Comprehensive analysis of Novel mutations in CCM1/KRIT1 and CCM2/MGC4607 and their clinical implications in Cerebral Cavernous malformations.

BACKGROUND: Cerebral Cavernous Malformations (CCM) is a genetic disease characterized by vascular abnormalities in the brain and spinal cord, affecting 0.4-0.5 % of the population. We identified two novel pathogenic mutations, CCM1/KRIT1 c.811delT (p.Trp271GlyfsTer5) and CCM2/MGC4607 c.613_614insGG p.Glu205GlyfsTer31), which disrupt crucial protein domains and potentially alter disease progression. OBJECTIVE: The study aims to comprehensively analyze a Brazilian cohort of CCM patients, integrating genetic, clinical, and structural aspects. Specifically, we sought to identify novel mutations within the CCM complex, and explore their potential impact on disease progression. METHODS: We conducted a detailed examination of neuroradiological and clinical features in both symptomatic and asymptomatic CCM patients, performing genetic analyses through sequencing of the CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10 genes In silico structural predictions were carried out using PolyPhen-2, SIFT, and Human Genomics Community tools. Protein-protein interactions and docking analyses were explored using the STRING database. RESULTS: Genetic analysis identifies 6 pathogenic mutations, 4 likely pathogenic, 1 variants of uncertain significance, and 7 unclassified mutations, including the novel mutations in CCM1 c.811delT and CCM2 c.613_614insGG. In silico structural analysis revealed significant alterations in protein structure, supporting their pathogenicity. Protein-protein interaction analysis indicated nuanced impacts on cellular processes. Clinically, we observed a broad spectrum of symptoms, including seizures and focal neurological deficits. However, no statistically significant differences were found in lesion burden, age of first symptom onset, or sex between the identified CCM1/KRIT1 and CCM2/MGC4607 mutations among all patients studied. CONCLUSION: This study enhances the understanding of CCM by linking clinical variability, genetic mutations, and structural effects. The identification of these novel mutations opens new avenues for research and potential therapeutic strategies.

Comprehensive CCM3 Mutational Analysis in Two Patients with Syndromic Cerebral Cavernous Malformation.

Cerebral cavernous malformation (CCM) is a vascular disease that affects the central nervous system, which familial form is due to autosomal dominant mutations in the genes KRIT1(CCM1), MGC4607(CCM2), and PDCD10(CCM3). Patients affected by the PDCD10 mutations usually have the onset of symptoms at an early age and a more aggressive phenotype. The aim of this study is to investigate the molecular mechanism involved with CCM3 disease pathogenesis. Herein, we report two typical cases of CCM3 phenotype and compare the clinical and neuroradiological findings with five patients with a familial form of KRIT1 or CCM2 mutations and six patients with a sporadic form. In addition, we evaluated the PDCD10 gene expression by qPCR and developed a bioinformatic pipeline to understand the structural changes of mutations. The two CCM3 patients had an early onset of symptoms and a high lesion burden. Furthermore, the sequencing showed that Patient 1 had a frameshift mutation in c.222delT; p.(Asn75Thrfs*14) that leads to lacking the last 124 C-terminal amino acids on its primary structure and Patient 2 had a variant on the splicing site region c.475-2A > G. The mRNA expression was fourfold lower in both patients with PDCD10 mutation. Using in silico analysis, we identify that the frameshift mutation transcript lacks the C-terminal FAT-homology domain compared to the wild-type PDCD10 and preserves the N-terminal dimerization domain. The two patients studied here allow estimating the potential impact of mutations in clinical interpretation as well as support to better understand the mechanism and pathogenesis of CCM3.

Shared Molecular Signatures Across Zika Virus Infection and Multiple Sclerosis Highlight AP-1 Transcription Factor as a Potential Player in Post-ZIKV MS-Like Phenotypes.

Zika virus (ZIKV) is an arbovirus of the Flaviviridae genus that has rapidly disseminated from across the Pacific to the Americas. Robust evidence has indicated a crucial role of ZIKV in congenital virus syndrome, including neonatal microcephaly. Moreover, emerging evidence suggests an association between ZIKV infection and the development of an extensive spectrum of central nervous system inflammatory demyelinating diseases (CNS IDD), such as multiple sclerosis-like clinical phenotypes. However, the underlying mechanisms of host-pathogen neuro-immune interactions remain to be elucidated. This study aimed to identify common transcriptional signatures between multiple sclerosis (MS) and ZIKV infection to generate molecular interaction networks, thereby leading to the identification of deregulated processes and pathways, which could give an insight of these underlying molecular mechanisms. Our investigation included publicly available transcriptomic data from MS patients in either relapse or remission (RR-MS) and datasets of subjects acutely infected by ZIKV for both immune peripheral cells and central nervous system cells. The protein-protein interaction (PPI) analysis showed upregulated AP-1 transcription factors (JUN and FOS) among the top hub and bottleneck genes in RR-MS and ZIKV data. Gene enrichment analysis retrieved a remarkable presence of ontologies and pathways linked to oxidative stress responses, immune cell function, inflammation, interleukin signaling, cell division, and transcriptional regulation commonly enriched in both scenarios. Considering the recent findings concerning AP-1 function in immunological tolerance breakdown, regulation of inflammation, and its function as an oxidative stress sensor, we postulate that the ZIKV trigger may contribute as a boost for the activation of such AP-1-regulated mechanisms that could favor the development of MS-like phenotypes following ZIKV infection in a genetically susceptible individual.

