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1.
Commun Biol ; 6(1): 1240, 2023 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-38066057

RESUMO

Skeletal muscle aging is characterized by the loss of muscle mass, strength and function, mainly attributed to the atrophy of glycolytic fibers. Underlying mechanisms driving the skeletal muscle functional impairment are yet to be elucidated. To unbiasedly uncover its molecular mechanisms, we recurred to gene expression and metabolite profiling in a glycolytic muscle, Extensor digitorum longus (EDL), from young and aged C57BL/6JRj mice. Employing multi-omics approaches we found that the main age-related changes are connected to mitochondria, exhibiting a downregulation in mitochondrial processes. Consistent is the altered mitochondrial morphology. We further compared our mouse EDL aging signature with human data from the GTEx database, reinforcing the idea that our model may recapitulate muscle loss in humans. We are able to show that age-related mitochondrial downregulation is likely to be detrimental, as gene expression signatures from commonly used lifespan extending interventions displayed the opposite direction compared to our EDL aging signature.


Assuntos
Mitocôndrias , Músculo Esquelético , Animais , Humanos , Camundongos , Envelhecimento/genética , Regulação para Baixo , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Músculo Esquelético/metabolismo
2.
Front Endocrinol (Lausanne) ; 14: 1128564, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36992810

RESUMO

Introduction: The number of frozen embryo transfers increased substantially in recent years. To increase the chances of implantation, endometrial receptivity and embryo competency must be synchronized. Maturation of the endometrium is facilitated by sequential administration of estrogens, followed by administration of progesterone prior to embryo transfer. The use of progesterone is crucial for pregnancy outcomes. This study compares the reproductive outcomes and tolerability of five different regimens of hormonal luteal phase support in artificial frozen embryo transfer cycles, with the objective of determining the best progesterone luteal phase support in this context. Design: This is a single-center retrospective cohort study of all women undergoing frozen embryo transfers between 2013 and 2019. After sufficient endometrial thickness was achieved by estradiol, luteal phase support was initiated. The following five different progesterone applications were compared: 1) oral dydrogesterone (30 mg/day), 2) vaginal micronized progesterone gel (90 mg/day), 3) dydrogesterone (20 mg/day) plus micronized progesterone gel (90 mg/day) (dydrogesterone + micronized progesterone gel), 4) micronized progesterone capsules (600 mg/day), and (5) subcutaneous injection of progesterone 25 mg/day (subcutan-P4). The vaginal micronized progesterone gel application served as the reference group. Ultrasound was performed after 12-15 days of oral estrogen (≥4 mg/day) administration. If the endometrial thickness was ≥7 mm, luteal phase support was started, up to six days before frozen embryo transfer, depending on the development of the frozen embryo. The primary outcome was the clinical pregnancy rate. Secondary outcomes included live birth rate, ongoing pregnancy, and miscarriage and biochemical pregnancy rate. Results: In total, 391 cycles were included in the study (median age of study participants 35 years; IQR 32-38 years, range 26-46 years). The proportions of blastocysts and single transferred embryos were lower in the micronized progesterone gel group. Differences among the five groups in other baseline characteristics were not significant. Multiple logistic regression analysis, adjusting for pre-defined covariates, showed that the clinical pregnancy rates were higher in the oral dydrogesterone only group (OR = 2.87, 95% CI 1.38-6.00, p=0.005) and in the dydrogesterone + micronized progesterone gel group (OR = 5.19, 95% CI 1.76-15.36, p = 0.003) compared to micronized progesterone gel alone. The live birth rate was higher in the oral dydrogesterone-only group (OR = 2.58; 95% CI 1.11-6.00; p=0.028) and showed no difference in the smaller dydrogesterone + micronized progesterone gel group (OR = 2.49; 95% CI 0.74-8.38; p=0.14) compared with the reference group. Conclusion: The application of dydrogesterone in addition to micronized progesterone gel was associated with higher clinical pregnancy rate and live birth rate and then the use of micronized progesterone gel alone. DYD should be evaluated as a promising LPS option in FET Cycles.


