Hepatic glycogen storage diseases: pathogenesis, clinical symptoms and therapeutic management

A case study of a liver transplant-treated patient with glycogen storage disease type Ia presenting with multiple inflammatory hepatic adenomas: an analysis of clinicopathologic and genetic data

BACKGROUND

Glycogen storage disease (GSD) is a disease caused by excessive deposition of glycogen in tissues due to genetic disorders in glycogen metabolism. Glycogen storage disease type I (GSD-I) is also known as VonGeirk disease and glucose-6-phosphatase deficiency. This disease is inherited in an autosomal recessive manner, and both sexes can be affected. The main symptoms include hypoglycaemia, hepatomegaly, acidosis, hyperlipidaemia, hyperuricaemia, hyperlactataemia, coagulopathy and developmental delay.

CASE PRESENTATION

Here, we present the case of a 13-year-old female patient with GSD Ia complicated with multiple inflammatory hepatic adenomas. She presented to the hospital with hepatomegaly, hypoglycaemia, and epistaxis. By clinical manifestations and imaging and laboratory examinations, we suspected that the patient suffered from GSD I. Finally, the diagnosis was confirmed by liver pathology and whole-exome sequencing (WES). WES revealed a synonymous mutation, c.648 G > T (p.L216 = , NM_000151.4), in exon 5 and a frameshift mutation, c.262delG (p.Val88Phefs*14, NM_000151.4), in exon 2 of the G6PC gene. According to the pedigree analysis results of first-generation sequencing, heterozygous mutations of c.648 G > T and c.262delG were obtained from the patient's father and mother. Liver pathology revealed that the solid nodules were hepatocellular hyperplastic lesions, and immunohistochemical (IHC) results revealed positive expression of CD34 (incomplete vascularization), liver fatty acid binding protein (L-FABP) and C-reactive protein (CRP) in nodule hepatocytes and negative expression of β-catenin and glutamine synthetase (GS). These findings suggest multiple inflammatory hepatocellular adenomas. PAS-stained peripheral hepatocytes that were mostly digested by PAS-D were strongly positive. This patient was finally diagnosed with GSD-Ia complicated with multiple inflammatory hepatic adenomas, briefly treated with nutritional therapy after diagnosis and then underwent living-donor liver allotransplantation. After 14 months of follow-up, the patient recovered well, liver function and blood glucose levels remained normal, and no complications occurred.

CONCLUSION

The patient was diagnosed with GSD-Ia combined with multiple inflammatory hepatic adenomas and received liver transplant treatment. For childhood patients who present with hepatomegaly, growth retardation, and laboratory test abnormalities, including hypoglycaemia, hyperuricaemia, and hyperlipidaemia, a diagnosis of GSD should be considered. Gene sequencing and liver pathology play important roles in the diagnosis and typing of GSD.

Platelet glycogenolysis is important for energy production and function

Although the presence of glycogen in platelets was established in the 1960s, its importance to specific functions (i.e., activation, secretion, aggregation, and clot contraction) remains unclear. Patients with glycogen storage disease often present with increased bleeding and glycogen phosphorylase (GP) inhibitors, when used as treatments for diabetes, induce bleeding in preclinical studies suggesting some role for this form of glucose in hemostasis. In the present work, we examined how glycogen mobilization affects platelet function using GP inhibitors (CP316819 and CP91149) and a battery of ex vivo assays. Blocking GP activity increased glycogen levels in resting and thrombin-activated platelets and inhibited platelet secretion and clot contraction, with minimal effects on aggregation. Seahorse energy flux analysis and metabolite supplementation experiments suggested that glycogen is an important metabolic fuel whose role is affected by platelet activation and the availability of external glucose and other metabolic fuels. Our data shed light on the bleeding diathesis in glycogen storage disease patients and offer insights into the potential effects of hyperglycemia on platelets.

