Fat Body Research Articles

Trehalose metabolism mediates trade-offs between reproduction and survival in beet webworm, Loxostege sticticalis, under heat stress.

Temperature is an important determinant of developmental and reproductive rates in insects. Here, we investigated the physiological responses of adult beet webworm, Loxostege sticticalis L. (Lepidoptera: Crambidae), to three temperatures (16, 23 and 30 °C) focusing on trehalose metabolism. Exposure of moths to 30 °C accelerated eclosion and ovarian development, but shortened the oviposition period and adult longevity, whereas exposure to 16 °C had opposite effects. Transcriptome analysis revealed that vitellogenin (VG) and vitellogenin receptor (VR) genes were up-regulated at 30 °C, as were numerous genes related to energy metabolism, including those involved in the insulin signaling pathway, the tricarboxylic acid (TCA) cycle, and glycolysis. Expression of the trehalose transporter gene TRET1 was also induced at high temperature, primarily in the ovaries, where trehalose content increased, accompanied by lipid degradation in the fat body. Treatment with the trehalase inhibitor validamycin A reduced female fecundity and longevity at 23 °C, but enhanced the expression of genes related to stress resistance and reproduction, mimicking the effect of high temperature. Besides their practical utility for predicting the oviposition behavior and geographic distribution of L. sticticalis in the field, these results elucidate the various physiological roles of trehalose in L. sticticalis during exposure of moths to high temperature and may provide insights into the relationship between stress resistance and reproduction in insects more generally. © 2024 Society of Chemical Industry.

Characterizing body composition modifying effects of a glucagon-like peptide 1 receptor-based agonist: A meta-analysis.

Diabetes is an independent risk factor for muscle mass loss, with possible mechanisms including impaired insulin signalling and chronic inflammation. The use of a glucagon-like peptide 1 (GLP-1) receptor-based agonist could lead to weight reduction, which might result from the loss of both fat and skeletal muscle. However, the body composition-modifying effects of GLP-1 receptor-based agonists have not been systematically characterized. PubMed, EMBASE, the Cochrane Center Register of Controlled Trials for Studies and Clinicaltrial.gov were searched from inception to October 2023. Randomized controlled trials of GLP-1 receptor agonist or glucose-dependent insulinotropic polypeptide/GLP-1 receptor dual agonist, which reported the changes of body composition, were included. The results were computed as weighted mean differences (WMDs) and 95% confidence intervals (CIs) in a random-effects model. In all, 19 randomized controlled trials were included. When compared with controls, substantial reductions in fat body mass were observed in patients using GLP-1 receptor-based agonist treatment (WMD = -2.25 kg, 95% CI -3.40 to -1.10 kg), with decrease in areas of both subcutaneous fat (WMD = -38.35 cm2, 95% CI, -54.75 to -21.95 cm2) and visceral fat (WMD = -14.61 cm2, 95% CI, -23.77 to -5.44 cm2). Moreover, greater reductions in lean body mass were also observed in GLP-1 receptor-based agonist users compared with non-users (WMD = -1.02 kg, 95% CI, -1.46 to -0.57 kg), while the changes in lean mass percentage were comparable between GLP-1 receptor-based agonist users and non-users. Compared with the controls, GLP-1 receptor-based agonist users experienced greater reductions in fat body mass, with body shaping effects in terms of both subcutaneous fat mass and visceral fat mass. Although greater reductions in lean body mass were also observed in GLP-1 receptor-based agonist users, the changes in lean mass percentage were comparable between the users and non-users.

Nutrition and Physical Activity in Older Adults with CKD patients: Two Sides of the Same Coin.

