The Effect of Trophic Modes on Biomass and Lipid Production of Five Microalgal Strains

Five microalgae strains, namely Isochrysis galbana, Microchloropsis gaditana, Scenedesmus obliquus, Nannochloropsis oculata and Tetraselmis suecica, were selected as potential candidates for polyunsaturated fatty acids’ production, evaluating biomass productivity and their capacity to accumulate high lipid contents under different trophic modes. Microalgae strains were cultivated in the presence of 1% glucose using mixotrophic and heterotrophic conditions, while autotrophic cultures served as control experiments. The results demonstrate that S. obliquus performed the highest biomass productivity that reached 0.13 and 0.14 g L−1 d−1 under mixotrophic and heterotrophic conditions, respectively. I. galbana and S. obliquus utilized elevated contents of glucose in mixotrophy, removing 55.9% and 95.6% of the initial concentration of the carbohydrate, respectively, while glucose consumption by the aforementioned strains also remained high under heterotrophic cultivation. The production of lipids was maximal for I. galbana in mixotrophy and S. obliquus in heterotrophy, performing lipid productivities of 24.85 and 22.77 mg L−1 d−1, respectively. The most abundant saturated acid detected for all microalgae strains evaluated was palmitic acid (C16:0), while oleic and linolenic acids (C18:1n9c/C18:3n3) comprised the most abundant unsaturated fatty acids. I. galbana performed the highest linoleic acid (C18:2n6c) content under heterotrophic nutrition, which reached 87.9 mg g−1 of ash-free dry weight. Among the microalgae strains compared, the biomass and lipid production monitored for I. galbana and S. obliquus confirm that both strains could serve as efficient bioproducers for application in algal biorefineries.

A Preclinical Model of Cutaneous Melanoma Based on Reconstructed Human Epidermis

Malignant melanoma is among the tumor entities with the highest increase of incidence worldwide. To elucidate melanoma progression and develop new effective therapies, rodent models are commonly used. While these do not adequately reflect human physiology, two-dimensional cell cultures lack crucial elements of the tumor microenvironment. To address this shortcoming, we have developed a melanoma skin equivalent based on an open-source epidermal model. Melanoma cell lines with different driver mutations were incorporated into these models forming distinguishable tumor aggregates within a stratified epidermis. Although barrier properties of the skin equivalents were not affected by incorporation of melanoma cells, their presence resulted in a higher metabolic activity indicated by an increased glucose consumption. Furthermore, we re-isolated single cells from the models to characterize the proliferation state within the respective model. The applicability of our model for tumor therapeutics was demonstrated by treatment with a commonly used v-raf murine sarcoma viral oncogene homolog B (BRAF) inhibitor vemurafenib. This selective BRAF inhibitor successfully reduced tumor growth in the models harboring BRAF-mutated melanoma cells. Hence, our model is a promising tool to investigate melanoma development and as a preclinical model for drug discovery.

Continuous Production of Fumaric Acid with Immobilised Rhizopus oryzae: The Role of pH and Urea Addition

Fumaric acid is widely used in the food and beverage, pharmaceutical and polyester resin industries. Rhizopus oryzae is the most successful microorganism at excreting fumaric acid compared to all known natural and genetically modified organisms. It has previously been discovered that careful control of the glucose feed rate can eliminate the by-product formation of ethanol. Two key parameters affecting fumaric acid excretion were identified, namely the medium pH and the urea feed rate. A continuous fermentation with immobilised R. oryzae was utilised to determine the effect of these parameters. It was found that the selectivity for fumaric acid production increased at high glucose consumption rates for a pH of 4, different from the trend for pH 5 and 6, achieving a yield of 0.93 gg−1. This yield is higher than previously reported in the literature. Varying the urea feed rate to 0.255 mgL−1h−1 improved the yield of fumaric acid but experienced a lower glucose uptake rate compared to higher urea feed rates. An optimum region has been found for fumaric acid production at pH 4, a urea feed rate of 0.625 mgL−1h−1 and a glucose feed rate of 0.329 gL−1h−1.

