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1.
Commun Biol ; 7(1): 802, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38956302

RESUMO

G protein-coupled receptors (GPCRs) are mainly regulated by GPCR kinase (GRK) phosphorylation and subsequent ß-arrestin recruitment. The ubiquitously expressed GRKs are classified into cytosolic GRK2/3 and membrane-tethered GRK5/6 subfamilies. GRK2/3 interact with activated G protein ßγ-subunits to translocate to the membrane. Yet, this need was not linked as a factor for bias, influencing the effectiveness of ß-arrestin-biased agonist creation. Using multiple approaches such as GRK2/3 mutants unable to interact with Gßγ, membrane-tethered GRKs and G protein inhibitors in GRK2/3/5/6 knockout cells, we show that G protein activation will precede GRK2/3-mediated ß-arrestin2 recruitment to activated receptors. This was independent of the source of free Gßγ and observable for Gs-, Gi- and Gq-coupled GPCRs. Thus, ß-arrestin interaction for GRK2/3-regulated receptors is inseparably connected with G protein activation. We outline a theoretical framework of how GRK dependence on free Gßγ can determine a GPCR's potential for biased agonism. Due to this inherent cellular mechanism for GRK2/3 recruitment and receptor phosphorylation, we anticipate generation of ß-arrestin-biased ligands to be mechanistically challenging for the subgroup of GPCRs exclusively regulated by GRK2/3, but achievable for GRK5/6-regulated receptors, that do not demand liberated Gßγ. Accordingly, GRK specificity of any GPCR is foundational for developing arrestin-biased ligands.


Assuntos
Quinases de Receptores Acoplados a Proteína G , Subunidades beta da Proteína de Ligação ao GTP , Subunidades gama da Proteína de Ligação ao GTP , Humanos , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/genética , Células HEK293 , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Subunidades beta da Proteína de Ligação ao GTP/genética , Quinases de Receptores Acoplados a Proteína G/metabolismo , Quinases de Receptores Acoplados a Proteína G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/genética , Fosforilação , Animais , Transdução de Sinais
3.
Ann Surg Oncol ; 31(6): 4073-4083, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38459418

RESUMO

BACKGROUND: Although addition of adjuvant chemotherapy is the current standard, the prognosis of pancreatic cancers still remains poor. The NEPAFOX trial evaluated perioperative treatment with FOLFIRINOX in resectable pancreatic cancer. PATIENTS AND METHODS: This multicenter phase II trial randomized patients with resectable or borderline resectable pancreatic cancer without metastases into arm (A,) upfront surgery plus adjuvant gemcitabine, or arm (B,) perioperative FOLFIRINOX. The primary endpoint was overall survival (OS). RESULTS: Owing to poor accrual, recruitment was prematurely stopped after randomization of 40 of the planned 126 patients (A: 21, B: 19). Overall, approximately three-quarters were classified as primarily resectable (A: 16, B: 15), and the remaining patients were classified as borderline resectable (A: 5, B: 4). Of the 12 evaluable patients, 3 achieved partial response under neoadjuvant FOLFIRINOX. Of the 21 patients in arm A and 19 patients in arm B, 17 and 7 underwent curative surgery, and R0-resection was achieved in 77% and 71%, respectively. Perioperative morbidity occurred in 72% in arm A and 46% in arm B, whereas non-surgical toxicity was comparable in both arms. Median RFS/PFS was almost doubled in arm B (14.1 months) compared with arm A (8.4 months) in the population with surgical resection, whereas median OS was comparable between both arms. CONCLUSIONS: Although the analysis was only descriptive owing to small patient numbers, no safety issues regarding surgical complications were observed in the perioperative FOLFIRINOX arm. Thus, considering the small number of patients, perioperative treatment approach appears feasible and potentially effective in well-selected cohorts of patients. In pancreatic cancer, patient selection before initiation of neoadjuvant therapy appears to be critical.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Desoxicitidina , Fluoruracila , Gencitabina , Irinotecano , Leucovorina , Terapia Neoadjuvante , Oxaliplatina , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Desoxicitidina/análogos & derivados , Desoxicitidina/administração & dosagem , Masculino , Feminino , Leucovorina/administração & dosagem , Leucovorina/uso terapêutico , Irinotecano/administração & dosagem , Irinotecano/uso terapêutico , Fluoruracila/administração & dosagem , Oxaliplatina/administração & dosagem , Oxaliplatina/uso terapêutico , Pessoa de Meia-Idade , Idoso , Quimioterapia Adjuvante , Taxa de Sobrevida , Seguimentos , Prognóstico , Pancreatectomia , Adulto , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Adenocarcinoma/mortalidade
4.
Vet Surg ; 53(4): 761-768, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38525897

