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Changes in the metabolic profile within the intestine of lenok (Brachymystax lenok) when challenged to acute and lethal heat stress (HS) are studied using no-target HPLC-MS/MS metabonomic analysis. Of 51 differentially expressed metabolites identified in response to HS, 34 occurred in the positive ion mode and 17 in negative ion mode (VIP > 1, P < 0.05). Changes in metabolites (i.e. alpha-D-glucose, stachyose and L-lactate) related to carbohydrate and glycolysis are identified in HS-treated lenok. Fatty acid β-oxidation in HS-treated lenok was inhibited by accumulation of acetyl carnitine, palmitoylcarnitine, carnitine, and erucic acid. Many amino acids (L-tryptophan, D-proline, L-leucine, L-phenylalanine, L-aspartate, L-tyrosine, L-methionine, L-histidine and L-glutamine) decreased to support energy demands in HS-treated lenok. Oxidative damage in HS-treated lenok was indicated by decreased glycerophospholipid metabolites (i.e. glycerophosphocholine, 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphoethanolamine, 1-palmitoyl-sn-glycero-3-phosphocholine, 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine, and 1, 2-dioleoyl-sn-glycero-3-phosphatidylcholine), and increased oxylipin production (12-HETE and 9R, 10S-EpOME). Oxidative stress increased formation of eicosanoids and dicarboxylic acids, overwhelming the mitochondrial β-oxidation pathway, while minor oxidative pathways (omega-oxidation and peroxisomal beta-oxidation) were likely to be activated in HS-treated lenok.

Amperometric nanobiosensors are crucial time and cost effective analytical tools for the detection of a wide range of bioanalytes, viz. glucose present in complex environments at very low concentrations. Although the excellent analytical performance of nanobiosensors is undoubted, their exact molecular structure often remains unclear. Here, by combining advanced nanoanalytical approaches with theoretical modeling, we conducted a comprehensive study towards the investigation of the molecular structure of a hybrid GOx/Nafion/Pd-NPs layer deposited by electroplating from the multicomponent electrolyte solution on the surface of screen printed electrodes modified with graphene oxide. Specifically, we revealed that Pd2+ cations were adsorbed on GOx amino acid residues, forming the GOx·nPd2+ enzymatic complex. The highest adsorption energy of Pd2+ cations on GOx was found during their interaction with the side chains of basic amino acids and methionine. In addition, we showed and fully validated the end-structure of the one-step designed GOx/Nafion/Pd-NPs nanobiosensor as a structural model mainly composed of GOx and water molecules incorporated into the metal-polymer scaffold. Our approach will thus serve as a guideline for the study of molecular interactions occurring in complex systems and will contribute to the design of the next generation of hybrid nanobiosensors. The proposed mechanism, driving the self-assembly of the hybrid layer, will allow us to construct modular enzymatic nanoanalytical devices with tailored sequences in the future.

The coqui frog (Eleutherodactylus coqui) is an invasive species in Hawai‘i, and has spread across much of the island. While elevational temperature differences are thought to restrict the coqui’s spread, it is unclear if they have resulted in changes to the coqui’s physiology and microhabitat use as it has expanded into higher elevations. We first sought to determine if the coqui’s substrate use and baseline physiology differs between elevations. We found that frogs at high elevation were found closer to the forest floor and used different substrates than frogs from low and mid-elevations. This change in microhabitat use is likely in response to air temperature which tends to be warmer close to the ground at high elevation. We also found that two energy stores increased with elevation, likely to help coqui frogs cope with energetic demands of colder, less ideal temperatures. Taken together, our first study suggests the coqui’s microhabitat use and physiology does change in response to elevation. Our second study concerned the thermal tolerance of the coqui frog in relation to elevation. We collected frogs from different elevations and tested their cold tolerance, glucose levels, and stress after three days in captivity to test for baseline elevational differences. We collected a second group of frogs and kept them in a cold- or warm-treatment for three weeks, after which we tested the same traits as above to assess the coqui’s acclimation ability according to elevation. Frogs from high elevations in the three-day group had greater cold tolerance than low elevation frogs. Cold-treated frogs in the three-week group had greater cold tolerance than warm-treated frogs. Glucose increased with elevation and was higher in cold-treated frogs after the three-week period, suggesting glucose is important for coping with cold temperatures. Finally, females had higher glucose and cellular damage than males in the three-day group. Our results indicate that coqui are more cold tolerant at high elevations, and can readily acclimate their thermal tolerance to cold temperatures, suggesting expansion into higher elevation habitats is possible.

Tiger pufferfish (Takifugu rubripes) is one of Asia's most economically valuable aquaculture species. However, winter production of this species in North China is limited by low water temperature and unavailability of high-quality feed, resulting in high mortality and low profitability. Therefore, the aim of this study was to evaluate the effect of feeding frequency (F1: one daily meal; F2: two daily meals; F3: four daily meals; F4: continuous diurnal feeding using a belt feeder) on the growth performance, plasma biochemistry, digestive and antioxidant enzyme activities, and expression of appetite-related genes in T. rubripes (initial weight: 266.80 ± 12.32 g) cultured during winter (18.0 ± 1.0 °C) for 60 days. The results showed that fish in the F3 group had the highest final weight, weight gain rate, specific growth rate, survival rate, and best feed conversion ratio. Additionally, daily feed intake increased significantly with increasing feeding frequency. The protein efficiency and lipid efficiency ratios of fish in the F3 group were significantly higher than those of fish in the other groups. Furthermore, total cholesterol, triglycerides, and glucose levels increased with increasing feeding frequency, peaking in the F2 group and decreasing under higher feeding frequencies. The antioxidant (superoxide dismutase, catalase, glutathione, and glutathione peroxidase) and digestive (trypsin, amylase, and lipase) enzyme activities of fish in the F1 group were significantly higher than those of fish in the F3 and F4 groups. Additionally, there was a decrease in orexin expression with increasing feeding frequency. In contrast, the expression levels of tachykinin, cholecystokinin, and leptin increased with increasing feeding frequency, peaking in the F4 group. Overall, the findings of this study indicated that a feeding frequency of four meals per day was optimal for improved growth performance of pufferfish juveniles cultured during winter.

One of the biological features of cancer cells is their aerobic glycolysis by extensive glucose fermentation to harvest energy, so called Warburg effect. Melanoma is one of the most aggressive human cancers with poor prognosis and high mortality for its high metastatic ability. During the metastatic process, the metastatic tumor cells should survive under detachment stress. However, whether the detachment stress could affect the tumor phenotype is worthy to investigate. We had established the cell model of human melanoma cells under detachment stress, which mimicked circulating melanoma. It had been demonstrated that the detachment stress altered melanoma cell activities, malignancy, and drug sensitivity. In this study, we found that adherent melanoma cells were more sensitive to glucose depletion. Gene expression profiling altered expressions of transporters associated with glucose metabolism. In addition, detachment stress reduced lactate secretion owing to the reduced MCT4 and GLUT1 expressions, the altered glycolytic and respiratory capacities, and the increased superoxide production. Detachment stress also increases the sensitivity of melanoma cells toward the blockade of electron transport chains. Investigation of the change in glucose metabolism of melanoma cells under detachment stress would be critical to provide a novel molecular mechanism to develop potential therapeutics.

