ecossistema , Secas , Água/metabolismo , Árvores/metabolismo , Carboidratos , Folhas de Planta/metabolismo
2.
Neuropsychol Rev ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38867020

RESUMO

Transcranial magnetic stimulation (TMS) has been found to be promising in the neurorehabilitation of post-stroke patients. Aphasia and cognitive impairment (CI) are prevalent post-stroke; however, there is still a lack of consensus about the characteristics of interventions based on TMS and its neuropsychological and anatomical-functional benefits. Therefore, studies that contribute to creating TMS protocols for these neurological conditions are necessary. To analyze the evidence of the neuropsychological and anatomical-functional TMS effects in post-stroke patients with CI and aphasia and determine the characteristics of the most used TMS in research practice. The present study followed the PRISMA guidelines and included articles from PubMed, Scopus, Web of Science, ScienceDirect, and EMBASE databases, published between January 2010 and March 2023. In the 15 articles reviewed, it was found that attention, memory, executive function, language comprehension, naming, and verbal fluency (semantic and phonological) are the neuropsychological domains that improved post-TMS. Moreover, TMS in aphasia and post-stroke CI contribute to greater frontal activation (in the inferior frontal gyrus, pars triangularis, and opercularis). Temporoparietal effects were also found. The observed effects occur when TMS is implemented in repetitive modality, at a frequency of 1 Hz, in sessions of 30 min, and that last more than 2 weeks in duration. The use of TMS contributes to the neurorehabilitation process in post-stroke patients with CI and aphasia. However, it is still necessary to standardize future intervention protocols based on accurate TMS characteristics.

3.
Am J Primatol ; 86(1): e23568, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37850516

RESUMO

Anthropogenic noise is a major global pollutant but its effects on primates are poorly understood, limiting our ability to develop mitigation actions that favor their welfare and conservation. In this study, we used an experimental approach to determine the impact of variation in noise intensity on mantled howler monkeys (Alouatta palliata). We conducted the study at Los Tuxtlas (México), where we studied the physiological stress (proxied via fecal glucocorticoid metabolites, fGCM) and behavioral responses of 16 males. We played back chainsaw noise at two intensities (40 and 80 dB) and used days in which groups were not exposed to noise as matched controls. With increased noise intensity fGCM increased, vigilance and vocalizations were longer, and vigilance, vocalizations, and flight occurred quicker. Physiological and behavioral responses occurred even after low-intensity noise playbacks (i.e., 40 dB). Therefore, noise intensity is a significant factor explaining the responses of mantled howler monkeys to anthropogenic noise. These results imply that management actions aimed at eradicating anthropogenic noise are required for the conservation and welfare of mantled howler monkeys at Los Tuxtlas.


Assuntos
Alouatta , Glucocorticoides , Masculino , Animais , Glucocorticoides/metabolismo , Comportamento Animal/fisiologia , Alouatta/fisiologia , Primatas , México
4.
J Enzyme Inhib Med Chem ; 39(1): 2301767, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38205514

RESUMO

Cell division cycle 7 kinase (CDC7) has been found overexpressed in many cancer cell lines being also one of the kinases involved in the nuclear protein TDP-43 phosphorylation in vivo. Thus, inhibitors of CDC7 are emerging drug candidates for the treatment of oncological and neurodegenerative unmet diseases. All the known CDC7 inhibitors are ATP-competitives, lacking of selectivity enough for success in clinical trials. As allosteric sites are less conserved among kinase proteins, discovery of allosteric modulators of CDC7 is a great challenge and opportunity in this field.Using different computational approaches, we have here identified new druggable cavities on the human CDC7 structure and subsequently selective CDC7 inhibitors with allosteric modulation mainly targeting the pockets where the interaction between this kinase and its activator DBF4 takes place.


