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1.
Mol Neurobiol ; 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39375286

RESUMO

In humans and mice, Nkx2-1 and Pax8 are crucial morphogenic transcription factors defining the early development of the thyroid and specific extrathyroidal tissues. By using 3-month-old single or double heterozygotes for Nkx2-1- and Pax8-null mutations (DHTP) mice, we studied brain abnormalities under different human-like dysthyroidisms, focusing on putative alterations of specific neurotransmitter systems, expression of markers of pre- and post-synaptic function and, given the physio-pathological role mitochondria have in controlling the bioenergetic status of neurons, of mitochondrial dynamics and oxidative balance. Compared to Wt controls, DHTP mice, bearing both systemic and brain hypothyroidism, showed altered expression of synaptic markers, generic and cholinergic (corroborated by immunohistochemistry in caudate, putamen, hippocampus, and basal forebrain) and glutamatergic ones, and reduced expression of key proteins of synaptic plasticity potency and several isoforms of glutamate receptors. The brain of DHTP mice was characterized by lower levels of H2O2 and imbalanced mitochondrial dynamics. Nkx2-1 + / - mice showed dopaminergic neuron-specific alterations, morphologically, more evident in the substantia nigra of DHTP mice. Nkx2-1 + / - mice also showed enhanced mitochondrial biogenesis and oxidative capacity likely as a global response of the brain to Nkx2-1 haploinsufficiency and/or to their elevated T3 circulating levels. Reduced transcription of both tyrosine hydroxylase and dopamine transporter was observed in Pax8 + / - euthyroid mice, suggesting a dopaminergic dysfunction, albeit likely at an early stage, but consistent with the deregulated glucose homeostasis observed in such animals. Overall, new information was obtained on the impact of haploinsufficiency of Pax8 and NKx2-1 on several brain neuroanatomical, molecular, and neurochemical aspects, thus opening the way for future targeting brain dysfunctions in the management of both overt and subclinical thyroid dysfunctions.

2.
Front Endocrinol (Lausanne) ; 15: 1432819, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39301315

RESUMO

Maintaining a well-functioning mitochondrial network through the mitochondria quality control (MQC) mechanisms, including biogenesis, dynamics and mitophagy, is crucial for overall health. Mitochondrial dysfunction caused by oxidative stress and further exacerbated by impaired quality control can trigger inflammation through the release of the damage-associated molecular patterns (mtDAMPs). mtDAMPs act by stimulating the cyclic GMP-AMP synthase (cGAS) stimulator of interferon genes (STING) pathway. Recently, aberrant signalling of the cGAS-STING axis has been recognised to be closely associated with several sterile inflammatory diseases (e.g. non-alcoholic fatty liver disease, obesity). This may fit the pathophysiology of hypothyroidism, an endocrine disorder characterised by the reduction of thyroid hormone production associated with impaired metabolic fluxes, oxidative balance and inflammatory status. Both 3,5,3'-triiodo-L-tyronine (T3) and its derivative 3,5-diiodo-L-thyronine (3,5-T2), are known to mitigate processes targeting mitochondria, albeit the underlying mechanisms are not yet fully understood. Therefore, we used a chemically induced hypothyroidism rat model to investigate the effect of 3,5-T2 or T3 administration on inflammation-related factors (inflammatory cytokines, hepatic cGAS-STING pathway), oxidative stress, antioxidant defence enzymes, mitochondrial DNA (mtDNA) damage, release and repair, and the MQC system in the liver. Hypothyroid rats showed: i) increased oxidative stress, ii) accumulation of mtDNA damage, iii) high levels of circulating cytokines, iv) hepatic activation of cGAS-STING pathways and v) impairment of MQC mechanisms and autophagy. Both iodothyronines restored oxidative balance by enhancing antioxidant defence, preventing mtDNA damage through the activation of mtDNA repair mechanisms (OGG1, APE1, and POLγ) and promoting autophagy progression. Concerning MQC, both iodothyronines stimulated mitophagy and dynamics, with 3,5-T2 activating fusion and T3 modulating both fusion and fission processes. Moreover, only T3 enhanced mitochondrial biogenesis. Notably, 3,5-T2, but not T3, reversed the hypothyroidism-induced activation of the cGAS-STING inflammatory cascade. In addition, it is noteworthy that 3,5-T2 seems more effective than T3 in reducing circulating pro-inflammatory cytokines IL-6 and IL-1B and in stimulating the release of IL-10, a known anti-inflammatory cytokine. These findings reveal novel molecular mechanisms of hepatic signalling pathways involved in hypothyroidism, which could be targeted by natural iodothyronines, particularly 3,5-T2, paving the way for the development of new treatment strategies for inflammatory diseases.