Type 2 diabetes is a common manifestation of metabolic dysfunction due to obesity and constitutes a major burden for modern health care systems, in concert with the alarming rise in obesity worldwide. In recent years, several successful pharmacotherapies improving glucose metabolism have emerged and some of these also promote weight loss, thus, ameliorating insulin resistance. However, the progressive nature of type 2 diabetes is not halted by these new anti-diabetic pharmacotherapies. Therefore, novel therapies promoting weight loss further and delaying diabetes progression are needed. Amylin, a beta cell hormone, has satiating properties and also delays gastric emptying and inhibits postprandial glucagon secretion with the net result of reducing postprandial glucose excursions. Amylin acts through the six amylin receptors, which share the core component with the calcitonin receptor. Calcitonin, derived from thyroid C cells, is best known for its role in humane calcium metabolism, where it inhibits osteoclasts and reduces circulating calcium. However, calcitonin, particularly of salmon origin, has also been shown to affect insulin sensitivity, reduce the gastric emptying rate and promote satiation. Preclinical trials with agents targeting the calcitonin receptor and the amylin receptors, show improvements in several parameters of glucose metabolism including insulin sensitivity and some of these agents are currently undergoing clinical trials. Here, we review the physiological and pharmacological effects of amylin and calcitonin and discuss the future potential of amylin and calcitonin-based treatments for patients with type 2 diabetes and obesity.

Biosynthesis of plant cell walls requires UDP-glucose as the substrate for cellulose biosynthesis, and as an intermediate for the synthesis of other matrix polysaccharides. The sucrose cleaving enzyme sucrose synthase (SUS) is thought to have a central role in UDP-glucose biosynthesis, and a long held and much debated hypothesis postulates that SUS is required to supply UDP-glucose to cellulose biosynthesis. To investigate the role of SUS in cellulose biosynthesis of Arabidopsis thaliana we characterized mutants in which four, or all six Arabidopsis SUS genes were disrupted. These sus mutants showed no growth phenotypes, vascular tissue cell wall defects or changes in cellulose content. Moreover, the UDP-glucose content of rosette leaves of the sextuple sus mutants was increased by approximately 20% compared to wild type. It can thus be concluded that cellulose biosynthesis is able to employ alternative UDP-glucose biosynthesis pathway(s), and thereby the model of SUS requirement for cellulose biosynthesis in Arabidopsis can be refuted.

BACKGROUND: Colorectal cancer (CRC), one of the most common human malignancies, is a leading cause of the cancer-related mortality. 5-FU is a first-line chemotherapeutic agent against CRC. Although CRC patients responded to 5-FU therapy initially, a part of patients succumbed to CRC due to the acquired drug resistance. Thus, investigating molecular mechanisms underlying chemoresistance will contribute to developing novel strategies against colorectal cancer. OBJECTIVE: Accumulation evidence revealed pivotal roles of long non-coding RNAs (lncRNAs) in tumorigenesis and chemoresistance of CRC. However, the precise roles and molecular mechanisms of lncRNA-HCG11 in CRC remain unclear. This study aimed to investigate the biological roles and underlying mechanisms of HCG11 as well as its molecular targets in regulating the cellular metabolism processes, which facilitate the chemoresistance of CRC. METHODS AND RESULTS: This study uncovers that HCG11 was significantly upregulated in CRC tumors tissues and cell lines. Moreover, HCG11 was elevated in 5-FU resistant CRC tumors. Silencing HCG11 inhibited colon cancer cell proliferation, migration, invasion and glucose metabolism and sensitized CRC cells to 5-FU. In addition, we detected increased HCG11 expression level and glucose metabolism in the established 5-FU resistant CRC cell line (DLD-1 5-FU Res). Furthermore, microRNA-microArray, RNA pull-down and luciferase assays demonstrated that HCG11 inhibited miR-144-3p which displays suppressive roles in colon cancer via sponging it to form a ceRNA network. We identified pyruvate dehydrogenase kinase 4 (PDK4), which is a glucose metabolism key enzyme, was directly targeted by miR-144-3p in CRC cells. Rescue studies validated that the miR-144-3p-inhibited glucose metabolism and 5-FU sensitization were through targeting PDK4. Finally, restoration of miR-144-3p in HCG11-overexpressing DLD-1 5-FU resistant cells successfully overcame the HCG11-faciliated 5-FU resistance via targeting PDK4. CONCLUSION: In summary, this study reveals critical roles and molecular mechanisms of the HCG11-mediated 5-FU resistance through modulating the miR-144-3p-PDK4-glucose metabolism pathway in CRC.

How does progesterone improve fetal outcome and change the expression of placental glucose transporters (GLUT) in dexamethasone-induced intrauterine growth restriction (IUGR)?A total of 64 rats were divided randomly into four different treatment groups based on daily i.p. injections of either saline or dexamethasone in the presence or absence of progesterone. Injections started on the 15th day of gestation (15dg) and lasted until the day of sacrifice at 19dg or 21dg. Maternal plasma progesterone concentrations were measured by enzyme-linked immunosorbent assay. The gene and protein expression of placental GLUT1 and GLUT3 were evaluated in the placental labyrinth and basal zones by real-time polymerase chain reaction and Western blotting, respectively. The localization of GLUT1 and GLUT3 was evaluated by immunohistochemistry.Dexamethasone induced significant decreases in maternal serum progesterone concentrations (P = 0.029) and placental (P 0.001) and fetal body (P = 0.009) weights. Dexamethasone also reduced the expression of GLUT1 in the labyrinth zone (P = 0.028) and GLUT3 in both the labyrinth (P = 0.002) and basal zones (P = 0.026). Coadministration of dexamethasone and progesterone prevented the reduction in fetal body weight, placental weight and placental GLUT expression compared with that seen in dexamethasone-treated groups.These results suggest that progesterone prevents the significant reduction in fetal and placental weights in dexamethasone-induced IUGR, possibly through improving the expression of placental GLUT.

Objective To compare the gut microbiome composition and serum metabolome profile among individuals with spinal cord injury (SCI) and normal glucose tolerance (NGT) or prediabetes/type 2 diabetes (preDM/T2D). Design Cross-sectional design. Setting Research university. Participants A total of 25 adults (N=25) with SCI were included in the analysis and categorized as NGT (n=16) or preDM/T2D (n=9) based on their glucose concentration at minute 120 during a 75-g oral glucose tolerance test. The American Diabetes Association diagnosis guideline was used for grouping participants. Interventions Not applicable. Main Outcome Measures A stool sample was collected and used to assess the gut microbiome composition (alpha and beta diversity, microbial abundance) via the 16s ribosomal RNA sequencing technique. A fasting serum sample was used for liquid chromatography–mass spectrometry–based untargeted metabolomics analysis, the results from which reflect the relative quantity of metabolites detected and identified. Gut microbiome and metabolomics data were analyzed by the Quantitative Insights into Microbial Ecology 2 and Metaboanalyst platforms, respectively. Results Gut microbiome alpha diversity (Pielou's evenness index, Shannon's index) and beta diversity (weighted UniFrac distances) differed between groups. Compared with participants with NGT, participants with preDM/T2D had less evenness in microbial communities. In particular, those with preDM/T2D had a lower abundance of the Clostridiales order and higher abundance of the Akkermansia genus, as well as higher serum levels of gut-derived metabolites, including indoxyl sulfate and phenylacetylglutamine (P Conclusions Our results provide evidence for altered gut microbiome composition and dysregulation of gut-derived metabolites in participants with SCI and preDM/T2D. Both indoxyl sulfate and phenylacetylglutamine have been implicated in the development of cardiovascular diseases in the able-bodied population. These findings may inform future investigations in the field of SCI and cardiometabolic health.