Assuntos
Didrogesterona , Progesterona , Gravidez , Feminino , Humanos , Adulto , Fase Luteal , Estudos Retrospectivos , Transferência Embrionária , Resultado da Gravidez , Estrogênios
3.
Int J Mol Sci ; 24(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36614300

RESUMO

Type 2 diabetes (T2D) represents a multifactorial metabolic disease with a strong genetic predisposition. Despite elaborate efforts in identifying the genetic variants determining individual susceptibility towards T2D, the majority of genetic factors driving disease development remain poorly understood. With the aim to identify novel T2D risk genes we previously generated an N2 outcross population using the two inbred mouse strains New Zealand obese (NZO) and C3HeB/FeJ (C3H). A linkage study performed in this population led to the identification of the novel T2D-associated quantitative trait locus (QTL) Nbg15 (NZO blood glucose on chromosome 15, Logarithm of odds (LOD) 6.6). In this study we used a combined approach of positional cloning, gene expression analyses and in silico predictions of DNA polymorphism on gene/protein function to dissect the genetic variants linking Nbg15 to the development of T2D. Moreover, we have generated congenic strains that associated the distal sublocus of Nbg15 to mechanisms altering pancreatic beta cell function. In this sublocus, Cbx6, Fam135b and Kdelr3 were nominated as potential causative genes associated with the Nbg15 driven effects. Moreover, a putative mutation in the Kdelr3 gene from NZO was identified, negatively influencing adaptive responses associated with pancreatic beta cell death and induction of endoplasmic reticulum stress. Importantly, knockdown of Kdelr3 in cultured Min6 beta cells altered insulin granules maturation and pro-insulin levels, pointing towards a crucial role of this gene in islets function and T2D susceptibility.


Assuntos
Diabetes Mellitus Tipo 2 , Predisposição Genética para Doença , Obesidade , Receptores de Peptídeos , Animais , Camundongos , Diabetes Mellitus Tipo 2/genética , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Camundongos Endogâmicos C3H , Camundongos Obesos , Obesidade/genética , Receptores de Peptídeos/genética
4.
Nat Cell Biol ; 25(1): 20-29, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36543979

RESUMO

Impaired proinsulin-to-insulin processing in pancreatic ß-cells is a key defective step in both type 1 diabetes and type 2 diabetes (T2D) (refs. 1,2), but the mechanisms involved remain to be defined. Altered metabolism of sphingolipids (SLs) has been linked to development of obesity, type 1 diabetes and T2D (refs. 3-8); nonetheless, the role of specific SL species in ß-cell function and demise is unclear. Here we define the lipid signature of T2D-associated ß-cell failure, including an imbalance of specific very-long-chain SLs and long-chain SLs. ß-cell-specific ablation of CerS2, the enzyme necessary for generation of very-long-chain SLs, selectively reduces insulin content, impairs insulin secretion and disturbs systemic glucose tolerance in multiple complementary models. In contrast, ablation of long-chain-SL-synthesizing enzymes has no effect on insulin content. By quantitatively defining the SL-protein interactome, we reveal that CerS2 ablation affects SL binding to several endoplasmic reticulum-Golgi transport proteins, including Tmed2, which we define as an endogenous regulator of the essential proinsulin processing enzyme Pcsk1. Our study uncovers roles for specific SL subtypes and SL-binding proteins in ß-cell function and T2D-associated ß-cell failure.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Humanos , Proinsulina/genética , Proinsulina/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Esfingolipídeos/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Insulina/metabolismo , Homeostase , Proteínas de Transporte/metabolismo , Glucose/metabolismo , Células Secretoras de Insulina/metabolismo
6.
ACS Appl Mater Interfaces ; 14(14): 16147-16156, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35357146

RESUMO

Realization of all-solid-state batteries combined with metallic Li/Na is still hindered due to the unstable interface between the alkali metal and solid electrolytes, especially for highly promising thiophosphate materials. Artificial and uniform solid-electrolyte interphases (SEIs), serving as thin ion-conducting films, have been considered as a strategy to overcome the issues of such reactive interfaces. Here, we synthesized sulfide-based artificial SEIs (LixSy and NaxSy) on Li and Na by solid/gas reaction between the alkali metal and S vapor. The synthesized films are carefully characterized with various chemical/electrochemical techniques. We show that these artificial SEIs are not beneficial from an application point of view since they either contribute to additional resistances (Li) or do not prevent reactions at the alkali metal/electrolyte interface (Na). We show that NaxSy is more porous than LixSy, supported by (i) its rough morphology observed by focused ion beam-scanning electron microscopy, (ii) the rapid decrease of Rinterface (interfacial resistance) in NaxSy-covered-Na symmetric cells with liquid electrolyte upon aging under open-circuit potential, and (iii) the increase of Rinterface in NaxSy-covered-Na solid-state symmetric cells with Na3PS4 electrolyte. The porous SEI allows the penetration of liquid electrolyte or alkali metal creep through its pores, resulting in a continuous chemical reaction. Hence, porosity of SEIs in general should be carefully taken into account in the application of batteries containing both liquid electrolyte and solid electrolyte.