Assuntos
Proteínas Nucleares , Proteínas Serina-Treonina Quinases , Humanos , Fosforilação , Sítio Alostérico , Linhagem Celular , Ciclo Celular , Proteínas de Ciclo Celular
5.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-34607942

RESUMO

Type 1 diabetes (T1D) results from immune infiltration and destruction of insulin-producing ß cells within the pancreatic islets of Langerhans (insulitis). Early diagnosis during presymptomatic T1D would allow for therapeutic intervention prior to substantial ß-cell loss at onset. There are limited methods to track the progression of insulitis and ß-cell mass decline. During insulitis, the islet microvasculature increases permeability, such that submicron-sized particles can extravasate and accumulate within the islet microenvironment. Ultrasound is a widely deployable and cost-effective clinical imaging modality. However, conventional microbubble contrast agents are restricted to the vasculature. Submicron nanodroplet (ND) phase-change agents can be vaporized into micron-sized bubbles, serving as a microbubble precursor. We tested whether NDs extravasate into the immune-infiltrated islet microenvironment. We performed ultrasound contrast-imaging following ND infusion in nonobese diabetic (NOD) mice and NOD;Rag1ko controls and tracked diabetes development. We measured the biodistribution of fluorescently labeled NDs, with histological analysis of insulitis. Ultrasound contrast signal was elevated in the pancreas of 10-wk-old NOD mice following ND infusion and vaporization but was absent in both the noninfiltrated kidney of NOD mice and the pancreas of Rag1ko controls. High-contrast elevation also correlated with rapid diabetes onset. Elevated contrast was also observed as early as 4 wk, prior to mouse insulin autoantibody detection. In the pancreata of NOD mice, infiltrated islets and nearby exocrine tissue were selectively labeled with fluorescent NDs. Thus, contrast ultrasound imaging with ND phase-change agents can detect insulitis prior to diabetes onset. This will be important for monitoring disease progression, to guide and assess preventative therapeutic interventions for T1D.


Assuntos
Meios de Contraste/química , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/patologia , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/irrigação sanguínea , Ultrassonografia/métodos , Animais , Autoanticorpos/análise , Diagnóstico Precoce , Feminino , Proteínas de Homeodomínio/genética , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Microbolhas
6.
Odontology ; 112(2): 399-407, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37874511

RESUMO

To evaluate the osteogenic potential of platelet-rich fibrin (PRF) and low-level laser therapy (LLLT) on human stem cells from the apical papilla (SCAP) we isolated, characterized, and then cultured in an osteogenic medium cells with PRF and/or LLLT (660 nm, 6 J/m2-irradiation). Osteogenic differentiation was assessed by bone nodule formation and expression of bone morphogenetic proteins (BMP-2 and BMP-4), whereas the molecular mechanisms were achieved by qRT-PCR and RNA-seq analysis. Statistical analysis was performed by ANOVA and Tukey's post hoc tests (p < 0.05* and p < 0.01**). Although PRF and LLLT increased bone nodule formation after 7 days and peaked at 21 days, the combination of PRF + LLLT led to the uppermost nodule formation. This was supported by increased levels of BMP-2 and -4 osteogenic proteins (p < 0.005). Furthermore, the PRF + LLLT relative expression of specific genes involved in osteogenesis, such as osteocalcin, was 2.4- (p = 0.03) and 28.3- (p = 0.001) fold higher compared to the PRF and LLLT groups, and osteopontin was 22.9- and 1.23-fold higher, respectively (p < 0.05), after 7 days of interaction. The transcriptomic profile revealed that the combination of PRF + LLLT induces MSX1, TGFB1, and SMAD1 expression, after 21 days of osteogenic differentiation conditions exposition. More studies are required to understand the complete cellular and molecular mechanisms of PRF plus LLLT on stem cells. Overall, we demonstrated for the first time that the combination of PRF and LLLT would be an excellent therapeutic tool that can be employed for dental, oral, and craniofacial repair and other tissue engineering applications.


