GANAB as a Novel Biomarker in Multiple Sclerosis: Correlation with Neuroinflammation and IFI35

Multiple sclerosis (MS) still lacks reliable biomarkers of neuroinflammation predictive for disease activity and treatment response. Thus, in a prospective study we assessed 55 MS patients (28 interferon (IFN)-treated, 10 treated with no-IFN therapies, 17 untreated) and 20 matched healthy controls (HCs) for the putative correlation of the densitometric expression of glucosidase II alpha subunit (GANAB) with clinical/paraclinical parameters and with interferon-induced protein 35 (IFI35). We also assessed the disease progression in terms of the Rio Score (RS) in order to distinguish the responder patients to IFN therapy (RS = 0) from the non-responder ones (RS ≥ 1). We found GANAB to be 2.51-fold downregulated in the IFN-treated group with respect to the untreated one (p < 0.0001) and 3.39-fold downregulated in responder patients compared to the non-responders (p < 0.0001). GANAB correlated directly with RS (r = 0.8088, p < 0.0001) and lesion load (LL) (r = 0.5824, p = 0.0014) in the IFN-treated group and inversely with disease duration (DD) (r = −0.6081, p = 0.0096) in the untreated one. Lower mean values were expressed for GANAB than IFI35 in IFN responder (p < 0.0001) and higher mean values in the non-responder patients (p = 0.0022). Inverse correlations were also expressed with IFI35 in the overall patient population (r = −0.6468, p < 0.0001). In conclusion, the modular expression of GANAB reflects IFI35, RS, DD, and LL values, making it a biomarker of neuroinflammation that is predictive for disease activity and treatment response in MS.

Novel GANAB variants associated with polycystic liver disease

Background Polycystic liver disease (PLD) is an inherited disorder characterized by numerous cysts in the liver. Autosomal dominant polycystic kidney and liver disease (ADPKD and ADPLD, respectively) have been linked to pathogenic GANAB variants. GANAB encodes the α-subunit of glucosidase II (GIIα). Here, we report the identification of novel GANAB variants in an international cohort of patients with the primary phenotype of PLD using molecular inversion probe analysis. Results Five novel GANAB variants were identified in a cohort of 625 patients with ADPKD or ADPLD. In silico analysis revealed that these variants are likely to affect functionally important domains of glucosidase II α-subunit. Missense variant c.1835G>C p.(Arg612Pro) was predicted to disrupt the structure of the active site of the protein, likely reducing its activity. Frameshift variant c.687delT p.(Asp229Glufs*60) introduces a premature termination codon predicted to have no activity. Two nonsense variants (c.2509C>T; p.(Arg837*), and c.2656C>T; p.(Arg886*)) and splice variant c.2002+1G>C, which causes aberrant pre-mRNA splicing and affecting RNA processing, result in truncated proteins and are predicted to cause abnormal binding of α- and β-subunits of glucosidase II, thus affecting its enzymatic activity. Analysis of glucosidase II subunits in cell lines shows expression of a truncated GIIα protein in cells with c.687delT, c.2509C>T, c.2656C>T, and c.2002+1G>C variants. Incomplete colocalization of the subunits was present in cells with c.687delT or c.2002+1G>C variants. Other variants showed normal distribution of GIIα protein. Conclusions We identified five novel GANAB variants associated with PLD in both ADPKD and ADPLD patients supporting a common pathway in cystogenesis. These variants may lead to decreased or complete loss of enzymatic activity of glucosidase II which makes GANAB a candidate gene to be screened in patients with an unknown genetic background.

Virtual Screening Based on Pharmacophore to Discover Host ER Alpha-Glucosidase II Inhibitor for Dengue Therapy

Dengue is one of the crucial diseases in human-caused by dengue virus (DENV) infection. However, the development of DENV antiviral is often facing a problem because no effective drug to treat infection caused by all DENV serotypes. The inhibition of host protein involved in DENV life cycle can be a potential approach in dengue drug discovery, and also avoiding antiviral resistance. Endoplasmic Reticulum (ER) α-glucosidase II is one of the target host protein in DENV endoplasmic reticulum that plays an important role in the maturation process of DENV envelope glycoprotein. Natural products have been known as an essential source of a lead compound for drug discovery due to their therapeutic potency. In this research, pharmacophore-based virtual screening and molecular docking simulations were performed to find ligand that has potential to inhibit α-glucosidase II activity. About 67,609 natural products from InterBioScreen (IBS) database were used in the simulation as ligands with α-glucosidase II as the protein target. After subjected to Lipinski’s Rule of Five, druglikeness, nasty functions, and toxicity screening using DataWarrior software, 17,462 ligands were obtained. The pharmacophore features for molecular docking simulation was obtained from Protein-Ligand Interaction Fingerprint (PLIF) analysis using eight α-glucosidase II protein with different ligands. Based on virtual screening, rigid, and flexible docking simulations using Molecular Operating Environment (MOE) software, 32 ligands have lower Gibbs free binding energy (ΔGbinding) compared to the standards. Two best ligands, namely STOCK1N-85545 and STOCK1N-86400 which belong alkaloid derivatives, showed the exceptional ligand interaction and had the lowest ΔGbinding of-11.204 and-10.276 kcal/mol, respectively. The ligands were identified to have a binding interaction with amino acid Asp564 and Asp640 in α-glucosidase II catalytic site. STOCK1N-85545 and STOCK1N-86400 were also identified to have a good pharmacological properties after subjected to ADME-tox test using Toxtree, SwissADME, admetSAR, and pkCSM software.