Trias Thireou

Background/Objectives: FAM111A is a trypsin-like serine protease that has emerged as a regulator of DNA replication, and is directly related to genome stability, protein homeostasis, antiviral defense and cancer progression. Pathogenic variants in FAM111A are correlated with genetic syndromes such as Kenny–Caffey syndrome type 2 (KCS2) and gracile bone dysplasia/osteocraniostenosis (GCLEB/OCS). This study focuses on the evolutionary, genetic, and structural analysis of FAM111A, in order to identify key regions and candidate pharmacological targets that are related to this enzyme’s function. Methods: The methodology of this in silico study includes separate analyses at the sequence, structural and functional levels. Initially, data mining was carried out using NCBI/Protein (2025), and then data filtering was performed in order to identify representative FAM111A sequences for several species. Sequence analysis was then executed through multiple alignments and phylogenetic analyses. Through this, conserved domains and motifs were identified. For structural analysis, human pathogenic mutations and protein structures were identified through searches in biological databases including PDB and ClinVar, and then all data were analyzed in order to identify candidate pharmacological targets related to FAM111A function. Results: Approximately 1850 FAM111A protein sequences were retrieved for several species, and after filtering processes a dataset of 85 representative sequences was generated. Evolutionary analysis indicates that FAM111A originated in early metazoans, with progressive domain specialization leading to mammal-restricted acquisition of regulatory elements, including the PIP-box PCNA (proliferating cell nuclear antigen) interacting peptide and UBL (ubiquitin-like) domains. The ubiquitin-like/DNA binding domain and catalytic serine protease domain (SPD) are the most conserved, containing seven highly conserved motifs. The structural analysis was based on two protein structures and 34 critical mutations that accumulate in two distinct regions. Finally, by combining the results, six pharmacological targets and 100 inhibitors are proposed. Conclusions: Advancing the structural and function characterization of FAM111A, coupled with pharmacological target identification and evolutionary insights, will be critical to validate this underexplored protease as a therapeutic genetic target in genetic disorders, cancer, and antiviral responses.

Background: 22q11.2 deletion syndrome (DiGeorge Syndrome) is a rare disorder that involves a de novo hemizygous microdeletion within the 22q11.2 chromosomal locus. Individuals affected by this condition display a wide array of clinical phenotypes as well as haplotype sequences, which render understanding the genotype–phenotype relationship quite difficult. Additionally, the complex structure of the 22q11.2 low-copy repeats (LCRs), which usually inhibits sequencing efforts, has complicated the study of possible breakpoints that instigate the deletion events. In this study, 22q11.2 deletion syndrome is investigated on a genomic and phenotypic level for the purpose of determining the impact of each deletion type and identifying possible candidate breakpoints. Methods: In the present study, a systematic review combined with a secondary genomic analysis has been executed following PRISMA guidelines using PubMed and Scopus publications in order to estimate its holistic genomic map, genomic functional elements, and key genomic regions such as LCRs. A statistical content analysis of the affected chromosomal regions was also performed. Groups of functional elements with common traits were composed, and their contribution to the deletion events was investigated. Finally, the 22q11.2 repeat regions were screened for palindromic AT-rich repeats. Results: Of the 8202 unique publications studied in this work, only 65 met the inclusion criteria. The estimated genomic map of 22q11.2 deletion syndrome in the secondary genomic analysis revealed 11 distinct microdeletions occurring between eight LCRs, and a new repeat region within the CES region (CESRR), of which the LCR22A-LCR22D deletion was the most frequently reported. Last but not least, the palindromic analyses indicated eight critical groups as candidate breakpoints that potentially form four distinct patterns, and ten palindromic AT-rich repeat (PATRR) regions were identified amongst LCR22A, LCR22B, LCR22D, LCR22F and LCR22H. Conclusions: The study results validate the differentiating clinical contribution between the proximal and the distal segments. Eight novel candidate breakpoints and five new PATRRs were identified that require further study to establish their involvement in 22q11.2 microdeletion events.

