In Vitro Skeletal Muscle Model of PGM1 Deficiency Reveals Altered Energy Homeostasis.

Phosphoglucomutase 1 (PGM1) is a key enzyme for the regulation of energy metabolism from glycogen and glycolysis, as it catalyzes the interconversion of glucose 1-phosphate and glucose 6-phosphate. PGM1 deficiency is an autosomal recessive disorder characterized by a highly heterogenous clinical spectrum, including hypoglycemia, cleft palate, liver dysfunction, growth delay, exercise intolerance, and dilated cardiomyopathy. Abnormal protein glycosylation has been observed in this disease. Oral supplementation with D-galactose efficiently restores protein glycosylation by replenishing the lacking pool of UDP-galactose, and rescues some symptoms, such as hypoglycemia, hepatopathy, and growth delay. However, D-galactose effects on skeletal muscle and heart symptoms remain unclear. In this study, we established an in vitro muscle model for PGM1 deficiency to investigate the role of PGM1 and the effect of D-galactose on nucleotide sugars and energy metabolism. Genome-editing of C2C12 myoblasts via CRISPR/Cas9 resulted in Pgm1 (mouse homologue of human PGM1, according to updated nomenclature) knockout clones, which showed impaired maturation to myotubes. No difference was found for steady-state levels of nucleotide sugars, while dynamic flux analysis based on 13C6-galactose suggested a block in the use of galactose for energy production in knockout myoblasts. Subsequent analyses revealed a lower basal respiration and mitochondrial ATP production capacity in the knockout myoblasts and myotubes, which were not restored by D-galactose. In conclusion, an in vitro mouse muscle cell model has been established to study the muscle-specific metabolic mechanisms in PGM1 deficiency, which suggested that galactose was unable to restore the reduced energy production capacity.

Enhancement of Galactose Uptake from Kappaphycus alvarezii Hydrolysate Using Saccharomyces cerevisiae Through Overexpression of Leloir Pathway Genes.

A total 42.68 g/L monosaccharide with 0.10 g/L HMF was obtained from 10% (w/v) Kappaphycus alvarezii with thermal acid hydrolysis using 350 mM HNO3 at 121 °C for 60 min and enzymatic saccharification with a 1:1 mixture of Viscozyme L and Celluclast 1.5 L for 72 h. To enhance the galactose utilization rate, fermentation was performed with overexpression of GAL1 (galactokinase), GAL7 (galactose-1-phosphate uridyltransferase), GAL10 (UDP-glucose-4-epimerase), and PGM2 (phosphoglucomutase 2) in Saccharomyces cerevisiae CEN.PK2 using CCW12 as a strong promoter. Among the strains, the overexpression of PGM2 showed twofold high galactose utilization rate (URgal) and produced ethanol 1.4-fold more than that of the control. Transcriptional analysis revealed the increase of PGM2 transcription level leading to enhance glucose-6-phosphate and fructose-6-phosphate and plays a key role in ensuring a higher glycolytic flux in the PGM2 strain. This finding shows particular importance in biofuel production from seaweed because galactose is one of the major monosaccharides in seaweeds such as K. alvarezii.

Effective treatment of a platinum-resistant cutaneous squamous cell carcinoma case by EGFR pathway inhibition.

Cutaneous squamous cell carcinoma (cSCC) is the second most common type of non-melanoma skin cancer. Platinum-based regimens have been an integral part of palliative care for patients with locally advanced or metastatic disease. There is no evidence of efficacy for later lines of chemotherapy and no targeted therapy has been introduced as 'standard of care'. Here we report on the case of an elderly cSCC patient, resistant to conventional therapy, however successfully treated with anti-epidermal growth factor receptor (EGFR) agent (Cetuximab) in addition to a daily dose of Curcumin phospholipid. The patient responded to treatment and experienced no recurrence for 11 months with only minor skin-related toxicity. To our knowledge, this is the first report of clinical evidence that an anti EGFR targeted therapy with a daily oral dose of Curcumin phospholipid is well tolerated and results in a highly effective disease control in a heavily pretreated cSCC patient.

Magnetic bead-liposome hybrids enable sensitive and portable detection of DNA methyltransferase activity using personal glucose meter.

DNA methyltransferase (MTase) plays a critical role in maintaining genome methylation patterns, which has a close relationship to cancer and bacterial diseases. This encouraged the need to develop highly sensitive, simple, and robust assays for DNA MTase detection and inhibitor screening. Herein, a simple, sensitive, and specific DNA MTase activity assay was developed based on magnetic beads-liposome hybrids combined with personal glucose meter (PGM) for quantitative detection of DNA MTase and inhibitor screening. First, a magnetic beads-liposome hybrid probe is designed by the hybridization of p1DNA-functionalized magnetic bead with p2DNA-functionalized glucoamylase-encapsulated liposome (GEL). It integrates target recognition, magnetic separation and signal amplification within one multifunctional design. Then, in the presence of Dam MTase, the hybrids probe was methylated, and cleaved by methylation-sensitive restriction endonuclease Dpn I, making liposome separated from magnetic bead by magnetic separation. Finally, the separated liposome was decomposed, liberating the encapsulated glucoamylase to catalyze the hydrolysis of the signal substrate amylose with multiple turnovers, producing a large amount of glucose for quantitative readout by the PGM. In the proposed assay, the magnetic beads-liposome hybrids offered excellent sensitivity due to primary amplification via releasing numerous glucoamylase from a liposome followed by a secondary enzymatic amplification. The use of portable quantitative device PGM bypasses the requirement of complicated instruments and sophisticated operations, making the method simple and feasible for on-site detection. Moreover, the proposed assay was successfully applied in complex biological matrix and screen suitable inhibitor drugs for DAM for disease(s) treatment. The results reveal that the approach provides a simple, sensitive, and robust platform for DNA MTases detection and screening potential drugs in medical research and early clinical diagnostics.

MRNA and miRNA expression patterns associated to pathways linked to metal mixture health effects.

Metals are a threat to human health by increasing disease risk. Experimental data have linked altered miRNA expression with exposure to some metals. MiRNAs comprise a large family of non-coding single-stranded molecules that primarily function to negatively regulate gene expression post-transcriptionally. Although several human populations are exposed to low concentrations of As, Cd and Pb as a mixture, most toxicology research focuses on the individual effects that these metals exert. Thus, this study aims to evaluate global miRNA and mRNA expression changes induced by a metal mixture containing NaAsO2, CdCl2, Pb(C2H3O2)2·3H2O and to predict possible metal-associated disease development under these conditions. Our results show that this metal mixture results in a miRNA expression profile that may be responsible for the mRNA expression changes observed under experimental conditions in which coding proteins are involved in cellular processes, including cell death, growth and proliferation related to the metal-associated inflammatory response and cancer.