Assuntos
Osteogênese , Fibrina Rica em Plaquetas , Humanos , Fibrina Rica em Plaquetas/metabolismo , Proliferação de Células , Células Cultivadas , Células-Tronco , Diferenciação Celular , Lasers
7.
Breast Cancer Res Treat ; 199(3): 457-469, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37061619

RESUMO

PURPOSE: Neoadjuvant anti-PD-(L)1 therapy improves the pathological complete response (pCR) rate in unselected triple-negative breast cancer (TNBC). Given the potential for long-term morbidity from immune-related adverse events (irAEs), optimizing the risk-benefit ratio for these agents in the curative neoadjuvant setting is important. Suboptimal clinical response to initial neoadjuvant therapy (NAT) is associated with low rates of pCR (2-5%) and may define a patient selection strategy for neoadjuvant immune checkpoint blockade. We conducted a single-arm phase II study of atezolizumab and nab-paclitaxel as the second phase of NAT in patients with doxorubicin and cyclophosphamide (AC)-resistant TNBC (NCT02530489). METHODS: Patients with stage I-III, AC-resistant TNBC, defined as disease progression or a < 80% reduction in tumor volume after 4 cycles of AC, were eligible. Patients received atezolizumab (1200 mg IV, Q3weeks × 4) and nab-paclitaxel (100 mg/m2 IV,Q1 week × 12) as the second phase of NAT before undergoing surgery followed by adjuvant atezolizumab (1200 mg IV, Q3 weeks, × 4). A two-stage Gehan-type design was employed to detect an improvement in pCR/residual cancer burden class I (RCB-I) rate from 5 to 20%. RESULTS: From 2/15/2016 through 1/29/2021, 37 patients with AC-resistant TNBC were enrolled. The pCR/RCB-I rate was 46%. No new safety signals were observed. Seven patients (19%) discontinued atezolizumab due to irAEs. CONCLUSION: This study met its primary endpoint, demonstrating a promising signal of activity in this high-risk population (pCR/RCB-I = 46% vs 5% in historical controls), suggesting that a response-adapted approach to the utilization of neoadjuvant immunotherapy should be considered for further evaluation in a randomized clinical trial.


Assuntos
Neoplasias da Mama , Neoplasias de Mama Triplo Negativas , Humanos , Feminino , Antraciclinas/uso terapêutico , Neoplasias de Mama Triplo Negativas/patologia , Terapia Neoadjuvante , Neoplasias da Mama/tratamento farmacológico , Paclitaxel/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
8.
Br J Surg ; 110(7): 818-830, 2023 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-37131298

RESUMO

BACKGROUND: Skin metastases are an important co-morbidity in melanoma. Despite broad adoption, electrochemotherapy implementation is hindered by a lack of treatment indications, uncertainty regarding procedural aspects, and the absence of quality indicators. An expert consensus may harmonize the approach among centres and facilitate comparison with other therapies. METHODS: An interdisciplinary panel was recruited for a three-round e-Delphi survey. A literature-based 113-item questionnaire was proposed to 160 professionals from 53 European centres. Participants rated each item for relevance and degree of agreement on a five-point Likert scale, and received anonymous controlled feedback to allow revision. The items that reached concordant agreement in two successive iterations were included in the final consensus list. In the third round, quality indicator benchmarks were defined using a real-time Delphi method. RESULTS: The initial working group included 122 respondents, of whom 100 (82 per cent) completed the first round, thus qualifying for inclusion in the expert panel (49 surgeons, 29 dermatologists, 15 medical oncologists, three radiotherapists, two nurse specialists, two clinician scientists). The completion rate was 97 per cent (97 of 100) and 93 per cent (90 of 97) in the second and third rounds respectively. The final consensus list included 54 statements with benchmarks (treatment indications, (37); procedural aspects, (1); quality indicators, (16)). CONCLUSION: An expert panel achieved consensus on the use of electrochemotherapy in melanoma, with a core set of statements providing general direction to electrochemotherapy users to refine indications, align clinical practices, and promote quality assurance programmes and local audits. The residual controversial topics set future research priorities to improve patient care.


