In Traditional Chinese Medicine (TCM), Atractylodes macrocephala Koidz. (Baizhu) is a fundamental herb for fortifying the spleen and replenishing qi, specifically used to treat syndromes characterized by weakness, and poor appetite due to spleen qi deficiency. Despite its long-standing use, the scientific basis for its anti-fatigue effect remains unclear. This study aimed to systematically evaluate the anti-peripheral fatigue activity of AMWE and elucidate its underlying mechanisms, thereby providing a scientific basis for its development as a functional food ingredient. A mouse model of peripheral fatigue was established over 33 days using forced swimming combined with intermittent fasting. During this period, mice were administered AMWE at doses of 0.75-3.0 g/kg body weight. The chemical composition of AMWE was characterized, and its effects on exercise performance, metabolic markers, muscle histology, and mitochondrial function were assessed. AMWE primarily contained 23.84 % polysaccharides (composed of 62.20 % glucose), 2.44 % Atractylenolide II, and 7.22 % Atractylenolide III. Treatment with AMWE improved physical condition, enhanced grip strength and exercise endurance, and increased liver and muscle glycogen storage. It also reduced anaerobic metabolites such as lactic acid (LA), lactate dehydrogenase (LDH), and blood urea nitrogen (BUN). AMWE ameliorated damage to the gastrocnemius and soleus muscles and elevated blood amino acid levels. Importantly, AMWE up-regulated the mRNA and protein expression of the PGC-1α/NRF1/TFAM axis, improved mitochondrial function, increased substrate levels of pyruvate (PA) and acetyl-CoA (A-CoA) in the TCA cycle, enhanced the activity of key enzymes pyruvate dehydrogenase (PDH) and citrate synthase (CS), and promoted ATP synthesis. AMWE exhibits significant anti-fatigue activity, which is achieved by promoting mitochondrial biogenesis and enhancing mitochondrial function via activation of the PGC-1α/NRF1/TFAM axis. The underlying mechanism is associated with the activation of the AMPK/SIRT1/PGC-1α signaling axis and the subsequent upregulation of downstream NRF1/TFAM, leading to improved TCA cycle flux and ATP production.

Pompe disease (PD) is a progressive myopathy caused by the aberrant accumulation of glycogen in skeletal and cardiac muscle resulting from the deficiency of the enzyme acid alpha-glucosidase (GAA). Administration of recombinant human GAA as enzyme replacement therapy (ERT) works well in alleviating the cardiac manifestations of PD but loses sustained benefit in ameliorating the skeletal muscle pathology. The limited efficacy of ERT in skeletal muscle is partially attributable to its inability to curb the accumulation of new glycogen produced by the muscle enzyme glycogen synthase 1 (GYS1). Substrate reduction therapies aimed at knocking down GYS1 expression represent a promising avenue to improve Pompe myopathy. However, finding specific inhibitors for GYS1 is challenging given the presence of the highly homologous GYS2 in the liver. Antisense oligonucleotides (ASOs) are chemically modified oligomers that hybridise to their complementary target RNA to induce their degradation with exquisite specificity. In the present study, we show that ASO-mediated Gys1 knockdown in the Gaa-/- mouse model of PD led to a robust reduction in glycogen accumulation in skeletal muscle. In addition, combining Gys1 ASO with ERT slightly further reduced glycogen content in muscle, eliminated autophagic buildup and lysosomal dysfunction, and improved motor function in Gaa-/- mice. Our results provide a strong foundation for validation of the use of Gys1 ASO, alone or in combination with ERT, as a therapy for PD. We propose that early administration of Gys1 ASO in combination with ERT may be the key to preventative treatment options in PD. KEY POINTS: Antisense oligonucleotide (ASO) treatment in a mouse model of Pompe disease achieves robust knockdown of glycogen synthase (GYS1). ASO treatment reduces glycogen content in skeletal muscle. Combination of ASO and enzyme replacement therapy (ERT) further improves motor performance compared to ASO alone in a mouse model of Pompe disease. Glycogen storage diseases (GSDs) are inherited inborn errors of carbohydrate metabolism that result in abnormal glycogen storage. The onset can range from neonatal life to adulthood, and clinical manifestations result either from a failure to convert glycogen into energy or the toxic accumulation of glycogen.  Glycogen is a branched polymer comprised of glucose monomers (see Image. Glycogen, Free Glucose Release, and Glycogen Storage Diseases, Figure 1). After a meal, the plasma glucose level rises, stimulating the storage of the excess in cytoplasmic glycogen. The liver contains the highest percentage of glycogen by weight (about 10%), whereas muscles can store about 2% by weight. Nevertheless, since the total muscle mass is greater than the liver mass, the total mass of glycogen in muscles is about twice that of the liver. When needed, the glycogen polymer can be broken down into glucose monomers and utilized for energy production. Defects in the enzymes and transporters for these processes cause GSDs. An increasing number of GSDs are being identified, but most are very rare. These subtypes are classified numerically in the order of recognition and identification of the enzyme defect causing the disorder. Classification of Glycogen Storage Disorder GSDs that primarily affect the liver include the following: Glycogen synthase-2 deficiency (GSD type 0a). Glucose-6-phosphatase deficiency (GSD type Ia). Glucose-6-phosphate transporter deficiency (GSD type Ib) . Glycogen debrancher deficiency (GSD type III) . Glycogen branching enzyme deficiency (GSD type IV) . Liver phosphorylase deficiency (GSD type VI) . Phosphorylase kinase deficiency (GSD type IXa). GLUT2 deficiency or Fanconi-Bickel disease. GSDs that primarily affect the skeletal muscles include the following: Muscle phosphorylase deficiency (GSD type V). Phosphofructokinase deficiency (GSD type VII). Phosphoglycerate mutase deficiency (GSD type X). Lactate dehydrogenase A deficiency (GSD type XI) . Aldolase A deficiency (GSD type XII); β-enolase deficiency (GSD type XIII). Phosphoglucomutase-1 deficiency (GSD type XIV). GSDs that affect both skeletal and cardiac muscles include the following: Lysosomal acid maltase deficiency (GSD type IIa). Lysosome-associated membrane protein 2 deficiency (GSD type IIb). Glycogenin-1 deficiency (GSD type XV). Muscle glycogen synthase deficiency (GSD type 0b).