7.
Diabetes Care ; 45(4): 928-937, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35113139

RESUMO

OBJECTIVE: Individuals with type 2 diabetes are at higher risk of progression of nonalcoholic fatty liver (steatosis) to steatohepatitis (NASH), fibrosis, and cirrhosis. The hepatic metabolism of obese individuals adapts by upregulation of mitochondrial capacity, which may be lost during the progression of steatosis. However, the role of type 2 diabetes with regard to hepatic mitochondrial function in NASH remains unclear. RESEARCH DESIGN AND METHODS: We therefore examined obese individuals with histologically proven NASH without (OBE) (n = 30; BMI 52 ± 9 kg/m2) or with type 2 diabetes (T2D) (n = 15; 51 ± 7 kg/m2) as well as healthy individuals without liver disease (CON) (n = 14; 25 ± 2 kg/m2). Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamps with d-[6,6-2H2]glucose. Liver biopsies were used for assessing mitochondrial capacity by high-resolution respirometry and protein expression. RESULTS: T2D and OBE had comparable hepatic fat content, lobular inflammation, and fibrosis. Oxidative capacity in liver tissue normalized for citrate synthase activity was 59% greater in OBE than in CON, whereas T2D presented with 33% lower complex II-linked oxidative capacity than OBE and higher H2O2 production than CON. Interestingly, those with NASH and hepatic fibrosis score ≥1 had lower oxidative capacity and antioxidant defense than those without fibrosis. CONCLUSIONS: Loss of hepatic mitochondrial adaptation characterizes NASH and type 2 diabetes or hepatic fibrosis and may thereby favor accelerated disease progression.


Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Fígado/metabolismo , Cirrose Hepática/complicações , Mitocôndrias/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/complicações
8.
Antioxidants (Basel) ; 10(5)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946318

RESUMO

Mitochondria are critical for hypothalamic function and regulators of metabolism. Hypothalamic mitochondrial dysfunction with decreased mitochondrial chaperone expression is present in type 2 diabetes (T2D). Recently, we demonstrated that a dysregulated mitochondrial stress response (MSR) with reduced chaperone expression in the hypothalamus is an early event in obesity development due to insufficient insulin signaling. Although insulin activates this response and improves metabolism, the metabolic impact of one of its members, the mitochondrial chaperone heat shock protein 10 (Hsp10), is unknown. Thus, we hypothesized that a reduction of Hsp10 in hypothalamic neurons will impair mitochondrial function and impact brain insulin action. Therefore, we investigated the role of chaperone Hsp10 by introducing a lentiviral-mediated Hsp10 knockdown (KD) in the hypothalamic cell line CLU-183 and in the arcuate nucleus (ARC) of C57BL/6N male mice. We analyzed mitochondrial function and insulin signaling utilizing qPCR, Western blot, XF96 Analyzer, immunohistochemistry, and microscopy techniques. We show that Hsp10 expression is reduced in T2D mice brains and regulated by leptin in vitro. Hsp10 KD in hypothalamic cells induced mitochondrial dysfunction with altered fatty acid metabolism and increased mitochondria-specific oxidative stress resulting in neuronal insulin resistance. Consequently, the reduction of Hsp10 in the ARC of C57BL/6N mice caused hypothalamic insulin resistance with acute liver insulin resistance.