RESUMO

OBJECTIVE: To report the long-term outcome of utilization of a silicone stent to support the management of a permanent tracheostomy. STUDY DESIGN: Short case series. ANIMALS: Two client-owned brachycephalic dogs. METHODS: Two brachycephalic dogs with stage III laryngeal collapse underwent permanent tracheostomy. After the tracheostomy had healed, a silicone stent was inserted to support the stoma and facilitate home care. One dog wore a commercially available silicone stent for the follow-up period of 2 years. For the dog in Case 2, a 3D-printed, medical-grade silicone stent with an increased length was designed, as the dog had developed skin sores from the commercial device. RESULTS: Both dogs tolerated the silicone stent well. Stent care was managed by the owners without need for assistance. They reported that the silicone stent facilitated cleaning of the stoma surroundings and that they felt an increased confidence in airway patency, as the device prevented the tracheal stoma from collapsing. In Case 1, tracheoscopy 1 year after first stent insertion revealed minimal visible changes to the tracheal stoma. In Case 2, the 3D printed silicone stent led to a remission of skin sores and the dog wore the device comfortably until succumbing to an unrelated disease 13 months later. CONCLUSION: The insertion of a silicone stent is a simple and cost-effective method to improve home care of dogs with permanent tracheostomy. Larger dogs, as in Case 2, may benefit from custom-designed 3D-printed stents.


Assuntos
Doenças do Cão , Impressão Tridimensional , Silicones , Stents , Traqueostomia , Animais , Cães , Traqueostomia/veterinária , Traqueostomia/instrumentação , Traqueostomia/métodos , Stents/veterinária , Doenças do Cão/cirurgia , Masculino , Feminino , Resultado do Tratamento
5.
Rambam Maimonides Med J ; 15(1)2024 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-38261345

RESUMO

Coronary artery bypass grafting (CABG) is the most commonly performed and studied major cardiac operation worldwide. An understanding of the evolution of CABG, including the early days of cardiac surgery, the first bypass operation, continuous improvements in techniques, and streamlining of the operation, is important to inform current trends and future innovations. This article will examine how CABG evolved (from techniques to conduits), describe current trends in the field, and explore what lies on the horizon for the future of CABG.

6.
Soc Sci Med ; 342: 116538, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38181719

RESUMO

The relationship between economic activity and suicides has been the subject of much scrutiny, but the focus in the extant literature has been almost exclusively on estimating associations rather than causal effects. In this paper, using data from England and Wales between January 1, 1997 and December 31, 2017, we propose a plausible set of assumptions to estimate the causal impacts of well-known macroeconomic variables on the daily suicide rate. Our identification strategy relies on scheduled macroeconomic announcements and professional economic forecasts. An important advantage of using these variables to model suicide rates is that they can efficiently capture the elements of 'surprise or shock' via the observed difference between how the economy actually performed and how it was expected to perform. Provided that professional forecasts are unbiased and efficient, the estimated 'surprises or shocks' are 'as good as random', and therefore are exogenous. We employ time series regressions and present robust evidence that these exogenous macroeconomic shocks affect the suicide rate. Overall, our results are consistent with economic theory that shocks that reduce estimated permanent income, and therefore expected lifetime utility, can propel suicide rates. Specifically, at the population level, negative shocks to consumer confidence and house prices accelerate the suicide rate. However, there is evidence of behavioural heterogeneity between sexes, states of the economy, and levels of public trust in government. Negative shocks to the retail price index (RPI) raise the suicide rate for males. Negative shocks to the growth rate in gross domestic product (GDP) raise the population suicide rate when the economy is doing poorly. When public trust in government is low, increases in the unemployment rate increase the suicide rate for females.