Nutrition and physical activity are two major issues in the management of CKD patients who are often older, have comorbidities and are prone to malnutrition and physical inactivity, conditions that cause loss of quality of life and increase the risk of death. We performed a multidimensional assessment of nutritional status and of physical performance and activity in CKD patients on conservative therapy in order to assess the prevalence of sedentary behaviour and its relationship with body composition. 115 consecutive stable CKD patients aged 45-80 years were included in the study. They had no major skeletal, muscular or neurological disabilities. All patients underwent a multidimensional assessment of body composition, physical activity and exercise capacity. Sedentary patients, as defined by mean daily METs < 1.5 were older and differed from non-sedentary patients in terms of body composition, exercise capacity and nutrient intake, even after adjusting for age. Average daily METs were positively associated with lean body mass, muscle strength, 6-MWT performance, but negatively associated with fat body mass, body mass index and waist circumference. In addition, a sedentary lifestyle may have negative effects on free fat mass, muscle strength and exercise capacity, and may increase fat body mass. Conversely, s decrease in muscle mass and/or an increase in fat mass may lead to a decrease in physical activity and exercise capacity. There is a clear association and potential interrelationship between nutritional aspects and exercise capacity in older adults with CKD: they are really the two sides of the same coin.

Structural Derivatives of β-Asarone from Acorus calamus Linn. as Insecticide Candidates and the Insecticidal Mechanism Against Small Brown Planthopper

The small brown planthopper (SBPH), Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae), is an increasing threat to Gramineae crops, posing significant risks to both the environment and food safety. β-asarone, as a promising green alternative to chemical insecticides, possesses wide application prospects in the crop protection field. To enhance the insecticidal activity of β-asarone, a series of derivatives were prepared through an active substructure splicing strategy, and their insecticidal activities against SBPH were evaluated. Among the 7 commercial compounds with chemical structures similar to β-asarone and 12 structural derivatives of β-asarone, compound 10, which incorporates the 2-chloropyridine functional group from flupyrimin, exhibited the most potent insecticidal activity against SBPH, with an 8.31-fold increase in insecticidal activity compared to β-asarone. Furthermore, transcriptome analysis showed that among the selected genes that may play important roles in insecticidal activity, an ABC transporter gene, MDR49, was most significantly down-regulated. MDR49 was highly expressed in the 4th-instar nymphs, with the highest expression level in the fat body, midgut, and abdomen. RNA interference (RNAi) against MDR49 significantly reduced susceptibility to compound 10 in SBPH, which revealed that MDR49 may be the candidate insecticidal target of compound 10. Additionally, the insecticidal spectrum revealed that compound 10 showed excellent efficacy against Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and Tetranychus cinnabarinus (Boisduval) (Acarina: Tetranychidae). This study indicates that compound 10 could be further developed as a novel eco-friendly pesticide.

Metabolic rewiring in fat-depleted Drosophila reveals triglyceride:glycogen crosstalk and identifies cDIP as a new regulator of energy metabolism.

Tissues store excess nutrients as triglyceride or glycogen, but how these reserves are sensed and communicate remains poorly understood. Here we identify molecular players orchestrating this metabolic balance during fat depletion. We show fat body (FB)-specific depletion of fatty acyl-CoA synthase FASN1 in Drosophila causes near-complete fat loss and metabolic remodeling that dramatically elevates glycogen storage and carbohydrate metabolism. Proteomics and metabolomics identify key factors necessary for rewiring including glycolysis enzymes and target-of-brain-insulin (tobi). FASN1-deficient flies are viable but starvation sensitive, oxidatively stressed, and infertile. We also identify CG10824/cDIP as upregulated in FASN1-depleted Drosophila. cDIP is a leucine-rich-repeat protein with homology to secreted adipokines that fine-tune energy signaling, and is required for fly development in the absence of FASN1. Collectively, we show fat-depleted Drosophila rewire their metabolism to complete development, and identify cDIP as a putative new cytokine that signals fat insufficiency and may regulate energy homeostasis.

Bioelectrical Impedance Analysis Demonstrates Reliable Agreement with Dual-Energy X-ray Absorptiometry in Identifying Reduced Skeletal Muscle Mass in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease and Hypertension.