Synergetic Fermentation of Glucose and Glycerol for High-Yield N-Acetylglucosamine Production in Escherichia coli

N-acetylglucosamine (GlcNAc) is an amino sugar that has been widely used in the nutraceutical and pharmaceutical industries. Recently, microbial production of GlcNAc has been developed. One major challenge for efficient biosynthesis of GlcNAc is to achieve appropriate carbon flux distribution between growth and production. Here, a synergistic substrate co-utilization strategy was used to address this challenge. Specifically, glycerol was utilized to support cell growth and generate glutamine and acetyl-CoA, which are amino and acetyl donors, respectively, for GlcNAc biosynthesis, while glucose was retained for GlcNAc production. Thanks to deletion of the 6-phosphofructokinase (PfkA and PfkB) and glucose-6-phosphate dehydrogenase (ZWF) genes, the main glucose catabolism pathways of Escherichia coli were blocked. The resultant mutant showed a severe defect in glucose consumption. Then, the GlcNAc production module containing glucosamine-6-phosphate synthase (GlmS*), glucosamine-6-phosphate N-acetyltransferase (GNA1*) and GlcNAc-6-phosphate phosphatase (YqaB) expression cassettes was introduced into the mutant, to drive the carbon flux from glucose to GlcNAc. Furthermore, co-utilization of glucose and glycerol was achieved by overexpression of glycerol kinase (GlpK) gene. Using the optimized fermentation medium, the final strain produced GlcNAc with a high stoichiometric yield of 0.64 mol/mol glucose. This study offers a promising strategy to address the challenge of distributing carbon flux in GlcNAc production.

Identification of the Glucose Metabolism Biomarkers of NASH: Weighted Gene Co-Expression Network Analysis

Background The genetic mechanism of glucose metabolism has not been elucidated in nonalcoholic steatohepatitis (NASH), and many genes are took part in glucose metabolism of NASH. In this study, we used the weighted gene co-expression network analysis (WGCNA) to find the key genes associated with glucose metabolism; Methods Data sets GSE96971 and GSE89632 from Gene Expression Omnibus (GEO) were analyzed by WGCNA. We screened the Hub gene from the GSE96971 dataset, and the selected Hub genes were verified by GSE89632 dataset. We then analyzed the dataset using the Gene Ontology (GO) term enrichment and the Kyoto Encyclopedia of Genome (KEGG) path analysis. Expression levels of the hub genes are assessed by qPCR analysis. The function of hub genes was verified by Nile Red staining and relative glucose consumption detection; Results The hub genes are mannosidase beta like (MANBAL), myc proto-oncogene protein (MYC), caspase 4 (CASP4), CDK5 regulatory subunit associated protein 3 (CDK5RAP3) and ZFP36 ring finger protein (ZFP36) in the datasets GSE96971 and the GSE89632. Further, these genes are mainly involved in the integral component of membrane and plasma membrane, the PI3K-AKT signaling pathway and the olfactory transduction according to the GO and KEGG results. These hub genes were significantly up-regulated in the palmitic acid (PA) cell model and methionine-choline-deficient medium (MCD) cell model. After knocking out the hub genes in PA model and the MCD model of NASH, relative glucose consumption was increased and lipid deposition was reduced compared with the control group; Conclusions MANBAL, MYC, CASP4, CDK5RAP3 and ZFP36 are elevated and involved in the pathogenesis of NASH. Further research on these genes are warranted.

Inhibition of AMPK/PFKFB3 Mediated Glycolysis Synergizes with Penfluridol to Suppress Gallbladder Cancer Growth

Background Penfluridol (PF) is an FDA approved antipsychotic drug, which shows anticancer activity recently. However, the anticancer effects and underlying mechanisms of PF on gallbladder cancers (GBCs) is not well-established. Methods Herein, cytotoxicity, cell proliferation, cell apoptosis, and cell metastasis assays were used to investigate the anticancer activity of PF on GBCs. Glucose consumption and lactic production assays were used to detect the glycolysis alteration. Western blotting was used to detect the corresponding signaling change after PF treatment. Nude mice were utilized to study the anticancer activity of PF in vivo. Results Here, we first observed that PF significantly suppress GBC cells proliferation and metastasis. After PF treatment, the glucose consumption and lactic production of GBCs were significantly increased. In addition, we found that inhibition of glycolysis enhanced the anticancer activity of PF. Further studies demonstrated that glycolysis was medicated by the activation of AMPK/PFKFB3 signaling pathway. Mechanistically, we demonstrated that AMPK/PFKFB3 signaling pathway mediated glycolysis was a resistant mechanism of PF in GBCs. Conclusions Inhibition of AMPK enhanced the anticancer effects of PF on GBCs. therefore, our studies provided a novel insight into repurposing PF as anticancer agent for GBCs, and AMPK inhibition in combination with PF could be a potential therapeutic approach for GBCs.