9.
J Mol Cell Cardiol ; 141: 17-29, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32201174

RESUMO

AIMS: We aimed to unravel the genetic, molecular and cellular pathomechanisms of DSC2 truncation variants leading to arrhythmogenic cardiomyopathy (ACM). METHODS AND RESULTS: We report a homozygous 4-bp DSC2 deletion variant c.1913_1916delAGAA, p.Q638LfsX647hom causing a frameshift carried by an ACM patient. Whole exome sequencing and comparative genomic hybridization analysis support a loss of heterozygosity in a large segment of chromosome 18 indicating segmental interstitial uniparental isodisomy (UPD). Ultrastructural analysis of the explanted myocardium from a mutation carrier using transmission electron microscopy revealed a partially widening of the intercalated disc. Using qRT-PCR we demonstrated that DSC2 mRNA expression was substantially decreased in the explanted myocardial tissue of the homozygous carrier compared to controls. Western blot analysis revealed absence of both full-length desmocollin-2 isoforms. Only a weak expression of the truncated form of desmocollin-2 was detectable. Immunohistochemistry showed that the truncated form of desmocollin-2 did not localize at the intercalated discs. In vitro, transfection experiments using induced pluripotent stem cell derived cardiomyocytes and HT-1080 cells demonstrated an obvious absence of the mutant truncated desmocollin-2 at the plasma membrane. Immunoprecipitation in combination with fluorescence measurements and Western blot analyses revealed an abnormal secretion of the truncated desmocollin-2. CONCLUSION: In summary, we unraveled segmental UPD as the likely genetic reason for a small homozygous DSC2 deletion. We conclude that a combination of nonsense mediated mRNA decay and extracellular secretion is involved in DSC2 related ACM.


Assuntos
Arritmias Cardíacas/genética , Cardiomiopatias/genética , Desmocolinas/genética , Deleção de Genes , Dissomia Uniparental/genética , Sequência de Aminoácidos , Arritmias Cardíacas/complicações , Sequência de Bases , Cardiomiopatias/complicações , Linhagem Celular Tumoral , Desmocolinas/química , Desmocolinas/metabolismo , Feminino , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Miocárdio/patologia , Miocárdio/ultraestrutura , Miócitos Cardíacos/metabolismo , Linhagem
10.
Am J Physiol Endocrinol Metab ; 318(5): E590-E599, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31891536

RESUMO

Besides a therapeutic target for type 2 diabetes, dipeptidyl peptidase 4 (DPP4) is an adipokine potentially upregulated in human obesity. We aimed to explore the role of adipocyte-derived DPP4 in diet-induced obesity and insulin resistance with an adipose tissue-specific knockout (AT-DPP4-KO) mouse. Wild-type and AT-DPP4-KO mice were fed for 24 wk with a high fat diet (HFD) and characterized for body weight, glucose tolerance, insulin sensitivity by hyperinsulinemic-euglycemic clamp, and body composition and hepatic fat content. Image and molecular biology analysis of inflammation, as well as adipokine secretion, was performed in AT by immunohistochemistry, Western blot, real-time-PCR, and ELISA. Incretin levels were determined by Luminex kits. Under HFD, AT-DPP4-KO displayed markedly reduced circulating DPP4 concentrations, proving AT as a relevant source. Independently of glucose-stimulated incretin hormones, AT-DPP4-KO had improved glucose tolerance and hepatic insulin sensitivity. AT-DPP4-KO displayed smaller adipocytes and increased anti-inflammatory markers. IGF binding protein 3 (IGFBP3) levels were lower in AT and serum, whereas free IGF1 was increased. The absence of adipose DPP4 triggers beneficial AT remodeling with decreased production of IGFBP3 during HFD, likely contributing to the observed, improved hepatic insulin sensitivity.


Assuntos
Tecido Adiposo/metabolismo , Dipeptidil Peptidase 4/metabolismo , Resistência à Insulina/fisiologia , Fígado/metabolismo , Obesidade/metabolismo , Adipócitos/metabolismo , Adipocinas/metabolismo , Animais , Peso Corporal , Dieta Hiperlipídica/efeitos adversos , Dipeptidil Peptidase 4/genética , Imuno-Histoquímica , Insulina/metabolismo , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Masculino , Camundongos , Obesidade/etiologia , Obesidade/genética
11.
Nat Commun ; 10(1): 4179, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519890

RESUMO

The mechanisms underlying improved insulin sensitivity after surgically-induced weight loss are still unclear. We monitored skeletal muscle metabolism in obese individuals before and over 52 weeks after metabolic surgery. Initial weight loss occurs in parallel with a decrease in muscle oxidative capacity and respiratory control ratio. Persistent elevation of intramyocellular lipid intermediates, likely resulting from unrestrained adipose tissue lipolysis, accompanies the lack of rapid changes in insulin sensitivity. Simultaneously, alterations in skeletal muscle expression of genes involved in calcium/lipid metabolism and mitochondrial function associate with subsequent distinct DNA methylation patterns at 52 weeks after surgery. Thus, initial unfavorable metabolic changes including insulin resistance of adipose tissue and skeletal muscle precede epigenetic modifications of genes involved in muscle energy metabolism and the long-term improvement of insulin sensitivity.