Background To investigate the causality between metformin and gut microbiome in the treatment of type 2 diabetes (T2D). Methods This study was conducted on individuals with newly diagnosed and treatment-naive T2D. We used 16s rRNA sequencing to understand the effect of metformin on the composition and diversity of the gut microbiota. We also compared the differences in relative abundances of gut microbiome at the genus level in treatment-naive T2D patients before and after metformin treatment for 2 months and used Spearman rank correlation coefficient analysis of genus abundance in relation to blood glucose and related factors. Results Metformin significantly reduced blood glucose and levels of the related factors in treatment-naive individuals with T2D after 2 months of treatment. 16s rRNA sequencing showed that metformin treatment altered the composition and diversity of the gut microbiome. Differences in relative abundances at the genus level among groups revealed that Megamonas and Klebsiella in T2D groups were significantly higher compared with those in the control group. Treatment with metformin caused a significant reduction in the abundances of Megamonas and Klebsiella. Spearman rank correlation coefficient analysis showed a significant positive correlation between Megamonas and blood glucose, HbA1c, GSP, and ALT. In Klebsiella, a significant positive correlation between HbA1c and ALT was found. Conclusions Metformin reduces blood glucose in T2D by interaction with different gut bacteria, possibly Megamonas and Klebsiella pneumoniae.

The AMP-activated protein kinase (AMPK) and the target of rapamycin complex 1 (TORC1) are central kinase modules of two opposing signaling pathways that control eukaryotic cell growth and metabolism in response to the availability of energy and nutrients. Accordingly, energy depletion activates AMPK to inhibit growth, while nutrients and high energy levels activate TORC1 to promote growth. Both in mammals and lower eukaryotes such as yeast, the AMPK and TORC1 pathways are wired to each other at different levels, which ensures homeostatic control of growth and metabolism. In this context, a previous study (Hughes Hallett et al., 2015) reported that AMPK in yeast, that is Snf1, prevents the transient TORC1 reactivation during the early phase following acute glucose starvation, but the underlying mechanism has remained elusive. Using a combination of unbiased mass spectrometry (MS)-based phosphoproteomics, genetic, biochemical, and physiological experiments, we show here that Snf1 temporally maintains TORC1 inactive in glucose-starved cells primarily through the TORC1-regulatory protein Pib2. Our data, therefore, extend the function of Pib2 to a hub that integrates both glucose and, as reported earlier, glutamine signals to control TORC1. We further demonstrate that Snf1 phosphorylates the TORC1 effector kinase Sch9 within its N-terminal region and thereby antagonizes the phosphorylation of a C-terminal TORC1-target residue within Sch9 itself that is critical for its activity. The consequences of Snf1-mediated phosphorylation of Pib2 and Sch9 are physiologically additive and sufficient to explain the role of Snf1 in short-term inhibition of TORC1 in acutely glucose-starved cells. ispartof: Elife vol:12 pages:e84319- ispartof: location:England status: Published online

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research CentreMDFRC item.The bacterial community of an aerobic:anaerobic non-P removing SBR biomass fed a mixture of acetateand glucose was analysed using several 16S rRNA based methods. Populations responsible for anaerobicglucose and acetate assimilation were determined with fluorescent in situ hybridization (FISH) in combinationwith microautoradiography (FISH/MAR). At ‘steady state’ this community consisted of α-Proteobacteria(26%) and γ-Proteobacteria (14%), mainly appearing as large cocci in tetrads (i.e. typical ‘GBacteria’).Large numbers of low G+C bacteria (22%), and high G+C Gram-positive bacteria (29%) seenas small cocci in clusters or in sheets were also detected after FISH. DGGE fingerprinting of PCR amplified16S rDNA fragments and subsequent cloning and sequencing of several of the major bands led tothe identification of some of these populations. They included an organism 98% similar in its 16S rRNAsequence to Micropruina glycogenica, and ca. 76% of the high G+C bacteria responded to a probe MIC184, designed against it. The rest responded to the KSB 531 probe designed against a high G+C clone sequence,sbr-gs28 reported in other similar systems. FISH analyses showed that both these high G+C populationswere almost totally dominated by small clustered cocci. Only ca. 2% of cells were β-Proteobacteria.None of the α- and γ-Proteobacterial ‘G-bacteria’ responded to FISH probes designed for the ‘GBacteria’Amaricoccus spp. or Defluvicoccus vanus. FISH/MAR revealed that not all the α-Proteobacterial‘G-Bacteria’ could take up acetate or glucose anaerobically. Almost all of the γ-Proteobacterial ‘G-Bacteria’assimilated acetate anaerobically but not glucose, the low G+C clustered cocci only took up glucose,whereas the high G+C bacteria including M. glycogenica and the sbr-gs28 clone assimilated both acetateand glucose. All bacteria other than the low G+C small cocci and a few of the α-Proteobacteria accumulatedPHB. The low G+C bacteria showing anaerobic glucose assimilation ability were considered responsiblefor the lactic acid produced anaerobically by this SBR biomass, and M. glycogenica for its highglycogen content.

Diabetes mellitus (DM) is a non-communicable disease throughout the world in which there is persistently high blood glucose level from the normal range. The diabetes and insulin resistance are mainly responsible for the morbidities and mortalities of humans in the world. This disease is mainly regulated by various enzymes and hormones among which Glycogen synthase kinase-3 (GSK-3) is a principle enzyme and insulin is the key hormone regulating it. The GSK-3, that is the key enzyme is normally showing its actions by various mechanisms that include its phosphorylation, formation of protein complexes, and other cellular distribution and thus it control and directly affects cellular morphology, its growth, mobility and apoptosis of the cell. Disturbances in the action of GSK-3 enzyme may leads to various disease conditions that include insulin resistance leading to diabetes, neurological disease like Alzheimer’s disease and cancer. Fluoroquinolones are the most common class of drugs that shows dysglycemic effects via interacting with GSK-3 enzyme. Therefore, it is the need of the day to properly understand functions and mechanisms of GSK-3, especially its role in glucose homeostasis via effects on glycogen synthase. Resumo O diabetes mellitus (DM) é uma doença não transmissível em todo o mundo, na qual existe nível glicêmico persistentemente alto em relação à normalidade. O diabetes e a resistência à insulina são os principais responsáveis pelas morbidades e mortalidades de humanos no mundo. Essa doença é regulada principalmente por várias enzimas e hormônios, entre os quais a glicogênio sintase quinase-3 (GSK-3) é uma enzima principal e a insulina é o principal hormônio que a regula. A GSK-3, que é a enzima-chave, normalmente mostra suas ações por vários mecanismos que incluem sua fosforilação, formação de complexos de proteínas e outras distribuições celulares e, portanto, controla e afeta diretamente a morfologia celular, seu crescimento, mobilidade e apoptose do célula. Perturbações na ação da enzima GSK-3 podem levar a várias condições de doença que incluem resistência à insulina que leva ao diabetes, doenças neurológicas como a doença de Alzheimer e câncer. As fluoroquinolonas são a classe mais comum de drogas que apresentam efeitos disglicêmicos por meio da interação com a enzima GSK-3. Portanto, é necessário hoje em dia compreender adequadamente as funções e mecanismos da GSK-3, principalmente seu papel na homeostase da glicose via efeitos na glicogênio sintase.