Electrochemotherapy is an effective locoregional therapy for skin metastases from melanoma, a problem faced by almost half of patients with metastatic disease. The lack of comparative studies and the heterogeneity of its clinical application among centres make it challenging to support consistent, evidence-based recommendations. To address this unmet need, a three-round online survey was conducted to establish a consensus on treatment indications, standard operating procedures, and quality indicators. In the survey, a panel of 100 European melanoma experts agreed on 56 statements that can be used to improve patient selection, homogenize treatment application, and monitor outcomes.


Assuntos
Eletroquimioterapia , Melanoma , Humanos , Indicadores de Qualidade em Assistência à Saúde , Consenso , Benchmarking , Técnica Delphi
9.
Int J Mol Sci ; 24(16)2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37628731

RESUMO

Malaria is the most lethal parasitic disease worldwide; the severity of symptoms and mortality are higher in men than in women, exhibiting an evident sexual dimorphism in the immune response; therefore, the contribution of 17ß-estradiol and testosterone to this phenomenon has been studied. Both hormones differentially affect several aspects of innate and adaptive immunity. Dehydroepiandrosterone (DHEA) is the precursor of both hormones and is the sexual steroid in higher concentrations in humans, with immunomodulatory properties in different parasitic diseases; however, the involvement of DHEA in this sexual dimorphism has not been studied. In the case of malaria, the only information is that higher levels of DHEA are associated with reduced Plasmodium falciparum parasitemia. Therefore, this work aims to analyze the DHEA contribution to the sexual dimorphism of the immune response in malaria. We assessed the effect of modifying the concentration of DHEA on parasitemia, the number of immune cells in the spleen, cytokines, and antibody levels in plasma of CBA/Ca mice infected with Plasmodium berghei ANKA (P. berghei ANKA). DHEA differentially affected the immune response in males and females: it decreased IFN-γ, IL-2 and IL-4 concentrations only in females, whereas in gonadectomized males, it increased IgG2a and IgG3 antibodies. The results presented here show that DHEA modulates the immune response against Plasmodium differently in each sex, which helps to explain the sexual dimorphism present in malaria.


Assuntos
Citocinas , Plasmodium berghei , Masculino , Humanos , Camundongos , Feminino , Animais , Camundongos Endogâmicos CBA , Parasitemia , Desidroepiandrosterona
10.
Molecules ; 28(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37175132

RESUMO

The flavonoid izalpinin was isolated from the aerial parts of Chromolaena leivensis. Its structural determination was carried out using MS and NMR spectroscopic techniques (1H, 13C). This compound was evaluated for its anti-inflammatory effect in a rat model on λ-carrageenan-induced plantar edema. Paw inflammation was measured at one-hour intervals for seven hours following the administration of λ-carrageenan. Serum creatine kinase (CK) levels were evaluated, obtaining statistically significant results with the treatments at doses of 10 mg/kg (* p < 0.01) and 20 mg/kg (** p < 0.005). The anti-inflammatory effect of the compound was evaluated by using plethysmography, and the results showed significant differences at the three concentrations (10 mg/kg, 20 mg/kg, 40 mg/kg) in the first and third hours after treatment. * p < 0.05; ** p < 0.001; **** p < 0.0001 vs. the negative control group treated with vehicle (DMSO). Lastly, molecular docking analyses reveal that izalpinin has a strong binding affinity with five target proteins involved in the inflammatory process. The analysis using molecular dynamics allowed demonstrating that the ligand-protein complexes present acceptable stability, with RMSD values within the allowed range.


