Glucose Medium Research Articles

Cell Geometry and Membrane Protein Crowding Constrain Growth Rate, Overflow Metabolism, Respiration, and Maintenance Energy.

A metabolic theory is presented for predicting maximum growth rate, overflow metabolism, respiration efficiency, and maintenance energy flux based on the intersection of cell geometry, membrane protein crowding, and metabolism. The importance of cytosolic macromolecular crowding on phenotype has been established in the literature but the importance of surface area has been largely overlooked due to incomplete knowledge of membrane properties. We demonstrate that the capacity of the membrane to host proteins increases with growth rate offsetting decreases in surface area-to-volume ratios (SA:V). This increase in membrane protein is hypothesized to be essential to competitive Escherichia coli phenotypes. The presented membrane-centric theory uses biophysical properties and metabolic systems analysis to successfully predict the phenotypes of E. coli K-12 strains, MG1655 and NCM3722, which are genetically similar but have SA:V ratios that differ up to 30%, maximum growth rates on glucose media that differ by 40%, and overflow phenotypes that start at growth rates that differ by 80%. These analyses did not consider cytosolic macromolecular crowding, highlighting the distinct properties of the presented theory. Cell geometry and membrane protein crowding are significant biophysical constraints on phenotype and provide a theoretical framework for improved understanding and control of cell biology.

In vitro, the aging of stallion spermatozoa at 22 °C is linked to alteration in Ca2+ and redox homeostasis and may be slowed by regulating metabolism

BackgroundConservation of equine semen in the liquid state is a central procedure in horse breeding and constitutes the basis of associated reproductive technologies. The intense mitochondrial activity of the stallion spermatozoa increases oxidative stress along the storage period, leading to sperm demise within 24–48 h of storage, particularly when maintained at room temperature. Recently, the relationship between metabolism and oxidative stress has been revealed. The study aimed to extend the period of conservation of equine semen, at room temperature through modification of the metabolites present in the media. Material and methodsProcessed ejaculates (n = 9) by single-layer colloid centrifugation were split in different aliquots and extended in Tyrode's basal media, or modified Tyrode's consisting of 1 mM glucose, 1 mM glucose 10 mM pyruvate, 40 mM glucose, 40 mM Glucose 10 mM pyruvate, 67 mM glucose and 67 mM glucose 10 mM pyruvate. At time 0h, and after 24 and 96 h of storage, motility was evaluated by CASA, while mitochondrial production of Reactive oxygen species (ROS), and intracellular Ca2+ concentrations were determined via flow cytometry using Mitosox Red and Fluo-4 respectively. ROS and Ca2+ were estimated as Relative Fluorescence Units (RFU) in compensated, arcsin-transformed data in the live sperm population. ResultsAfter 48 h of incubation, motility was greater in all the 10 mM pyruvate-based media, with the poorest result in the 40 mM glucose (41 ± 1.1 %) while the highest motility was yielded in the 40 mM glucose 10 mM pyruvate aliquot (60.3 ± 3.5 %; P < 0.001); after 96 h of storage highest motility values were observed in the 40 mM glucose 10 mM pyruvate media (23.0 ± 6.2 %) while the lowest was observed in the 1 mM glucose media was 9.2 ± 2.0 % (P < 0.05). Mitochondrial ROS was lower in the 40 mM glucose 10 mM pyruvate group compared to the 40 mM glucose (P < 0.01). Over time Ca2+ increased in all treatment groups compared to time 0h. Discussion and conclusionViable spermatozoa may experience oxidative stress and alterations in Ca2+ homeostasis during prolonged storage, however, these effects can be reduced by regulating metabolism. The 40 mM glucose- 10 mM pyruvate group yielded the highest sperm quality parameters.