Monosaccharides and disaccharides are important dietary components, but if insufficiently metabolized by some population subgroups, they are also linked to disease patterns. Thus, the correct analytical identification, quantification, and labeling of these food components are crucial to inform and potentially protect consumers. Enzymatic assays and high-performance anion-exchange chromatography with pulsed amperometric detection are established methods for the quantification of monosaccharides and disaccharides that, however, require long measuring times (60-180 min). Accelerated methods for the identification and quantification of the nutritionally relevant monosaccharides and disaccharides d-glucose, d-galactose, d-fructose, sucrose, lactose, and maltose were therefore developed. To realize this goal, the NMR experiments HSQC (heteronuclear single quantum coherence) and acceleration by sharing adjacent polarization (ASAP)-HSQC were applied. Measurement times were reduced to 27 and 6 min, respectively, by optimizing the interscan delay and applying non-uniform sampling. The optimized methods were used to quantify d-glucose, d-galactose, d-fructose, sucrose, and lactose in various dairy products. Results of the HSQC and ASAP-HSQC methods are equivalent to the results of the reference methods in terms of both precision and accuracy, demonstrating that these methods can be used to correctly analyze nutritionally relevant monosaccharides and disaccharides in short times.

Genome sequencing was used to identify key genes for the generation of hydrogen gas through cotton stalk hydrolysate fermentation by Klebsiella sp. WL1316. Genome annotation indicated that the genome size was 5.2 Mb with GC content 57.6%. Xylose was metabolised in the pentose phosphate pathway via the conversion of xylose to xylulose in Klebsiella sp. WL1316. This strain contained diverse formate-hydrogen lyases and hydrogenases with gene numbers higher than closely related species. A metabolic network involving glucose, xylose utilisation, and fermentative hydrogen production was reconstructed. Metabolic analysis of key node metabolites showed that glucose and xylose metabolism influenced biomass synthesis and biohydrogen production. Formic acid accumulated during fermentation at 24–48 h but decreased sharply after 48 h, illustrating the splitting of formic acid to hydrogen gas during early-to-mid fermentation. The Kreb’s cycle was the main competitive metabolic branch of biohydrogen synthesis at 24 h of fermentation. Lactic and acetic acid fermentation and late ethanol accumulation competed the carbon skeleton of biohydrogen synthesis after 72 h of fermentation, indicating that these competitive pathways are regulated in middle-to-late fermentation (48–96 h). This study is the first to elucidate the metabolic mechanisms of mixed sugar utilisation and biohydrogen synthesis based on genomic information.

β-Arrestin-1 and -2 (also known as arrestin-2 and -3, respectively) are ubiquitously expressed cytoplasmic proteins that dampen signaling through G protein-coupled receptors. However, β-arrestins can also act as signaling molecules in their own right. To investigate the potential metabolic roles of the two β-arrestins in modulating glucose and energy homeostasis, recent studies analyzed mutant mice that lacked or overexpressed β-arrestin-1 and/or -2 in distinct, metabolically important cell types. Metabolic analysis of these mutant mice clearly demonstrated that both β-arrestins play key roles in regulating the function of most of these cell types, resulting in striking changes in whole-body glucose and/or energy homeostasis. These studies also revealed that β-arrestin-1 and -2, though structurally closely related, clearly differ in their metabolic roles under physiological and pathophysiological conditions. These new findings should guide the development of novel drugs for the treatment of various metabolic disorders, including type 2 diabetes and obesity. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The collective movement of African trypanosomes on semi-solid surfaces, known as social motility, is presumed to be due to migration factors and repellents released by the parasites. Here we show that procyclic (insect midgut) forms acidify their environment as a consequence of glucose metabolism, generating pH gradients by diffusion. Early and late procyclic forms exhibit self-organising properties on agarose plates. While early procyclic forms are repelled by acid and migrate outwards, late procyclic forms remain at the inoculation site. Furthermore, trypanosomes respond to exogenously formed pH gradients, with both early and late procyclic forms being attracted to alkali. pH taxis is mediated by multiple cyclic AMP effectors: deletion of one copy of adenylate cyclase ACP5, or both copies of the cyclic AMP response protein CARP3, abrogates the response to acid, while deletion of phosphodiesterase PDEB1 completely abolishes pH taxis. The ability to sense pH is biologically relevant as trypanosomes experience large changes as they migrate through their tsetse host. Supporting this, a CARP3 null mutant is severely compromised in its ability to establish infections in flies. Based on these findings, we propose that the expanded family of adenylate cyclases in trypanosomes might govern other chemotactic responses in their two hosts., African trypanosomes collectively move in a process called social motility. Here, the authors show that procyclic forms acidify their environment as a consequence of glucose metabolism, generating pH gradients by diffusion that are sensed via cyclic AMP signalling. Parasite mutants defective in cAMP signaling are inhibited in fly infection.

The aim of this study was to investigate the relationship between mitochondrial content and respiratory function and whole-body insulin resistance in high-fat diet (HFD) fed rats. Male Wistar rats were given either a chow diet or an HFD for 12 weeks. After 4 weeks of the dietary intervention, half of the rats in each group began 8 weeks of interval training. In vivo glucose and insulin tolerance were assessed. Mitochondrial respiratory function was assessed in permeabilised soleus and white gastrocnemius (WG) muscles. Mitochondrial content was determined by the measurement of citrate synthase (CS) activity and protein expression of components of the electron transport system (ETS). We found HFD rats had impaired glucose and insulin tolerance but increased mitochondrial respiratory function and increased protein expression of components of the ETS. This was accompanied by an increase in CS activity in WG. Exercise training improved glucose and insulin tolerance in the HFD rats. Mitochondrial respiratory function was increased with exercise training in the chow-fed animals in soleus muscle. This exercise effect was absent in the HFD animals. In conclusion, exercise training improved insulin resistance in HFD rats but without changes in mitochondrial respiratory function and content. The lack of an association between mitochondrial characteristics and whole-body insulin resistance was reinforced by the absence of strong correlations between these measures. Our results suggest that improvements in mitochondrial respiratory function and content are not responsible for improvements in whole-body insulin resistance in HFD rats.

Even though supplementations of essential AA (EAA) are often related to increased lactose yields in dairy cows, underlying mechanisms connecting EAA availability to the mammary glands and lactose synthesis are poorly understood. The objective of this study was to examine the effects of branched-chain AA (BCAA) including Leu, Ile, and Val on (1) glucose transporter (GLUT1) abundance and glucose uptake, (2) the abundance of proteins regulating lactose synthesis pathway, and (3) fractional synthesis rates of lactose (FSR) using bovine mammary epithelial cells (BMEC) and mammary tissues slices (MTS). The BMEC (n = 4) were allocated randomly to regular Dulbecco's Modified Eagle Medium with Ham's F12 (DMEM/F12) medium (+EAA) or +EAA deficient (by 90%) in all EAA (- EAA), all BCAA (-BCAA), only Leu (-Leu), only Ile (-Ile) or only Val (-Val). Western immunoblotting analyses, depletion of glucose in media, and a proteomic analysis were performed to determine the abundance of GLUT1 in the cell membrane, net glucose uptake, and the abundance of enzymes involved in lactose synthesis pathway in BMEC, respectively. The MTS (n = 6) were allocated randomly to DMEM/F12 medium having all EAA and C-13-glucose at concentrations similar to plasma concentrations of cows (+EAA(p)), and +EAA(p) deprived of all BCAA (-BCAA(p)) or only Leu (-Leup) for 3 h. The C-13 enrichments of free glucose pool in MTS (EGlu-free) and the enrichments of glucose incorporated into lactose in MTS and media [ELactose-bound ((T&M))] were determined and used in calculating FSR. In BMEC, -BCAA increased the fraction of total GLUT1 translocated to the cell membrane and the fraction that was potentially glycosylated compared with +EAA. Among individual BCAA, only-Leu was associated with a 63% increase in GLUT1 translocated to the cell membrane and a 40% increase in glucose uptake of BMEC. The-BCAA tended to be related to a 75% increase in the abundance of hexokinase in BMEC. Deprivation of Leu tended to increase glucose uptake of MTS but did not affect EGlu-free, ELactose-bound ((T&M)), or FSR relative to +EAA(p). On the other hand, -BCAA(p) did not affect glucose uptake of MTS but was related to lower ELactose-bound (T&M), or FSR relative to +EAA(p). Considering together, decreasing Leu supply to mammary tissues enhances GLUT1 and thus glucose uptake, which, however, does not affect lactose synthesis rates. Moreover, the deficiency of other BCAA, Ile, and Val alone or together with the deficiency of Leu seemed to decrease lactose synthesis rates without affecting glucose uptake. The data also emphasize the importance of addressing the effect of the supply of other nutrients to the mammary glands than the precursor supply in describing the synthesis of a milk component.

