Regulation Of Carbohydrate Metabolism Research Articles

Transcriptional Responses of Lacticaseibacillus rhamnosus to TNFα, IL-6, IL-8, and IL-10 Cytokines

The interaction between gut microbiota and the host immune system is a complex and understudied field, with cytokines like TNFα, IL-6, IL-8, and IL-10 playing pivotal roles. Commensal bacteria, including lactobacilli, respond to these cytokines through adaptive mechanisms that support their survival and function within the gut. While the influence of cytokines on pathogenic bacteria is well documented, their impact on commensal bacteria, particularly lactobacilli, remains underexplored. This study investigates the transcriptional responses of Lacticaseibacillus rhamnosus strains K32 and R19-3 to various cytokines using next-generation RNA sequencing (RNA-seq). Our findings reveal that cytokines, especially IL-8 and IL-10, significantly alter the L. rhamnosus transcriptome, affecting genes involved in carbohydrate metabolism, stress response, and transcriptional regulation. Notably, IL-8 and IL-10 induce a significant downregulation of genes related to the phosphotransferase system, suggesting a reduction in metabolic activity in response to inflammatory signals. This study unveils a previously unexplored aspect of L. rhamnosus adaptation, highlighting its intricate response to cytokine signals. By modulating gene expression, L. rhamnosus may mitigate the adverse effects of inflammation and promote gut health. These insights could inform the development of targeted probiotic therapies for inflammatory bowel disease (IBD) and other conditions with altered cytokine levels. Our results suggest that co-evolution between a host and gut microbiota enables bacteria to respond to specific cytokines through gene expression changes, revealing a unique and underexplored facet of the interaction between commensal bacteria and the host organism.

Linalool and 1,8-Cineole as Constitutive Disease-Resistant Factors of Norway Spruce Against Necrotrophic Pathogen Heterobasidion Parviporum.

Norway spruce is an important coniferous species in boreal forests. Root and stem rot diseases caused by the necrotrophic pathogen Heterobasidion parviporum threaten the wood production of Norway spruce which necessitates the search for durable control and management strategies. Breeding for resistant traits is considered a viable long-term strategy. However, identification of potential resistant traits and markers remains a major challenge. In this study, short-term disease resistance screening was conducted using 218 Norway spruce clones from 17 families. Disease resistance was evaluated based on the size of necrosis lesion length following infection with the pathogen. A subset of needles/branches from clones with small (partial resistant) or large (susceptible) lesions were used for terpene analysis and transcriptomic profiling. The results revealed that the content of monoterpene linalool and 1,8-cineole and their respective encoded genes were significantly more abundant and highly expressed in the partial resistant group. Furthermore, linalool and 1,8-cineole were demonstrated to have inhibitory effect on the growth of the pathogen H. parviporum, with morphological distortion of the hyphae. RNAseq analysis revealed that transcript of pathogen genes involved in the regulation of carbohydrate metabolism and stress responses were significantly decreased in presence of the terpenes. The results suggest the relevance of monoterpenes together with jasmonic acid precursor and some genes involved in phenylpropanoid biosynthesis, as constitutive tolerance factors for Norway spruce tolerance against necrotrophic pathogen. The high level of necrosis related cell death gene expression might be factors critical for host susceptibility and disease development.

Overexpression of vacuolar H+-pyrophosphatase from a recretohalophyte Reaumuria trigyna enhances vegetative growth and salt tolerance in transgenic Arabidopsis thaliana

