scholarly journals Larval nutrition influences adult fat stores and starvation resistance in Drosophila

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247175
Author(s):  
Niyas Rehman ◽  
Jishy Varghese

Insulin plays a major role in connecting nutrient availability to energy homeostasis by regulating metabolic pathways. Defects in insulin signalling is the primary cause for diabetes, obesity and various metabolic disorders. Nutritional status during growth and developmental stages play a crucial role in determining adult size, fecundity and ageing. However, the association between developmental nutrition and adult metabolic disorders has not been fully explored. Here, we address the effects of nutrient status during the larval growth phase on adult metabolism in Drosophila. We report that restricted food supply in larvae led to higher fat reserves and starvation resistance in mature adult flies, which we attribute to low insulin signalling. A lesser amount of stored fat was mobilised during early adult stages and during acute starvation, which accounts for the metabolic effects. Furthermore, larval diet influenced the expression of fat mobilisation genes brummer and lipid storage droplet-2 in adult flies, which led to the metabolic phenotypes reported here. Thus, the restricted nutrient environment in developing larvae led to adaptive changes that entrain the adult flies for scarce food availability.

2009 ◽  
Vol 44 (2) ◽  
pp. 87-97 ◽  
Author(s):  
Chung Thong Lim ◽  
Blerina Kola ◽  
Márta Korbonits

AMP-activated protein kinase (AMPK) is a key molecular player in energy homeostasis at both cellular and whole-body levels. AMPK has been shown to mediate the metabolic effects of hormones such as leptin, ghrelin, adiponectin, glucocorticoids and insulin as well as cannabinoids. Generally, activated AMPK stimulates catabolic pathways (glycolysis, fatty acid oxidation and mitochondrial biogenesis) and inhibits anabolic pathways (gluconeogenesis, glycogen, fatty acid and protein synthesis), and has a direct appetite-regulating effect in the hypothalamus. Drugs that activate AMPK, namely metformin and thiazolidinediones, are often used to treat metabolic disorders. Thus, AMPK is now recognised as a potential target for the treatment of obesity and associated co-morbidities.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Khoa D.A Nguyen ◽  
Khanh V Doan ◽  

AMP-activated protein kinase (AMPK) is a cellular energy sensor which plays a crucial role in regulation of whole-body energy homeostasis. Activation of AMPK signaling results in favorable effects on mitochondrial function, autophagy, glucose/lipid metabolism, and insulin sensitivity, making it an important therapeutic target in treatment/prevention of metabolic disorders and cancer. Recently, pharmacological studies of natural phenolic compounds indicated that the benefits on metabolic health of these phytochemicals are not only related to their protogenic antioxidant property but also to their AMPK-activating potential. Due to their diverse structures, identification of phenolic compound molecules which have potential to target the AMPK activation for beneficial metabolic effects may be promising in order to develop novel therapeutics in the prevention and/or treatment of metabolic disorders. In this minireview, we summarize beneficial metabolic outcomes of AMPK activation and discuss the capability of natural polyphenols to activate the AMPK pathway focusing on the phenolic acids as potential lead compounds.


ISRN Obesity ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Moira S. Lewitt

Ghrelin plays key roles in energy homeostasis by central and peripheral actions that include effects on insulin signalling pathways in liver. Insulin is an important inhibitor of production by hepatocytes of insulin-like growth factor-binding protein-1 (IGFBP-1) which has an endocrine role to inhibit IGF availability. The effects of ghrelin, insulin, an AMPK activator, and an AMPK inhibitor on IGFBP-1 secretion were studied in H4-II-E rat liver cells. Ghrelin (100 nM) blocked the inhibitory effect of a maximally effective concentration of insulin (10 ng/mL) on IGFBP-1 secretion during a 5 h incubation period () in the absence and presence of an AMPK inhibitor. Ghrelin, alone, had no effect on IGFBP-1 production, but enhanced secretion independently of insulin under conditions of AMPK activation (). In conclusion, IGFBP-1 is identified as a novel target of ghrelin action in liver that may contribute to its metabolic effects in obesity.