Type 2 diabetes rates continue to rise unabated, underscoring the need to better understand the etiology and potential therapeutic options available for this disease. The gut microbiome plays a role in glucose homeostasis, and diabetes is associated with alterations in the gut microbiome. Given that consumption of a Western diet is associated with increased metabolic disease, and that a Western diet alters the gut microbiome, it is plausible that changes in the gut microbiota mediate the dysregulation in glucose homeostasis. In this review, we highlight a few of the most significant mechanisms by which the gut microbiome can influence glucose regulation, including changes in gut permeability, gut-brain signaling, and production of bacteria-derived metabolites like short-chain fatty acids and bile acids. A better understanding of these pathways could lead to the development of novel therapeutics to target the gut microbiome in order to restore glucose homeostasis in metabolic disease. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Dementias, including the type associated with Alzheimer’s disease (AD), are on the rise worldwide. Similarly, type 2 diabetes mellitus (T2DM) is one of the most prevalent chronic diseases globally. Although mechanisms and treatments are well-established for T2DM, there remains much to be discovered. Recent research efforts have further investigated factors involved in the etiology of AD. Previously perceived to be unrelated diseases, commonalities between T2DM and AD have more recently been observed. As a result, AD has been labeled as “type 3 diabetes”. In this review, we detail the shared processes that contribute to these two diseases. Insulin resistance, the main component of the pathogenesis of T2DM, is also present in AD, causing impaired brain glucose metabolism, neurodegeneration, and cognitive impairment. Dysregulation of insulin receptors and components of the insulin signaling pathway, including protein kinase B, glycogen synthase kinase 3β, and mammalian target of rapamycin are reported in both diseases. T2DM and AD also show evidence of inflammation, oxidative stress, mitochondrial dysfunction, advanced glycation end products, and amyloid deposition. The impact that changes in neurovascular structure and genetics have on the development of these conditions is also being examined. With the discovery of factors contributing to AD, innovative treatment approaches are being explored. Investigators are evaluating the efficacy of various T2DM medications for possible use in AD, including but not limited to glucagon-like peptide-1 receptor agonists and peroxisome proliferator-activated receptor-gamma agonists. Furthermore, there are 136 active trials involving 121 therapeutic agents targeting novel AD biomarkers. With these efforts, we are one step closer to alleviating the ravaging impact of AD on our communities.

Mitochondrial homeostasis is crucial for the function of pancreatic β-cells. ATP synthase inhibitory factor subunit 1 (IF1) is a mitochondrial protein interacting with ATP synthase to inhibit its enzyme activity. IF1 may also play a role in maintaining ATP synthase oligomerization and mitochondrial inner membrane formation. A recent study confirmed IF1 expresses in β-cells. IF1 knockdown in cultured INS-1E β-cells enhances glucose-induced insulin release. However, the role of IF1 in islet β-cells remains little known. The present study investigates islets freshly isolated from mouse lines with global IF1 knockout (IF1-/-) and overexpression (OE). The glucose-stimulated insulin secretion was increased in islets from IF1-/- mice but decreased in islets from IF1 OE mice. Transmitted Electronic Microscopic assessment of isolated islets revealed that the number of matured insulin granules (with dense core) was relatively higher in IF1-/-, but fewer in IF1 OE islets than those of controlled islets. The mitochondrial ultrastructure within β-cells of IF1 overexpressed islets was comparable with those of wild-type mice, whereas those in IF1-/- β-cells showed increased mitochondrial mass. Mitochondrial network analysis in cultured INS-1 β-cells showed a similar pattern with an increased mitochondrial network in IF1 knockdown cells. IF1 overexpressed INS-1 β-cells showed a compromised rate of mitochondrial oxidative phosphorylation with attenuated cellular ATP content. In contrast, INS-1 cells with IF1 knockdown showed markedly increased cellular respiration with improved ATP production. These results support that IF1 is a negative regulator of insulin production and secretion via inhibiting mitochondrial mass and respiration in β-cells. Therefore, inhibiting IF1 to improve β-cell function in patients can be a novel therapeutic strategy to treat diabetes.

Obesity impairs host defense against Klebsiella pneumoniae, but responsible mechanisms are incompletely understood. To determine the impact of diet-induced obesity on pulmonary host defense against K. pneumoniae, we fed 6-wk-old male C57BL/6j mice a normal diet (ND) or high-fat diet (HFD) (13% vs. 60% fat, respectively) for 16 wk. Mice were intratracheally infected with Klebsiella, assayed at 24 or 48 h for bacterial colony-forming units, lung cytokines, and leukocytes from alveolar spaces, lung parenchyma, and gonadal adipose tissue were assessed using flow cytometry. Neutrophils from uninfected mice were cultured with and without 2-deoxy-d-glucose (2-DG) and assessed for phagocytosis, killing, reactive oxygen intermediates (ROI), transport of 2-DG, and glucose transporter (GLUT1–4) transcripts, and protein expression of GLUT1 and GLUT3. HFD mice had higher lung and splenic bacterial burdens. In HFD mice, baseline lung homogenate concentrations of IL-1β, IL-6, IL-17, IFN-γ, CXCL2, and TNF-α were reduced relative to ND mice, but following infection were greater for IL-6, CCL2, CXCL2, and IL-1β (24 h only). Despite equivalent lung homogenate leukocytes, HFD mice had fewer intraalveolar neutrophils. HFD neutrophils exhibited decreased Klebsiella phagocytosis and killing and reduced ROI to heat-killed Klebsiella in vitro. 2-DG transport was lower in HFD neutrophils, with reduced GLUT1 and GLUT3 transcripts and protein (GLUT3 only). Blocking glycolysis with 2-DG impaired bacterial killing and ROI production in neutrophils from mice fed ND but not HFD. Diet-induced obesity impairs pulmonary Klebsiella clearance and augments blood dissemination by reducing neutrophil killing and ROI due to impaired glucose transport.