Glycogen storage disease type Ia (GSDIa) is an inborn metabolic disorder caused by the deficiency of glucose-6-phospatase-α (G6Pase-α) leading to mitochondrial dysfunction. It remains unclear whether mitochondrial dysfunction is present in patients' peripheral blood mononuclear cells (PBMC) and whether dietary treatment can play a role. The aim of this study was to investigate mitochondrial function in PBMC of GSDIa patients. Ten GSDIa patients and 10 age-, sex- and fasting-time matched controls were enrolled. Expression of genes involved in mitochondrial function and activity of key fatty acid oxidation (FAO) and Krebs cycle proteins were assessed in PBMC. Targeted metabolomics and assessment of metabolic control markers were also performed. Adult GSDIa patients showed increased CPT1A, SDHB, TFAM, mTOR expression (p < 0.05) and increased VLCAD, CPT2 and citrate synthase activity in PBMC (p < 0.05). VLCAD activity directly correlated with WC (p < 0.01), BMI (p < 0.05), serum malonycarnitine levels (p < 0.05). CPT2 activity directly correlated with BMI (p < 0.05). Mitochondrial reprogramming is detectable in PBMC of GSDIa patients. This feature may develop as an adaptation to the liver enzyme defect and may be triggered by dietary (over)treatment in the frame of G6Pase-α deficiency. PBMC can represent an adequate mean to assess (diet-induced) metabolic disturbances in GSDIa.

It was shown that maternal endothelial nitric oxide synthase (eNOS) deficiency causes fatty liver disease and numerically lower fasting glucose in female wild-type offspring, suggesting that parental genetic variants may influence the offspring's phenotype via epigenetic modifications in the offspring despite the absence of a primary genetic defect. The aim of the current study was to analyse whether paternal eNOS deficiency may cause the same phenotype as seen with maternal eNOS deficiency. Heterozygous (+/-) male eNOS (Nos3) knockout mice or wild-type male mice were bred with female wild-type mice. The phenotype of wild-type offspring of heterozygous male eNOS knockout mice was compared with offspring from wild-type parents. Global sperm DNA methylation decreased and sperm microRNA pattern altered substantially. Fasting glucose and liver glycogen storage were increased when analysing wild-type male and female offspring of +/- eNOS fathers. Wild-type male but not female offspring of +/- eNOS fathers had increased fasting insulin and increased insulin after glucose load. Analysing candidate genes for liver fat and carbohydrate metabolism revealed that the expression of genes encoding glucocorticoid receptor (Gr; also known as Nr3c1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc1a; also known as Ppargc1a) was increased while DNA methylation of Gr exon 1A and Pgc1a promoter was decreased in the liver of male wild-type offspring of +/- eNOS fathers. The endocrine pancreas in wild-type offspring was not affected. Our study suggests that paternal genetic defects such as eNOS deficiency may alter the epigenome of the sperm without transmission of the paternal genetic defect itself. In later life wild-type male offspring of +/- eNOS fathers developed increased fasting insulin and increased insulin after glucose load. These effects are associated with increased Gr and Pgc1a gene expression due to altered methylation of these genes.

Adult polyglucosan body disease (APBD) is an adult-onset neurological variant of glycogen storage disease type IV. APBD is caused by recessive mutations in the glycogen branching enzyme gene, and the consequent accumulation of poorly branched glycogen aggregates called polyglucosan bodies in the nervous system. There are presently no treatments for APBD. Here, we test whether downregulation of glycogen synthesis is therapeutic in a mouse model of the disease. We characterized the effects of knocking out two pro-glycogenic proteins in an APBD mouse model. APBD mice were crossed with mice deficient in glycogen synthase (GYS1), or mice deficient in protein phosphatase 1 regulatory subunit 3C (PPP1R3C), a protein involved in the activation of GYS1. Phenotypic and histological parameters were analyzed and glycogen was quantified. APBD mice deficient in GYS1 or PPP1R3C demonstrated improvements in life span, morphology, and behavioral assays of neuromuscular function. Histological analysis revealed a reduction in polyglucosan body accumulation and of astro- and micro-gliosis in the brains of GYS1- and PPP1R3C-deficient APBD mice. Brain glycogen quantification confirmed the reduction in abnormal glycogen accumulation. Analysis of skeletal muscle, heart, and liver found that GYS1 deficiency reduced polyglucosan body accumulation in all three tissues and PPP1R3C knockout reduced skeletal muscle polyglucosan bodies. GYS1 and PPP1R3C are effective therapeutic targets in the APBD mouse model. These findings represent a critical step toward the development of a treatment for APBD and potentially other glycogen storage disease type IV patients.