Abnormal polyamine metabolism is unique to the neuropathic forms of MPS: potential for biomarker development and insight into pathogenesis

Artificial neural network-based gene screening and immune cell infiltration analysis of osteosarcoma feature

BACKGROUND

The present study aimed to construct an artificial neural network (ANN) model that leverages characteristic genes associated with osteosarcoma (OS) to enable accurate prognostication for OS patients.

METHODS

Our research revealed 467 differentially expressed genes (DEGs) via gene expression contrast analysis, consisting of 345 downregulated genes and 122 upregulated genes. Gene Ontology (GO) enrichment analysis illuminated functions primarily encompassing T-cell activation, secretory granule lumen and antioxidant activity, among others. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, we discovered significant correlations between the DEGs and certain pathways, including phagosome, Staphylococcus aureus infection and human T-cell leukemia virus 1 infection. We then screened out 30 characteristic DEGs (CDEGs) based on random forest analysis and constructed the ANN model using the gene score matrix. To verify the credibility and accuracy of the ANN model, we performed internal and external validation processes, which affirmed our model's predictive capabilities.

RESULTS

The study further delved into the analysis of immune cell infiltration and its correlation with the target CDEGs, revealing disparities in the infiltration of 22 types of immune cells across different groups and their interrelationships. Moreover, we probed the expression of the two foremost CDEGs (YES1 and MFNG) in OS and normal tissues. We noted a positive relationship between the expression of YES1 and MFNG in OS tissues and the clinicopathological characteristics of OS patients.

CONCLUSIONS

Collectively, the findings of the present study validate the effectiveness of the CDEGs-based ANN model in predicting OS patients, which might facilitate early diagnosis and treatment of OS.

Precision Medicine for Lysosomal Disorders

Precision medicine (PM) is an emerging approach for disease treatment and prevention that accounts for the individual variability in the genes, environment, and lifestyle of each person. Lysosomal diseases (LDs) are a group of genetic metabolic disorders that include approximately 70 monogenic conditions caused by a defect in lysosomal function. LDs may result from primary lysosomal enzyme deficiencies or impairments in membrane-associated proteins, lysosomal enzyme activators, or modifiers that affect lysosomal function. LDs are heterogeneous disorders, and the phenotype of the affected individual depends on the type of substrate and where it accumulates, which may be impacted by the type of genetic change and residual enzymatic activity. LDs are individually rare, with a combined incidence of approximately 1:4000 individuals. Specific therapies are already available for several LDs, and many more are in development. Early identification may enable disease course prediction and a specific intervention, which is very important for clinical outcome. Driven by advances in omics technology, PM aims to provide the most appropriate management for each patient based on the disease susceptibility or treatment response predictions for specific subgroups. In this review, we focused on the emerging diagnostic technologies that may help to optimize the management of each LD patient and the therapeutic options available, as well as in clinical developments that enable customized approaches to be selected for each subject, according to the principles of PM.

Large animal models contribute to the development of therapies for central and peripheral nervous system dysfunction in patients with lysosomal storage diseases

Lysosomal storage diseases (LSDs) are a group of 70 monogenic disorders characterized by the lysosomal accumulation of a substrate. As a group, LSDs affect ~1 in 5000 live births; however, each individual storage disease is rare, limiting the ability to perform natural history studies or to perform clinical trials. Perhaps in no other biomedical field have naturally occurring large animal (canine, feline, ovine, caprine, and bovine) models been so essential for understanding the fundamentals of disease pathogenesis and for developing safe and effective therapies. These models were critical for the development of hematopoietic stem cell transplantation in α- and β- mannosidosis, fucosidosis, and the mucopolysaccharidoses; enzyme replacement therapy for fucosidosis, the mucopolysaccharidoses, and neuronal ceroid lipofuscinosis; and small molecule therapy in Niemann-Pick type C disease. However, their most notable contributions to the biomedical field are in the development of gene therapy for LSDs. Adeno-associated viral vectors to treat nervous system disease have been evaluated in the large animal models of α-mannosidosis, globoid cell leukodystrophy, GM1 and GM2 gangliosidosis, the mucopolysaccharidoses, and neuronal ceroid lipofuscinosis. This review article will summarize the large animal models available for study as well as their contributions to the development of central and peripheral nervous system dysfunction in LSDs.

Standardized Method for Intra-Cisterna Magna Delivery Under Fluoroscopic Guidance in Nonhuman Primates

Intrathecal delivery of adeno-associated virus vectors and other therapeutics are currently being evaluated for the treatment of central nervous system sequelae of lysosomal storage diseases, motor neuron diseases, and neurodegenerative diseases. As products transition from preclinical to clinical studies, a standardized and clinically relevant method of intrathecal delivery is increasingly germane. Here, we describe a method of intrathecal delivery via suboccipital puncture into the cisterna magna under fluoroscopic guidance in nonhuman primates. This procedure is suitable for use in good laboratory practice compliant studies, has an excellent safety profile, and is highly similar to the procedure currently being explored for use in humans.

Increased polyamines as protective disease modifiers in congenital muscular dystrophy

Most Mendelian disorders, including neuromuscular disorders, display extensive clinical heterogeneity that cannot be solely explained by primary genetic mutations. This phenotypic variability is largely attributed to the presence of disease modifiers, which can exacerbate or lessen the severity and progression of the disease. LAMA2-deficient congenital muscular dystrophy (LAMA2-CMD) is a fatal degenerative muscle disease resulting from mutations in the LAMA2 gene encoding Laminin-α2. Progressive muscle weakness is predominantly observed in the lower limbs in LAMA2-CMD patients, whereas upper limbs muscles are significantly less affected. However, very little is known about the molecular mechanism underlying differential pathophysiology between specific muscle groups. Here, we demonstrate that the triceps muscles of the dy2j/dy2j mouse model of LAMA2-CMD demonstrate very mild myopathic findings compared with the tibialis anterior (TA) muscles that undergo severe atrophy and fibrosis, suggesting a protective mechanism in the upper limbs of these mice. Comparative gene expression analysis reveals that S-Adenosylmethionine decarboxylase (Amd1) and Spermine oxidase (Smox), two components of polyamine pathway metabolism, are downregulated in the TA but not in the triceps of dy2j/dy2j mice. As a consequence, the level of polyamine metabolites is significantly lower in the TA than triceps. Normalization of either Amd1 or Smox expression in dy2j/dy2j TA ameliorates muscle fibrosis, reduces overactive profibrotic TGF-β pathway and leads to improved locomotion. In summary, we demonstrate that a deregulated polyamine metabolism is a characteristic feature of severely affected lower limb muscles in LAMA2-CMD. Targeted modulation of this pathway represents a novel therapeutic avenue for this devastating disease.