Reaumuria trigyna, a wild and endangered salt-secreting small shrub, is distributed in arid and semi-arid areas of Inner Mongolia, China. An H+-pyrophosphatase gene (RtVP1) was isolated from R. trigyna according to transcriptomic data, which encoded a plasma membrane and tonoplast-localized protein. RtVP1 was quickly upregulated by NaCl and exogenous abscisic acid treatment and rescued the sucrose deficiency sensitive phenotype of the AtVP1 mutant (avp1). Transgenic Arabidopsis overexpressing RtVP1 exhibited a higher leaf area, plant height, fresh weight, root length, and soluble carbohydrate accumulation compared to the wild type (WT) under normal conditions. RtVP1 overexpression increased the seed germination rate and decreased the reduction rate of fresh weight, root length, and chlorophyll content in transgenic plants under salt stress. Catalase enzyme activity, proline content, relative water content, and soluble sugar content were significantly increased in transgenic Arabidopsis under salt stresses, but the malondialdehyde content was dramatically decreased. More K+ and less Na+ were accumulated in transgenic Arabidopsis leaves, resulting in a relatively lower Na+/K+ ratio. In transgenic Arabidopsis roots, K+ was unchanged, but Na+ and the Na+/K+ ratios were reduced compared to those in WT. More Na+ and K+ were accumulated in the intracellular of transgenic yeast, and the Na+/K+ ratio was significantly reduced compared to the control. These results showed that R. trigyna RtVP1 promotes the vegetative growth of plants, mainly by regulating carbohydrate metabolism, and confers salt tolerance in transgenic Arabidopsis by maintaining Na+/K+ homeostasis and enhancing the antioxidant and osmotic regulatory capacity. These results indicated that RtVP1 can serve as an important candidate gene for genetic improvement of crop yield and salt tolerance.

Lipid metabolism and food ingredients from the perspective of thermogenic adipocytes.

The high heat-producing capacity of brown and beige adipocytes, collectively known as thermogenic adipocytes, contributes to whole-body energy expenditure and is an attractive target for the management of obesity. It has been revealed that the functions of thermogenic adipocytes are important for the regulation of whole-body carbohydrate and lipid metabolism, and the activation of thermogenic adipocytes seems to have beneficial effects for the management of obesity-related metabolic disorders, such as dyslipidemia. Recent studies have showed that specific food ingredients have the potential to activate thermogenic adipocytes via various mechanisms. Some of these are effective not only in rodents, but also in humans, and effective prevention of obesity using these food ingredients is expected. In this review, we introduce the recent findings on the regulatory mechanisms of lipid metabolism by thermogenic adipocytes and food ingredients, demonstrating the potential to activate thermogenic adipocytes and their underlying mechanisms.

A Comprehensive Review on the Anti-Obesity Potential of Limonia acidissima L., and its Bioactive Compounds: Mechanisms and Applications in Weight Management

Introduction: Obesity is a global health challenge associated with numerous metabolic disorders, including diabetes and cardiovascular disease. With growing interest in natural remedies for weight management, Limonia acidissima L., has garnered attention due to its rich bioactive composition. Objectives: This systematic review evaluates the anti-obesity potential of Limonia acidissima L., and its key bioactive compounds, including fibres, phytosterols, saponins, polyphenols, flavonoids, and ascorbic acid. Methods: A comprehensive search of databases such as PubMed, Scopus, and Google Scholar was conducted, focusing on studies published between 2000 and 2023 that investigated the metabolic effects of these compounds on lipid and carbohydrate metabolism, fat absorption, and glucose regulation. Results: The results demonstrated that Limonia acidissima L., significantly reduced body weight and fat mass, improved lipid profiles, and enhanced insulin sensitivity in both animal and human studies.Phytosterols and saponins played key roles in modulating lipid metabolism, while fibres and polyphenols were found to regulate carbohydrate metabolism and improve glycemic control. Additionally, the synergistic effects of multiple bioactive compounds amplified their collective anti-obesity potential, with few reported adverse effects, suggesting a favourable safety profile. The discussion highlights the multifaceted mechanisms through which Limonia acidissima L., combats obesity, emphasizing its ability to target multiple metabolic pathways simultaneously.While the findings are promising, the need for further large-scale clinical trials to validate these effects in diverse populations is underscored. Conclusions: In conclusion, Limonia acidissima L., emerges as a potent natural remedy for obesity management, with strong potential for inclusion in weight loss supplements and functional foods.Its bioactive compounds offer a comprehensive and safe approach to addressing the global obesity epidemic, although further research is needed to establish its long-term efficacy and optimal use.