VmSom1 is essential for growth, development, maintenance of cell wall integrity and virulence in Valsa mali

Apple Valsa canker disease, caused by Valsa mali Miyabe et Yamada, severely endangers the healthy growth of apple trees. The Som1, located downstream of the cyclic AMP-dependent protein kinase A (cAMP-PKA) pathway, plays crucial roles in the growth, development, morphological differentiation, and virulence of filamentous fungi. In this study, we identify and functionally characterize VmSom1, a homolog of Som1, in Valsa mali. The VmSom1 gene is located on chromosome 12, encoding an 824 amino acid protein. Phylogenetic analysis reveals VmSom1 as a fungal Som1 homolog. The VmSom1 deletion mutants exhibit slower growth rates and fail to produce pycnidia. Additionally, their hyphal growth is significantly inhibited on media containing Calcofluor White, Congo Red, NaCl, and sorbitol. The growth rate of VmSom1 deletion mutants is reduced on maltose, lactose, sucrose and fructose media but increases on glucose medium. Moreover, the mycelial growth rate of the VmSom1 deletion mutant is significantly lower than that of the wild-type strain in peptone, NH4SO4, NaNO3, and no nitrogen. Notably, the distances between the septa increase, and chitin concentration shifts to the hyphal tip in the VmSom1 deletion mutant. Furthermore, compared with the wild-type strain, the VmSom1 deletion mutant exhibits fewer diseased spots on apple fruit and branches. Overall, our findings demonstrate that VmSom1 is involved in regulating the growth and development, colony surface hydrophobicity, osmotic stress, cell wall integrity maintenance, carbon and nitrogen source utilization, septa formation, and virulence of V. mali.

In vitro protein digestibility and mineral accessibility of edible filamentous Fungi cultivated in oat flour

Edible filamentous fungi, a source of mycoprotein, are one of the sustainable alternative protein. This study compares protein digestibility (DH%) and amino acid and mineral accessibility in Rhizopus oligosporus cultivated in oat flour (OatRO) or glucose media (GluRO) by using the INFOGEST in vitro digestion protocol. Fungal total amino acids was higher in GluRO (39.0 ± 1.1 % dw) than OatRO (21.8 ± 1.3 % dw) which was also the case for calcium and magnesium content. After completed gastrointestinal digestion, there were no significant differences between GluRO and OatRO regarding DH% (27.21 ± 10.4 % and 29.4 ± 0.5 %), however, GluRO provided significantly higher amino acid accessibility compared to OatRO (64.3 ± 1.6 % and 55.1 ± 3.1 %). Mineral accessibility of GluRO was for Ca: 37.9 ± 1.8 %, Zn: 9.3 ± 0.4 %, Fe: 38.2 ± 1.9 %, Mg: 66.5 ± 1.4 % and Cu: 24.7 ± 1.3 % and for OatRO; Ca: −40.2 ± 2.4 %, Zn: −4.13 ± 0.15 %, Fe:14.6 ± 1.6 %, Mg: 74.5 ± 3.1 %, and Cu: 55.95 ± 0.8 %. Despite the low phytic acid content, OatRO thus showed antinutrient properties with respect to calcium, and zinc, suggesting that oat-derived fungi had antinutrients other than phytic acid. This study hereby revealed that the cultivation substrate affect amino acid and mineral accessibility of filamentous fungi and calls for deeper evaluations of antinutrients in oat-derived fungi.

Targeting TXNIP in endothelial progenitors mitigates IL-8-induced neutrophil recruitment under metabolic stress

BackgroundThis study explores the potential role of Thioredoxin-interacting protein (TXNIP) silencing in endothelial colony-forming cells (ECFCs) within the scope of age-related comorbidities and impaired vascular repair. We aim to elucidate the effects of TXNIP silencing on vasculogenic properties, paracrine secretion, and neutrophil recruitment under conditions of metabolic stress.MethodsECFCs, isolated from human blood cord, were transfected with TXNIP siRNA and exposed to a high glucose and β-hydroxybutyrate (BHB) medium to simulate metabolic stress. We evaluated the effects of TXNIP silencing on ECFCs’ functional and secretory responses under these conditions. Assessments included analyses of gene and protein expression profiles, vasculogenic properties, cytokine secretion and neutrophil recruitment both in vitro and in vivo. The in vivo effects were examined using a murine model of hindlimb ischemia to observe the physiological relevance of TXNIP modulation under metabolic disorders.ResultsTXNIP silencing did not mitigate the adverse effects on cell recruitment, vasculogenic properties, or senescence induced by metabolic stress in ECFCs. However, it significantly reduced IL-8 secretion and consequent neutrophil recruitment under these conditions. In a mouse model of hindlimb ischemia, endothelial deletion of TXNIP reduced MIP-2 secretion and prevented increased neutrophil recruitment induced by age-related comorbidities.ConclusionsOur findings suggest that targeting TXNIP in ECFCs may alleviate ischemic complications exacerbated by metabolic stress, offering potential clinical benefits for patients suffering from age-related comorbidities.