Author(s):  
Chiyuki Sassa

The feeding habits of myctophid larvae of Symbolophorus californiensis were examined in the southern transition region of the western North Pacific where the main spawning and nursery grounds of S. californiensis are formed. This species is a key component of the pelagic ecosystems of this region, and their larvae attain one of the largest sizes among myctophids. To analyse gut contents larvae, including most life history stages after yolk-sac absorption (3.7 to 22.2 mm body length (BL)), were collected in the upper 100 m layer in 1997 and 1998. Feeding incidence was higher during the day than at night (53.1–92.3% versus 0–5.6%), and daytime feeding incidence increased gradually with larval growth. Larvae fed mainly on copepods of various developmental stages. Larvae of S. californiensis showed an ontogenetic change in their diet: larvae ≤7.9 mm BL (i.e. preflexion stage) fed mainly on copepod eggs and nauplii, while the larvae ≥8 mm BL consumed mainly calanoid copepodites such as Pseudocalanus and Paracalanus spp. In the largest size-class (16–22.2 mm BL), the furcilia stage of euphausiids was also an important prey item. There was an increase in the average prey size with growth in larvae ≤11.9 mm BL, while the number of prey eaten positively correlated with growth in larvae ≥12 mm BL. The trophic niche breadth also increased with larval growth, which would ensure a wide range of available food resources for the larger size-class larvae.


2019 ◽  
Author(s):  
Vanessa Teckentrup ◽  
Sandra Neubert ◽  
João C. P. Santiago ◽  
Manfred Hallschmid ◽  
Martin Walter ◽  
...  

AbstractMetabolic feedback between the gut and the brain relayed via the vagus nerve contributes to energy homeostasis. We investigated in healthy adults whether non-invasive stimulation of vagal afferents impacts energy homeostasis via efferent effects on metabolism or digestion. In a randomized crossover design, we applied transcutaneous auricular vagus nerve stimulation (taVNS) while recording efferent metabolic effects using simultaneous electrogastrography (EGG) and indirect calorimetry. We found that taVNS reduced gastric myoelectric frequency (p =.008), but did not alter resting energy expenditure. We conclude that stimulating vagal afferents induces gastric slowing via vagal efferents without acutely affecting net energy expenditure at rest. Collectively, this highlights the potential of taVNS to modulate digestion by activating the dorsal vagal complex. Thus, taVNS-induced changes in gastric frequency are an important peripheral marker of brain stimulation effects.


2021 ◽  
Vol 184 (1) ◽  
pp. R29-R40
Author(s):  
Poupak Fallahi ◽  
Silvia Martina Ferrari ◽  
Giusy Elia ◽  
Francesca Ragusa ◽  
Sabrina Rosaria Paparo ◽  
...  

Tyrosine kinase inhibitors (TKIs) are emerging as potentially effective options in the treatment of cancer, acting on the pathways involved in growth, avoidance of apoptosis, invasiveness, angiogenesis, and local and distant spread. TKIs induce significant adverse effects, that can negatively affect patients’ quality of life. The most common adverse events (AEs) include fatigue, hand–foot skin reaction, decreased appetite, nausea, diarrhea, hypertension, vomiting, weight loss, endocrinopaties and metabolic disorders. Patients in therapy with TKIs can develop endocrine-metabolic disorders, including dyslipidemia (~50%), diabetes (~15–40%), and dysthyroidism (~20%). In some cases, patients show an improved glycemia or hypoglycemia. The effects of TKIs on adrenal or gonadal function are still not completely known. It was shown a higher prevalence of subclinical hypocortisolism in patients treated with imatinib, while an increase of cortisol was reported in patients receiving vandetanib. Long-term treatment with imatinib could impact significantly the ovarian reserve and embryo developmental capacity. It is important to evaluate patients, measure glucose levels, and manage hyperglycemia. Mild treatment-related hyperglycemia can be controlled modifying the diet and with exercise, while grade 3 and 4 hyperglycemia can lead to dose reductions and/or oral antihyperglycemic therapy. Regarding thyroid dysfunctions, it is recommendable to measure the thyroid-stimulating hormone (TSH)/free thyroxine (FT4) levels before starting the therapy, and every 3–4 weeks during the first 6 months as changes in FT4 levels precede the changes in TSH by 3–6 weeks. Additional studies are necessary to definitely clarify the mechanism of TKIs-induced endocrine-metabolic effects.


2018 ◽  
Vol 15 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Liudmila I. Astafieva ◽  
Irina S. Klochkova ◽  
Pavel L. Kalinin ◽  
Boris A. Kadashev ◽  
Aleksandr N. Konovalov ◽  
...  

The key structure in the regulation of energy homeostasis is the hypothalamus. The damage of the hypothalamic region can lead to imbalance of energy exchange with the development of obesity or cachexia. The most common metabolic disorders occur in case of craniopharyngiomas. The article presents two clinical observations of papillary craniopharyngioma in young women. Cases were accompanied by different disturbances of the energy balance, in one - with the development of obesity, in the other - cachexia.