Assuntos
Di-Iodotironinas , Hipotireoidismo , Inflamação , Fígado , Proteínas de Membrana , Nucleotidiltransferases , Estresse Oxidativo , Animais , Ratos , Hipotireoidismo/metabolismo , Hipotireoidismo/induzido quimicamente , Hipotireoidismo/tratamento farmacológico , Hipotireoidismo/patologia , Fígado/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Nucleotidiltransferases/metabolismo , Masculino , Inflamação/metabolismo , Inflamação/tratamento farmacológico , Inflamação/patologia , Di-Iodotironinas/farmacologia , Proteínas de Membrana/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Tri-Iodotironina , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Ratos Wistar , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/patologia , Transdução de Sinais/efeitos dos fármacos
3.
Animals (Basel) ; 13(20)2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37893948

RESUMO

Here, we evaluated the effect of dietary supplementation with an Olea europaea L. extract on the animal welfare and milk quality of dairy cows. Thirty Italian Holstein-Friesian dairy cows in the mid-lactation phase (90 to 210 days) were blocked into experimental groups based on parity class (namely, primiparous (P) (n = 10), secondiparous (S) (n = 10) and pluriparous (PL) (n = 10)) and received, for 60 days, Phenofeed Dry® at 500 mg/cow/day. Milk and blood samples were collected before the start of the treatment (T0), subsequently every 15 days (T1-T4) and at 45 days after the end of treatment (T5). In the serum, glucose and triglycerides, stress, the thyroid, lactation and sex hormones were measured; in the milk, lysozyme content as well as the fatty acid profile were assessed. In the whole animal, the enriched feed helped to maintain hormonal parameters in the physiological range while producing hypoglycemic (T4 vs. T0, for P and PL p < 0.001) and hypolipidemic effects (T4 vs. T0, for P p < 0.001 and for PL p < 0.01). At the milk level, it resulted in a reduction in total fat (T5 vs. T0, for P, S and PL p < 0.001) and in the saturated fatty acids (SFAs)/monounsaturated fatty acids (MUFAs) ratio paralleled by an increase in polyunsaturated fatty acids (PUFAs) (T5 vs. T0, for P, S and PL p < 0.001), protein content (lysozyme (T4 vs. T0, for P and PL p < 0.001)) and lactose (T5 vs. T0, for P, S and PL p < 0.001). Thus, the inclusion of natural bioactive molecules such as O. europaea L. polyphenols in the dairy cow diet may help to improve animal welfare and milk quality.

4.
Int J Mol Sci ; 24(14)2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37511435

RESUMO

The adipose organ is involved in many metabolic functions, ranging from the production of endocrine factors to the regulation of thermogenic processes. Aging is a natural process that affects the physiology of the adipose organ, leading to metabolic disorders, thus strongly impacting healthy aging. Cellular senescence modifies many functional aspects of adipose tissue, leading to metabolic alterations through defective adipogenesis, inflammation, and aberrant adipocytokine production, and in turn, it triggers systemic inflammation and senescence, as well as insulin resistance in metabolically active tissues, leading to premature declined physiological features. In the various aging fat depots, senescence involves a multiplicity of cell types, including mature adipocytes and immune, endothelial, and progenitor cells that are aging, highlighting their involvement in the loss of metabolic flexibility, one of the common features of aging-related metabolic disorders. Since mitochondrial stress represents a key trigger of cellular senescence, and senescence leads to the accumulation of abnormal mitochondria with impaired dynamics and hindered homeostasis, this review focuses on the beneficial potential of targeting mitochondria, so that strategies can be developed to manage adipose tissue senescence for the treatment of age-related metabolic disorders.


Assuntos
Doenças Metabólicas , Mitocôndrias , Humanos , Mitocôndrias/metabolismo , Tecido Adiposo/metabolismo , Envelhecimento/metabolismo , Senescência Celular , Obesidade/metabolismo , Doenças Metabólicas/metabolismo
5.
Nutrients ; 15(14)2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37513513