Quercetin-4'-O-β-D-glucopyranoside inhibits podocyte injury by SIRT5-mediated desuccinylation of NEK7.

Diabetic kidney disease (DKD) is a complication of diabetic mellitus. New treatments need to be developed. This study aimed to investigate the effects of quercetin-4'-O-β-D-glucopyranoside (QODG) on podocyte injury. Podocytes were cultured in high glucose (HG) medium, treated with QODG, and overexpressing or knocking down SIRT5. Oxidative stress indicators were assessed using corresponding kits. Pyroptosis was detected by flow cytometry and western blot analysis. Succinylation modification was detected using immunoprecipitation (IP) and western blot analysis. The interaction between NEK7 and NLRP3 was determined by co-IP. The results indicated that QODG inhibited oxidative stress and pyroptosis of podocytes induced by HG. Besides, QODG suppressed succinylation levels in HG-induced podocytes, with the upregulation of SIRT5. Knockdown of SIRT5 reversed the effects of QODG on oxidative stress and pyroptosis. Moreover, SIRT5 inhibited the succinylation of NEK7 and the interaction between NLRP3 and NEK7. In conclusion, QODG upregulates SIRT5 to inhibit the succinylation modification of NEK7, impedes the interaction between NEK7 and NLRP3, and then inhibits the pyroptosis and oxidative stress injury of podocytes under HG conditions. The findings suggested that QODG has the potential to treat DKD and explore a novel underlying mechanism of QODG function.

Microbial Induced Biotechnological Processes for Biofuel Production from Waste Organics Conversion

In the current era there are huge quantities of waste organic matter available, creating a big burden to the environment. To address these issues, researchers started to apply effective and microbial induced biotechnological processes that can mitigate these waste matters. In this context, different nature of microbial systems are involved in hydrolysing the waste organic material into fermentable sugar. These can be easily consumed by specific microbial systems like Saccharomyces cerevisiae MTCC 3821 and Clostridium acetobutylicum that produced bioethanol and biobutanol, respectively. Saccharomyces cerevisiae was cultured in specific media and incubated at rotary shaker with 150 rpm at 30°C for 72 to 96 hours. Ethanol concentrations from different waste matters were found in the range of 1.2-1.5 g.L-1. Ethanol synthesis was done by shake flask experiment with addition of glucose (50 g.L-1) to waste organic hydrolyzed solution. Non-glucose media produced less than 3 g.L-1 ethanol but glucose media produced 4.5 g.L-1. Next, Clostridium acetobutylicum was grown in culture media containing waste organics as sole carbon substrate with pH 7 and then was incubated in anaerobic conditions at 35°C for 72 hours, produced butanol (0.7 to 1.25 g.L-1). This research work promoted biofuels synthesis by keeping a waste mitigation strategy.

Culture of Bovine Aortic Endothelial Cells in Galactose Media Enhances Mitochondrial Plasticity and Changes Redox Sensing, Altering Nrf2 and FOXO3 Levels.

Understanding the complex biological processes of cells in culture, particularly those related to metabolism, can be biased by culture conditions, since the choice of energy substrate impacts all of the main metabolic pathways. When glucose is replaced by galactose, cells decrease their glycolytic flux, working as an in vitro model of limited nutrient availability. However, the effect of these changes on related physiological processes such as redox control is not well documented, particularly in endothelial cells, where mitochondrial oxidation is considered to be low. We evaluated the differences in mitochondrial dynamics and function in endothelial cells exposed to galactose or glucose culture medium. We observed that cells maintained in galactose-containing medium show a higher mitochondrial oxidative capacity, a more fused mitochondrial network, and higher intercellular coupling. These factors are documented to impact the cellular response to oxidative stress. Therefore, we analyzed the levels of two main redox regulators and found that bovine aortic endothelial cells (BAEC) in galactose media had higher levels of FOXO3 and lower levels of Nrf2 than those in glucose-containing media. Thus, cultures of endothelial cells in a galactose-containing medium may provide a more suitable target for the study of in vitro mitochondrial-related processes than those in glucose-containing media; the medium deeply influences redox signaling in these cells.