Background: Deficiency of IL-36 Receptor Antagonist (DITRA) is a rare monogenic autoinflammatory disease, characterized by dysregulation of IL-36 signaling and phenotypically classified as a subtype of generalized pustular psoriasis. Objectives: This study aimed to explore the role of potentially coding and non-coding RNAs (ncRNAs) in the IL36RN interactome to identify putative pathogenic mechanisms, biomarkers, and therapeutic targets for DITRA. Methods: A systems biology approach was applied using the STRING database to construct the IL36RN protein–protein interaction network. Key ncRNA interactions were identified using RNAInter. The networks were visualized and analyzed with Cytoscape v3 and the CytoHubba plugin to identify central nodes and interaction hubs. Pathway enrichment analysis was then performed to determine the biological relevance of candidate ncRNAs and genes. Results: Analysis identified thirty-eight ncRNAs interacting with the IL36RN network, including six lncRNAs and thirty-two miRNAs. Of these, thirty-three were associated with key DITRA-related signaling pathways, while five remain to be validated. Additionally, seven protein-coding genes were highlighted, with three (TINCR, PLEKHA1, and HNF4A) directly implicated in biological pathways related to DITRA. Many of the identified ncRNAs have prior associations with immune-mediated diseases, including psoriasis, supporting their potential relevance in DITRA pathogenesis. Conclusions: This study provides novel insights into the ncRNA-mediated regulation of IL36RN and its network in the context of DITRA. The findings support the potential utility of specific ncRNAs and genes, such as TINCR, PLEKHA1, and HNF4A, as key genomic elements warrant further functional characterization to confirm their mechanistic roles and may inform biomarker discovery and targeted therapeutic development in DITRA.

Background: Ankylosing Spondylitis (AS) is a rare autoinflammatory disorder affecting 0.1–1.4% of the population, with increasing recognition over the past 20 years. Although the specific causes of AS remain unclear, the presence of the HLA-B27 gene is associated with increased risk, though only 1–5% of carriers develop the disease. Despite extensive research, no definitive lab tests exist, and many patients are diagnosed years after symptom onset. Methods: In the present study, in order to investigate the disease’s genetic background in correlation with autoimmune diseases, a metanalysis has been performed following PRISMA guidelines using Scopus and PubMed publications towards extracting single-nucleotide polymorphisms (SNPs) of high importance for the disease. Moreover, the polymorphisms have been annotated and analyzed using information from several databases, including PubMed, LitVar2, ClinVar, and Gene Ontology. Results: From 1940 screened titles and abstracts, 57,909 studies were selected, with 539 meeting the inclusion criteria. The genetic background of AS is described through 794 genetic variants, of which 76 SNPs are directly associated with AS (Classes A and B), predominantly located in intronic regions. ERAP1 and IL23R emerged as key genes implicated in AS, while chromosomes 1, 2, and 5 accumulated the most associated SNPs. Functional enrichment revealed strong associations with immune regulation and interleukin signaling pathways, particularly IL6 and IL10 signaling. IL-6 promotes inflammation in AS, while IL-10 tries to suppress it, acting as an anti-inflammatory cytokine. Of the 78 AS-related SNPs, 16 were unique to AS, while 66 were common to autoimmune diseases, especially rheumatoid arthritis (RA) and psoriasis (PsO), suggesting genetic overlap between these diseases. Conclusions: This study creates a comprehensive genetic map of AS-associated SNPs, highlighting key pathways and genetic overlap with autoimmune diseases. These findings contribute to understanding disease mechanisms and could guide therapeutic interventions, advancing precision medicine in AS management.

Background/Objectives: Kenny–Caffey syndrome 2 (KCS2) is a rare cause of hypoparathyroidism, inherited in an autosomal dominant mode, resulting from pathogenic variants of the FAM111A gene, which is implicated in intracellular pathways regulating parathormone (PTH) synthesis and skeletal and parathyroid gland development. Methods: The case of a boy is reported, presenting with the characteristic and newly identified clinical, biochemical, radiological, and genetic abnormalities of KCS2. Results: The proband had noticeable dysmorphic features, and the closure of the anterior fontanel was delayed until the age of 4 years. Biochemical evaluation at several ages revealed persistent hypocalcemia, high normal phosphorous, and inappropriately low normal PTH. To exclude other causes of short stature, the diagnostic approach revealed low levels of IGF-1, and on CNS MRI, small pituitary gland and empty sella. Nocturnal levels of growth hormone were normal. MRI also revealed bilateral symmetrical microphthalmia and torturous optic nerves. Skeletal survey was compatible with cortical thickening and medullary stenosis of the long bones. Genomic data analysis revealed a well-known pathogenic variant of the FAM111A gene (c.1706G>A, p. R569H), which is linked with KCS2 or nanophthalmos. Conclusions: KCS2, although a rare disease, should be included in the differential diagnosis of hypoparathyroidism and short stature. Understanding the association of pathogenic variants with KCS2 phenotypic variability will allow the advancement of clinical genetics and personalized long-term follow-up and will offer insights into the role of the FAM111A gene in the disease pathogenesis and normal embryogenesis of implicated tissues and organs.