Little is known of the impact of individual saturated fatty acids (SFAs) and their isoenergetic substitution with other SFAs or unsaturated fatty acids (UFAs) on the prevention of cardiometabolic disease (CMD). This systematic literature review (POSPERO registration: CRD42020084241) assessed the impact of such dietary substitutions on a range of fasting CMD risk markers, including lipid profile, markers of glycemic control and inflammation, and metabolic hormone concentrations. Eligible randomized controlled trials (RCTs) investigated the effect of isoenergetic replacements of individual dietary SFAs for at least 14 days on one or more CMD risk markers in humans. Searches of PubMed, Embase, Scopus and Cochrane CENTRAL databases on 14th February 2021 identified 44 RCTs conducted in participants aged 39.9y (SD 15.2). Studies' risk of bias was assessed using the Cochrane Risk of Bias tool 2.0 for RCTs. Random-effect meta-analyses assessed the effect of at least three similar dietary substitutions on the same CMD risk marker. Other dietary interventions were described in qualitative syntheses. We observed reductions in low-density lipoprotein cholesterol concentrations after the replacement of palmitic acid (C16:0) with UFA (-0.36 mmol/L, 95%CI [-0.50, -0.21], I2 = 96.0%, n = 18 RCTs) or oleic acid (C18:1) (-0.16 mmol/L, 95% CI [-0.28, -0.03], I2 = 89.6%, n = 9 RCTs), with a similar impact on total cholesterol and apolipoprotein B concentrations. No effects on other CMD risk markers, including high-density lipoprotein cholesterol, triacylglycerol, glucose, insulin, or C-reactive protein concentrations, were evident. Similarly, we found no evidence of a benefit from replacing dietary stearic acid with UFA on CMD risk markers (n = 4 RCTs). In conclusion, the impact of replacing dietary palmitic acid with UFA on lipid biomarkers is aligned with current public health recommendations. However, due to the high heterogeneity and limited studies, relationships between all individual SFAs and biomarkers of cardiometabolic health need further confirmation from RCTs.

Maltodextrin glucosidase (MalZ) is a key enzyme in the maltose utilization pathway in Escherichia coli that liberates glucose from the reducing end of the short malto-oligosaccharides. Unlike other enzymes in the GH13_21 subfamily, the hydrolytic activity of MalZ is limited to maltodextrin rather than long starch substrates, forming various transglycosylation products in α-1,3, α-1,4 or α-1,6 linkages. The mechanism for the substrate binding and hydrolysis of this enzyme is not well understood yet. Here, we present the dimeric crystal structure of MalZ, with the N-domain generating a unique substrate binding groove. The N-domain bears CBM34 architecture and forms a part of the active site in the catalytic domain of the adjacent molecule. The groove found between the N-domain and catalytic domain from the adjacent molecule, shapes active sites suitable for short malto-oligosaccharides, but hinders long stretches of oligosaccharides. The conserved residue of E44 protrudes at subsite +2, elucidating the hydrolysis pattern of the substrate by the glucose unit from the reducing end. The structural analysis provides a molecular basis for the substrate specificity and the enzymatic property, and has potential industrial application for protein engineering.

Hyperglycemia, which occurs under the diabetic conditions, induces serious diabetic complications. Diabetic encephalopathy has been defined as one of the major complications of diabetes, and is characterized by neurochemical and neurodegenerative changes. However, little is known about the effect of long-term exposure to high glucose on neuronal cells. In the present study, we showed that exposure to glutamate (100 mM) for 7 days induced toxicity in primary cortical neurons using the MTT assay. Additionally, high glucose increased the sensitivity of AMPA- or NMDA-induced neurotoxicity, and decreased extracellular glutamate levels in primary cortical neurons. In Western blot analyses, the protein levels of the GluA1 and GluA2 subunits of the AMPA receptor as well as synaptophysin in neurons treated with high glucose were significantly increased compared with the control (25 mM glucose). Therefore, long-term exposure to high glucose induced neuronal death through the disruption of glutamate homeostasis.

The aim of the present study was to investigate the linkage between the molecular clock and the metabolic processes in horses. Ten clinically healthy Italian Saddle horses of 8-11 years old (body weight of 480 ± 25 Kg) were housed in individual boxes under natural photoperiod (sunrise at 6:10 h, sunset at 18:10 h) and natural environmental conditions (T max 18°C, T min 16°C, Rh 70%). They were fed 3 times a day (07.00, 12.00, and 19.00) and water was available ad libitum. On each horse, blood sample collections were performed every 4 hours over a 48-hour period. Glucose, total proteins, total lipids levels and clock genes (Clock and Bmal1) expression were assed. The method of single Cosinor was applied to evaluate the daily rhythmicity of the texted parameters. Glucose, total proteins and total lipids showed a robust daily rhythmicity; diurnal for glucose and total lipids, and nocturnal for total proteins and Bmal1. Clock no showed daily rhythmicity in horses. Two ways ANOVA was applied to compare acrophase and robustness of rhythm. Only Clock no showed an effect of time. No effect of day was observed on each tested parameter, acrophase and robustness. Statistical differences in acrophase were observed among diurnal and nocturnal parameters. Further studies are necessary to better understand the peripheral circadian rhythmicity in this species.

T1R3 is a class C G protein-coupled receptor family member that forms heterodimeric umami and sweet taste receptors with T1R1 and T1R2, respectively, in the taste cells of taste buds. T1R3 is expressed in 3T3-L1 cells in homomeric form and negatively regulates adipogenesis in a Gαs-dependent but cAMP-independent manner. Although T1R3 expression is markedly upregulated during adipogenesis, its physiological role in mature adipocytes remains obscure. Here, we show that stimulation of T1R3 with sucralose or saccharin induces microtubule disassembly in differentiated 3T3-L1 adipocytes. The effect was reproduced by treatment with cholera toxin or isoproterenol but not with forskolin. Treatment with sucralose or saccharin for 3 h inhibited insulin-stimulated glucose uptake by 32% and 45% in differentiated adipocytes, respectively, similar to the inhibitory effect of nocodazole (by 33%). Isoproterenol treatment inhibited insulin-stimulated glucose transport by 26%, whereas sucralose did not affect the intrinsic activity of the glucose transporter, indicating that it inhibited insulin-induced GLUT4 translocation to the plasma membrane. Immunostaining analysis showed that insulin-stimulated GLUT4 accumulation on the plasma membrane was abrogated in sucralose-treated cells, in association with depolymerization of microtubules. Sucralose-mediated inhibition of GLUT4 translocation was reversed by the overexpression of dominant-negative Gαs (Gαs-G226A) or knockdown of Gαs. Additionally, membrane fractionation analysis showed that sucralose treatment reduced GLUT4 levels in the plasma membrane fraction from insulin-stimulated adipocytes. We have identified a novel non-gustatory role for homomeric T1R3 in adipocytes, and activation of the T1R3 receptor negatively regulates insulin action of glucose transport via Gαs-dependent microtubule disassembly.

Background Beta-Glucosidases (3.2.1.21) play essential roles in the removal of nonreducing terminal glucosyl residues from saccharides and glycosides. However, the full potential and different applications of recombinant high-yield microbial β-glucosidase-producing systems remain to be tackled. Results A β-glucosidase gene designated as Mg132 was isolated from a coral microorganism by high-throughput sequencing and functional screening. The deduced amino acid sequences of Mg132 showed a highest identity of 97% with β-glucosidase predicted in the GenBank database. This gene was cloned and overexpressed in Escherichia coli BL21 (DE3) for the first time. The optimal pH and temperature of purified recombinant Mg132 were 8.0 and 50 °C, respectively. It exhibited a high level of stability at high concentration of glucose and ethanol, and glucose concentrations below 300 mM distinctly stimulated p-nitrophenyl-β-D-glucopyranoside hydrolysis, reaching 200% at 15% ethanol. The Km and Vmax values were 0.293 mM and 320 μmol min-1 mg-1 , respectively, while using p-nitrophenyl-β-D-glucopyranoside as a substrate. Wine treated with Mg132 had an obvious positive catalytic specificity for glycosides, which give a pleasant flavor of temperate fruity and floral aromas. The total concentration of fermentative volatiles was 201.42 ± 10.22 μg·L-1 following Mg132 treatment and 99.21 ± 7.72 μg·L-1 in control samples. Conclusion Good tolerance of winemaking and aroma fermentative properties suggest that Mg132 has potential application in aroma enhancement in wine for the further study. This article is protected by copyright. All rights reserved.