Influence of different light wavelengths and carbon sources on energy utilization efficiency by Chromochloris zofingiensis for cell growth and carotenoid synthesis

Chromochloris zofingiensis was cultured with different carbon sources (carbonate/glucose/acetate/pyruvate) and light conditions (dark/blue/red) under heterotrophic, autotrophic, and mixotrophic conditions to evaluate its energy utilization efficiency in terms of biomass and carotenoid accumulation. Enhanced specific growth rates of 0.58 d−1 and 0.51 d−1 were observed under blue- and red-light mixotrophic conditions, respectively, which both exceeded the rate of 0.44 d−1 obtained under heterotrophic conditions using a glucose-supplemented medium. The glucose medium showed superior cell synthesis compared to other carbon sources owing to its high utilization. Astaxanthin and neoxanthin accumulation were enhanced under mixotrophic conditions with blue-light. The energy efficiency for the synthesis of new cells was evaluated from a thermodynamic perspective. The efficiency was 1.1 to 2.1 % under autotrophic conditions, while 5.2 to 100 % was observed under heterotrophic conditions. Efficiencies in between were observed under mixotrophic conditions.

Analysis of the Correlation between Persimmon Fruit-Sugar Components and Taste Traits from Germplasm Evaluation.

Persimmon fruits are brightly colored and nutritious and are fruits that contain large amounts of sugar, vitamins, mineral elements, and phenolic substances. The aim of this study was to explore the differences in fruit-sugar components of different persimmon germplasms and their relationships with phenotypic and flavor indices through the determination of phenotypes and sugar components and through electronic-tongue indices, which provided the basis and inspiration for the selection of different sugar-accumulating types of persimmon fruits and the selection of high-sugar persimmon varieties. Our results showed that persimmon germplasm fruit-sugar components were dominated by sucrose, glucose and fructose and that the remaining sugar components were more diverse but less distributed among the various germplasm types. Based on the proportion of each sugar component in the fruit, persimmon germplasms can be categorized into sucrose-accumulating and reduced-sugar-accumulation types. Sucrose-accumulating types are dominated by sucrose, galactose, fucose and inositol, while reduced-sugar-accumulation types are dominated by glucose, fructose, mannose-6-phosphate, and xylose. The content of sugar components in the germplasm persimmon of fruits of different types and maturity periods of also differed, with significant differences in sugar components between PCNA (pollination-constant non-astringent) and PCA (pollination-constant astringent) fruits. Cluster analysis classified 81 persimmon germplasms into three clusters, including cluster I-A, with low glucose and fructose content, and cluster I-B, with medium glucose, fructose, and sucrose contents. Cluster II was high in sucrose and fructose. Cluster III had high contents of glucose and fructose and low contents of sucrose and inositol.

Mesenchymal stem cells-derived exosomes alleviate senescence of retinal pigment epithelial cells by activating PI3K/AKT-Nrf2 signaling pathway in early diabetic retinopathy

Diabetic retinopathy (DR) is a major cause of vision loss and blindness in adults. Cellular senescence was involved in the pathogenesis of early-stage DR and is positively correlated with progression. Thus, our study aimed at exploring the effect and potential mechanism of Mesenchymal stem cells-derived exosomes (MSCs-EXOs) on Retinal Pigment Epithelial (RPE) cells senescence at an early stage of DR in vivo and in vitro. ARPE-19 cells were incubated in high glucose (HG) medium mixed with MSCs-EXOs to observe the changes in cell viability. Senescence-associated β-galactosidase (SA-β-gal) staining, Western blot and qRT-PCR were used to assess the expression of senescence-related genes and antioxidant mediators. Quantitative Real-Time polymerase chain reaction (qRT-PCR), Optical coherence tomography (OCT) Hematoxylin and eosin (HE) staining and Electroretinogram (ERG) were respectively used to verify cellular senescence, the structure and function of the retina. Our findings demonstrated that MSCs-EXOs inhibited HG-induced senescence in ARPE-19 cells. Furthermore, MSCs-EXOs reduced HG-induced cell apoptosis and oxidative stress levels while promoting cell proliferation. Mechanistically, HG suppressed PI3K/AKT phosphorylation as well as nuclear factor erythroid 2-related factor 2 (Nrf2) expression along with its downstream target gene expression in ARPE-19 cells. However, MSCs-EXOs reversed these changes by alleviating cellular senescence while enhancing antioxidant activity. In line with our results in vitro, MSCs-EXOs significantly ameliorated hyperglycemia-induced senescence in DR mice by downregulating mRNA expression of P53, P21, P16, and SASP. Additionally, MSCs-EXOs improved the functional and structural integrity of the retina in DR mice. Our study revealed the protective effect of MSCs-EXOs on cellular senescence, offering new insights for the treatment of DR.