RESUMO

Combining exercise with fasting is known to boost fat mass-loss, but detailed analysis on the consequential mobilization of visceral and subcutaneous WAT-derived fatty acids has not been performed. In this study, a subset of fasted male rats (66 h) was submitted to daily bouts of mild exercise. Subsequently, by using gas chromatography-flame ionization detection, the content of 22 fatty acids (FA) in visceral (v) versus subcutaneous (sc) white adipose tissue (WAT) depots was compared to those found in response to the separate events. Findings were related to those obtained in serum and liver samples, the latter taking up FA to increase gluconeogenesis and ketogenesis. Each separate intervention reduced scWAT FA content, associated with increased levels of adipose triglyceride lipase (ATGL) protein despite unaltered AMP-activated protein kinase (AMPK) Thr172 phosphorylation, known to induce ATGL expression. The mobility of FAs from vWAT during fasting was absent with the exception of the MUFA 16:1 n-7 and only induced by combining fasting with exercise which was accompanied with reduced hormone sensitive lipase (HSL) Ser563 and increased Ser565 phosphorylation, whereas ATGL protein levels were elevated during fasting in association with the persistently increased phosphorylation of AMPK at Thr172 both during fasting and in response to the combined intervention. As expected, liver FA content increased during fasting, and was not further affected by exercise, despite additional FA release from vWAT in this condition, underlining increased hepatic FA metabolism. Both fasting and its combination with exercise showed preferential hepatic metabolism of the prominent saturated FAs C:16 and C:18 compared to the unsaturated FAs 18:1 n-9 and 18:2 n-6:1. In conclusion, depot-specific differences in WAT fatty acid molecule release during fasting, irrelevant to their degree of saturation or chain length, are mitigated when combined with exercise, to provide fuel to surrounding organs such as the liver which is correlated with increased ATGL/ HSL ratios, involving AMPK only in vWAT.


Assuntos
Ácidos Graxos , Esterol Esterase , Ratos , Masculino , Animais , Esterol Esterase/metabolismo , Ácidos Graxos/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Lipase/metabolismo , Lipólise/fisiologia , Obesidade/metabolismo , Jejum/metabolismo , Tecido Adiposo/metabolismo
6.
Int J Mol Sci ; 24(11)2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37298533

RESUMO

Early life exposure to Endocrine Disruptor Chemicals (EDCs), such as the organophosphate pesticide Chlorpyrifos (CPF), affects the thyroid activity and dependent process, including the glucose metabolism. The damage of thyroid hormones (THs) as a mechanism of action of CPF is underestimated because the studies rarely consider that TH levels and signaling are customized peripherally. Here, we investigated the impairment of metabolism/signaling of THs and lipid/glucose metabolism in the livers of 6-month-old mice, developmentally and lifelong exposed to 0.1, 1, and 10 mg/kg/die CPF (F1) and their offspring similarly exposed (F2), analyzing the levels of transcripts of the enzymes involved in the metabolism of T3 (Dio1), lipids (Fasn, Acc1), and glucose (G6pase, Pck1). Both processes were altered only in F2 males, affected by hypothyroidism and by a systemic hyperglycemia linked to the activation of gluconeogenesis in mice exposed to 1 and 10 mg/kg/die CPF. Interestingly, we observed an increase in active FOXO1 protein due to a decrease in AKT phosphorylation, despite insulin signaling activation. Experiments in vitro revealed that chronic exposure to CPF affected glucose metabolism via the direct modulation of FOXO1 activity and T3 levels in hepatic cells. In conclusion, we described different sex and intergenerational effects of CPF exposure on the hepatic homeostasis of THs, their signaling, and, finally, glucose metabolism. The data points to FOXO1-T3-glucose signaling as a target of CPF in liver.


Assuntos
Clorpirifos , Hiperglicemia , Animais , Masculino , Camundongos , Clorpirifos/metabolismo , Glucose/metabolismo , Hiperglicemia/induzido quimicamente , Hiperglicemia/metabolismo , Fígado/metabolismo , Glândula Tireoide/metabolismo , Hormônios Tireóideos/metabolismo , Iodotironina Desiodinase Tipo II
7.
Front Cell Dev Biol ; 11: 1101844, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36875756

RESUMO

Dietary high fructose (HFrD) is known as a metabolic disruptor contributing to the development of obesity, diabetes, and dyslipidemia. Children are more sensitive to sugar than adults due to the distinct metabolic profile, therefore it is especially relevant to study the metabolic alterations induced by HFrD and the mechanisms underlying such changes in animal models of different ages. Emerging research suggests the fundamental role of epigenetic factors such as microRNAs (miRNAs) in metabolic tissue injury. In this perspective, the aim of the present study was to investigate the involvement of miR-122-5p, miR-34a-5p, and miR-125b-5p examining the effects induced by fructose overconsumption and to evaluate whether a differential miRNA regulation exists between young and adult animals. We used young rats (30 days) and adult rats (90 days) fed on HFrD for a short period (2 weeks) as animal models. The results indicate that both young and adult rats fed on HFrD exhibit an increase in systemic oxidative stress, the establishment of an inflammatory state, and metabolic perturbations involving the relevant miRNAs and their axes. In the skeletal muscle of adult rats, HFrD impair insulin sensitivity and triglyceride accumulation affecting the miR-122-5p/PTP1B/P-IRS-1(Tyr612) axis. In liver and skeletal muscle, HFrD acts on miR-34a-5p/SIRT-1: AMPK pathway resulting in a decrease of fat oxidation and an increase in fat synthesis. In addition, liver and skeletal muscle of young and adult rats exhibit an imbalance in antioxidant enzyme. Finally, HFrD modulates miR-125b-5p expression levels in liver and white adipose tissue determining modifications in de novo lipogenesis. Therefore, miRNA modulation displays a specific tissue trend indicative of a regulatory network that contributes in targeting genes of various pathways, subsequently yielding extensive effects on cell metabolism.