Steviol Represses Glucose Metabolism and Translation Initiation in Pancreatic Cancer Cells

Pancreatic cancer has the worst prognosis and lowest survival rate among all cancers. Pancreatic cancer cells are highly metabolically active and typically reprogrammed for aberrant glucose metabolism; thus they respond poorly to therapeutic modalities. It is highly imperative to understand mechanisms that are responsible for high glucose metabolism and identify natural/synthetic agents that can repress glucose metabolic machinery in pancreatic cancer cells, to improve the therapeutic outcomes/management of pancreatic cancer patients. We have identified a glycoside, steviol that effectively represses glucose consumption in pancreatic cancer cells via the inhibition of the translation initiation machinery of the molecular components. Herein, we report that steviol effectively inhibits the glucose uptake and lactate production in pancreatic cancer cells (AsPC1 and HPAF-II). The growth, colonization, and invasion characteristics of pancreatic cancer cells were also determined by in vitro functional assay. Steviol treatment also inhibited the tumorigenic and metastatic potential of human pancreatic cancer cells by inducing apoptosis and cell cycle arrest in the G1/M phase. The metabolic shift by steviol was mediated through the repression of the phosphorylation of mTOR and translation initiation proteins (4E-BP1, eIF4e, eIF4B, and eIF4G). Overall, the results of this study suggest that steviol can effectively suppress the glucose metabolism and translation initiation in pancreatic cancer cells to mitigate their aggressiveness. This study might help in the design of newer combination therapeutic strategies for pancreatic cancer treatment.

Adenoid cystic carcinoma with a leptomeningeal dissemination in a ‘wash’ pattern

A 39-year-old woman was referred to the neurology department due to headache, instability and difficulty walking for 5 months. Several ancillary tests were performed. The blood test showed leucocytosis and the cerebrospinal fluid revealed an increased total protein and glucose consumption. Other infections or autoimmune causes were excluded. The MRI showed non-specific brain and spinal cord lesions. Given the findings described, a differential diagnosis between granulomatous meningoencephalitis and primary tumour or metastasis was proposed. Empirical treatment with tuberculostatic agents and corticosteroids was started. The neurological state of the patient worsened, she fell into a non-responsive coma and died in few days. The clinical autopsy performed revealed an adenoid cystic carcinoma with involvement of the central nervous system that developed leptomeningeal dissemination along the spinal cord in a fluid ‘wash’ pattern.

Alcohol and Glucose D consumption decreases grip muscle strengths in graded doses

Alcohol, Blood Sugar, and Grip muscle strengths (GMS) may play key role in injury prevention and rehabilitation. In many cases, strengthening of the grip has been a prescription for rehabilitation from injuries such as golf and tennis elbow. In this study, the effects of alcohol and glucose consumption on grip muscle strength in early adult male subject was investigated. A total of thirty (200) human subjects of about18+ years old were recruited for the study. The subjects were administered varying doses of alcohol and glucose D, then allowed to rest for a period of 5 and 10 minutes before assessing their grip muscle strength, fasting blood sugar (FBS) and body weights. Obtained records were then compared with those of control (normal) subject who neither received alcohol nor glucose D. Differences in mean was obtained between groups using the student t-test. From the result, study found a statistically significant decrease (p < 0.05) in GMS for different times (5 min and 10 min) of alcohol administration as compared with control subjects. A notable significant decrease (p > 0.05) was also observed for FBS with increasing administration times as compared with control. This decrease was however insignificant for 10 min duration compared with 5 minutes. This decrease was however significant (p < 0.05) for alcohol 5 min intake as compared with control group. All test group (experimental) showed a statistically significant decrease in GMS after alcohol administration as compared with control. Lastly, a statistically significant decrease (p < 0.05) was observed in GMS for 10 min of Glucose D intake. Whereas, subject who took glucose D in 5 min showed an insignificant decrease as compared with control. It is recommended that more studies be conducted to corroborate the result of this study.