Assuntos
Suicídio , Masculino , Feminino , Humanos , País de Gales/epidemiologia , Causalidade , Recessão Econômica , Inglaterra/epidemiologia
7.
Am J Biol Anthropol ; 183(1): 60-78, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37607125

RESUMO

OBJECTIVES: The investigation of morphological variation in animals is widely used in taxonomy, ecology, and evolution. Using large datasets for meta-analyses has dramatically increased, raising concerns about dataset compatibilities and biases introduced by contributions of multiple researchers. MATERIALS AND METHODS: We compiled morphological data on 13 variables for 3073 individual mouse lemurs (Cheirogaleidae, Microcebus spp.) from 25 taxa and 153 different sampling locations, measured by 48 different researchers. We introduced and applied a filtering pipeline and quantified improvements in data quality (Shapiro-Francia statistic, skewness, and excess kurtosis). The filtered dataset was then used to test for genus-wide sexual size dimorphism and the applicability of Rensch's, Allen's, and Bergmann's rules. RESULTS: Our pipeline reduced inter-observer bias (i.e., increased normality of data distributions). Inter-observer reliability of measurements was notably variable, highlighting the need to reduce data collection biases. Although subtle, we found a consistent pattern of sexual size dimorphism across Microcebus, with females being the larger (but not heavier) sex. Sexual size dimorphism was isometric, providing no support for Rensch's rule. Variations in tail length but not in ear size were consistent with the predictions of Allen's rule. Body mass and length followed a pattern contrary to predictions of Bergmann's rule. DISCUSSION: We highlighted the usefulness of large multi-researcher datasets for testing ecological hypotheses after correcting for inter-observer biases. Using genus-wide tests, we outlined generalizable patterns of morphological variability across all mouse lemurs. This new methodological toolkit aims to facilitate future large-scale morphological comparisons for a wide range of taxa and applications.


Assuntos
Cheirogaleidae , Animais , Feminino , Humanos , Tamanho Corporal , Variações Dependentes do Observador , Confiabilidade dos Dados , Reprodutibilidade dos Testes
8.
Curr Opin Cardiol ; 38(6): 464-470, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37751395

RESUMO

PURPOSE OF REVIEW: The surgical management of patients undergoing coronary artery bypass grafting (CABG) with low ejection fraction presents unique challenges that require meticulous attention to details and good surgical technique and judgement. This review details the latest evidence and best practices in the care of such patients. RECENT FINDINGS: CABG in patients with low ejection fraction carries a significant risk of perioperative mortality and morbidity related to the development of postcardiotomy shock. Preoperative optimization with pharmacological or mechanical support is required, especially in patients with cardiogenic shock. Rapid and complete revascularization is what CABG surgeons aim to achieve. Multiple arterial revascularization should be reserved to selected patients. Off-pump CABG, on-pump breathing heart CABG, and new cardioplegic solutions remain of uncertain benefit compared with traditional CABG. SUMMARY: Tremendous advancements in CABG allowed surgeons to offer revascularization to patients with severe left ventricular dysfunction and multivessel disease with acceptable risk. Despite that, there is a lack of comprehensive and robust studies particularly on long-term outcomes. Individualized patient assessment and a heart team approach should be used to determine the optimal surgical strategy for each patient.


Assuntos
Ponte de Artéria Coronária sem Circulação Extracorpórea , Doença da Artéria Coronariana , Disfunção Ventricular Esquerda , Humanos , Resultado do Tratamento , Ponte de Artéria Coronária/métodos , Disfunção Ventricular Esquerda/cirurgia , Ponte de Artéria Coronária sem Circulação Extracorpórea/métodos , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/cirurgia , Estudos Retrospectivos
9.
Genes (Basel) ; 14(7)2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37510355

RESUMO

Habitat loss and fragmentation are of concern to conservation biologists worldwide. However, not all organisms are affected equally by these processes; thus, it is important to study the effects of living in fragmented habitats on species that differ in lifestyle and habitat requirements. In this study, we examined the dispersal and connectivity patterns of rodents, one endemic (Eliurus myoxinus) and one invasive (Rattus rattus), in two landscapes containing forest fragments and adjacent continuous forest patches in northwestern Madagascar. We generated genetic (RADseq) data for 66 E. myoxinus and 81 R. rattus individuals to evaluate differences in genetic diversity as well as inbreeding and connectivity in two landscapes. We found higher levels of inbreeding and lower levels of genetic diversity in E. myoxinus compared with R. rattus. We observed related dyads both within and between habitat patches and positive spatial autocorrelation at lower distance classes for both species, with a stronger pattern of spatial autocorrelation in R. rattus. Across each site, we identified contrasting migration rates for each species, but these did not correspond to habitat-matrix dichotomies. The relatively low genetic diversity in the endemic E. myoxinus suggests ecological constraints that require further investigation.