8.
Nutrients ; 14(21)2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36364781

RESUMO

Metabolic syndrome (MS), a cluster of metabolic risk factors, ranging from abdominal obesity, dyslipidaemia, hypertension, type 2 diabetes and non-alcoholic fatty liver disease [...].


Assuntos
Diabetes Mellitus Tipo 2 , Síndrome Metabólica , Hepatopatia Gordurosa não Alcoólica , Humanos , Síndrome Metabólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/metabolismo , Dieta , Fatores de Risco
9.
Gen Comp Endocrinol ; 328: 114104, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35973585

RESUMO

High-fat diet (HFD) affects the physiology of reproduction in males, and many studies have investigated its detrimental effects. In this study, we investigated the cellular response induced by an HFD in the rat testis, focusing on the mitochondrial compartment. After five weeks of HFD, an increase in the levels of malondialdehyde and of reduced form of glutathione in the rat testis indicated an increase in lipid peroxidation. The results showed an increase in autophagy, apoptosis, and mitochondrial damage in the testis of HFD rats. We found a decrease in the protein expression of mitochondrial antioxidant enzymes, such as catalase and SOD2. Immunohistochemical analysis revealed a decrease in the immunofluorescent signal of SOD2, mainly in the spermatogonia and spermatocytes of HFD rats. HFD-induced mitochondrial damage caused a reduction in mitochondria, as evidenced by a decrease in the protein expression of TOM20, a mitochondrial outer membrane receptor. Consistently, HFD enhanced the levels of the PINK1 protein, a mitophagy marker, suggesting the removal of damaged mitochondria under these conditions. Induction of mtDNA damage and repair was stronger in the HFD rat testis. Finally, we found a decrease in the mtDNA copy number and expression of the POLG enzyme, which is involved in mtDNA replication. In conclusion, our results showed that autophagy and apoptosis are activated in the testis of HFD rats as a survival strategy to cope with oxidative stress. Furthermore, HFD-induced oxidative stress affects the mitochondria, inducing mtDNA damage and mtDNA copy number reduction. Mitophagy and mtDNA repair mechanisms might represent a mitochondrial adaptive response.


Assuntos
Antioxidantes , Dieta Hiperlipídica , Animais , Antioxidantes/metabolismo , Autofagia/genética , Catalase/metabolismo , Catalase/farmacologia , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , DNA Mitocondrial/farmacologia , Glutationa/metabolismo , Masculino , Malondialdeído/metabolismo , Estresse Oxidativo , Proteínas Quinases/metabolismo , Proteínas Quinases/farmacologia , Ratos , Testículo/metabolismo
10.
J Exp Zool A Ecol Integr Physiol ; 337(9-10): 1025-1038, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35927786

RESUMO

The Harderian gland (HG) of Rattus norvegicus is an orbital gland secreting lipids that accumulate in excess under condition of increased lipid metabolism. To study the response elicitated by lipid overload in rat HG, we housed the animals in thermoneutral conditions (28-30°C) in association to high fat diet (HFD). In HFD rats alterated blood lipid levels result in lipid accumulation in HG as demonstrated by the increased gland weight and histochemical/ultrastructural analyses. The HFD-caused oxidative stress forces the gland to trigger antioxidant defense mechanisms and autophagic process, such as lipophagy and mitophagy. Induction of mitochondrial DNA (mtDNA) damage and repair was stronger in HFD-rat HGs. An increase in marker expression levels of mitochondrial biogenesis, fission, and fusion occurred to counteract mtDNA copy number reduction and mitophagy. Therefore, the results demonstrate that rat HG activates autophagy as survival strategy under conditions of increased lipid metabolism and suggest a key role for mitophagy and membrane dynamics in the mitochondrial adaptive response to HFD.