8026 Growth Hormone Receptor (GHR) is Independently Associated with Body Composition and Glycemic Measures in Youth with Type 2 Diabetes (T2D)

Abstract Disclosure: C. Lu: None. D. Wolfs: None. L. El ghormli: None. L.M. Laffel: None. M. Patti: Advisory Board Member; Self; Fractyl Health. Consulting Fee; Self; AstraZeneca, Hamni, MBX Biosciences. Grant Recipient; Self; Dexcom. E. Isganaitis: None. Background: T2D is more severe in youth than in adults, with growth and puberty as potential drivers. Growth hormone (GH) action, which peaks during puberty, also regulates carbohydrate metabolism. We previously showed that higher plasma levels of GHR are associated with hyperglycemia, insulin resistance, and decreased insulin secretion in youth with T2D. Plasma GHR is higher in obesity, and reductions in GHR after bariatric surgery may mediate improvements in glycemia. The association of GHR with body composition in youth with T2D has not been previously studied. Hypothesis: We hypothesize that the association of GHR with glycemic outcomes in youth with T2D is mediated by differences in body composition, and that associations between GHR and body composition differ by sex. Methods: Utilizing plasma samples from Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study (N=398), we examined association of plasma GHR (ELISA; ng/mL) with a) body composition measures including zBMI, absolute lean mass (kg), percent body fat (dual-energy x-ray absorptiometry), and b) glycemic outcomes including hemoglobin A1c (HbA1c), fasting glucose (mg/dL), 1/fasting C-peptide (mL/ng), C-peptide index (ng/mL per mg/dL), and C-peptide oral disposition index (CODI; mL/uU x ng/mL per mg/dL), stratified by sex. Linear regressions were adjusted for age, race/ethnicity, and Tanner stage in the base models, with additional adjustments for HbA1c, zBMI, lean mass, or percent fat. Results: This subcohort of youth with T2D from the TODAY study included 150 males and 248 females, mean age 13.9 ± 2.0 years. Females had lower zBMI (+2.2 ± 0.4 vs. +2.3 ± 0.5, p=0.005), lower lean mass (51 ± 10 vs. 59 ± 14, p<0.001), and higher percent body fat (39 ± 5 vs. 34 ± 6, p<0.001). Higher log2 GHR was associated with higher zBMI (B=0.44, SE=0.04, p<0.001), higher lean mass (B=4.3, SE=1.2, p<0.001), and higher percent fat (B=4.4, SE=0.7, p<0.001), even after adjustment for HbA1c, and without sex-specific differences. Higher log2 GHR was associated with higher HbA1c (B=0.35, SE=0.08, p<0.001), higher fasting glucose (B=9.0, SE=2.6, p<0.001), lower 1/fasting C-peptide (B=-0.17, SE=0.01, p<0.001), and lower CODI (B=-0.001, SE=0.001, p=0.02). These associations did not change with further adjustments for zBMI, lean mass, or percent fat, suggesting that associations between GHR and glycemia are independent of obesity or body composition. In analyses stratified by sex, the effect of GHR on CODI was attenuated after adjustment for lean mass in males only. Conclusion: Plasma GHR is independently associated with body composition and glycemia in youth with T2D. There were no sex differences in associations of GHR with HbA1c and insulin resistance. However, the association of GHR with beta cell function may be mediated by lean mass in boys but not in girls, although power was more limited in the sex-stratified analyses. Presentation: 6/3/2024

Role of chemerin in the metabolic regulation of type 1 diabetes in children

Introduction and objective: Type 1 diabetes is one of the most common chronic diseases of childhood, leading to the development of chronic micro- and macrovascular complications. Recently, many researchers have been focusing their efforts on identifying new markers for the progression of this disease. It is known that adipokines play a significant role in the regulation of lipid and carbohydrate metabolism. The aim of this study was to evaluate the level of serum chemerin in children with type 1 diabetes and assess their correlation with body mass index, glycated haemoglobin, and lipid profile. Materials and methods: The study group included 40 children with newly diagnosed, 40 with long-term diabetes, and 14 children without diabetes as a control group. Chemerin levels were measured using a sandwich enzyme-linked immunosorbent assay. Results: We did not find any statistically differences in chemerin levels in the studied groups of children. In the group of patients with long-term, metabolically well-controlled diabetes, chemerin levels were higher in girls than in boys (p = 0.028). Moreover, no difference in chemerin levels was observed between the studied groups of children depending on the body mass index percentiles. A negative correlation was found between chemerin level and age in children with newly diagnosed diabetes and metabolically well-controlled diabetes. Conclusions: Our study provides new insights into the status of chemerin among paediatric patients with varying degrees of type 1 diabetes control. However, further research is needed involving larger groups of patients with differing degrees of sexual maturation and with the presence of microvascular complications.