Background/Objectives: Body composition (BC) affects the risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD) and hypertension (HTN). Currently, dual-energy X-ray absorptiometry (DEXA) is considered the gold standard for assessing BC, even though it has some limitations, including immobility, ionizing radiation, and patient weight restrictions. The aim of the study was to evaluate the correlations of BC parameters measured by bioelectrical impedance analysis (BIA) with those measured by DEXA in patients with MASLD and HTN. Methods: Overall, 78 patients with MASLD and HTN underwent the following study procedures: compilation of an anamnesis, physical examination of a patient, laboratory tests, abdominal ultrasound, BIA, DEXA, and anthropometric measurements. Results: The agreement between BIA and DEXA in diagnosing reduced skeletal muscle mass (SMM) in patients with MASLD and HTN was moderate (kappa values were 0.440 and 0.404 in males and females, respectively). Significant strong direct correlations were found between fat mass (FM) and body fat percentage measured by BIA with corresponding measurements by DEXA (p < 0.001 for both). The area under the receiver operating characteristic curves (AUC) of SMM to body weight ratios calculated using BIA data were 0.834 and 0.929 for reduced appendicular SMM determined by DEXA in males and females with MASLD and HTN, respectively. Conclusions: In conclusion, BIA is an easy-to-use and widely available tool for assessing SMM and FM in patients with MASLD and HTN, demonstrating reliable agreement with DEXA measurement results and completely free of its limitations.

Histological Investigations on Potato Tuber Moths, Phthorimaea operculella Treated with a Botanical Extract of Basil (Ocimum basilicum L), with Particular Attention to the Alterations in the Ultrastructure of the Larval Digestive Tract

Background: Phthorimaea operculella (Zeller), the potato tuber moth (PTM) is one of the most important pests that attacks potato, Solanum tuberosum L. crops worldwide. Adult moths attack tubers in fields as well as in storage. Infested tubers become unsuitable for trade or consumption, the tuber damage increases gradually after several generations of the pest during storage time. Botanicals have been found to be an efficient control method especially when they act as antifeedant or repellent, or even stomach poisons. The estimation of the mortal impact of some extracts against PTM was examined by emphasizing the Ultrastructure changes in the larval digestive tract by using scanning and transmission electron microscope. Results: Structural changes throughout the entire digestive tract (Fore-, Mid- and Hind-gut), induced by Basil extract were detected through both microscope, these changes leading lastly to the death of the treated larvae. Many different ruptures and malformations were detected throughout all the digestive tract assessment. Conclusions: Studies of the occurred changes revealed some histopathological changes through out all the digestive tract (Fore-, Mid- and Hind-gut), the attached muscular layer, tracheal system, and visceral fat bodies of the larvae when fed with tubers treated with Basil extract. From this findings, the use of plant extracts can be recommended for protection of potato tuber against the infestation by the tubers moths.

Multi-omics analysis reveal the fall armyworm Spodoptera frugiperda tolerate high temperature by mediating chitin-related genes

Climate change facilitates the rapid invasion of agricultural pests, threatening global food security. The fall armyworm Spodoptera frugiperda is a highly polyphagous migratory pest tolerant to high temperatures, allowing its proliferation in harsh thermal environments. We aimed to demonstrate mechanisms of its high-temperature tolerance, particularly transcriptional and metabolic regulation, which are poorly understood. To achieve the aim, we examined the impact and mechanism of heat events on S. frugiperda by using multiple approaches: ecological measurements, transcriptomics, metabolomics, RNAi, and CRISPR/Cas9 technology. We observed that several physiological indices (larval survival rate, larval period, pupation rate, pupal weight, eclosion rate, and average fecundity) decreased as the temperature increased, with the 32 °C treatment displaying a significant difference from the control group at 26 °C. Significantly upregulated expression of genes encoding endochitinase and chitin deacetylase was observed in the chitin-binding, extracellular region, and carbohydrate metabolic process GO terms of hemolymph, fat body, and brain, exhibiting a tissue-specific pattern. Significantly enriched pathways (e.g., cutin, suberin, and wax biosynthesis; oxidative phosphorylation and cofactor biosynthesis; diverse amino acid biosynthesis and degradation; carbon metabolism; and energy metabolism), all of which are essential for S. frugiperda larvae to tolerate temperature, were found in metabolites that were expressed differently. Successful RNA interference targeting of the three chitin-related genes reduced gene expression levels and larval survival rate. Knockout of the endochitinase gene by using the CRISPR/Cas9 system significantly reduced the relative gene expression and increased sensitivity to high-temperature exposure. On the basis of our findings, theoretical foundations for understanding the high-temperature tolerance of S. frugiperda populations and latent genetic control strategies were established.