Assuntos
Dieta Hiperlipídica , Glândula de Harder , Ratos , Animais , Dieta Hiperlipídica/efeitos adversos , Glândula de Harder/metabolismo , Autofagia/fisiologia , DNA Mitocondrial/metabolismo , Lipídeos
11.
FASEB J ; 36(5): e22325, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35452152

RESUMO

The physiological role played by uncoupling protein 3 (UCP3) in white adipose tissue (WAT) has not been elucidated so far. In the present study, we evaluated the impact of the absence of the whole body UCP3 on WAT physiology in terms of ability to store triglycerides, oxidative capacity, response to insulin, inflammation, and adipokine production. Wild type (WT) and UCP3 Knockout (KO) mice housed at thermoneutrality (30°C) have been used as the animal model. Visceral gonadic WAT (gWAT) from KO mice showed an impaired capacity to store triglycerides (TG) as indicated by its lowered weight, reduced adipocyte diameter, and higher glycerol release (index of lipolysis). The absence of UCP3 reduces the maximal oxidative capacity of gWAT, increases mitochondrial free radicals, and activates ER stress. These processes are associated with increased levels of monocyte chemoattractant protein-1 and TNF-α. The response of gWAT to in vivo insulin administration, revealed by (ser473)-AKT phosphorylation, was blunted in KO mice, with a putative role played by eif2a, JNK, and inflammation. Variations in adipokine levels in the absence of UCP3 were observed, including reduced adiponectin levels both in gWAT and serum. As a whole, these data indicate an important role of UCP3 in regulating the metabolic functionality of gWAT, with its absence leading to metabolic derangement. The obtained results help to clarify some aspects of the association between metabolic disorders and low UCP3 levels.


Assuntos
Resistência à Insulina , Adipocinas/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Inflamação/metabolismo , Insulina/metabolismo , Lipólise , Camundongos , Camundongos Knockout , Triglicerídeos/metabolismo , Proteína Desacopladora 3/metabolismo
12.
Nutrients ; 14(6)2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-35334826

RESUMO

Mild endurance exercise has been shown to compensate for declined muscle quality and may positively affect the brain under conditions of energy restriction. Whether this involves brain-derived neurotrophic factor (BDNF) and mammalian target of rapamycin (mTOR) activation in relation to central and peripheral tissue levels of associated factors such as beta hydroxy butyrate (BHB), branched-chain amino acids (BCAA) and thyroid hormone (T3) has not been studied. Thus, a subset of male Wistar rats housed at thermoneutrality that were fed or fasted was submitted to 30-min-mild treadmill exercise bouts (five in total, twice daily, 15 m/min, 0° inclination) over a period of 66 h. Prefrontal cortex and gastrocnemius muscle BHB, BCAA, and thyroid hormone were measured by LC-MS/MS analysis and were related to BDNF and mammalian target of rapamycin (mTOR) signaling. In gastrocnemius muscle, mild endurance exercise during fasting maintained the fasting-induced elevated BHB levels and BDNF-CREB activity and unlocked the downstream Akt-mTORC1 pathway associated with increased tissue BCAA. Consequently, deiodinase 3 mRNA levels decreased whereas increased phosphorylation of the mTORC2 target FOXO1 was associated with increased deiodinase 2 mRNA levels, accounting for the increased T3 tissue levels. These events were related to increased expression of CREB and T3 target genes beneficial for muscle quality previously observed in this condition. In rat L6 myoblasts, BHB directly induced BDNF transcription and maturation. Mild endurance exercise during fasting did not increase prefrontal cortex BHB levels nor was BDNF activated, whereas increased leucine levels were associated with Akt-independent increased phosphorylation of the mTORC1 target P70S6K. The associated increased T3 levels modulated the expression of known T3-target genes involved in brain tissue maintenance. Our observation that mild endurance exercise modulates BDNF, mTOR and T3 during fasting provides molecular clues to explain the observed beneficial effects of mild endurance exercise in settings of energy restriction.


Assuntos
Aminoácidos de Cadeia Ramificada , Fator Neurotrófico Derivado do Encéfalo , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cromatografia Líquida , Jejum , Masculino , Mamíferos/metabolismo , Músculo Esquelético/metabolismo , Córtex Pré-Frontal/metabolismo , Ratos , Ratos Wistar , Serina-Treonina Quinases TOR/metabolismo , Espectrometria de Massas em Tandem , Hormônios Tireóideos/metabolismo
13.
Cells ; 11(6)2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35326451

RESUMO

Much is known, but there is also much more to discover, about the actions that thyroid hormones (TH) exert on metabolism. Indeed, despite the fact that thyroid hormones are recognized as one of the most important regulators of metabolic rate, much remains to be clarified on which mechanisms control/regulate these actions. Given their actions on energy metabolism and that mitochondria are the main cellular site where metabolic transformations take place, these organelles have been the subject of extensive investigations. In relatively recent times, new knowledge concerning both thyroid hormones (such as the mechanisms of action, the existence of metabolically active TH derivatives) and the mechanisms of energy transduction such as (among others) dynamics, respiratory chain organization in supercomplexes and cristes organization, have opened new pathways of investigation in the field of the control of energy metabolism and of the mechanisms of action of TH at cellular level. In this review, we highlight the knowledge and approaches about the complex relationship between TH, including some of their derivatives, and the mitochondrial respiratory chain.