SlNAP1 promotes tomato fruit ripening by regulating carbohydrate metabolism

Many studies showed NAC transcription factors play an important role in fruit ripening. Moreover, sucrose and starch metabolism is also closely related to fruit ripening. However, there are a few studies focus on whether NAC regulates sucrose and starch metabolism to influence fruit ripening. In this study, virus-induced gene silencing (VIGS) of SlNAP1 suppressed fruit ripening and delayed color transformation. The chlorophyll (including Chla, Chlb, and Chla + b) degradation and carotenoid synthesis in SlNAP1-silenced fruits were dramatically suppressed. Silencing SlNAP1 decreased soluble sugar and reducing sugar accumulation in fruits, and increased starch content. The activity of starch degrading enzymes, including α amylase (AMY) and β amylase (BAM) was significantly lower in SlNAP1-silenced fruits than in the control fruits, whereas denosine diphosphoglucose pyrophosphorylase (AGP) activity was significantly higher. In addition, the expression of starch degradation-related genes (SlAMY1, SlAMY2, SlBAM1, SlBAM7, SlGWD, SlPWD) in SlNAP1-silenced fruits was significantly suppressed, while starch synthesis-related genes (SlAGPase1, SlAGPase2) was significantly increased. Compared with the control fruits, SlNAP1-silenced fruits showed significantly lower sucrose and glucose content. The expression level of sucrose and glucose metabolism-related genes such as Slsus1, Slsus3, SlSPS, SlHxk1, SlHxk2, SlPK1, and SlPK2 was significantly lower in SlNAP1-silenced fruits than in the control fruits. Overall, this study revealed that SlNAP1 gene might positively regulate fruit ripening by influencing carbohydrate metabolism.

Unveiling the multifaceted role of adropin in various diseases (Review).

Adropin is a secreted peptide encoded by the energy homeostasis‑associated gene, which also functions as a membrane‑bound protein facilitating intercellular communication. This peptide has been detected in various tissues and body fluids, including the brain, liver, kidney, heart, pancreas, small intestine, endothelial cells and colostrum. Notably, the amino acid sequences of adropin are identical in humans, mice and rats. Previous studies have demonstrated that adropin levels fluctuate under different physiological and pathological conditions. Adropin plays a role in regulating carbohydrate metabolism, lipid metabolism and intercellular molecular signaling pathways, implicating its involvement in the progression of numerous diseases, such as acute myocardial infarction, lung injury, non‑alcoholic fatty liver disease/non‑alcoholic steatohepatitis, kidney disease, polycystic ovary syndrome, obesity, and diabetes, atherosclerosis, systemic sclerosis and cancer. Despite its significance, the precise role and mechanism of this protein remain inadequately understood and studied. To elucidate the function of adropin and its clinical research status, a systematic review of recent studies on adropin across various diseases was conducted. Additionally, several challenges and limitations associated with adropin research in both animal and clinical contexts were identified, aiming to offer valuable insights for future investigation.

Knockout of Hsp70 genes significantly affects locomotion speed and gene expression in leg skeletal muscles of Drosophila melanogaster.

The functions of the heat shock protein 70 (Hsp70) genes were studied using a line of Drosophila melanogaster with a knockout of 6 of these genes out of 13. Namely, the effect of knockout of Hsp70 genes on negative geotaxis climbing (locomotor) speed and the ability to adapt to climbing training (0.5-1.5 h/day, 7 days/wk, 19 days) were examined. Seven- and 23-day-old Hsp70- flies demonstrated a comparable reduction (twofold) in locomotor speed and widespread changes in leg skeletal muscle transcriptome (RNA sequencing) compared with w1118 flies. To identify the functions of genes related to decreased locomotor speed, the overlapped differentially expressed genes at both time points were analyzed: the upregulated genes encoded extracellular proteins, regulators of drug metabolism, and the antioxidant response, whereas downregulated genes encoded regulators of carbohydrate metabolism and transmembrane proteins. In addition, in Hsp70- flies, activation of transcription factors related to disruption of the fibril structure and heat shock response (Hsf) was predicted, using the position weight matrix approach. In control flies, adaptation to chronic exercise training was associated mainly with gene response to a single exercise bout, whereas the predicted transcription factors were related to stress/immune (Hsf, NF-κB, etc.) and early gene response. In contrast, Hsp70- flies demonstrated no adaptation to training as well as a significantly impaired gene response to a single exercise bout. In conclusion, the knockout of Hsp70 genes not only reduced physical performance but also disrupted adaptation to chronic physical training, which is associated with changes in the leg skeletal muscle transcriptome and impaired gene response to a single exercise bout.NEW & NOTEWORTHY Knockout of six heat shock protein 70 (Hsp70) genes in Drosophila melanogaster reduced locomotion (climbing) speed that is associated with genotype-specific differences in leg skeletal muscle gene expression. Disrupted adaptation of Hsp70- flies to chronic exercise training is associated with impaired gene response to a single exercise bout.