Assuntos
Anti-Inflamatórios , Chromolaena , Ratos , Animais , Carragenina/efeitos adversos , Anti-Inflamatórios/uso terapêutico , Simulação de Acoplamento Molecular , Extratos Vegetais/uso terapêutico , Edema/induzido quimicamente , Edema/tratamento farmacológico , Edema/metabolismo
11.
Development ; 146(1)2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30538100

RESUMO

The gynoecium, the female reproductive part of the flower, is key for plant sexual reproduction. During its development, inner tissues such as the septum and the transmitting tract tissue, important for pollen germination and guidance, are formed. In Arabidopsis, several transcription factors are known to be involved in the development of these tissues. One of them is NO TRANSMITTING TRACT (NTT), essential for transmitting tract formation. We found that the NTT protein can interact with several gynoecium-related transcription factors, including several MADS-box proteins, such as SEEDSTICK (STK), known to specify ovule identity. Evidence suggests that NTT and STK control enzyme and transporter-encoding genes involved in cell wall polysaccharide and lipid distribution in gynoecial medial domain cells. The results indicate that the simultaneous loss of NTT and STK activity affects polysaccharide and lipid deposition and septum fusion, and delays entry of septum cells to their normal degradation program. Furthermore, we identified KAWAK, a direct target of NTT and STK, which is required for the correct formation of fruits in Arabidopsis These findings position NTT and STK as important factors in determining reproductive competence.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/embriologia , Frutas/embriologia , Proteínas de Domínio MADS/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Arabidopsis/ultraestrutura , Proteínas de Arabidopsis/genética , Parede Celular/genética , Parede Celular/metabolismo , Frutas/genética , Frutas/ultraestrutura , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Metabolismo dos Lipídeos/genética , Proteínas de Domínio MADS/genética , Mananas/metabolismo , Meristema/metabolismo , Mutação/genética , Tubo Polínico/embriologia , Tubo Polínico/metabolismo , Tubo Polínico/ultraestrutura , Ligação Proteica , Reprodução , Transcrição Gênica
12.
J Am Acad Dermatol ; 87(3): 551-558, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35104588

RESUMO

BACKGROUND: Congenital nail matrix nevi (NMN) are difficult to diagnose because they feature clinical characteristics suggestive of adult subungual melanoma. Nail matrix biopsy is difficult to perform, especially in children. OBJECTIVE: To describe the initial clinical and dermatoscopic features of NMN appearing at birth (congenital) or after birth but before the age of 5 years (congenital-type). METHODS: We conducted a prospective, international, and consecutive data collection in 102 hospitals or private medical offices across 30 countries from 2009 to 2019. RESULTS: There were 69 congenital and 161 congenital-type NMNs. Congenital and congenital-type NMN predominantly displayed an irregular pattern of longitudinal microlines (n = 146, 64%), reminiscent of subungual melanoma in adults. The distal fibrillar ("brush-like") pattern, present in 63 patients (27.8%), was more frequently encountered in congenital NMN than in congenital-type NMN (P = .012). Moreover, congenital NMN more frequently displayed a periungual pigmentation (P = .029) and Hutchinson's sign (P = .027) than did congenital-type NMN. LIMITATIONS: Lack of systematic biopsy-proven diagnosis and heterogeneity of clinical and dermatoscopic photographs. CONCLUSION: Congenital and congenital-type NMN showed worrisome clinical and dermatoscopic features similar to those observed in adulthood subungual melanoma. The distal fibrillar ("brush-like") pattern is a suggestive feature of congenital and congenital-type NMN.


Assuntos
Melanoma , Doenças da Unha , Nevo , Neoplasias Cutâneas , Adulto , Criança , Pré-Escolar , Dermoscopia , Diagnóstico Diferencial , Humanos , Recém-Nascido , Melanoma/diagnóstico por imagem , Melanoma/patologia , Doenças da Unha/diagnóstico por imagem , Doenças da Unha/patologia , Nevo/diagnóstico , Estudos Prospectivos , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/patologia
13.
Planta Med ; 88(9-10): 735-744, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35777366