Assuntos
Florestas , Roedores , Ratos , Animais , Roedores/genética , Madagáscar , Ecossistema , Variação Genética/genética
11.
J Chem Ecol ; 49(9-10): 549-569, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37453001

RESUMO

The cyclic depsipeptide FR900359 (FR) is derived from the soil bacterium Chromobacterium vaccinii and known to bind Gq proteins of mammals and insects, thereby abolishing the signal transduction of their Gq protein-coupled receptors, a process that leads to severe physiological consequences. Due to their highly conserved structure, Gq family of proteins are a superior ecological target for FR producing organisms, resulting in a defense towards a broad range of harmful organisms. Here, we focus on the question whether bacteria like C. vaccinii are important factors in soil in that their secondary metabolites impair, e.g., plant harming organisms like nematodes. We prove that the Gq inhibitor FR is produced under soil-like conditions. Furthermore, FR inhibits heterologously expressed Gαq proteins of the nematodes Caenorhabditis elegans and Heterodera schachtii in the micromolar range. Additionally, in vivo experiments with C. elegans and the plant parasitic cyst nematode H. schachtii demonstrated that FR reduces locomotion of C. elegans and H. schachtii. Finally, egg-laying of C. elegans and hatching of juvenile stage 2 of H. schachtii from its cysts is inhibited by FR, suggesting that FR might reduce nematode dispersion and proliferation. This study supports the idea that C. vaccinii and its excreted metabolome in the soil might contribute to an ecological equilibrium, maintaining and establishing the successful growth of plants.


Assuntos
Depsipeptídeos , Nematoides , Animais , Solo , Caenorhabditis elegans , Depsipeptídeos/farmacologia , Bactérias , Transdução de Sinais , Mamíferos
12.
J Endocrinol ; 258(3)2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37399525

RESUMO

Estrogens regulate synaptic properties and influence hippocampus-related learning and memory via estrogen receptors, which include the G-protein-coupled estrogen receptor 1 (GPER1). Studying mice, in which the GPER1 gene is dysfunctional (GPER1-KO), we here provide evidence for sex-specific roles of GPER1 in these processes. GPER1-KO males showed reduced anxiety in the elevated plus maze, whereas the fear response ('freezing') was specifically increased in GPER1-KO females in a contextual fear conditioning paradigm. In the Morris water maze, spatial learning and memory consolidation was impaired by GPER1 deficiency in both sexes. Notably, in the females, spatial learning deficits and the fear response were more pronounced if mice were in a stage of the estrous cycle, in which E2 serum levels are high (proestrus) or rising (diestrus). On the physiological level, excitability at Schaffer collateral synapses in CA1 increased in GPER1-deficient males and in proestrus/diestrus ('E2 high') females, concordant with an increased hippocampal expression of the AMPA-receptor subunit GluA1 in GPER1-KO males and females as compared to wildtype males. Further changes included an augmented early long-term potentiation (E-LTP) maintenance specifically in GPER1-KO females and an increased hippocampal expression of spinophilin in metestrus/estrus ('E2 low') GPER1-KO females. Our findings suggest modulatory and sex-specific functions of GPER1 in the hippocampal network, which reduce rather than increase neuronal excitability. Dysregulation of these functions may underlie sex-specific cognitive deficits or mood disorders.


Assuntos
Hipocampo , Receptores de Estrogênio , Masculino , Feminino , Camundongos , Animais , Receptores de Estrogênio/genética , Potenciação de Longa Duração/genética , Sinapses/fisiologia , Cognição , Plasticidade Neuronal/genética
13.
ACS Chem Biol ; 18(8): 1748-1759, 2023 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-37366538

RESUMO

Nonheme diiron monooxygenases (NHDMs) interact with nonribosomal peptide synthetase (NRPS) assembly lines to install ß-hydroxylations at thiolation-domain-bound amino acids during nonribosomal peptide biosynthesis. The high potential of this enzyme family to diversify the products of engineered assembly lines is disproportionate to the currently small knowledge about their structures and mechanisms of substrate recognition. Here, we report the crystal structure of FrsH, the NHDM which catalyzes the ß-hydroxylation of l-leucines during biosynthesis of the depsipeptide G protein inhibitor FR900359. Using biophysical approaches, we provide evidence that FrsH interacts with the cognate monomodular NRPS FrsA. By AlphaFold modeling and mutational studies, we detect and examine structural features within the assembly line crucial to recruit FrsH for leucine ß-hydroxylation. These are, in contrast to cytochrome-dependent NRPS ß-hydroxylases, not located on the thiolation domain, but on the adenylation domain. FrsH can be functionally substituted by homologous enzymes from biosyntheses of the cell-wall-targeting antibiotics lysobactin and hypeptin, indicating that these features are generally applicable to members of the family of trans-acting NHDMs. These insights give important directions for the construction of artificial assembly lines to yield bioactive and chemically complex peptide products.