BIOCHEMICAL IMBALANCE IN ISCHEMIC HEART DAMAGE COMBINED WITH STEATOHEPATOSIS

The development of steatohepatosis in most cases is the primary process and consequence of the metabolic syndrome. This disease has a long asymptomatic course. The connection of steatohepatosis with the development and progression of coronary heart disease occurs when steatohepatosis is associated with metabolic syndrome and obesity. Patients with steatohepatosis usually have signs of metabolic syndrome: arterial hypertension, abdominal obesity, impaired glucose tolerance, atherogenic dyslipidemia, which are considered risk factors for cardiovascular diseases. Biochemical parameters were determined in coronary artery disease complicated by steatohepatosis. 101 people were examined. When examining the serum level of brain natriuretic peptide in patients with ischemic heart disease in combination with steatohepatosis, a higher level was found than in uncomplicated coronary heart disease, which indicates a deeper violation of the functional state of the myocardium in ischemic heart disease in combination with steatohepatosis. When examining the cytolytic syndrome markers LDH, AST and ALT, a probable increase in their activity is observed. The detected activation of LDH is associated with damage, tissue necrosis, which is observed in the case of damage to the myocardium and hepatocytes in the examined groups, which indicates an inflammatory type of pathogenesis. Apparently, activation of transaminases is associated with cytolytic syndrome in myocardial damage and increased energy expenditure of hepatocytes in fatty hepatosis. Signs of impaired glucose tolerance were found in the examined subjects: the fasting glucose level and the postprandial glucose level probably exceeded normal values, the HbA1c level was 1.5 times higher than the control in myocardial ischemia, and 1.7 times higher in coronary heart disease and steatohepatosis (p< 0.05). Disruption of hormonal regulation of carbohydrate metabolism was detected in both examined groups. An elevated level of total cholesterol and dyslipoproteinemia were also found in both groups of examined patients, however, the most pronounced changes are observed in the case of complications of steatohepatosis. The obtained results indicate complex disorders of lipid metabolism in myocardial ischemia and ischemic heart damage in combination with steatohepatosis, which confirms the development of metabolic syndrome.

Environmental circadian disruption re-writes liver circadian proteomes

Circadian gene expression is fundamental to the establishment and functions of the circadian clock, a cell-autonomous and evolutionary-conserved timing system. Yet, how it is affected by environmental-circadian disruption (ECD) such as shiftwork and jetlag are ill-defined. Here, we provided a comprehensive and comparative description of male liver circadian gene expression, encompassing transcriptomes, whole-cell proteomes and nuclear proteomes, under normal and after ECD conditions. Under both conditions, post-translation, rather than transcription, is the dominant contributor to circadian functional outputs. After ECD, post-transcriptional and post-translational processes are the major contributors to whole-cell or nuclear circadian proteome, respectively. Furthermore, ECD re-writes the rhythmicity of 64% transcriptome, 98% whole-cell proteome and 95% nuclear proteome. The re-writing, which is associated with changes of circadian regulatory cis-elements, RNA-processing and protein localization, diminishes circadian regulation of fat and carbohydrate metabolism and persists after one week of ECD-recovery.