Assuntos
Mitocôndrias , Hormônios Tireóideos , Metabolismo Energético/fisiologia , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Hormônios Tireóideos/metabolismo
14.
J Endocrinol ; 253(3): 115-132, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35289766

RESUMO

Thyroid dysfunctions are associated with liver diseases ranging, in severity, from insulin resistance (IR) to hepatocellular carcinoma. The pathogenic mechanisms appear complex and are not attributable, exclusively, to the impaired thyroid hormone (TH) signalling. Using a mouse model of human congenital hypothyroidism, young double heterozygote for both NK2 homeobox 1 (Nkx2-1)- and Paired box 8 (Pax8)-null mutations (DHTP) mice, and single heterozygous Pax8+/- and Nkx2-1+/- mice, we studied the liver pathways, the endocrine and metabolic factors affected in conditions of different dysthyroidisms. Young Nkx2-1+/- females displayed a slight hyperthyroidism and, in liver, increased TH signalling (i.e. increased expression of Dio1 and Trß1) and lipogenic gene expression, with triglycerides accumulation. Hypothyroid DHTP and euthyroid Pax8+/- females shared liver and skeletal muscle IR and hepatic hypothyroidism (i.e. reduced expression of Mct8, Dio1 and TRß1), activation of AKT and increased expression of glutathione peroxidase 4. Oxidative stress and reduced mitochondrial COX activity were observed in DHTP mice only. Pax8+/- females, but, unexpectedly, not DHTP ones, displayed transcriptional activation of the hepatic (and renal) gluconeogenic pathway, hypercortisolemia, fasting hyperglycaemia and hyperinsulinemia, reduced serum ß-hydroxybutyrate, associated with hepatic AMPK activation. DHTP mice showed hypercholesterolemia and activation of mTOR. Collectively, the data indicate that heterozygote mutations of Pax8 and Nkx2-1 genes may produce multiple dysmetabolisms, even under systemic euthyroidism. Differential liver pathways and multiple hormonal axes are affected with implications for energy and nutrient homeostasis. The identified players may be specific target in the management of thyroid dysfunction-associated dysmetabolisms in terms of prevention/counteraction of IR, type 2 diabetes and related comorbidities.


Assuntos
Hipotireoidismo Congênito , Diabetes Mellitus Tipo 2 , Animais , Hipotireoidismo Congênito/genética , Hipotireoidismo Congênito/patologia , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Haploinsuficiência , Fígado/metabolismo , Redes e Vias Metabólicas , Camundongos , Fator de Transcrição PAX8/genética , Fator de Transcrição PAX8/metabolismo , Fatores de Transcrição Box Pareados/metabolismo , Fator Nuclear 1 de Tireoide
15.
Genes (Basel) ; 13(2)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35205361

RESUMO

Metabolic dysfunction-associated fatty liver disease (MAFLD) is defined as the presence of hepatic steatosis in addition to one of three metabolic conditions: overweight/obesity, type 2 diabetes mellitus, or metabolic dysregulation. Chronic exposure to excess dietary fatty acids may cause hepatic steatosis and metabolic disturbances. The alteration of the quality of mitochondria is one of the factors that could contribute to the metabolic dysregulation of MAFDL. This study was designed to determine, in a rodent model of MAFLD, the effects of a long-term high-fat diet (HFD) on some hepatic processes that characterize mitochondrial quality control, such as biogenesis, dynamics, and mitophagy. To mimic the human manifestation of MAFLD, the rats were exposed to both an HFD and a housing temperature within the rat thermoneutral zone (28-30 °C). After 14 weeks of the HFD, the rats showed significant fat deposition and liver steatosis. Concomitantly, some important factors related to the hepatic mitochondrial quality were markedly affected, such as increased mitochondrial reactive oxygen species (ROS) production and mitochondrial DNA (mtDNA) damage; reduced mitochondrial biogenesis, mtDNA copy numbers, mtDNA repair, and mitochondrial fusion. HFD-fed rats also showed an impaired mitophagy. Overall, the obtained data shed new light on the network of different processes contributing to the failure of mitochondrial quality control as a central event for mitochondrial dysregulation in MAFLD.


Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatias , Animais , DNA Mitocondrial/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Dieta Hiperlipídica/efeitos adversos , Hepatopatias/metabolismo , Mitocôndrias/metabolismo , Ratos
16.
Diagnostics (Basel) ; 11(7)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206932

RESUMO

Since the beginning of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic, it has been clear that testing large groups of the population was the key to stem infection and prevent the effects of the coronavirus disease of 2019, mostly among sensitive patients. On the other hand, time and cost-sustainability of virus detection by molecular analysis such as reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) may be a major issue if testing is extended to large communities, mainly asymptomatic large communities. In this context, sample-pooling and test grouping could offer an effective solution. Here we report the screening on 1195 oral-nasopharyngeal swabs collected from students and staff of the Università degli Studi del Sannio (University of Sannio, Benevento, Campania, Italy) and analyzed by an in-house developed multiplex RT-qPCR for SARS-CoV-2 detection through a simple monodimensional sample pooling strategy. Overall, 400 distinct pools were generated and, within 24 h after swab collection, five positive samples were identified. Out of them, four were confirmed by using a commercially available kit suitable for in vitro diagnostic use (IVD). High accuracy, sensitivity and specificity were also determined by comparing our results with a reference IVD assay for all deconvoluted samples. Overall, we conducted 463 analyses instead of 1195, reducing testing resources by more than 60% without lengthening diagnosis time and without significant losses in sensitivity, suggesting that our strategy was successful in recognizing positive cases in a community of asymptomatic individuals with minor requirements of reagents and time when compared to normal testing procedures.

17.
Int J Sport Nutr Exerc Metab ; 30(6): 386-395, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32998111

RESUMO

Fasting enhances the beneficial metabolic outcomes of exercise; however, it is unknown whether body composition is favorably modified on the short term. A baseline-follow-up study was carried out to assess the effect of an established protocol involving short-term combined exercise with fasting on body composition. One hundred seven recreationally exercising males underwent a 10-day intervention across 15 fitness centers in the Netherlands involving a 3-day gradual decrease of food intake, a 3-day period with extremely low caloric intake, and a gradual 4-day increase to initial caloric intake, with daily 30-min submaximal cycling. Using dual-energy X-ray absorptiometry analysis, all subjects substantially lost total body mass (-3.9 ± 1.9 kg; p < .001) and fat mass (-3.3 ± 1.3 kg; p < .001). Average lean mass was lost (-0.6 ± 1.5 kg; p < .001), but lean mass as a percentage of total body mass was not reduced. The authors observed a loss of -3.9 ± 1.9% android fat over total fat mass (p < .001), a loss of -2.2 ± 1.9% gynoid over total fat mass (p < .001), and reduced android/gynoid ratios (-0.05 ± 0.1; p < .001). Analyzing 15 preselected single-nucleotide polymorphisms in 13 metabolism-related genes revealed trending associations for thyroid state-related single-nucleotide polymorphisms rs225014 (deiodinase 2) and rs35767 (insulin-like growth factor1), and rs1053049 (PPARD). In conclusion, a short period of combined fasting and exercise leads to a substantial loss of body and fat mass without a loss of lean mass as a percentage of total mass.


Assuntos
Composição Corporal , Exercício Físico , Jejum , Absorciometria de Fóton , Adulto , Ingestão de Energia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos , Polimorfismo de Nucleotídeo Único , Adulto Jovem
18.
Artigo em Inglês | MEDLINE | ID: mdl-32477274