Assuntos
Resistência à Insulina/fisiologia , Músculo Esquelético/metabolismo , Tecido Adiposo/metabolismo , Adulto , Metilação de DNA/genética , Metilação de DNA/fisiologia , Epigênese Genética/genética , Feminino , Derivação Gástrica , Humanos , Resistência à Insulina/genética , Metabolismo dos Lipídeos/genética , Metabolismo dos Lipídeos/fisiologia , Masculino , Pessoa de Meia-Idade , Obesidade/genética , Obesidade/metabolismo , Obesidade/cirurgia
12.
Int J Mol Sci ; 20(14)2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31373310

RESUMO

Bacteria colonize most of the human body, and the female genital tract is not an exception. While the existence of a vaginal microbiota has been well established, the upper genital tract has been considered a sterile environment, with a general assumption that bacterial presence is associated with adverse clinical manifestation. However, recent metagenomic studies identified specific patterns of microbiota colonizing the uterus, fallopian tubes, ovaries, and placenta. These results need confirmation and further investigations since the data are only scarce. Bacterial colonization of these sites appears different from the vaginal one, despite evidence that vaginal bacteria could ascend to the upper genital tract through the cervix. Are these bacteria only commensal or do they play a role in the physiology of the female upper genital tract? Which are the genera that may have a negative and a positive impact on the female reproductive function? The aim of this review is to critically present all available data on upper genital tract microbiota and discuss its role in human reproduction, ranging from the technical aspects of these types of analyses to the description of specific bacterial genera. Although still very limited, research focusing on genital colonization of bacteria other than the vaginal milieu might bring novel insights into physiopathology of human reproduction.


Assuntos
Tubas Uterinas/microbiologia , Lactobacillus/isolamento & purificação , Ovário/microbiologia , Placenta/microbiologia , Útero/microbiologia , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Feminino , Humanos , Lactobacillus/genética , Microbiota/fisiologia , Gravidez , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S/genética
13.
Mol Metab ; 21: 68-81, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30670351

RESUMO

OBJECTIVE: Insulin action in the brain controls metabolism and brain function, which is linked to proper mitochondrial function. Conversely, brain insulin resistance associates with mitochondrial stress and metabolic and neurodegenerative diseases. In the present study, we aimed to decipher the impact of hypothalamic insulin action on mitochondrial stress responses, function and metabolism. METHODS: To investigate the crosstalk of insulin action and mitochondrial stress responses (MSR), namely the mitochondrial unfolded protein response (UPRmt) and integrated stress response (ISR), qPCR, western blotting, and mitochondrial activity assays were performed. These methods were used to analyze the hypothalamic cell line CLU183 treated with insulin in the presence or absence of the insulin receptor as well as in mice fed a high fat diet (HFD) for three days and STZ-treated mice without or with insulin therapy. Intranasal insulin treatment was used to investigate the effect of acute brain insulin action on metabolism and mitochondrial stress responses. RESULTS: Acute HFD feeding reduces hypothalamic mitochondrial stress responsive gene expression of Atf4, Chop, Hsp60, Hsp10, ClpP, and Lonp1 in C57BL/6N mice. We show that insulin via ERK activation increases the expression of MSR genes in vitro as well as in the hypothalamus of streptozotocin-treated mice. This regulation propagates mitochondrial function by controlling mitochondrial proteostasis and prevents excessive autophagy under serum deprivation. Finally, short-term intranasal insulin treatment activates MSR gene expression in the hypothalamus of HFD-fed C57BL/6N mice and reduces food intake and body weight development. CONCLUSIONS: We define hypothalamic insulin action as a novel master regulator of MSR, ensuring proper mitochondrial function by controlling mitochondrial proteostasis and regulating metabolism.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Hipotálamo/metabolismo , Insulina/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Aumento de Peso/fisiologia , Administração Intranasal , Animais , Autofagia , Linhagem Celular , Diabetes Mellitus/induzido quimicamente , Diabetes Mellitus/tratamento farmacológico , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Expressão Gênica , Técnicas de Inativação de Genes , Hipotálamo/patologia , Insulina/administração & dosagem , Insulina/uso terapêutico , Fator de Crescimento Insulin-Like I/metabolismo , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Proteostase , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Estreptozocina/farmacologia
14.
Endocrinology ; 159(4): 1748-1761, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29481597