Cardarin effect on the formation of histopathological and behavioral abnormalities in the lithium-pilocarpine model of temporal lobe epilepsy in rats

Epilepsy is a severe neuropsychological disease accompanied by the development of spontaneous recurrent seizures (SRS) and associated behavioral disorders that are difficult to treat. In recent years, the neuroprotective properties of agonists of peroxisome proliferator-activated receptors (PPAR α, β/δ, γ), nuclear transcription factors involved in the regulation of lipid and carbohydrate metabolism, as well as inflammatory signaling pathways involved in the pathogenesis of epilepsy, have been actively investigated. The neuroprotective properties of PPARγ agonists have been repeatedly described in models of epilepsy; the effects of PPARβ/δ agonists in these models have not been sufficiently investigated. The aim of this work was to study the effects of administering the PPARβ/δ agonist cardarin on the formation of histopathological and behavioral abnormalities in the lithium-pilocarpine model of temporal lobe epilepsy (TLE). The lithium-pilocarpine model is one of the best experimental models of chronic temporal lobe epilepsy. In this study, epilepsy was induced by administration of pilocarpine to male Wistar rats at the age of 7 weeks one day after LiCl injection. Cardarin (2.5 mg/kg) was administered daily for 7 days after pilocarpine, with the first injection one day after pilocarpine injection. Behavioral testing was performed 2‒3 months after induction of the model in the following tests: Open Field, Resident Stranger, New Object Exploration, Y Maze Spontaneous Alternation and Morris Water Maze. Brain sampling for histological studies (assessment of neuronal death, Nissl staining) was performed after the end of behavioral experiments, 95 days after TLE induction. It was shown that untreated rats with TLE exhibited significant hippocampal neuron death and behavioral disorders: increased motor activity, anxiety, memory disorders, research and communicative behavior. Caradrin did not affect the survival rate of hippocampal neurons, but reduced the manifestation of almost all the above-mentioned behavioral disorders, except for hyperactivity. Thus, this study demonstrated the promising use of PPARβ/δ agonists to attenuate the development of behavioral disorders characteristic of epilepsy.

Silicon and Potassium-Induced Modulations in Leaf Carbohydrate Metabolism Confer Freezing Tolerance in Satsuma Mandarin

Freezing temperatures are a severe issue in North Florida, primarily due to occasional cold snaps and frost events in winter and early spring that cause damage to citrus groves, resulting in reduced fruit yield. The apoplasm is the primary cell component that interacts with environmental stress and is essential for plant tolerance to freezing temperatures. The present study was conducted to gain insight into how the application of silicon (Si) and potassium (K) are involved in the leaf apoplasm contributes to freezing stress tolerance, and regulates carbohydrate metabolism. We used Satsuma mandarin (Citrus unshiu Marc.), the most successful commercially grown citrus cultivar in North Florida, and treated trees with two concentrations of Si and K (50 and 100 ppm) both individually and combined as foliar spray to determine their effect as they relate to improving cold hardiness. Freezing stress (-6 °C) caused a severe reduction in photosynthesis, and modulations in leaf carbohydrate metabolism resulted in inhibited plant growth. The exogenous application of Si and K both improved the photosynthesis rate, soluble sugars, and activities of enzymes of carbohydrate metabolism such as fructokinase, phosphofructokinase, hexokinase, sucrose and phosphate synthase, and acid and neutral invertase. Applying Si (100 ppm) and combined treatment (Si + K-50) showed the best response by inducing the maximum tolerance to freeze stress. Our data demonstrated the ameliorative effect of Si and K under freezing stress in citrus is associated with modification in carbohydrate metabolism in the leaf apoplasm. This study provides direction for future research to investigate the effect of Si and K on the transcriptome and metabolome in citrus plants and their tissues under freezing stress.Graphical

Disturbances in dynamics of glucose, insulin and C-peptide in blood after a normalized intake of mixed meal in obesity and type 2 diabetes mellitus

The aim of the study is to investigate the dynamics of venous blood glucose, insulin, and C-peptide in response to intake a meal normalized to body mass in obese patients without and with type 2 diabetes mellitus. Venous blood samples were taken from 7 healthy subjects, 9 obese patients, and 10 obese patients with type 2 diabetes mellitus (mean period of diagnosed diabetes 7 years) before and 30, 60, 90, 120, and 180 min after a mixed meal (6 kcal/kg of body mass); additionally, 9 patients with obesity and type 2 diabetes mellitus and 3 healthy volunteers completed a hyperinsulinemic euglycemic clamp test. In patient groups the energy content of food did not differ, but was 1.8 times higher than in the control. An increase in glucose level one hour after a meal was maximal in patients with type 2 diabetes, but an increase in insulin and C-peptide — in obese patients, that related to impairment of insulin-dependent glucose uptake by tissues and of the rate of insulin secretion (dysfunction of â-cells) in patients. At the same time, an increase in the total area under the curve “C-peptide–time” shows that the maximum secretory response of â-cells is comparable in obese patients without and with type 2 diabetes mellitus. The absolute blood glucose level 90 minutes after a meal was closely correlated with the M-index — the marker of systemic sensitivity to insulin (rs = –0.82, p = 0.002). Our results characterize the features in the regulation of carbohydrate metabolism after intake a mixed meal, normalized to body mass, in people with the varying severity of metabolic disorders, and open up prospects for a wider application of this test in practice.