Properties of cellulose nitrates produced by nitration of bacterial cellulose using mixed sulfuric-nitric acids

The study set out to investigate the chemical functionalization of bacterial cellulose as an alternative means of satisfying the high demand for nano-sized cellulose nitrates. Using a Medusomyces gisevii Sa-12 symbiotic culture as a microbial producer, bacterial cellulose having a polymerization degree of 3950 was obtained on a synthetic glucose medium. Nitration was carried out using mixed sulfuric-nitric acids differing in their water content, followed by stabilization of the synthesized bacterial cellulose nitrates. Subject to a varying water content (14, 16 and 20 %) in the nitrating mixture, the obtained bacterial cellulose nitrates exhibited a nitrogen mass content of 8.68–11.56 %, a solubility in alcohol-ether mixture of 16.5–91.0 % and a viscosity of 32–255 mPa×s. The bacterial cellulose nitrate fibers were shown to have a nanoscale nature. Coupled thermogravimetric and differential thermal analyses revealed the bacterial cellulose nitrates to have a high chemical purity and energy content. FTIR spectroscopy confirmed the high quality of the bacterial cellulose based on the presence of basic functional groups characteristic of conventional cellulose: 3371, 2943, 1633, 1428, 1371, 1163, and 1112 cm-1. According to their infrared spectra, the detected basic functional groups corroborate that the synthesized products are low-substituted cellulose nitrate esters: 1660–1643, 1282-1276, 847–837, 752–749, and 691–690 cm-1. The relationship between the properties of the synthesized bacterial cellulose nitrates and the water mass content in mixed sulfuric-nitric acids is shown to have a complex nature.

Ketomimetic Medium Promotes Metastatic Disposition and Chemoresistance in Breast Cancer Cells through Hypersialylation and Lipid Synthesis.

Although metastasis accounts for the vast majority of cancer-related fatalities, the triggers for the metastatic transformation of breast cancer (BC) cells remain unknown. Recent evidence suggests that a common feature of invasive and resistant cells could be their metabolic state. However, attempts to control metabolic state via nutrient intake, e.g., ketogenic or low carbohydrate diets, have shown inconsistent results with respect to improving chemotherapy efficacy and curbing metastasis. Aiming to decode the molecular mechanisms that alter cell phenotype upon nutrient alteration, we study how a ketomimetic (ketone body-rich, low glucose) medium affects Doxorubicin (DOX) susceptibility and invasive disposition of BC cells. We quantified glycocalyx sialylation and found an inverse correlation with DOX-induced cytotoxicity and DOX internalization. These measurements were coupled with single-cell metabolic imaging, bulk migration studies, and transcriptomic and metabolomic analyses to map the mechanisms involved in ketone body-driven BC cell metabolic maneuvering. Our findings revealed that a ketomimetic medium enhances chemoresistance and invasive disposition of BC cells via two main oncogenic pathways: hypersialylation and lipid accumulation. We propose that the crosstalk between these pathways leads to synthesis of the glycan precursor UDP-GlcNAc, which leads to advancement of a metastatic phenotype in BC cells under ketomimetic conditions.

The Anti-candidal and Absorbtion Performance of PVA/PVP-Based Jania rubens Hydrogel on Candida tropicalis and Some Physicochemical Properties of the Hydrogel.