RESUMO

Diabetes is a life-threatening and debilitating disease with pathological hallmarks, including glucose intolerance and insulin resistance. Plant compounds are a source of novel and effective therapeutics, and the flavonoid (-)-epicatechin, common to popular foods worldwide, has been shown to improve carbohydrate metabolism in both clinical studies and preclinical models. We hypothesized that (-)-epicatechin would alleviate thermoneutral housing-induced glucose intolerance. Male rats were housed at either thermoneutral (30 °C) or room temperature (24 °C) for 16 weeks and gavaged with either 1 mg/kg body weight or vehicle for the last 15 days before sacrifice. Rats housed at thermoneutrality had a significantly elevated serum glucose area under the curve (p < 0.05) and reduced glucose-mediated insulin secretion. In contrast, rats at thermoneutrality treated with (-)-epicatechin had improved glucose tolerance and increased insulin secretion (p < 0.05). Insulin tolerance tests revealed no differences in insulin sensitivity in any of the four groups. Pancreatic immunohistochemistry staining showed significantly greater islet insulin positive cells in animals housed at thermoneutrality. In conclusion, (-)-epicatechin improved carbohydrate tolerance via increased insulin secretion in response to glucose challenge without a change in insulin sensitivity.


Assuntos
Catequina , Intolerância à Glucose , Resistência à Insulina , Animais , Glicemia/metabolismo , Catequina/farmacologia , Glucose/farmacologia , Intolerância à Glucose/induzido quimicamente , Intolerância à Glucose/tratamento farmacológico , Habitação , Insulina , Resistência à Insulina/fisiologia , Ratos
14.
Sensors (Basel) ; 22(19)2022 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-36236716

RESUMO

This research presents the technical considerations for implementing the CeCi (Computer Electronic Communication Interface) social robot. In this case, this robot responds to the need to achieve technological development in an emerging country with the aim of social impact and social interaction. There are two problems with the social robots currently on the market, which are the main focus of this research. First, their costs are not affordable for companies, universities, or individuals in emerging countries. The second is that their design is exclusively oriented to the functional part with a vision inherent to the engineers who create them without considering the vision, preferences, or requirements of the end users, especially for their social interaction. This last reason ends causing an aversion to the use of this type of robot. In response to the issues raised, a low-cost prototype is proposed, starting from a commercial platform for research development and using open source code. The robot design presented here is centered on the criteria and preferences of the end user, prioritizing acceptability for social interaction. This article details the selection process and hardware capabilities of the robot. Moreover, a programming section is provided to introduce the different software packages used and adapted for the social interaction, the main functions implemented, as well as the new and original part of the proposal. Finally, a list of applications currently developed with the robot and possible applications for future research are discussed.


Assuntos
Robótica , Engenharia , Humanos , Interação Social , Software , Interface Usuário-Computador
15.
Int J Mol Sci ; 23(3)2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35163519

RESUMO

Glucosinolate transporters (GTRs) are part of the nitrate/peptide transporter (NPF) family, members of which also transport specialized secondary metabolites as substrates. Glucosinolates are defense compounds derived from amino acids. We selected 4-methylthiobutyl (4MTB) and indol-3-ylmethyl (I3M) glucosinolates to study how GTR1 from Arabidopsis thaliana transports these substrates in computational simulation approaches. The designed pipeline reported here includes massive docking of 4MTB and I3M in an ensemble of GTR1 conformations (in both inward and outward conformations) extracted from molecular dynamics simulations, followed by clustered and substrate-protein interactions profiling. The identified key residues were mutated, and their role in substrate transport was tested. We were able to identify key residues that integrate a major binding site of these substrates, which is critical for transport activity. In silico approaches employed here represent a breakthrough in the plant transportomics field, as the identification of key residues usually takes a long time if performed from a purely wet-lab experimental perspective. The inclusion of structural bioinformatics in the analyses of plant transporters significantly speeds up the knowledge-gaining process and optimizes valuable time and resources.