RESUMO

The Rab guanosine triphosphatase-activating protein (RabGAP) TBC1D1 has been shown to be a key regulator of glucose and lipid metabolism in skeletal muscle. Its function in pancreatic islets, however, is not yet fully understood. Here, we aimed to clarify the specific impact of TBC1D1 on insulin secretion and substrate use in pancreatic islets. We analyzed the dynamics of glucose-stimulated insulin secretion (GSIS) and lipid metabolism in isolated islets from Tbc1d1-deficient (D1KO) mice. To further investigate the underlying cellular mechanisms, we conducted pharmacological studies in these islets. In addition, we determined morphology and number of both pancreatic islets and insulin vesicles in ß-cells using light and transmission electron microscopy. Isolated pancreatic islets from D1KO mice exhibited substantially increased GSIS compared with wild-type (WT) controls. This was attributed to both enhanced first and second phase of insulin secretion, and this enhanced secretion persisted during repetitive glucose stimuli. Studies with sulfonylureas or KCl in isolated islets demonstrated that TBC1D1 exerts its function via a signaling pathway at the level of membrane depolarization. In line, ultrastructural analysis of isolated pancreatic islets revealed both higher insulin-granule density and number of docked granules in ß-cells from D1KO mice compared with WT controls. Like in skeletal muscle, lipid use in isolated islets was enhanced upon D1KO, presumably as a result of a higher mitochondrial fission rate and/or higher mitochondrial activity. Our results clearly demonstrate a dual role of TBC1D1 in controlling substrate metabolism of the pancreatic islet.


Assuntos
Ácidos Graxos/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/fisiologia , Metabolismo dos Lipídeos/genética , Animais , Proteínas Ativadoras de GTPase/genética , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos , Camundongos Knockout
15.
Zebrafish ; 14(6): 547-551, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28968196

RESUMO

The increasing importance of zebrafish as a biomedical model organism is reflected by the steadily growing number of publications and laboratories working with this species. Regulatory recommendations for euthanasia as issued in Directive 2010/63/EU are, however, based on experience with fish species used for food production and do not take the small size and specific physiology of zebrafish into account. Consequently, the currently recommended methods of euthanasia in the Directive 2010/63/EU are either not applicable or may interfere with research goals. An international workshop was held in Karlsruhe, Germany, March 9, 2017, to discuss and propose alternative methods for euthanasia of zebrafish. The aim was to identify methods that adequately address the physiology of zebrafish and its use as a biomedical research model, follow the principles of the 3Rs (Replacement, Reduction, and Refinement) in animal experimentation and consider animal welfare during anesthesia and euthanasia. The results of the workshop are summarized here in the form of a white paper.


Assuntos
Bem-Estar do Animal , Eutanásia Animal , Peixe-Zebra/fisiologia , Anestesia/veterinária , Animais , Ciência dos Animais de Laboratório/educação
16.
Nat Commun ; 7: 13560, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-27995929

RESUMO

An important question is how growing tissues establish a blood vessel network. Here we study vascular network formation in pancreatic islets, endocrine tissues derived from pancreatic epithelium. We find that depletion of integrin-linked kinase (ILK) in the pancreatic epithelial cells of mice results in glucose intolerance due to a loss of the intra-islet vasculature. In turn, blood vessels accumulate at the islet periphery. Neither alterations in endothelial cell proliferation, apoptosis, morphology, Vegfa expression and VEGF-A secretion nor 'empty sleeves' of vascular basement membrane are found. Instead, biophysical experiments reveal that the biomechanical properties of pancreatic islet cells, such as their actomyosin-mediated cortex tension and adhesive forces to endothelial cells, are significantly changed. These results suggest that a sorting event is driving the segregation of endothelial and epithelial cells and indicate that the epithelial biomechanical properties determine whether the blood vasculature invades or envelops a growing epithelial tissue.