Assuntos
Oxigenases de Função Mista , Biossíntese de Peptídeos Independentes de Ácido Nucleico , Oxigenases de Função Mista/metabolismo , Aminoácidos/química , Antibacterianos , Peptídeo Sintases/metabolismo
14.
Psychoneuroendocrinology ; 156: 106320, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37307791

RESUMO

In order to translate the findings from the vast animal literature on the effect of 17ß-estradiol (E2) on brain and behavior to humans, a placebo-controlled pharmacological enhancement of E2 levels for at least 24 h is necessary. However, an exogenous increase in E2 for such a prolonged period might affect the endogenous secretion of other (neuroactive) hormones. Such effects would be of relevance for the interpretation of the effects of this pharmacological regimen on cognition and its neural correlates as well as be of basic scientific interest. We therefore administered a double dose of 12 mg of estradiol-valerate (E2V) to men and of 8 mg to naturally cycling women in their low-hormone phase, and assessed the concentration of two steroids critical to hormone regulation: follicle stimulating hormone (FSH) and luteinizing hormone (LH). We also assessed any changes in concentration of the neuroactive hormones progesterone (P4), testosterone (TST), dihydrotestosterone (DHT) and immune-like growth factor 1 (IGF-1). This regimen resulted in similar E2 levels in both sexes (saliva and serum). FSH and LH levels in both sexes were down-regulated to the same degree. P4 concentration decreased in both sexes only in serum but not saliva. TST and DHT levels dropped only in men whereas sex-hormone binding globulin was not affected. Finally, the concentration of IGF-1 decreased in both sexes. Based on previous studies on the effects of these neuroactive hormones, only the degree of downregulation of TST and DHT levels in men might have an impact on brain and behavior, which should be considered when interpreting the effects of the presented E2V regimes.


Assuntos
Fator de Crescimento Insulin-Like I , Hormônio Luteinizante , Masculino , Animais , Humanos , Feminino , Estradiol/farmacologia , Hormônio Foliculoestimulante , Testosterona/farmacologia , Menopausa , Valeratos
15.
Int J Angiol ; 32(2): 136-139, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37207008

RESUMO

The objective of this study was to explain step by step how to achieve a complete resection of an intravascular leiomyoma. A 48-year-old woman was referred to our institution with progressive dyspnea on exertion, lightheadedness, and previous history of total abdominal hysterectomy and bilateral salpingo-oophorectomy for a uterine leiomyoma echocardiography, computed tomography, and magnetic resonance imaging of the heart and abdomen/pelvis were performed and an intracaval mass with extension into the right heart and pulmonary artery was identified. After multidisciplinary review, a single-stage sternotomy-laparotomy procedure on cardiopulmonary bypass (with beating heart, mild hypothermia, and no deep hypothermic circulatory arrest) ensured complete resection of a giant intravenous leiomyoma (IVL). Multidisciplinary approach, multimodality imaging, and single-stage sternotomy-laparotomy procedure on cardiopulmonary bypass (with heart beating and mild hypothermia) ensure complete resection of IVL.