Assuntos
Arabidopsis/metabolismo , Glucosinolatos/metabolismo , Proteínas de Transporte de Monossacarídeos/química , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Butiratos/metabolismo , Indóis/metabolismo , Modelos Moleculares , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica , Tioglucosídeos/metabolismo
16.
Int J Mol Sci ; 23(12)2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35742897

RESUMO

Excessive accumulation and release of fatty acids (FAs) in adipose and non-adipose tissue are characteristic of obesity and are associated with the leading causes of death worldwide. Chronic exposure to high concentrations of FAs such as palmitic acid (pal) is a risk factor for developing different neurodegenerative diseases (NDs) through several mechanisms. In the brain, astrocytic dysregulation plays an essential role in detrimental processes like metabolic inflammatory state, oxidative stress, endoplasmic reticulum stress, and autophagy impairment. Evidence shows that tibolone, a synthetic steroid, induces neuroprotective effects, but its molecular mechanisms upon exposure to pal remain largely unknown. Due to the capacity of identifying changes in the whole data-set of proteins and their interaction allowing a deeper understanding, we used a proteomic approach on normal human astrocytes under supraphysiological levels of pal as a model to induce cytotoxicity, finding changes of expression in proteins related to translation, transport, autophagy, and apoptosis. Additionally, tibolone pre-treatment showed protective effects by restoring those same pal-altered processes and increasing the expression of proteins from cell survival processes. Interestingly, ARF3 and IPO7 were identified as relevant proteins, presenting a high weight in the protein-protein interaction network and significant differences in expression levels. These proteins are related to transport and translation processes, and their expression was restored by tibolone. This work suggests that the damage caused by pal in astrocytes simultaneously involves different mechanisms that the tibolone can partially revert, making tibolone interesting for further research to understand how to modulate these damages.


Assuntos
Astrócitos , Ácido Palmítico , Astrócitos/metabolismo , Ácidos Graxos/metabolismo , Humanos , Norpregnenos , Ácido Palmítico/farmacologia , Biossíntese de Proteínas , Proteômica
17.
J Neurophysiol ; 125(2): 568-585, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33326305

RESUMO

Somatosensory input strength can be modulated by primary afferent depolarization (PAD) generated predominantly via presynaptic GABAA receptors on afferent terminals. We investigated whether ionotropic nicotinic acetylcholine receptors (nAChRs) also provide modulatory actions, focusing on myelinated afferent excitability in in vitro murine spinal cord nerve-attached models. Primary afferent stimulation-evoked synaptic transmission was recorded in the deep dorsal horn as extracellular field potentials (EFPs), whereas concurrently recorded dorsal root potentials (DRPs) were used as an indirect measure of PAD. Changes in afferent membrane excitability were simultaneously measured as direct current (DC)-shifts in membrane polarization recorded in dorsal roots or peripheral nerves. The broad nAChR antagonist d-tubocurarine (d-TC) selectively and strongly depressed Aδ-evoked synaptic EFPs (36% of control) coincident with similarly depressed A-fiber DRP (43% of control), whereas afferent electrical excitability remained unchanged. In comparison, acetylcholine (ACh) and the nAChR agonists, epibatidine and nicotine, reduced afferent excitability by generating coincident depolarizing DC-shifts in peripheral axons and intraspinally. Progressive depolarization corresponded temporally with the emergence of spontaneous axonal spiking and reductions in the DRP and all afferent-evoked synaptic actions (31%-37% of control). Loss of evoked response was long-lasting, independent of DC repolarization, and likely due to mechanisms initiated by spontaneous C-fiber activity. DC-shifts were blocked with d-TC but not GABAA receptor blockers and retained after tetrodotoxin block of voltage-gated Na+ channels. Notably, actions tested were comparable between three mouse strains, in rat, and when performed in different labs. Thus, nAChRs can regulate afferent excitability via two distinct mechanisms: by central Aδ-afferent actions, and by transient extrasynaptic axonal activation of high-threshold primary afferents.NEW & NOTEWORTHY Primary afferents express many nicotinic ACh receptor (nAChR) subtypes but whether activation is linked to presynaptic inhibition, facilitation, or more complex and selective activity modulation is unknown. Recordings of afferent-evoked responses in the lumbar spinal cord identified two nAChR-mediated modulatory actions: 1) selective control of Aδ afferent transmission and 2) robust changes in axonal excitability initiated via extrasynaptic shifts in DC polarization. This work broadens the diversity of presynaptic modulation of primary afferents by nAChRs.