This study was aimed to create a bioactive hydrogel form with PVA/PVP (polyvinyl alcohol/poly(N-vinylpyrrolidone) polymer using acetone and ethanol extractions of Jania rubens red algae and investigate some pharmaceutical properties. The anti-candidal activity and some inhibition performance of J. rubens/PVA/PVP hydrogel were investigated on Candida tropicalis which is one of the important causes of bloodstream infections. The physicochemical properties of J. rubens/PVA/PVP hydrogel were revealed using FTIR and swelling-absorption tests. The volatile compounds of J. rubens extracts were examined by GCMS. By mixing the extracts in equal proportions, PVA/PVP-based hydrogel was prepared. According to the results, Cumulative Drug Release was stable at 25°C for the first 5h. The IZ (inhibition zone) and MIC (minimum inhibitory concentration) of J. rubens/PVA/PVP hydrogel were 9.01mm and 80.20mg/mL, respectively. It was found that logarithmic reduction and percent reduction were seen as 1.5CFU/mL and 97.5%, respectively, on C. tropicalis exposed to J. rubens/PVA/PVP hydrogel in the first 5min of the incubation. After exposure of C. tropicalis to J. rubens/PVA/PVP, the number of viable cells transferred from the gel to water was between 76.1 and 73.1% in high glucose medium, while it was between 92.2 and 80.8% for the PVA/PVP hydrogel under the same conditions. As a result, PVA/PVP hydrogel was made bioactive with J. rubens extracts for the first time in this study, and its potential for use as a functional anticandidal hydrogel on C. tropicalis has been demonstrated.

Healthy and diabetic primary human osteoblasts exhibit varying phenotypic profiles in high and low glucose environments on 3D-printed titanium surfaces.

The revolution of orthopedic implant manufacturing is being driven by 3D printing of titanium implants for large bony defects such as those caused by diabetic Charcot arthropathy. Unlike traditional subtractive manufacturing of orthopedic implants, 3D printing fuses titanium powder layer-by-layer, creating a unique surface roughness that could potentially enhance osseointegration. However, the metabolic impairments caused by diabetes, including negative alterations of bone metabolism, can lead to nonunion and decreased osseointegration with traditionally manufactured orthopedic implants. This study aimed to characterize the response of both healthy and diabetic primary human osteoblasts cultured on a medical-grade 3D-printed titanium surface under high and low glucose conditions. Bone samples were obtained from six patients, three with Type 2 Diabetes Mellitus and three without. Primary osteoblasts were isolated and cultured on 3D-printed titanium discs in high (4.5 g/L D-glucose) and low glucose (1 g/L D-Glucose) media. Cellular morphology, matrix deposition, and mineralization were assessed using scanning electron microscopy and alizarin red staining. Alkaline phosphatase activity and L-lactate concentration was measured in vitro to assess functional osteoblastic activity and cellular metabolism. Osteogenic gene expression of BGLAP, COL1A1, and BMP7 was analyzed using reverse-transcription quantitative polymerase chain reaction. Diabetic osteoblasts were nonresponsive to variations in glucose levels compared to their healthy counterparts. Alkaline phosphatase activity, L-lactate production, mineral deposition, and osteogenic gene expression remained unchanged in diabetic osteoblasts under both glucose conditions. In contrast, healthy osteoblasts exhibited enhanced functional responsiveness in a high glucose environment and showed a significant increase in osteogenic gene expression of BGLAP, COL1A1, and BMP7 (p<.05). Our findings suggest that diabetic osteoblasts exhibit impaired responsiveness to variations in glucose concentrations, emphasizing potential osteoblast dysfunction in diabetes. This could have implications for post-surgery glucose management strategies in patients with diabetes. Despite the potential benefits of 3D printing for orthopedic implants, particularly for diabetic Charcot collapse, our results call for further research to optimize these interventions for improved patient outcomes.

Liraglutide reduces bone marrow adipogenesis by miR-150-5p/ GDF11 axis in diabetic rats