Maternal adiposity and perinatal and offspring outcomes: an umbrella review.

Maternal adiposity deleteriously affects obstetrical health and has been associated with long-term adverse consequences in offspring. Here we conducted an umbrella review encompassing 194 observational meta-analyses, 10 Mendelian randomization studies and 748 interventional meta-analyses to appraise the published evidence on the associations between maternal adiposity and perinatal and offspring outcomes. Evidence grading suggested that 17 (8.8%) observational meta-analyses were supported by convincing evidence for 12 outcomes: maternal adiposity was associated with an increased risk of caesarean delivery following labour induction, infant mortality, Apgar score <7 at 1 min, antenatal depression, offspring overweight and obesity, early timing of puberty onset in daughters, attention deficit hyperactivity disorder, cerebral palsy, congenital heart disease and spina bifida (OR/RR ranging from 1.14 to 2.31), as well as increased offspring body fat percent and fat mass (SMD 0.31 and 0.35, respectively). Among these outcomes, interventional meta-analyses supported that maternal weight loss interventions significantly reduced the risk of antenatal depression but not low Apgar scores; these interventions also could not reduce offspring fat mass or body fat percent. Evidence from Mendelian randomization studies supported a causal relationship between maternal adiposity and gestational diabetes mellitus, preeclampsia, birth size and offspring adiposity. Our findings highlight that while observational meta-analyses reveal associations between maternal adiposity and various adverse perinatal and offspring outcomes, convincing, unbiased evidence or support from Mendelian randomization studies is limited. Maternal pre-conceptional and prenatal weight loss interventions can reduce some, but not all, of these adverse effects.

The effect of an ultra-brief intervention to challenge fat talk: examination of fat talk engagement, body dissatisfaction, and negative affect

The effect of an ultra-brief intervention to challenge fat talk: examination of fat talk engagement, body dissatisfaction, and negative affect

Nosema ceranae infection reduces the fat body lipid reserves in the honeybee Apis mellifera

Nosema ceranae is an intestinal parasite frequently found in Apis mellifera colonies. This parasite belongs to Microsporidia, a group of obligate intracellular parasites known to be strongly dependent on their host for energy and resources. Previous studies have shown that N. ceranae could alter several metabolic pathways, including those involved in the nutrient storage. To explore the impact of N. ceranae on the fat body reserves, newly emerged summer bees were experimentally infected, and we measured (1) the lipid percentage of the abdominal fat body at 2-, 7- and 14-days post-inoculation (p.i.) using diethyl ether lipid extraction, (2) the triglyceride and protein concentrations by spectrophotometric assay methods, and (3) the amount of intracellular lipid droplets in trophocytes at 14- and 21-days p.i. using Nile Red staining. Comparing the three methods used to evaluate lipid stores, our data revealed that Nile Red staining seemed to be the simplest, fastest and reliable method. Our results first revealed that the percentage of fat body lipids significantly decreased in infected bees at D14 p.i. The protein stores did not seem to be affected by the infection, while triglyceride concentration was reduced by 30% and lipid droplet amount by 50% at D14 p.i. Finally, a similar decrease in lipid droplet reserves in response to N. ceranae infection was observed in bees collected in fall.

Complicated gene network for regulating feeding behavior: novel efficient target for pest management.