Aberrant glucose metabolism underlies impaired macrophage differentiation in glycogen storage disease type Ib

Glycogen storage disease type Ib (GSD-Ib) is an autosomal recessive disorder caused by a deficiency in the glucose-6-phosphate (G6P) transporter (G6PT) that is responsible for transporting G6P into the endoplasmic reticulum. GSD-Ib is characterized by disturbances in glucose homeostasis, neutropenia, and neutrophil dysfunction. Although some studies have explored neutrophils abnormalities in GSD-Ib, investigations regarding monocytes/macrophages remain limited so far. In this study, we examined the impact of G6PT deficiency on monocyte-to-macrophage differentiation using bone marrow-derived monocytes from G6pt-/- mice as well as G6PT-deficient human THP-1 monocytes. Our findings revealed that G6PT-deficient monocytes exhibited immature differentiation into macrophages. Notably, the impaired differentiation observed in G6PT-deficient monocytes seemed to be associated with abnormal glucose metabolism, characterized by enhanced glucose consumption through glycolysis, even under quiescent conditions with oxidative phosphorylation. Furthermore, we observed a reduced secretion of inflammatory cytokines in G6PT-deficient THP-1 monocytes during the inflammatory response, despite their elevated glucose consumption. In conclusion, this study sheds light on the significance of G6PT in monocyte-to-macrophage differentiation and underscores its importance in maintaining glucose homeostasis and supporting immune response in GSD-Ib. These findings may contribute to a better understanding of the pathogenesis of GSD-Ib and potentially pave the way for the development of targeted therapeutic interventions.

Genetics of enzymatic dysfunctions in metabolic disorders and cancer

Inherited metabolic disorders arise from mutations in genes involved in the biogenesis, assembly, or activity of metabolic enzymes, leading to enzymatic deficiency and severe metabolic impairments. Metabolic enzymes are essential for the normal functioning of cells and are involved in the production of amino acids, fatty acids and nucleotides, which are essential for cell growth, division and survival. When the activity of metabolic enzymes is disrupted due to mutations or changes in expression levels, it can result in various metabolic disorders that have also been linked to cancer development. However, there remains much to learn regarding the relationship between the dysregulation of metabolic enzymes and metabolic adaptations in cancer cells. In this review, we explore how dysregulated metabolism due to the alteration or change of metabolic enzymes in cancer cells plays a crucial role in tumor development, progression, metastasis and drug resistance. In addition, these changes in metabolism provide cancer cells with a number of advantages, including increased proliferation, resistance to apoptosis and the ability to evade the immune system. The tumor microenvironment, genetic context, and different signaling pathways further influence this interplay between cancer and metabolism. This review aims to explore how the dysregulation of metabolic enzymes in specific pathways, including the urea cycle, glycogen storage, lysosome storage, fatty acid oxidation, and mitochondrial respiration, contributes to the development of metabolic disorders and cancer. Additionally, the review seeks to shed light on why these enzymes represent crucial potential therapeutic targets and biomarkers in various cancer types.

The impact of postoperative blood glucose levels on complications and prognosis after esophagectomy in patients with esophageal cancer

PURPOSE

This study aimed to characterize postoperative blood glucose fluctuation in patients who underwent esophagectomy for esophageal cancer, and to define its impact on complications and prognosis.

METHODS

The subjects of this retrospective study were 284 patients who underwent esophagectomy at Osaka University Hospital between 2015 and 2017. Data analyzed included clinicopathological background, the immediate postoperative blood glucose level (IPBG), postoperative blood glucose variability (PBGV), insulin dosage, postoperative complications, and prognosis.

RESULTS

The median IPBG and PBGV were 170 (64-260) mg/dl and 64.5 (11-217) mg/dl, respectively. Postoperative pneumonia was more common in patients with PBGV > 100 mg/dl (P = 0.015). Patients with IPBG < 170 mg/dl had significantly worse 5-year overall survival (OS) and 5-year recurrence-free survival (RFS) than those with IPBG > 170 mg/dl (54.5% vs. 80.4%, respectively, [P < 0.001] and 44.3% vs. 69.3%, respectively, [P = 0.001]). The 5-year OS rates were 43.5%, 68.3%, 80.6%, and 79.0% for patients with IPBG < 154, 154-170, 170-190, and ≥ 190 mg/dl, respectively. The corresponding 5-year RFS rates were 38.1%, 52.4%, 77.0%, and 61.3%, respectively. Multivariate analysis revealed that IPBG < 154 mg/dl and pathological stage were independent poor prognostic factors for OS.