Key points Obesity can disrupt the structure and function of organ systems, including the olfactory system that is important for food selection and satiety. We designed dietary treatments in mice such that mice received fat, but the total calories provided were the same as in control diets so that they would not gain weight or increase adipose tissue. Mice that were not obese but consumed isocaloric fatty diets still lost olfactory neuronal circuits, had fewer numbers of olfactory neurons, had an elevation in inflammatory signals, and an intermediate ability to clear glucose (prediabetes). Mice were allowed access to running wheels while consuming fatty diets, yet still lost olfactory structures. We conclude that a long-term imbalance in nutrition that favors fat in the diet disrupts the olfactory system of mice in the absence of obesity. Abstract Excess nutrition causes loss of olfactory sensory neurons (OSNs) and reduces odor discrimination and odor perception in mice. To separate diet-induced obesity from the consumption of dietary fat, we designed pair-feeding experiments whereby mice were maintained on isocaloric diets for 5 months that prevented increased fat storage. To test our hypothesis that adiposity was not a prerequisite for loss of OSNs and bulbar projections, we used male and female mice with an odorant receptor-linked genetic reporter (M72tauLacZ; Olfr160) to visualize neural circuitry changes resulting from fat in the diet. Simultaneously we monitored glucose clearance (diagnostic for prediabetes), body fat deposition, ingestive behaviors, select inflammatory markers, and energy metabolism. Axonal projections to defined olfactory glomeruli were visualized in whole-mount brains and the number of OSNs were manually counted across whole olfactory epithelia. After being pair fed a moderately high-fat (MHF) diet, mice of both sexes had body weight, adipose deposits, energy expenditure, respiratory exchange ratios, and locomotor activity that were unchanged from control-fed mice. Despite this, they were still found to lose OSNs and associated bulbar projections. Even with unchanged adipocyte storage, pair-fed animals had an elevation in TNF cytokines and an intermediate ability for glucose clearance. Albeit improving health metrics, access to voluntary running while consuming an ad libitum fatty diet, still precipitated a loss of OSNs and associated axonal projections for male mice. Our results support that long-term macronutrient imbalance can drive anatomical loss in the olfactory system regardless of total energy expenditure. This article is protected by copyright. All rights reserved.

Objectives At present, diabetes is one of the leading causes of mortality across the world. It was hypothesized that muscle mass could have a significant influence on blood glucose level and this corelation if established successfully could pave way for novel treatment modalities for type 2 diabetes mellitus (T2DM). In the present study, the association between muscle mass and blood glucose level was examined in a healthy population who was not having T2DM at baseline and was undergoing a regular course of exercise. Methods The clinical study was performed involving 53 healthy male populations between 10 and 60 years of age. The participants were sampled in accordance with the quantitative experimental study design, using nonprobability sampling techniques. The independent variable measured among the subjects included muscle mass and blood glucose level, using bioelectrical impedance and a simple glucometer respectively. Subgroup analysis amongst different substantial parameters including body mass index (BMI), myostatin inhibitor usage, and age factor that could affect the muscle mass and glucose level correlation were also studied simultaneously. Results The study findings demonstrated a negative correlation between muscle mass and glucose utilization levels. There was a significant difference in the mean muscle mass of the participants which was 36.2453, and the mean glucose utilization level which was 15.1493%. Pearson correlation between the muscle mass and percentage of glucose utilization of the participants indicated a significant difference (since p-value . Conclusions The study finding suggests an inverse association of the skeletal muscle mass with blood glucose level which encourages the implication of muscle-building exercises as the preventive measure for T2DM.

Lectins from plants of the Diocleinae subtribe often exhibit specificity towards mannose/glucose and derived sugars, with some plants also displaying a second lectin specific to lactose/GalNAc. Here, we present a novel lectin from Collaea speciosa, named CsL, that displays specificity for GlcNAc/glucose. The lectin was extracted from Collaea speciosa seeds and purified by a single chromatographic step on a Sephadex G-50 matrix. In solution, the lectin appears as a dimeric protein composed of 25 kDa monomers. The protein is stable at pH 7–8 and dependent on divalent cations. CsL maintained its agglutination activity after heating to 90 °C for 1 h. Glycan array studies revealed that CsL binds to N-glycans with terminal GlcNAc residues, chitobiose and chitotriose moieties. The partial amino acid sequence of the lectin is similar to that of some lactose-specific lectins from the same subtribe. In contrast to other ConA-like lectins, CsL is not toxic to Artemia. Because of its remarkably different properties and specificity, this lectin could be the first member of a new group inside the Diocleinae lectins.

Trichoderma harzianum S7113 as an efficient fungal isolate for laccase production was identified using the 18S rRNA sequencing. T. harzianum S7113 attained its maximal laccase production level on the 14th day of static incubation at 28 °C and pH 5.0 using the inoculum size of 5 discs (14 mm), according to the one factor per time (OFT) method. The most appropriate carbon, organic and inorganic nitrogen sources to promote maximal laccase synthesis were glucose (15 g/L), beef extract (5 g/L), and ammonium chloride (4 g/L), respectively. Results of Response Surface Methodology (RSM) revealed that glucose, meat extract, and ammonium chloride concentrations of 17.54, 7.17, and 4.36 g/L respectively, at a pH value of 6.74 are the favorite conditions for high titer production. The ANOVA analysis highlighted an excellent match between the actual experimental results and the model predicted laccase production levels. The biodegradation of hydroquinone (HQ) by T. harzianum S7113 laccase was most efficient in the pH range of 5.0 to 6.5. The increase in laccase concentration led to a significant increase in the HQ conversion to get a biodegradation rate of 92 ± 2.6% with a laccase concentration of 0.75 U/mL after 3 h of reaction.

Hypoxia-inducible factor-1α (HIF-1α) is an important regulator of glucose metabolism and inflammatory cytokine production in innate immune responses. Viruses modulate HIF-1α to support viral replication and the survival of infected cells, but it is unclear if this transcription factor also plays an important role in regulating antiviral immune responses. In this study, we found that short and long dsRNA differentially engage TLR3, inducing distinct levels of proinflammatory cytokine production (TNF-α and IL-6) in bone marrow–derived macrophages from C57BL/6 mice. These responses are associated with differential accumulation of HIF-1α, which augments NF-κB activation. Unlike TLR4 responses, increased HIF-1α following TLR3 engagement is not associated with significant alterations in glycolytic activity and was more pronounced in low glucose conditions. We also show that the mechanisms supporting HIF-1α stabilization may differ following stimulation with short versus long dsRNA and that pyruvate kinase M2 and mitochondrial reactive oxygen species play a central role in these processes. Collectively, this work suggests that HIF-1α may fine-tune proinflammatory cytokine production during early antiviral immune responses, particularly when there is limited glucose availability or under other conditions of stress. Our findings also suggest we may be able to regulate the magnitude of proinflammatory cytokine production during antiviral responses by targeting proteins or molecules that contribute to HIF-1α stabilization.