Feeding behavior is a fundamental activity for insects, which is essential for their growth, development and reproduction. The regulation of their feeding behavior is a complicated process influenced by a variety of factors, including external stimuli and internal physiological signals. The current review introduces the signaling pathways in brain, gut and fat body involved in insect feeding behavior, and provides a series of target genes for developing RNA pesticides. Additionally, this review summaries the current challenges for the identification and application of functional genes involved in feeding behavior, and finally proposes the future research direction. © 2024 Society of Chemical Industry.

Chemical analysis of Alliin-Rich Allium sativum (Garlic) extract and its safety evaluation in Drosophila melanogaster

Garlic (Allium sativum) has been traditionally valued for its medicinal properties attributed to the presence of organosulfur compounds. Despite its benefits, concerns about herbal extract toxicity have arisen, necessitating safety assessment. This study was designed to evaluate the chemical analysis and safety profile of Alliin-Rich Garlic Extract (ARGE) using Drosophila melanogaster as a model organism. The ARGE was extracted from garlic cloves (Allium sativum Linn: UIH-23262) using a microwave-assisted method and characterized using UPLC-ESI-MS, 1H NMR, HPLC and IR. Its safety evaluation was determined using D. melanogaster (Harwich strain), and various assays were conducted on 1–3-day-old flies. Toxicological markers and oxidative stress were assessed to understand the impact of ARGE on the flies. Chemical profiling of ARGE using UPLC-ESI-MS, confirmed the presence of alliin (S-ally-L-cysteine-S-oxide), L-arginine, γ-glutamylmethionine, S-(2-carboxypropyl) glutathione, N-γ-glutamyl-S-(1-propenyl) cysteine, N-γ-glutamyl-S-(2-propenyl) cysteine, N-γ-glutamylphenylalanine, S-(allylthio) cysteine, γ-glutamyl-S-allylthiocysteine and eruboside B. HPLC confirmed an alliin content of 0.073 mg/g. Toxicological assessment in D. melanogaster revealed that ARGE enhanced antioxidant defenses by increasing total thiol levels and GST activity, while reducing acetylcholinesterase activity. No significant alteration was observed in catalase activity and cellular metabolic rate. Histological examination revealed no alterations in the histoarchitecture of the brain, fat body or gut of D. melanogaster. The study demonstrated the safety of ARGE in D. melanogaster, supporting its potential as a safe herbal remedy.

On the Origins of Symbiotic Fungi in Carmine Cochineals and Their Function in the Digestion of Plant Polysaccharides.

The cochineal insect Dactylopius coccus Costa (Hemiptera) has cultural and economic value because it produces carminic acid that is used commercially. In this study, distinct fungi were cultured from dissected tissue and identified as Penicillium, Coniochaeta, Arthrinium, Cladosporium, Microascus, Aspergillus, and Periconia. Fungi were microscopically observed inside cochineals in the gut, fat body, and ovaries. Since cochineals spend their lives attached to cactus leaves and use the sap as feed, they can obtain fungi from cacti plants. Indeed, we obtained Penicillium, Aspergillus, and Cladosporium fungi from cacti that were identical to those inside cochineals, supporting their plant origin. Fungi could be responsible for the degrading activities in the insect guts, since cellulase, pectinase, and amylase enzymatic activities in insect guts decreased in fungicide-treated cochineals. Our findings set the basis for the further study of the interactions between insects, fungi, and their host plants.

Identification and expression profiling of neuropeptides and neuropeptide receptor genes in a natural enemy, Coccinella septempunctata.