CONCLUSION

PBGV was associated with postoperative pneumonia, and low IPBG was an independent poor prognostic factor for patients with esophageal cancer.

Genotypic and phenotypic characteristics of 12 chinese children with glycogen storage diseases

Background: Glycogen storage diseases (GSDs) are known as a group of disorders characterized by genetic errors leading to accumulation of glycogen in various tissues. Since different types of GSD can sometimes be clinically indistinguishable, next generation sequencing is becoming a powerful tool for clinical diagnosis.

Methods: 12 patients with suspected GSDs and their parents were enrolled in this study. The clinical and laboratory data of the patients were reviewed. Causative gene variants were identified in the patients using whole exome sequencing (WES) and verified by Sanger sequencing.

Results: Genetic testing and analysis showed that 7 patients were diagnosed with GSD II (Pompe disease), 2 patients with GSD III, 1 patient with GSD VI, and 2 patients with GSD IXα. A total number of 18 variants were identified in 12 patients including 11 variants in GAA gene, 3 variants in AGL gene, 2 variants in PYGL gene and 2 variants in PHKA2 gene, of which 9 variants were reported and 9 variants were novel. SIFT, Polyphen-2, Mutation Taster, and REVEL predicted the novel variants (except GAA c.1052_1075 + 47del) to be disease-causing. The 3D structures of wild/mutant type GAA protein were predicted indicating that variants p. Trp621Gly, p. Pro541Leu, p. Ser800Ile and p. Gly293Trp might affect the proteins function via destroying hydrogen bonds or conformational constraints. Neither liver size nor laboratory findings allow for a differentiation among GSD III, GSD VI and GSD IXα.

Conclusion: Our study expanded the variation spectrum of genes associated with GSDs. WES, in combination with clinical, biochemical, and pathological hallmarks, could provide accurate results for diagnosing and sub-typing GSD and related diseases in clinical setting.

Hepatic glycogen storage diseases type 0, VI and IX: description of an italian cohort

Background

Glycogen storage disease (GSD) type 0, VI and IX are inborn errors of metabolism involving hepatic glycogen synthesis and degradation. We performed a characterization of a large Italian cohort of 30 patients with GSD type 0a, VI, IXa, IXb and IXc. A retrospective evaluation of genetical, auxological and endocrinological data, biochemical tests, and nutritional intakes was assessed. Eventual findings of overweight/obesity and insulin-resistance were correlated with diet composition.

Results

Six GSD-0a, 1 GSD-VI, and 23 GSD-IX patients were enrolled, with an age of presentation from 0 to 72 months (median 14 months). Diagnosis was made at a median age of 30 months, with a median diagnostic delay of 11 months and a median follow-up of 66 months. From first to last visit, patients gained a median height of 0.6 SDS (from − 1.1 to 2.1 SDS) and a median weight of 0.5 SDS (from − 2.5 to 3.3 SDS); mean and minimal glucose values significant improved (p < 0.05). With respect to dietary intakes, protein intake (g/kg) and protein intake (g/kg)/RDA ratio directly correlated with the glucose/insulin ratio (p < 0.05) and inversely correlated with HOMA-IR (Homeostasis model assessment of insulin resistance, p < 0.05), BMI SDS (p < 0.05) and %ibw (ideal body weight percentage, p < 0.01).

Conclusion

A prompt establishment of specific nutritional therapy allowed to preserve growth, improve glycemic control and prevent liver complication, during childhood. Remarkably, the administration of a high protein diet appeared to have a protective effect against overweight/obesity and insulin-resistance.