Assuntos
Epitélio/irrigação sanguínea , Epitélio/fisiologia , Ilhotas Pancreáticas/irrigação sanguínea , Proteínas Serina-Treonina Quinases/fisiologia , Actomiosina/fisiologia , Animais , Membrana Basal/fisiologia , Fenômenos Biomecânicos , Adesão Celular/fisiologia , Células Endoteliais/citologia , Células Endoteliais/fisiologia , Células Epiteliais/fisiologia , Feminino , Intolerância à Glucose/fisiopatologia , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neovascularização Fisiológica , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
17.
PLoS One ; 10(9): e0138535, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26422139

RESUMO

A hallmark feature of type 1 and type 2 diabetes mellitus is the progressive dysfunction and loss of insulin-producing pancreatic beta cells, and inflammatory cytokines are known to trigger beta cell death. Here we asked whether the anti-oxidant protein DJ-1 encoded by the Parkinson's disease gene PARK7 protects islet cells from cytokine- and streptozotocin-mediated cell death. Wild type and DJ-1 knockout mice (KO) were treated with multiple low doses of streptozotocin (MLDS) to induce inflammatory beta cell stress and cell death. Subsequently, glucose tolerance tests were performed, and plasma insulin as well as fasting and random blood glucose concentrations were monitored. Mitochondrial morphology and number of insulin granules were quantified in beta cells. Moreover, islet cell damage was determined in vitro after streptozotocin and cytokine treatment of isolated wild type and DJ-1 KO islets using calcein AM/ethidium homodimer-1 staining and TUNEL staining. Compared to wild type mice, DJ-1 KO mice became diabetic following MLDS treatment. Insulin concentrations were substantially reduced, and fasting blood glucose concentrations were significantly higher in MLDS-treated DJ-1 KO mice compared to equally treated wild type mice. Rates of beta cell apoptosis upon MLDS treatment were twofold higher in DJ-1 KO mice compared to wild type mice, and in vitro inflammatory cytokines led to twice as much beta cell death in pancreatic islets from DJ-1 KO mice versus those of wild type mice. In conclusion, this study identified the anti-oxidant protein DJ-1 as being capable of protecting pancreatic islet cells from cell death induced by an inflammatory and cytotoxic setting.


Assuntos
Citocinas/metabolismo , Diabetes Mellitus Experimental/metabolismo , Células Secretoras de Insulina/metabolismo , Mitocôndrias/metabolismo , Proteínas Oncogênicas/metabolismo , Peroxirredoxinas/metabolismo , Animais , Morte Celular , Citocinas/genética , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Insulina/genética , Insulina/metabolismo , Células Secretoras de Insulina/patologia , Camundongos , Camundongos Knockout , Mitocôndrias/genética , Mitocôndrias/patologia , Proteínas Oncogênicas/genética , Peroxirredoxinas/genética , Proteína Desglicase DJ-1 , Vesículas Secretórias/genética , Vesículas Secretórias/metabolismo
18.
PLoS One ; 10(9): e0137043, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26331477

RESUMO

BACKGROUND: Glomerular podocytes are highly differentiated cells that are key components of the kidney filtration units. The podocyte cytoskeleton builds the basis for the dynamic podocyte cytoarchitecture and plays a central role for proper podocyte function. Recent studies implicate that immunosuppressive agents including the mTOR-inhibitor everolimus have a protective role directly on the stability of the podocyte actin cytoskeleton. In contrast, a potential stabilization of microtubules by everolimus has not been studied so far. METHODS: To elucidate mechanisms underlying mTOR-inhibitor mediated cytoskeletal rearrangements, we carried out microarray gene expression studies to identify target genes and corresponding pathways in response to everolimus. We analyzed the effect of everolimus in a puromycin aminonucleoside experimental in vitro model of podocyte injury. RESULTS: Upon treatment with puromycin aminonucleoside, microarray analysis revealed gene clusters involved in cytoskeletal reorganization, cell adhesion, migration and extracellular matrix composition to be affected. Everolimus was capable of protecting podocytes from injury, both on transcriptional and protein level. Rescued genes included tubulin beta 2B class IIb (TUBB2B) and doublecortin domain containing 2 (DCDC2), both involved in microtubule structure formation in neuronal cells but not identified in podocytes so far. Validating gene expression data, Western-blot analysis in cultured podocytes demonstrated an increase of TUBB2B and DCDC2 protein after everolimus treatment, and immunohistochemistry in healthy control kidneys confirmed a podocyte-specific expression. Interestingly, Tubb2bbrdp/brdp mice revealed a delay in glomerular podocyte development as showed by podocyte-specific markers Wilm's tumour 1, Podocin, Nephrin and Synaptopodin. CONCLUSIONS: Taken together, our study suggests that off-target, non-immune mediated effects of the mTOR-inhibitor everolimus on the podocyte cytoskeleton might involve regulation of microtubules, revealing a potential novel role of TUBB2B and DCDC2 in glomerular podocyte development.