Neuropeptides and their receptors constitute diverse and abundant signal molecules in insects, primarily synthesized and released primarily from neurosecretory cells within the central nervous system Neuropeptides act as neurohormones and euromodulators, regulating insect behavior, lifecycle, and physiology by binding to receptors on cell surface. As a typical natural predator of agricultural pests, the lady beetle, Coccinella septempunctata, has been commercially mass-cultured and widely employed in pest management. Insect diapause is a physiological and ecological adaptative strategy acquired in adverse environments. In biological control programs, knowledge about diapause regulation in natural enemy insects provides important insight for improving long-term storage, transportation, and field adoption of these biological control agents. However, little is known about the function of neuropeptides and their receptors in controlling reproductive diapause of C. septempunctata. It is unclear which neuropeptides affect diapause of C. septempunctata. In this study, RNA-seq technology and bioinformatics were utilized to investigate genes encoding neuropeptides and their receptors in female adults of C. septempunctata. Quantitative real-time PCR (qRT-PCR) analysis was employed to examine gene expression across different development/diapause stages. A total of 17 neuropeptide precursor genes and 9 neuropeptide receptor genes were identified, implicated in regulating various behaviors such as feeding, reproduction, and diapause. Prediction of partial mature neuropeptides from precursor sequences was also performed using available information about these peptides from other species, conserved domains and motifs. During diapause induction, the mRNA abundance of AKH was notably higher on the 10th day compared to non-diapause females, but decreased by the 20th day. In contrast, GPHA showed lower expression levels on the 5th day of diapause induction compared to non-diapause females, but increased significantly by the 15th and 20th days. NPF was higher expressed in head and midgut while DH showed higher expression in the fat body and midgut. Additionally, NPF expression remained consistently lower throughout all stages of diapause induction compared to non-diapause conditions in females. This study represents the first sequencing, identification, and expression analysis of neuropeptides and neuropeptide receptor genes in C. septempunctata. Our results could provide a foundational framework for further investigations into the presence, functions, and potential targets of neuropeptides and their receptors, particularly in devising novel strategies for diapause regulation in C. septempunctata.

Body composition estimates from bioelectrical impedance and its association with cardiovascular risk.

Screening for traditional risk factors of cardiovascular disease is well known in primary healthcare (PHC) settings. However, other risk factors through newer tools (such as bioelectrical impedance analysis [BIA]) could also be predictors of increased cardiovascular risk (CVR). Body composition estimates (body fat percentage, body water percentage, body lean mass) by BIA and its association to CVR have been studied with variable results. This study assesses the body composition estimates and their association with CVR in the South African PHC setting. A retrospective record analysis was conducted on a cohort of de-identified patients utilising the ABBY®Health Check Machine at a PHC facility in South Africa between May 2020 and August 2022. The ABBY Machine estimates body fat percentage (BF%) and body water percentage (BW%) estimates from BIA. Cardiovascular risk based on the Framingham-risk-score was stratified into high, medium and low CVR. An analysis of variance was used to determine mean differences of BF% and BW% among these groups. A total of 4008 records (n= 4008) were used in the final analysis. The majority of patients were female (70.1%) with a mean age of 33.6 years. Higher mean BF% (35.75% vs. 31.10% vs. 27.73%;p 0.0001) and lower mean BW% (49.46% vs. 53.15% vs. 56.18%;p= 0000) were found to be significantly associated with high CVR. This study demonstrated the use of newer technologies that could assist in the identification of CVR in low resource PHC settings.

8631 Tanycytic TSHR Activation Regulates Blood-Hypothalamus Barrier Plasticity, Ingestive Behavior, Adipose Remodeling, and Body Weight