RESUMO

The present investigation was undertaken to increase our insight into the molecular basis of the physiological changes in rat testis induced by food withdrawal, and to clarify whether reduced testicular function can be ameliorated by mild exercise. Male rats were selected for four separate experiments. The first of each group was chow-fed, the second was chow-fed and submitted to exercise (5 bouts in total for 30 min at 15 m/min, and 0° inclination), the third was submitted to food withdrawal (66 h) and the fourth was submitted to food withdrawal and to exercise. At the end of experiments, we investigated (i) serum and testicular sex hormone levels; (ii) protein levels of StAR, 3ß-Hydroxysteroid dehydrogenase (3ß-HSD) and P450 aromatase, which play a key role in steroid hormone biosynthesis; and (iii) protein levels of mitotic and meiotic markers of spermatogenesis in rats, in relation to testis morphology and morphometry. We found that mild exercise or food withdrawal alone induced a significant increase or decrease in both serum and testis testosterone levels, respectively. Interestingly, we found that these levels were brought back to basal levels when food withdrawal was combined with mild exercise. The changes in testosterone levels observed in our experimental groups correlated well with the expression of steroidogenic enzymes as well as with spermatogenic activity. With mild exercise the increased testosterone/17ß-estradiol (T/E2) ratio in the testis correlated with an increased spermatogenic activity. The T/E2 ratio dropped in fasted rats and was significantly reversed when food withdrawal was combined with exercise. Histological and morphometric analyses confirmed that spermatogenic activity varied in concomitance with each experimental condition. Importantly, the testis and serum T/E2 ratios correlated, confirming that exercise rescues the decline in food withdrawal-induced spermatogenesis. In conclusion, this study highlights that mild exercise normalizes the reduced spermatogenic activity caused by food withdrawal through the modulation of the steroidogenic pathway and restoring the T/E2 ratio, underlining the beneficial effects of mild exercise on the prevention and/or amelioration of reduced testis function caused by restricted caloric intake.


Assuntos
Restrição Calórica , Jejum , Hormônios Esteroides Gonadais/biossíntese , Condicionamento Físico Animal , Espermatogênese , Esteroides/biossíntese , Testículo/metabolismo , 3-Hidroxiesteroide Desidrogenases/genética , 3-Hidroxiesteroide Desidrogenases/metabolismo , Animais , Aromatase/genética , Aromatase/metabolismo , Regulação da Expressão Gênica , Masculino , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Ratos , Ratos Wistar
19.
J Clin Med ; 9(6)2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32492950

RESUMO

Thyroid hormones (THs) exert pleiotropic effects in different mammalian organs, including gonads. Genetic and non-genetic factors, such as ageing and environmental stressors (e.g., low-iodine intake, exposure to endocrine disruptors, etc.), can alter T4/T3 synthesis by the thyroid. In any case, peripheral T3, controlled by tissue-specific enzymes (deiodinases), receptors and transporters, ensures organ homeostasis. Conflicting reports suggest that both hypothyroidism and hyperthyroidism, assessed by mean of circulating T4, T3 and Thyroid-Stimulating Hormone (TSH), could affect the functionality of the ovarian reserve determining infertility. The relationship between ovarian T3 level and functional ovarian reserve (FOR) is poorly understood despite that the modifications of local T3 metabolism and signalling have been associated with dysfunctions of several organs. Here, we will summarize the current knowledge on the role of TH signalling and its crosstalk with other pathways in controlling the physiological and premature ovarian ageing and, finally, in preserving FOR. We will consider separately the reports describing the effects of circulating and local THs on the ovarian health to elucidate their role in ovarian dysfunctions.

20.
Physiol Rep ; 8(3): e14354, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32034884

RESUMO

Exercise under fasting conditions induces a switch to lipid metabolism, eliciting beneficial metabolic effects. Knowledge of signaling responses underlying metabolic adjustments in such conditions may help to identify therapeutic strategies. Therefore, we studied the effect of mild exercise on rats submitted to food withdrawal at thermoneutrality (28°C) for 3 days. Animals were housed at thermoneutrality rather than the standard housing temperature (22°C) to avoid beta-adrenergic signaling responses that themselves affect metabolism and well-being. Quantitative analysis of multi-organ mRNA levels, myofibers, and serum metabolites shows that this protocol (a) boosts fat oxidation in muscle and liver, (b) reduces lipogenesis and increases gluconeogenesis in liver, (c) increases serum acylcarnitines (especially C4 OH) and ketone bodies and the use of the latter as fuel in muscle, (d) increases Type I myofibers, and (e) is associated with an increased thyroid hormone uptake and metabolism in muscle. In addition, stool microbiome DNA analysis revealed that food withdrawal dramatically alters the presence of bacterial genera associated with ketone metabolism. Taken together, this protocol induces a drastic switch toward increased lipid and ketone metabolism compared to exercise or food withdrawal alone, which may prove beneficial and may involve local thyroid hormones, which may be regarded as exercise mimetics.


Assuntos
Jejum/metabolismo , Microbioma Gastrointestinal , Metabolismo dos Lipídeos , Atividade Motora , Fibras Musculares Esqueléticas/metabolismo , Hormônios Tireóideos/sangue , Quinases Proteína-Quinases Ativadas por AMP , Animais , Carnitina/análogos & derivados , Carnitina/sangue , Metabolismo Energético , Jejum/fisiologia , Corpos Cetônicos/sangue , Fígado/metabolismo , Masculino , Fosforilação , Proteínas Quinases/metabolismo , Ratos , Ratos Wistar , Temperatura
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