2018 ◽  
Vol 19 (7) ◽  
pp. 2069 ◽  
Author(s):  
Chang Han

Farnesoid X receptor (FXR), a metabolic nuclear receptor, plays critical roles in the maintenance of systemic energy homeostasis and the integrity of many organs, including liver and intestine. It regulates bile acid, lipid, and glucose metabolism, and contributes to inter-organ communication, in particular the enterohepatic signaling pathway, through bile acids and fibroblast growth factor-15/19 (FGF-15/19). The metabolic effects of FXR are also involved in gut microbiota. In addition, FXR has various functions in the kidney, adipose tissue, pancreas, cardiovascular system, and tumorigenesis. Consequently, the deregulation of FXR may lead to abnormalities of specific organs and metabolic dysfunction, allowing the protein as an attractive therapeutic target for the management of liver and/or metabolic diseases. Indeed, many FXR agonists have been being developed and are under pre-clinical and clinical investigations. Although obeticholic acid (OCA) is one of the promising candidates, significant safety issues have remained. The effects of FXR modulation might be multifaceted according to tissue specificity, disease type, and/or energy status, suggesting the careful use of FXR agonists. This review summarizes the current knowledge of systemic FXR biology in various organs and the gut–liver axis, particularly regarding the recent advancement in these fields, and also provides pharmacological aspects of FXR modulation for rational therapeutic strategies and novel drug development.


2019 ◽  
Vol 317 (3) ◽  
pp. E526-E534 ◽  
Author(s):  
Marianna Sadagurski ◽  
Lucas Kniess Debarba ◽  
Joao Pedro Werneck-de-Castro ◽  
Abear Ali Awada ◽  
Tess A. Baker ◽  
...  

Branched-chain amino acid (BCAAs: leucine, isoleucine, and valine) contribute to the development of obesity-associated insulin resistance in the context of consumption of a high-fat diet (HFD) in humans and rodents. Maternal diet is a major determinant of offspring health, and there is strong evidence that maternal HFD alters hypothalamic developmental programming and disrupts offspring energy homeostasis in rodents. In this study, we exposed pregnant and lactating C57BL/6JB female mice to either HFD, HFD with supplemented BCAA (HFD+BCAA), or standard diet (SC), and we studied offspring metabolic phenotypes. Both maternal HFD and HFD supplemented with BCAA had similar effect rendering the offspring metabolic imbalance and impairing their ability to cope with HFD when challenged during aging. The metabolic effects of HFD challenge were more profound in females, worsening female offspring ability to cope with an HFD challenge by activating hypothalamic inflammation in aging. Moreover, the sex differences in hypothalamic estrogen receptor α (ER-α) expression levels were lost in female offspring upon HFD challenge, supporting a link between ER-α levels and hypothalamic inflammation in offspring and highlighting the programming potential of hypothalamic inflammatory responses and maternal nutrition.


2009 ◽  
Vol 296 (4) ◽  
pp. R929-R935 ◽  
Author(s):  
Stéphanie Migrenne ◽  
Amélie Lacombe ◽  
Anne-Laure Lefèvre ◽  
Marie-Pierre Pruniaux ◽  
Etienne Guillot ◽  
...  

The increase in adiponectin levels in obese patients with untreated dyslipidemia and its mRNA expression in adipose tissue of obese animals are one of the most interesting consequences of rimonabant treatment. Thus, part of rimonabant's metabolic effects could be related to an enhancement of adiponectin secretion and its consequence on the modulation of insulin action, as well as energy homeostasis. The present study investigated the effects of rimonabant in adiponectin knockout mice (Ad−/−) exposed to diet-induced obesity conditions. Six-week-old Ad−/− male mice and their wild-type littermate controls (Ad+/+) were fed a high-fat diet for 7 mo. During the last month, animals were administered daily either with vehicle or rimonabant by mouth (10 mg/kg). High-fat feeding induced weight gain by about 130% in both wild-type and Ad−/− mice. Obesity was associated with hyperinsulinemia and insulin resistance. Treatment with rimonabant led to a significant and similar decrease in body weight in both Ad+/+ and Ad−/− mice compared with vehicle-treated animals. In addition, rimonabant significantly improved insulin sensitivity in Ad+/+ mice compared with Ad+/+ vehicle-treated mice by decreasing hepatic glucose production and increasing glucose utilization index in both visceral and subcutaneous adipose tissue. In contrast, rimonabant failed to improve insulin sensitivity in Ad−/− mice, despite the loss in body weight. Rimonabant's effect on body weight appeared independent of the adiponectin pathway, whereas adiponectin seems required to mediate rimonabant-induced improvement of insulin sensitivity in rodents.


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