Assuntos
Gânglios Espinais/metabolismo , Neurônios Aferentes/metabolismo , Receptores Nicotínicos/metabolismo , Potenciais Sinápticos , Animais , Gânglios Espinais/citologia , Gânglios Espinais/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Neurônios Aferentes/efeitos dos fármacos , Neurônios Aferentes/fisiologia , Agonistas Nicotínicos/farmacologia , Antagonistas Nicotínicos/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores Nicotínicos/classificação
18.
New Phytol ; 230(1): 139-154, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33507548

RESUMO

Non-structural carbon (NSC) storage (i.e. starch, soluble sugras and lipids) in tree stems play important roles in metabolism and growth. Their spatial distribution in wood may explain species-specific differences in carbon storage dynamics, growth and survival. However, quantitative information on the spatial distribution of starch and lipids in wood is sparse due to methodological limitations. Here we assessed differences in wood NSC and lipid storage between tropical tree species with different growth and mortality rates and contrasting functional types. We measured starch and soluble sugars in wood cores up to 4 cm deep into the stem using standard chemical quantification methods and histological slices stained with Lugol's iodine. We also detected neutral lipids using histological slices stained with Oil-Red-O. The histological method allowed us to group individuals into two categories according to their starch storage strategy: fiber-storing trees and parenchyma-storing trees. The first group had a bigger starch pool, slower growth and lower mortality rates than the second group. Lipid storage was found in wood parenchyma in five species and was related to low mortality rates. The quantification of the spatial distribution of starch and lipids in wood improves our understanding of NSC dynamics in trees and reveals additional dimensions of tree growth and survival strategies.


Assuntos
Amido , Árvores , Carboidratos , Carbono , Madeira
19.
Invest New Drugs ; 39(2): 509-515, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32984932

RESUMO

Folate receptor alpha (FRα) has been reported to be expressed in up to 80% of triple-negative breast cancers (TNBC) with limited expression in normal tissues, making it a promising therapeutic target. Mirvetuximab soravtansine (mirvetuximab-s) is an antibody drug conjugate which has shown promise in the treatment of FRα-positive solid tumors in early phase clinical trials. Herein, are the results of the first prospective phase II trial evaluating mirvetuximab-s in metastatic TNBC. Patients with advanced, FRα-positive TNBC were enrolled on this study. Mirvetuximab-s was administered at a dose of 6.0 mg/kg every 3 weeks. 96 patients with advanced TNBC consented for screening. FRα staining was performed on tumor tissue obtained from 80 patients. The rate of FRα positivity by immunohistochemistry was 10.0% (8/80). Two patients were treated on study, with best overall responses of stable disease in one and progressive disease in the other. Adverse events were consistent with earlier studies. The study was terminated early due to the low rate of FRα positivity in the screened patient population and lack of disease response in the two patients treated. The observed rate of FRα positivity was considerably lower than previously reported and none of the patients had a partial or complete response. Treatment with mirvetuximab-s should only be further explored in TNBC if an alternate biomarker strategy is developed for patient selection on the basis of additional preclinical data.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Imunoconjugados/uso terapêutico , Maitansina/análogos & derivados , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Adulto , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Receptor 1 de Folato/biossíntese , Humanos , Imunoconjugados/efeitos adversos , Maitansina/efeitos adversos , Maitansina/uso terapêutico , Estudos Prospectivos , Neoplasias de Mama Triplo Negativas/patologia
20.
Glob Chang Biol ; 27(11): 2271-2272, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33666304

RESUMO

Carbon and element cycling models can be expressed in terms of the dynamics of individual particles or collection of them in aggregated pools. In both cases, the models represent the same dynamics and provide similar predictions. The time required for individual particles to pass through a system, that is, the transit time, can be obtained from both approaches. Pool models can be analyzed from a stochastic or a deterministic point of view.


Assuntos
Carbono , Solo , Processos Estocásticos
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