Molecular mimicry between Zika virus and central nervous system inflammatory demyelinating disorders: the role of NS5 Zika virus epitope and PLP autoantigens.

BACKGROUND: Evidence indicates a strong link between Zika virus (ZikV) and neurological complications. Acute myelitis, optic neuritis, polyneuropathy, and encephalomyelitis that mimic inflammatory idiopathic demyelination disorders (IIDD) after ZikV infection have been reported in Brazil. OBJECTIVE: The present study aims to investigate the possible occurrence of molecular mimicry between ZikV antigens and Multiple Sclerosis (MS) autoantigens, the most frequent IIDD of the central nervous system (CNS). METHODS: A retrospective cohort study with 305 patients admitted due to suspected arbovirus infection in Rio de Janeiro was performed, all subjects were submitted to neurological examination, and a biological sample was collected for serologic and molecular diagnostic. Bioinformatics tools were used to analyze the peptides shared between ZikV antigens and MS autoantigens. RESULTS: Of 305 patients, twenty-six were positive for ZikV and 4 presented IDD patterns found in MS cases. Sequence homology comparisons by bioinformatics approach between NS5 ZikV and PLP MS protein revealed a homology of 5/6 consecutive amino acids (CSSVPV/CSAVPV) with 83% identity, deducing a molecular mimicry. Analysis of the 3D structures revealed a similar conformation with alpha helix presentation. CONCLUSIONS: Molecular mimicry between NS5 Zika virus antigen and PLP MS autoantigens emerge as a possible mechanism for IDD spectrum in genetically susceptible individuals.

ANTECEDENTES: Evidências indicam uma forte ligação entre o vírus Zika (ZikV) e complicações neurológicas. Mielite aguda, neurite óptica, polineuropatia e encefalomielite que mimetizam distúrbios inflamatórios de desmielinização idiopáticos (DDII) após infecção por ZikV têm sido relatadas no Brasil. OBEJTIVO: O presente estudo tem como objetivo investigar a possível ocorrência de mimetismo molecular entre antígenos do ZikV e autoantígenos da Esclerose Múltipla (EM), a DDII mais frequente do sistema nervoso central (SNC). MéTODOS: Foi realizado um estudo de coorte retrospectivo com 305 pacientes internados por suspeita de infecção por arbovírus no Rio de Janeiro, todos os indivíduos foram submetidos a exame neurológico e coleta de amostra biológica para diagnóstico sorológico e molecular. Ferramentas de bioinformática foram usadas para analisar os peptídeos compartilhados entre antígenos do ZikV e autoantígenos da EM. RESULTADOS: Dos 305 pacientes, vinte e seis foram positivos para ZikV e 4 apresentaram padrão IDD encontrado em casos de EM. As comparações de homologia de sequência por abordagem de bioinformática entre a proteína NS5 ZikV e PLP EM revelaram uma homologia de 5/6 aminoácidos consecutivos (CSSVPV/CSAVPV) com 83% de identidade, deduzindo um mimetismo molecular. A análise das estruturas 3D revelou uma conformação semelhante com apresentação em alfa-hélice. CONCLUSõES: O mimetismo molecular entre o antígeno NS5 do vírus Zika e o autoantígeno PLP da EM surge como um possível mecanismo para o espectro IDD em indivíduos geneticamente suscetíveis.

Association of Variants in FCGR2A, PTPN2, and GM-CSF with Cerebral Cavernous Malformation: Potential Biomarkers for a Symptomatic Disease.

BACKGROUND: Cerebral Cavernous Malformations (CCM) predispose patients to a lifetime risk of seizures and symptomatic hemorrhage. Only a small percentage of people affected will develop clinical symptoms and the molecular mechanisms underlying lesional activity remain unclear. We analyzed a panel of Single Nucleotide Polymorphisms (SNPs) in CCM patients. We looked for plasmatic inflammatory cytokines, checking for a pattern of plasma expression heterogeneity and any correlation with genetic variations identified with different CCM clinical phenotypes. METHODS: This was a case-control study from a long-term follow-up cohort including 23 CCM patients, of which 16 were symptomatic, and 7 were asymptomatic. A 200-SNP panel was considered through next-generation sequencing and 18 different plasma molecules were assessed through a suspension array system. RESULTS: Fcγ receptor IIa rs1801274 (FCGR2A) and protein tyrosine phosphatase non-receptor type 2 rs72872125 PTPN2 were statistically different between groups. Patients who had a combination of the presence of FCGR2A and the absence of PTPN2 also had symptoms earlier in life. The combination of genetic polymorphisms and serum level of GM-CSF showed the best diagnostic biomarker to distinguish symptomatic patients as formulated: [0.296*(FCGR2A)] + [-0.788*(PTPN2)] + [-0.107*(GM-CSF)]. CONCLUSION: We have shown that SNPs in inflammation genes might be related to a symptomatic phenotype in CCM. We also demonstrated that a formula based on two of these polymorphisms (FCGR2A+ and PTPN2+) is possibly capable of predicting a symptomatic phenotype during a patient's lifetime.