Abstract Disclosure: L. Cullen: None. H.S. Kannangara: None. R. Witztum: None. J. Burgess: None. S. Miyashita: None. A. Gumerova: None. F. Korkmaz: None. S.L. Sims: None. U. Cheliadinova: None. G. Pevnev: None. O. Moldavski: None. O. Barak: None. S. Rojekar: None. V. Laurencin: None. T. Frolinger: None. T. Yuen: None. K. Goosens: None. W. Zhou: None. V. Ryu: None. M. Zaidi: None. The notion that TSH acts solely on its primary endocrine target, the thyroid gland, has long been challenged (Abe et al., 2003; PMID: 14567913). More recently, however, we and others have used single transcript technology to document, for the first time, Tshr expression in over 173 brain regions and nuclei, particularly hypothalamic tanycytes (eLife, 2022, PMID: 36052994). The latter cells are known to convey metabolic information across the blood-hypothalamus barrier (BHB) and regulate energy homeostasis. To study whether tanycytic TSHRs have a role in the regulation of BHB permeability, ingestive behavior, adipose tissue remodeling and body weight, we first compared BHB vascular permeability of food-deprived and ad libitum-fed Tshr+/- mice and their wild type (WT) littermates. Transmission electron microscopy and immunostaining was used to study the expression of the constitutive tight junction protein claudin-1 and the glycoprotein MECA-32, which are expressed in tanycytes and endothelial cells, respectively. In loss-of-function studies, fasting of Tshr+/- mice and of WT mice significantly increased the organization of tanycytic honeycomb pattern of claudin-1 and MECA-32-associated fenestral diaphragms in the median eminence and arcuate nucleus, suggesting decreased BHB permeability. As a result, peanut butter consumption following fasting was decreased significantly compared to control mice. In gain-of-function studies, intracerebroventricular (ICV) infusions of a highly specific TSHR agonist, MS438, profoundly increased BHB permeability in fasted mice, as evidenced by decreased claudin-1 and MECA-32 immunostaining and significant increases in peanut butter consumption. This was associated with greater loss of fat mass and body weight following food deprivation, as well as increased influx of fatty acids across the BHB, increased NPY expression (as a measure of increased appetite), and increased secretion of ghrelin from the stomach fundus. We further performed c-Fos immunostaining in brain centers regulating ingestive behavior. ICV MS438 significantly decreased c-Fos immunoreactivity in the hypothalamic paraventricular nucleus, arcuate nucleus and the nucleus of the solitary tract. Early studies using CRSIPR/Cas9 to delete Tshrs in tanycytes via ICV injection resulted in reduced body weight following food deprivation. Finally, using PRV152 (injected into fat tissue) and PRV614 (injected into stomach fundus), we colocalized immunostaining in the hypothalamic paraventricular nucleus, and hindbrain raphe pallidus. Collectively, these data establish a new role for tanycytic TSHRs in regulating BHB plasticity, ingestive behavior, adipose tissue remodeling, and body weight through a novel fast-forward circuit involving the hypothalamus, stomach fundus and fat depots. Presentation: 6/3/2024

8532 Circulating Neprilysin in Pregnancy

Abstract Disclosure: A. Kulovic-Sissawo: None. E. Weiss: None. E. Jantscher-Krenn: None. U. Hiden: None. Background: In the complex nature of pregnancy, the female organism undergoes pivotal vascular and metabolic changes orchestrated by a tightly regulated interplay of bioactive regulatory molecules. The neutral endopeptidase, neprilysin, exists both in a membrane-bound and a soluble form (sNEP), of with the latter present in the circulatory system. Neprilysin degrades an exciting range of bioactive peptides involved in glycemic control (insulin B chain, GLP-1) and vascular tone regulation (angiotensin I and II, bradykinin, ANP, BNP), and both of them are altered in pregnancy. Objective: Due to the substrate-specificity of neprilysin and its multifaceted role we hypothesize that neprilysin may be involved in metabolic and vascular adaptions during pregnancy. However, the link between sNEP and maternal metabolism in pregnancy has not yet been investigated. Methodology: Serum sNEP concentration (n=102), longitudinally collected from metabolically healthy women (trial number NTC05496712), was measured at three visits throughout gestation (gestational age: 12.5±0.7; 20±0.8; 33±1.6 weeks) and post-partum (2±1.2 days after delivery) using commercially available sandwich ELISA. In addition, sNEP levels in pregnancy were compared to a cohort of non-pregnant women within reproductive age (n=50). Clinical and anthropometric measurements were determined and the association of sNEP and metabolic characteristics elucidated. Results: Circulating sNEP levels were non-normally distributed (median ± IQR: 2334±232624 pg/ml, n=82, gestational age 12.5±0.7 weeks) and showed high biological variability, with individual levels remaining constant over gestation. After delivery, however, sNEP concentration decreased (median± IQR: 1968±171060 pg/ml n=82, p=0.0001). sNEP showed a positive correlation with systolic blood pressure (Spearman, n=56, r=0.321, p=0.02) at early stages of pregnancy and non-fasting GLP-1 (Spearman, n=98, r=0.309, p=0.002) throughout gestation, but not with blood glucose, insulin resistance or BMI. In the non-pregnant state sNEP concentration (median±IQR: 4322±392152 pg/ml, n=38) positively correlated with body fat percentage (Pearson, n=38, r=0.405, p=0.01), fasting glucose (Pearson, n=43, r=0.301, p=0.05) and body mass index (Spearman, n=38, r=0.369, p=0.02) but did not correlate with systolic blood pressure (Pearson, n=36, r=-0.120, p=0.48). Conclusion: For the first time, the link between sNEP, metabolism and blood pressure during uncomplicated pregnancy was investigated. The decrease in post-partum circulating sNEP as compared to levels throughout pregnancy suggests a particular way of sNEP regulation and release during gestation. Our data indicate that in both, pregnant and non-pregnant state, sNEP may be involved in metabolic and cardiovascular regulation, with circulating sNEP levels showing massive individual differences. Presentation: 6/3/2024