Objective: We aimed to investigate prospective associations between milk bioactives related to metabolic health (glucose, insulin, leptin, C reactive protein [CRP], and interleukin 6 [IL-6]) and incident formula initiation at 3 and 6 months postpartum. Design: This study included 363 mother–infant dyads who were fully breastfed at 1 month and participated in the prospective Mothers and Infants Linked for Healthy Growth study from pregnancy to 6 months postpartum. Associations between milk glucose, leptin, insulin, CRP, and IL-6 at 1 and 3 months and incident formula feeding (FF) at 3 and 6 months, respectively, were tested using multiple logistic regression, adjusting for numerous potential confounders such as maternal age and prepregnancy body mass index. Results: At 3 months postpartum, 1-month glucose (odds ratio [OR] 0.45 [95% confidence interval (CI): 0.27–0.75], p ≤ 0.01) and smaller decreases in glucose from 1 to 3 months (OR 0.51 [95% CI: 0.28–0.92], p = 0.03) were associated with lower odds of FF, whereas 1-month leptin (OR 2.30 [95% CI: 1.30–4.07], p

Steviol glycosides are the intensely sweet components of extracts from Stevia rebaudiana. These molecules comprise an invariant steviol aglycone decorated with variable glycans and could widely serve as a low-calorie sweetener. However, the most desirable steviol glycosides Reb D and Reb M, devoid of unpleasant aftertaste, are naturally produced only in trace amounts due to low levels of specific β (1–2) glucosylation in Stevia. Here, we report the biochemical and structural characterization of OsUGT91C1, a glycosyltransferase from Oryza sativa, which is efficient at catalyzing β (1–2) glucosylation. The enzyme’s ability to bind steviol glycoside substrate in three modes underlies its flexibility to catalyze β (1–2) glucosylation in two distinct orientations as well as β (1–6) glucosylation. Guided by the structural insights, we engineer this enzyme to enhance the desirable β (1–2) glucosylation, eliminate β (1–6) glucosylation, and obtain a promising catalyst for the industrial production of naturally rare but palatable steviol glycosides., Steviol glycosides from the plant Stevia rebaudiana are already used as lowcalorie sweeteners, but the most abundant naturally occurring compounds have a bitter aftertaste. Here, the authors characterize and engineer rice glycosyltransferase OsUGT91C1 to facilitate the large-scale production of naturally rare but palatable glycosides Reb D and Reb M

SGLTs are sodium glucose transporters found on the luminal membrane of the proximal tubule, where they reabsorb some 180 grams (one mole) of glucose from the glomerular filtrate each day. The natural glucoside phlorizin completely blocks glucose reabsorption. Oral SGLT2 inhibitors are rapidly absorbed into the blood stream where they remain in in the circulation for hours. On glomerular filtration, they bind specifically to SGLT2 in the luminal membrane of the early proximal tubule to reduce glucose reabsorption by 50-60%. Because of glucose excretion, these drugs lower plasma glucose and glycosylated hemoglobin levels in patients with type 2 diabetes mellitus. The drugs also protect against heart and renal failure. The aim of this review is to summarize what is currently known about the physiology of renal SGLTs and the pharmacology of SGLT drugs.

BACKGROUND/OBJECTIVES Religious fasting (RF) is practiced annually by millions of Christian and Muslim followers worldwide. Scarce data exist on the impact of RF on the metabolic and hematological profile of individuals with or without dyslipidemia. SUBJECTS/METHODS The present study included: (i) 60 Greek Orthodox participants, 30 with dyslipidemia and 30 without dyslipidemia, who abstained from meat, fish and dairy products for seven consecutive weeks, and (ii) 15 young, non-dyslipidemic Muslim participants abstaining totally from food and liquid from dawn till sunset during 30 days. Biochemical (iron, ferritin, vitamin B12, calcium, low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC), triglyceride and fasting glucose) and hematological (hemoglobin, hematocrit) serum blood test results of study participants were measured pre- and post- RF (at weeks 0 and 7 for Orthodox participants and at weeks 0 and 4 for Muslim participants). RESULTS In dyslipidemic and non-dyslipidemic Orthodox participants, a significant reduction of fasting glucose, HDL, LDL and TC levels was found post-RF. Hemoglobin, hematocrit, iron and ferritin levels were significantly increased, while post-RF vitamin B12 and calcium levels were substantially decreased. Subanalysis between dyslipidemic and non-dyslipidemic Orthodox participants revealed a greater decrease of cholesterol levels in the former. In Muslim participants, triglyceride, LDL and total cholesterol levels were increased post-RF (all p values < 0.05). CONCLUSIONS Our study adds to the existing literature evidence about the significant impact of RF on metabolic and hematological profiles of Orthodox and Muslim followers. The prevention of calcium and B12 deficiency during Orthodox RF by supplement consumption as well as the protection from dehydration and dysregulation of lipid metabolism during Ramadan RF should concern both clinicians and dietician nutritionists. Nevertheless, studies with larger sample size and/or long-term follow-up are warranted before reaching definite conclusions about the effects of RF on human health.

Summary Glucose and fructose are closely related simple sugars, but fructose has been associated more closely with metabolic disease. Until the 1960s, the major dietary source of fructose was fruit, but subsequently, high-fructose corn syrup (HFCS) became a dominant component of the Western diet. The exponential increase in HFCS consumption correlates with the increased incidence of obesity and type 2 diabetes mellitus, but the mechanistic link between these metabolic diseases and fructose remains tenuous. Although dietary fructose was thought to be metabolized exclusively in the liver, evidence has emerged that it is also metabolized in the small intestine and leads to intestinal epithelial barrier deterioration. Along with the clinical manifestations of hereditary fructose intolerance, these findings suggest that, along with the direct effect of fructose on liver metabolism, the gut-liver axis plays a key role in fructose metabolism and pathology. Here, we summarize recent studies on fructose biology and pathology and discuss new opportunities for prevention and treatment of diseases associated with high-fructose consumption.

Excessive sugar consumption is increasingly considered as a contributor to the emerging epidemics of obesity and the associated cardiometabolic disease. Sugar is added to the diet in the form of sucrose or high-fructose corn syrup, both of which comprise nearly equal amounts of glucose and fructose. The unique aspects of fructose metabolism and properties of fructose-derived metabolites allow for fructose to serve as a physiological signal of normal dietary sugar consumption. However, when fructose is consumed in excess, these unique properties may contribute to the pathogenesis of cardiometabolic disease. Here, we review the biochemistry, genetics, and physiology of fructose metabolism and consider mechanisms by which excessive fructose consumption may contribute to metabolic disease. Lastly, we consider new therapeutic options for the treatment of metabolic disease based upon this knowledge.

Funder: Wellcome-MRC, Institute of Metabolic Science, Metabolic Research Laboratories, Imaging Core, Insulin-induced GLUT4 translocation to the plasma membrane in muscle and adipocytes is crucial for whole-body glucose homeostasis. Currently, GLUT4 trafficking assays rely on overexpression of tagged GLUT4. Here we describe a high-content imaging platform for studying endogenous GLUT4 translocation in intact adipocytes. This method enables high fidelity analysis of GLUT4 responses to specific perturbations, multiplexing of other trafficking proteins and other features including lipid droplet morphology. Using this multiplexed approach we showed that Vps45 and Rab14 are selective regulators of GLUT4, but Trarg1, Stx6, Stx16, Tbc1d4 and Rab10 knockdown affected both GLUT4 and TfR translocation. Thus, GLUT4 and TfR translocation machinery likely have some overlap upon insulin-stimulation. In addition, we identified Kif13A, a Rab10 binding molecular motor, as a novel regulator of GLUT4 traffic. Finally, comparison of endogenous to overexpressed GLUT4 highlights that the endogenous GLUT4 methodology has an enhanced sensitivity to genetic perturbations and emphasises the advantage of studying endogenous protein trafficking for drug discovery and genetic analysis of insulin action in relevant cell types.