Zinc regulation of chlorophyll fluorescence and carbohydrate metabolism in saline-sodic stressed rice seedlings

Saline-sodic stress can limit the absorption of available zinc in rice, subsequently impacting the normal photosynthesis and carbohydrate metabolism of rice plants. To investigate the impact of exogenous zinc application on photosynthesis and carbohydrate metabolism in rice grown in saline-sodic soil, this study simulated saline-sodic stress conditions using two rice varieties, 'Changbai 9' and 'Tonghe 899', as experimental materials. Rice seedlings at 4 weeks of age underwent various treatments including control (CT), 2 μmol·L−1 zinc treatment alone (Z), 50 mmol·L−1 saline-sodic treatment (S), and 50 mmol·L−1 saline-sodic treatment with 2 μmol·L−1 zinc (Z + S). We utilized JIP-test to analyze the variations in excitation fluorescence and MR820 signal in rice leaves resulting from zinc supplementation under saline-sodic stress, and examined the impact of zinc supplementation on carbohydrate metabolism in both rice leaves and roots under saline-sodic stress. Research shows that zinc increased the chloroplast pigment content, specific energy flow, quantum yield, and performance of active PSII reaction centers (PIABS), as well as the oxidation (VOX) and reduction rate (Vred) of PSI in rice leaves under saline-sodic stress. Additionally, it decreased the relative variable fluorescence (WK and VJ) and quantum energy dissipation yield (φDO) of the rice. Meanwhile, zinc application can reduce the content of soluble sugars and starch in rice leaves and increasing the starch content in the roots. Therefore, the addition of zinc promotes electron and energy transfer in the rice photosystem under saline-sodic stress. It enhances rice carbohydrate metabolism, improving the rice plants’ ability to withstand saline-sodic stress and ultimately promoting rice growth and development.

Transcription profiling reveals tissue-specific metabolic pathways in the fat body and ovary of the diapausing mosquito Culex pipiens

The northern house mosquito, Culex pipiens, employs diapause as an essential survival strategy during winter, inducing important phenotypic changes such as enhanced stress tolerance, lipid accumulation, and extended longevity. During diapause, the cessation of reproductive development represents another distinctive phenotypic change, underlining the need for adjusted modulation of gene expressions within the ovary. Although considerable advancements in screening gene expression profiles in diapausing and non-diapausing mosquitoes, there remains a gap in tissue-specific transcriptomic profiling that could elucidate the complicated formation of diverse diapause features in Cx. pipiens. Here, we filled this gap by utilizing RNA sequencing, providing a detailed examination of gene expression patterns in the fat body and ovary during diapause compared to non-diapause conditions. Functional annotation of upregulated genes identified associations with carbohydrate metabolism, stress tolerance, immunity, and epigenetic regulation. The validation of candidate genes using quantitative real-time PCR verified the differentially expressed genes identified in diapausing mosquitoes. Our findings contribute novel insights into potential regulators during diapause in Cx. pipiens, thereby opening possible avenues for developing innovative vector control strategies.

Regulation of carbohydrate metabolism and insulin secretion in diabetic rats following treatment with Hypericum perforatum L. hairy root aqueous methanol extract