Assuntos
Everolimo/farmacologia , Proteínas Associadas aos Microtúbulos/genética , Microtúbulos/efeitos dos fármacos , Podócitos/efeitos dos fármacos , Tubulina (Proteína)/genética , Animais , Adesão Celular , Linhagem Celular Transformada , Humanos , Rim/metabolismo , Camundongos , Camundongos Mutantes , Microtúbulos/metabolismo , Podócitos/metabolismo , Transcriptoma
19.
J Perinat Med ; 43(2): 141-6, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24964255

RESUMO

OBJECTIVE: Obesity is an important issue among fertile women as it may affect obstetric and neonatal outcomes. METHODS: Obstetric and neonatal outcomes of primiparous women were retrospectively analyzed in non-obese (n=11387) and obese (n=943) women. A subgroup analysis was performed in obese women divided into three groups: Grade I obesity (Group A, n=654), Grade II obesity (Group B, n=192), and Grade III obesity (Group C, n=97). Odds ratios (OR) were expressed with the corresponding 95% confidence intervals (CI). RESULTS: The incidence of gestational diabetes (non-obese, 1.9%; obese, 7.6%; Group C, 19.6%) and preeclampsia (non-obese, 3.3%; obese, 13.5%; Group C, 17.5%) increased with rising weight. The risk of non-elective cesarean section was significantly higher in obese women than in non-obese women (21.7% vs. 13.2%). The risk of extreme preterm birth (before 28 weeks of gestation) doubled in the Grade I obesity group (OR, 2.1; 95% CI, 1.4-3.2) and nearly tripled in women with body mass index ≥35 kg/m2 (OR, 2.9; 95% CI, 1.7-4.9). CONCLUSION: Pre-pregnancy obesity is associated with higher incidences of gestational diabetes and preeclampsia. Our study shows that obese women have a higher risk of non-elective cesarean section and preterm birth.


Assuntos
Obesidade/complicações , Complicações na Gravidez/etiologia , Adulto , Cesárea/estatística & dados numéricos , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Paridade , Gravidez , Estudos Retrospectivos , Adulto Jovem
20.
Diabetes ; 63(11): 3856-67, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24917575

RESUMO

Although insulin resistance is known to underlie type 2 diabetes, its role in the development of type 1 diabetes has been gaining increasing interest. In a model of type 1 diabetes, the nonobese diabetic (NOD) mouse, we found that insulin resistance driven by lipid- and glucose-independent mechanisms is already present in the liver of prediabetic mice. Hepatic insulin resistance is associated with a transient rise in mitochondrial respiration followed by increased production of lipid peroxides and c-Jun N-terminal kinase activity. At the onset of diabetes, increased adipose tissue lipolysis promotes myocellular diacylglycerol accumulation. This is paralleled by increased myocellular protein kinase C θ activity and serum fetuin A levels. Muscle mitochondrial oxidative capacity is unchanged at the onset but decreases at later stages of diabetes. In conclusion, hepatic and muscle insulin resistance manifest at different stages and involve distinct cellular mechanisms during the development of diabetes in the NOD mouse.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina/fisiologia , Animais , Diabetes Mellitus Tipo 2/sangue , Modelos Animais de Doenças , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Peróxidos Lipídicos/metabolismo , Fígado/metabolismo , Camundongos , Estado Pré-Diabético/metabolismo , Proteína Quinase C/metabolismo , alfa-2-Glicoproteína-HS/metabolismo
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