16.
Diabetologia ; 66(8): 1501-1515, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37217659

RESUMO

AIMS/HYPOTHESIS: After birth, the neonatal islets gradually acquire glucose-responsive insulin secretion, a process that is subjected to maternal imprinting. Although NEFA are major components of breastmilk and insulin secretagogues, their role for functional maturation of neonatal beta cells is still unclear. NEFA are the endogenous ligands of fatty acid receptor 1 (FFA1, encoded by Ffar1 in mice), a Gq-coupled receptor with stimulatory effect on insulin secretion. This study investigates the role of FFA1 in neonatal beta cell function and in the adaptation of offspring beta cells to parental high-fat feeding. METHODS: Wild-type (WT) and Ffar1-/- mice were fed high-fat (HFD) or chow diet (CD) for 8 weeks before mating, and during gestation and lactation. Blood variables, pancreas weight and insulin content were assessed in 1-, 6-, 11- and 26-day old (P1-P26) offspring. Beta cell mass and proliferation were determined in P1-P26 pancreatic tissue sections. FFA1/Gq dependence of insulin secretion was evaluated in isolated islets and INS-1E cells using pharmacological inhibitors and siRNA strategy. Transcriptome analysis was conducted in isolated islets. RESULTS: Blood glucose levels were higher in CD-fed Ffar1-/- P6-offspring compared with CD-fed WT P6-offspring. Accordingly, glucose-stimulated insulin secretion (GSIS) and its potentiation by palmitate were impaired in CD Ffar1-/- P6-islets. In CD WT P6-islets, insulin secretion was stimulated four- to fivefold by glucose and five- and sixfold over GSIS by palmitate and exendin-4, respectively. Although parental HFD increased blood glucose in WT P6-offspring, it did not change insulin secretion from WT P6-islets. In contrast, parental HFD abolished glucose responsiveness (i.e. GSIS) in Ffar1-/- P6-islets. Inhibition of Gq by FR900359 or YM-254890 in WT P6-islets mimicked the effect of Ffar1 deletion, i.e. suppression of GSIS and of palmitate-augmented GSIS. The blockage of Gi/o by pertussis toxin (PTX) enhanced (100-fold) GSIS in WT P6-islets and rendered Ffar1-/- P6-islets glucose responsive, suggesting constitutive activation of Gi/o. In WT P6-islets, FR900359 cancelled 90% of PTX-mediated stimulation, while in Ffar1-/- P6-islets it completely abolished PTX-elevated GSIS. The secretory defect of Ffar1-/- P6-islets did not originate from insufficient beta cells, since beta cell mass increased with the offspring's age irrespective of genotype and diet. In spite of that, in the breastfed offspring (i.e. P1-P11) beta cell proliferation and pancreatic insulin content had a genotype- and diet-driven dynamic. Under CD, the highest proliferation rate was reached by the Ffar1-/- P6 offspring (3.95% vs 1.88% in WT P6), whose islets also showed increased mRNA levels of genes (e.g. Fos, Egr1, Jun) typically high in immature beta cells. Although parental HFD increased beta cell proliferation in both WT (4.48%) and Ffar1-/- (5.19%) P11 offspring, only the WT offspring significantly increased their pancreatic insulin content upon parental HFD (5.18 µg under CD to 16.93 µg under HFD). CONCLUSIONS/INTERPRETATION: FFA1 promotes glucose-responsive insulin secretion and functional maturation of newborn islets and is required for adaptive offspring insulin secretion in the face of metabolic challenge, such as parental HFD.


Assuntos
Células Secretoras de Insulina , Ilhotas Pancreáticas , Feminino , Camundongos , Animais , Glucose/farmacologia , Glucose/metabolismo , Secreção de Insulina , Glicemia/metabolismo , Animais Recém-Nascidos , Ilhotas Pancreáticas/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Palmitatos/metabolismo
17.
J Neuroendocrinol ; 35(5): e13276, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37170708

RESUMO

Microglia have been shown to sculpt postnatal circuitry from birth up to adulthood due to their role in both synapse formation, synaptic pruning, and the elimination of weak, redundant synapses. Microglia are differentiated in a sex-dependent manner. In this study, we tested whether sexual differentiation of microglia results in sex-dependent postnatal reorganization of CA1 synaptic connectivity in the hippocampus. The stereological counting of synapses in mice using electron microscopy showed a continuous rise in synapse density until the fourth week, followed by a plateau phase and loss of synapses from the eighth week onwards, with no difference between sexes. This course of alteration in synapse numbers did not differ between sexes. However, selectively, on postnatal day (P) 14 the density of synapses was significantly higher in the female than in the male hippocampus. Higher synapse density in females was paralleled by higher activity of microglia, as indicated by morphological changes, CD68 expression, and proximity of microglia to synaptic sites. In Thy1-GFP mice, consistent with increased synapse numbers, bouton density was also clearly increased in females at P14. At this time point, CD47 expression, the "don't eat me" signal of neurons, was similar in males and females. The decrease in bouton density thereafter in conjunction with increased synapse numbers argues for a role of microglia in the formation of multispine boutons (MSB). Our data in females at P14 support the regulatory role of microglia in synapse density. Sexual differentiation of microglia, however, does not substantially affect long-term synaptic reorganization in the hippocampus.