Insect olfactory receptors are heteromeric ligand-gated cation channels composed of an obligatory receptor subunit, ORco, and one of many variable subunits, ORx, in as yet undefined molar ratios. When expressed alone ex vivo , ORco forms homotetrameric channels gated by ORco-specific ligands acting as channel agonists. Using an insect cell-based system as a functional platform for expressing mosquito odorant receptors ex vivo, we identified small molecules of natural origin acting as specific ORco channel antagonists, orthosteric or allosteric relative to a postulated ORco agonist binding site, and causing severe inhibition of olfactory function in mosquitoes. In the present communication, we are reporting on the compilation of common structural features of such orthosteric antagonists and development of a ligand-based pharmacophore whose properties are deemed necessary for binding to the agonist binding site and inhibition of ORco’s biological function. In silico screening of an available collection of natural volatile compounds with this pharmacophore resulted in identification of several ORco antagonist hits. Cell-based functional screening of the same compound collection resulted in the identification of several compounds acting as orthosteric and allosteric antagonists of ORco channel function ex vivo and inducing anosmic behaviors to Aedes albopictus mosquitoes in vivo. Comparison of the in silico screening results with those of the functional assays revealed that the pharmacophore predicted correctly 7 out of the 8 confirmed orthosteric antagonists and none of the allosteric ones. Because the pharmacophore screen also produced additional hits that did not cause inhibition of the ORco channel function, we generated a Support Vector Machine (SVM) model based on two descriptors of all pharmacophore hits. Training of the SVM on the ex vivo validated compound collection resulted in the selection of the confirmed orthosteric antagonists with a very low cross-validation out-of-sample misclassification rate. Employment of the combined pharmacophore-SVM platform for in silico screening of a larger collection of olfaction-relevant volatiles produced several new hits. Functional validation of randomly selected hits and rejected compounds from this screen confirmed the power of this virtual screening platform as convenient tool for identifying novel vector control agents. To the best of our knowledge, this study is the first one that combines a pharmacophore with a SVM model for identification of AgamORco antagonists and specifically orthosteric ones.

Genome-wide association studies (GWAS) have identified that one of the autoimmune disease-associated loci, predisposing for the development of Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA) and Systemic Sclerosis (SSc), is the rs35677470 missense variant of the Deoxyribonuclease I like 3 (DNASE1L3) gene, leading to R206C substitution in DNASE1L3 enzyme. Molecular Dynamics (MD) simulations were implemented for the wild type and mutated enzyme, in order to investigate the structure-function relationship that leads to partial loss of enzyme function. Results showed loss of salt bridges, larger fluctuation in active site regions and lower charge of the catalytic and DNA binding sites after the mutation. The present study raises the necessity of in silico methods, in understanding and managing autoimmune diseases.

Numerous natural products and designed molecules have been evaluated as tyrosinase inhibitors that impede enzymes’ oxidation activity. In the present study, new potent natural inhibitors were retrieved from the ZINC database by the similarity-screening of 37 previously reported tyrosinase inhibitors. The screening resulted in 42 candidate inhibitory molecules that were categorized into five groups. Molecular-docking analysis for these compounds, as well as for three others known for their inhibition activity (caffeic acid, naringenin, and gallic acid), was carried out against the tyrosinase structure from Agaricus bisporus (AbTYR). The top-scoring compounds were used for further comparative analysis with their corresponding naturally occurring glycosides. The results suggested that the glycosylated inhibitors could interact better with the enzyme than their aglycon forms. In order to further examine the role of the sugar side group of potent tyrosinase inhibitors, the dynamic behavior of two such pairs of glycosidic/aglycol forms (naringin–naringenin and icariin–icaritin) in their complexes with the enzyme were studied by means of 20-ns MD simulations. The increased number of intermolecular hydrogen bonds and their augmented lifetime between AbTYR and the glycosidic analogues showed that the naringin and icariin molecules form more stable complexes than naringenin and icaritin with tyrosinase, and thus are more potent inhibitors.