Histone Deacetylase 3 Is Involved in Maintaining Queen Hallmarks of a Termite.

The role of epigenetics in regulating caste polyphenism in social insects has been debated. Here, we tested the importance of histone de/acetylation processes for the maintenance of queen hallmarks like a high fecundity and a long lifespan. To this end, we performed RNA interference experiments against histone deacetylase 3 (HDAC3) in the termite Cryptotermes secundus. Fat body transcriptomes and chemical communication profiles revealed that silencing of HDAC3 leads to signals indicative of queen hallmarks. This includes fostering of queen signalling, defence against ageing and a reduction of life-shortening IIS (insulin/insulin-like growth factor signalling) and endocrine JH (juvenile hormone) signalling via Kr-h1 (Krüppel-homologue 1). These observed patterns were similar to those of a protein-enriched diet, which might imply that histone acetylation conveys nutritional effects. Strikingly, in contrast to solitary insects, reduced endocrine JH signalling had no negative effect on fecundity-related vitellogenesis in the fat bodies. This suggests an uncoupling of longevity pathways from fecundity in fat bodies, which can help explain queens' extraordinary lifespans combined with high fecundity.

Fat deposition and body mass components of Mongolian urban children and adolescents living in various social conditions

Introduction. The purpose of the study is to characterize and to compare the indicators of fat deposition and body composition in groups of urban children and adolescents of the Republic of Mongolia in various living conditions. Materials and methods. The material for this study was the results of a comprehensive survey of 5 612 Mongolian children and adolescents aged 9-17 years (born and permanently residing in the capital city of Ulaanbaatar). In accordance with the objectives of the study, the body circumferences, the skinfolds, as well as the body mass components evaluated by bioimpedance technique were analyzed. Results. Based on the obtained statistical parameters of the studied features, as well as on the results of their comparison in the studied groups, it can be concluded that the value of most of the considered indicators in children and adolescents living in apartments is higher than in their peers living in yurts. Discussion. The increase in body weight in boys living in the apartments, recorded according to the results of our previous work, is associated with an increase in active cell mass, and, as a result, – lean body mass. To a lesser extent, judging by the existing differences, its value is influenced by the fat component. While the parameters of fat deposition show a small number of significant differences, unlike circumferences, it can also be concluded that the variability of the girths is more associated with the development of the muscular component. Similar patterns were obtained for girls. However, in this case they are less pronounced, but also correspond to the previously obtained results. Conclusion. The general increase in the welfare of the population of Ulaanbaatar and significant improvement in the living conditions of the younger generation, has a positive effect on the youth physical development, primarily due to a more pronounced increase in the metabolically active components of body weight. This may be considered as an important reflection of the socio-political processes taking place in the country. © 2024. This work is licensed under a CC BY 4.0 license