Assuntos
Hipocampo , Microglia , Camundongos , Masculino , Feminino , Animais , Microglia/metabolismo , Neurônios , Sinapses/metabolismo , Terminações Pré-Sinápticas
18.
iScience ; 26(4): 106492, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37091255

RESUMO

The macrocyclic depsipeptides YM-254890 (YM) and FR900359 (FR) are potent inhibitors of Gαq/11 proteins. They are important pharmacological tools and have potential as therapeutic drugs. The hydrogenated, tritium-labeled YM and FR derivatives display largely different residence times despite similar structures. In the present study we established a competition-association binding assay to determine the dissociation kinetics of unlabeled Gq protein inhibitors. Structure-affinity and structure-residence time relationships were analyzed. Small structural modifications had a large impact on residence time. YM and FR exhibited 4- to 10-fold higher residence times than their hydrogenated derivatives. While FR showed pseudo-irreversible binding, YM displayed much faster dissociation from its target. The isopropyl anchor present in FR and some derivatives was essential for slow dissociation. These data provide a basis for future drug design toward modulating residence times of macrocyclic Gq protein inhibitors, which has been recognized as a crucial determinant for therapeutic outcome.

19.
ACS Nano ; 17(9): 8807-8814, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37083204

RESUMO

Nucleation plays a critical role in the birth of crystals and is associated with a vast array of phenomena, such as protein crystallization and ice formation in clouds. Despite numerous experimental and theoretical studies, many aspects of the nucleation process, such as the polymorph selection mechanism in the early stages, are far from being understood. Here, we show that the hitherto unexplained excess of particles in a face-centered-cubic (fcc)-like environment, as compared to those in a hexagonal-close-packed (hcp)-like environment, in a crystal nucleus of hard spheres can be explained by the higher order structure in the fluid phase. We show using both simulations and experiments that in the metastable fluid phase, pentagonal bipyramids, clusters with fivefold symmetry known to be inhibitors of crystal nucleation, transform into a different cluster, Siamese dodecahedra. These clusters are closely similar to an fcc subunit, which explains the higher propensity to grow fcc than hcp in hard spheres. We show that our crystallization and polymorph selection mechanism is generic for crystal nucleation from a dense, strongly correlated fluid phase.

20.
Int J Antimicrob Agents ; 62(1): 106807, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37030471

RESUMO

Cryptococcus gattii and Cryptococcus neoformans are the main etiological agents of cryptococcosis, an invasive mycosis treated with amphotericin B, 5-fluorocytosine, and fluconazole. This limited arsenal is toxic and is associated with antifungal resistance. Cryptococcosis and malaria pathogens are eukaryotic organisms that have a high incidence in Sub-Saharan Africa. The antimalarials (ATMs) halofantrine (HAL) and amodiaquine (AQ) block Plasmodium heme polymerase, and artesunate (ART) induces oxidative stress. Considering that Cryptococcus spp. is susceptible to reactive oxygen species and that iron is essential for metabolism, the repurposing of ATMs for treating cryptococcosis was tested. ATMs reduced fungal growth, induced oxidative and nitrosative stresses, and altered ergosterol content, melanin production, and polysaccharide capsule size in C. neoformans and C. gattii, revealing a dynamic effect on fungal physiology. A comprehensive chemical-genetic analysis using two mutant libraries demonstrated that the deletion of genes involved in synthesizing components of the plasma membrane and cell wall, and oxidative stress responses are essential for fungal susceptibility to ATMs. Interestingly, the amphotericin B (AMB) fungicidal concentrations were ∼10 times lower when combined with ATMs, demonstrating a synergistic interaction. Further, the combinations showed reduced toxicity to murine macrophages. Finally, HAL+AMB and AQ+AMB efficiently reduced lethality and fungal burden in the lungs and brain in murine cryptococcosis. These findings provide perspectives for further studies with ATMs against cryptococcosis and other fungal infections.


Assuntos
Antimaláricos , Criptococose , Cryptococcus gattii , Cryptococcus neoformans , Animais , Camundongos , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Antifúngicos/metabolismo , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Antimaláricos/metabolismo , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Fluconazol/farmacologia , Fluconazol/uso terapêutico , Testes de Sensibilidade Microbiana
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