In recent years, a common-used antidiabetic drug, liraglutide, was identified with extra effects on lipid metabolism. Its effects against excessive lipid deposition in bone marrow were gained much attention but not well established. Our aim in the present study is to explore the interaction of miRNAs-mRNAs altered by liraglutide administration during bone marrow adipogenesis in diabetes. To establish the diabetic animal model, rats were treated with high fat diet (HFD) and STZ injection. We then identified the lowering effect of liraglutide on lipids metabolism in the diabetes. During this process, high-throughput sequencing and bioinformatics analyses on miRNAs extracted from bone marrow mesenchymal stem cells (BMSCs) were conducted after liraglutide administration. We then identified five differentially expressed miRNAs (miRNA-150-5p, miRNA-129-5p, miRNA-201-3p, miRNA-201-5p, and miRNA-214-5p). The expressions of the DE miRNAs were verified as temporal specific expression patterns in Day 3 and in Day 7. Among them, miRNA-150-5p expression was more stable and consistent with the sequencing data. Of interest, miR-150-5p overexpression facilitated adipogenesis of BMSCs. But this promotion was alleviated by liraglutide. The predicted target gene of miR-150-5p, GDF11, was validated to be involved in liraglutide alleviated BMSCs’ lipid accumulation in diabetes. In vitro, liraglutide increased the GDF11 expression, rescued its down-expression by siGDF11 and inhibit the adipogenesis of BMSCs cultured in high glucose medium. In vivo, liraglutide reversed the HFD-STZ induced excessive lipid droplets by up-regulation of GDF11 expression, which was discounted by agomiR-150-5p injection. Above all, liraglutide might alleviate bone marrow fat accumulation via inactivating miR-150-5p/GDF11 axis in diabetes.

Effects of different doses of glucose and fructose on central carbon metabolic pathways and intercellular wireless communication networks in humans

Fructose and glucose are often widely used in food processing and may contribute to many metabolic diseases. To observe the effects of different doses of glucose and fructose on human metabolism and cellular communication, volunteers were given low, medium, and high doses of glucose and fructose. Serum cytokines, glucose, lactate, nicotinamide adenine dinucleotide (NADH) and metabolic enzymes were assayed, and central carbon metabolic pathway networks and cytokine communication networks were constructed. The results showed that the glucose and fructose groups basically maintained the trend of decreasing catabolism and increasing anabolism with increasing dose. Compared with glucose, low-dose fructose decreased catabolism and increased anabolism, significantly enhanced the expression of the inflammatory cytokine interferon-γ (IFN-γ), macrophage-derived chemokine (MDC), induced protein-10 (IP-10), and eotaxin, and significantly reduced the activity of isocitrate dehydrogenase (ICDH) and pyruvate dehydrogenase complexes (PDHC). Both medium and high doses of fructose increase catabolism and anabolism, and there are more cytokines and enzymes with significant changes. Furthermore, multiple cytokines and enzymes show strong relevance to metabolic regulation by altering the transcription and expression of enzymes in central carbon metabolic pathways. Therefore, excessive intake of fructose should be reduced to avoid excessive inflammatory responses, allergic reactions and autoimmune diseases.

TRNA-derived RNA fragment, tRF-18-8R6546D2, promotes pancreatic adenocarcinoma progression by directly targeting ASCL2

Pancreatic adenocarcinoma (PAAD) is a life-threatening cancer. Exploring new diagnosis and treatment targets helps improve its prognosis. tRNA-derived small non-coding RNAs (tsRNAs) are a novel type of gene expression regulators and their dysregulation is closely related to many human cancers. Yet the expression and functions of tsRNAs in PAAD are not well understood. Our study used RNA sequencing to identify tsRNA expression profiles in PAAD cells cultured in no or high glucose media and found tRF-18-8R6546D2 was an uncharacterized tsRNA, which has significantly high expression in PAAD cells and tissues. Clinically, tRF-18-8R6546D2 is linked to poor prognosis in PAAD patients and can be used to distinguish them from healthy populations. Functionally, in vitro and vivo, tRF-18-8R6546D2 over-expression promoted PAAD cell proliferation, migration and invasion, inhibited apoptosis, whereas tRF-18-8R6546D2 knock-down showed opposite effects. Mechanistically, tRF-18-8R6546D2 promoted PAAD malignancy partly by directly silencing ASCL2 and further regulating its downstream genes such as MYC and CASP3. These findings show that tRF-18-8R6546D2 is a novel oncogenic factor and can be a promising diagnostic or prognostic biomarker and therapeutic target for PAAD.