Hairy root (HR) cultures of Hypericum perforatum L. have shown promise in controlling hyperglycemia, regulating blood lipid and enzyme profiles, and improving metabolic function in vivo. These benefits are mainly attributed to the phenolic acids, flavonoids, and xanthones present in HR extracts. However, the specific mechanism underlying these effects remains unclear. This study was performed to elucidate the biochemical and molecular mechanisms driving HR the antihyperglycemic and antidiabetic effects of HR extracts. HR extract (200 mg/kg body weight) was administered daily for 14 days to healthy rats and rats with streptozotocin-induced diabetes, with glibenclamide serving as a positive control. The phenolic composition of the HR extracts was confirmed through high-performance liquid chromatography/diode array detection/electrospray ionization mass spectrometry (HPLC/DAD/ESI-MSn ) analysis. The results showed that HR extract treatment increased the plasma insulin level and pancreatic poly (adenosine diphosphate-ribose) polymerase (PARP) activity in diabetic rats, thus normalizing blood glucose levels. Additionally, it reduced the activity of gluconeogenic enzymes, increased the activity of glycolytic enzymes, and normalized the glycogen content in the liver. HR extract-treated rats also exhibited increased hepatic adenosine monophosphate-activated protein kinase (AMPK) mRNA expression and a decreased protein kinase Cε (PKCε) concentration. In conclusion, HR extract demonstrated insulinotropic effects and effectively regulated hepatic carbohydrate metabolism in diabetic rats by modulating AMPK expression and the PKCε concentration. These findings suggest the potential use of HR extract as an herbal medicine for diabetes treatment and a source of antidiabetic drug development.

Advances in the Modulation of Potato Tuber Dormancy and Sprouting.

The post-harvest phase of potato tuber dormancy and sprouting are essential in determining the economic value. The intricate transition from dormancy to active growth is influenced by multiple factors, including environmental factors, carbohydrate metabolism, and hormonal regulation. Well-established environmental factors such as temperature, humidity, and light play pivotal roles in these processes. However, recent research has expanded our understanding to encompass other novel influences such as magnetic fields, cold plasma treatment, and UV-C irradiation. Hormones like abscisic acid (ABA), gibberellic acid (GA), cytokinins (CK), auxin, and ethylene (ETH) act as crucial messengers, while brassinosteroids (BRs) have emerged as key modulators of potato tuber sprouting. In addition, jasmonates (JAs), strigolactones (SLs), and salicylic acid (SA) also regulate potato dormancy and sprouting. This review article delves into the intricate study of potato dormancy and sprouting, emphasizing the impact of environmental conditions, carbohydrate metabolism, and hormonal regulation. It explores how various environmental factors affect dormancy and sprouting processes. Additionally, it highlights the role of carbohydrates in potato tuber sprouting and the intricate hormonal interplay, particularly the role of BRs. This review underscores the complexity of these interactions and their importance in optimizing potato dormancy and sprouting for agricultural practices.

Decreased inhibition of ventral brainstem liver-related neurons in high-fat diet fed mice

Pre-sympathetic liver-related neurons in the ventrolateral and ventromedial medulla (VLM/VMM) participate in the regulation of hepatic carbohydrate and lipid metabolism. Increased sympathetic activity observed in diet-induced obese mice likely contributes to excessive hepatic glucose production, and thus to the development, and/or progression of type 2 diabetes mellitus. At the cellular level, change in neuronal activity and/or synaptic balance is one of the underlying mechanisms that can lead to increased sympathetic outflow. In this study, we tested the hypothesis that high-fat diet (HFD) diminishes glycinergic inhibition of liver-related neurons in the VLM/VMM. We crossed heterozygous glycine transporter 2 Cre (GlyT2Cre) mice with floxed channelrhodopsin 2 (ChR2-EYFP) mice to generate GlyT2-ChR2 expressing mice (GlyT2ChR2/EYFP). Liver-related neurons were identified in the VLM/VMM with a retrograde viral tracer and patch-clamp recordings were conducted. Whole-cell recordings from pre-sympathetic, liver-related neurons revealed that spontaneous inhibitory postsynaptic currents (sIPSCs) are mediated by GABA and glycine. Our data showed that increasing the activity of inhibitory inputs leads to increased glycine release. Next, light stimulation was used to trigger glycine release in GlyT2ChR2/EYFP mice. Light stimulation of ChR2-expressing glycinergic fibers triggered evoked IPSCs (eIPSCs) generated by co-release of GABA and glycine with identical time courses for the two neurotransmitters. Intriguingly, in HFD-fed mice we found that the amplitude of light evoked IPSCs was significantly decreased. These data suggest that liver-related neurons in the VLM/VMM are co-inhibited by GABA and glycine and in HFD-fed mice inhibition of liver-related neurons is reduced. This reduced inhibition of ventral brainstem neurons may contribute to increased sympathetic activity in diet-induced obesity. Supported by: NIDDK122842 and Tulane Brain Institute Marko Spark Innovation Research Fund. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.