Nicotinate-curcumin improves NASH by inhibiting the AKR1B10/ACCα-mediated triglyceride synthesis

BackgroundNonalcoholic steatohepatitis (NASH) is a prevalent chronic liver condition. However, the potential therapeutic benefits and underlying mechanism of nicotinate-curcumin (NC) in the treatment of NASH remain uncertain.MethodsA rat model of NASH induced by a high-fat and high-fructose diet was treated with nicotinate-curcumin (NC, 20, 40 mg·kg− 1), curcumin (Cur, 40 mg·kg− 1) and metformin (Met, 50 mg·kg− 1) for a duration of 4 weeks. The interaction between NASH, Cur and Aldo-Keto reductase family 1 member B10 (AKR1B10) was filter and analyzed using network pharmacology. The interaction of Cur, NC and AKR1B10 was analyzed using molecular docking techniques, and the binding energy of Cur and NC with AKR1B10 was compared. HepG2 cells were induced by Ox-LDL (25 µg·ml− 1, 24 h) in high glucose medium. NC (20µM, 40µM), Cur (40µM) Met (150µM) and epalrestat (Epa, 75µM) were administered individually. The activities of ALT, AST, ALP and the levels of LDL, HDL, TG, TC and FFA in serum were quantified using a chemiluminescence assay. Based on the changes in the above indicators, score according to NAS standards. The activities of Acetyl-CoA and Malonyl-CoA were measured using an ELISA assay. And the expression and cellular localization of AKR1B10 and Acetyl-CoA carboxylase (ACCα) in HepG2 cells were detected by Western blotting and immunofluorescence.ResultsThe results of the animal experiments demonstrated that NASH rat model induced by a high-fat and high-fructose diet exhibited pronounced dysfunction in liver function and lipid metabolism. Additionally, there was a significant increase in serum levels of FFA and TG, as well as elevated expression of AKR1B10 and ACCα, and heightened activity of Acetyl-CoA and Malonyl-CoA in liver tissue. The administration of NC showed to enhance liver function in rats with NASH, leading to reductions in ALT, AST and ALP levels, and decrease in blood lipid and significant inhibition of FFA and TG synthesis in the liver. Network pharmacological analysis identified AKR1B10 and ACCα as potential targets for NASH treatment. Molecular docking studies revealed that both Cur and NC are capable of binding to AKR1B10, with NC exhibiting a stronger binding energy to AKR1B10. Western blot analysis demonstrated an upregulation in the expression of AKR1B10 and ACCα in the liver tissue of NASH rats, accompanied by elevated Acetyl-CoA and Malonyl-CoA activity, and increased levels of FFA and TG. The results of the HepG2 cell experiments induced by Ox-LDL suggest that NC significantly inhibited the expression and co-localization of AKR1B10 and ACCα, while also reduced levels of TC and LDL-C and increased level of HDL-C. These effects are accompanied by a decrease in the activities of ACCα and Malonyl-CoA, and levels of FFA and TG. Furthermore, the impact of NC appears to be more pronounced compared to Cur.ConclusionNC could effectively treat NASH and improve liver function and lipid metabolism disorder. The mechanism of NC is related to the inhibition of AKR1B10/ACCα pathway and FFA/TG synthesis of liver.

Metabolic Engineering of Bacillus subtilis for the Production of Poly-γ-Glutamic Acid from Glycerol Feedstock

Poly-γ-glutamic acid (γ-PGA) is an attractive biopolymer for medical, agri-food, and environmental applications. Although microbial synthesis by Bacilli fed on waste streams has been widely adopted, the obtainment of efficient sustainable production processes is still under investigation by bioprocess and metabolic engineering approaches. The abundant glycerol-rich waste generated in the biodiesel industry can be used as a carbon source for γ-PGA production. Here, we studied fermentation performance in different engineered Bacillus subtilis strains in glycerol-based media, considering a swrA+ degU32Hy mutant as the initial producer strain and glucose-based media for comparison. Modifications included engineering the biosynthetic pgs operon regulation (replacing its native promoter with Physpank), precursor accumulation (sucCD or odhAB deletion), and enhanced glutamate racemization (racE overexpression), predicted as crucial reactions by genome-scale model simulations. All interventions increased productivity in glucose-based media, with Physpank-pgs ∆sucCD showing the highest γ-PGA titer (52 g/L). Weaker effects were observed in glycerol-based media: ∆sucCD and Physpank-pgs led to slight improvements under low- and high-glutamate conditions, respectively, reaching ~22 g/L γ-PGA (26% increase). No performance decrease was detected by replacing pure glycerol with crude glycerol waste from a biodiesel plant, and by a 30-fold scale-up. These results may be relevant for improving industrial γ-PGA production efficiency and process sustainability using waste feedstock. The performance differences observed between glucose and glycerol media also motivate additional computational and experimental studies to design metabolically optimized strains.