Biomarkers of Periodontitis and Its Differential DNA Methylation and Gene Expression in Immune Cells: A Systematic Review.

The characteristic epigenetic profile of periodontitis found in peripheral leukocytes denotes its impact on systemic immunity. In fact, this profile not only stands for periodontitis as a low-grade inflammatory disease with systemic effects but also as an important source of potentially valuable clinical biomarkers of its systemic effects and susceptibility to other inflammatory conditions. Thus, we aimed to identify relevant genes tested as epigenetic systemic biomarkers in patients with periodontitis, based on the DNA methylation patterns and RNA expression profiles in peripheral immune cells. A detailed protocol was designed following the Preferred Reporting Items for Systematic Review and Meta-analysis -PRISMA guideline. Only cross-sectional and case-control studies that reported potential systemic biomarkers of periodontitis in peripheral immune cell types were included. DNA methylation was analyzed in leukocytes, and gene expression was in polymorphonuclear and mononuclear cells. Hypermethylation was found in TLR regulators genes: MAP3K7, MYD88, IL6R, RIPK2, FADD, IRAK1BP1, and PPARA in early stages of periodontitis, while advanced stages presented hypomethylation of these genes. TGFB1I1, VNN1, HLADRB4, and CXCL8 genes were differentially expressed in lymphocytes and monocytes of subjects with poorly controlled diabetes mellitus, dyslipidemia, and periodontitis in comparison with controls. The DAB2 gene was differentially overexpressed in periodontitis and dyslipidemia. Peripheral blood neutrophils in periodontitis showed differential expression in 163 genes. Periodontitis showed an increase in ceruloplasmin gene expression in polymorphonuclears in comparison with controls. Several genes highlight the role of the epigenetics of peripheral inflammatory cells in periodontitis that could be explored in blood as a source of biomarkers for routine testing.

ZNF718, HOXA4, and ZFP57 are differentially methylated in periodontitis in comparison with periodontal health: Epigenome-wide DNA methylation pilot study.

OBJECTIVE: To investigate the differences in the epigenomic patterns of DNA methylation in peripheral leukocytes between patients with periodontitis and gingivally healthy controls evaluating its functional meaning by functional enrichment analysis. BACKGROUND: The DNA methylation profiling of peripheral leukocytes as immune-related tissue potentially relevant as a source of biomarkers between periodontitis patients and gingivally healthy subjects has not been investigated. METHODS: A DNA methylation epigenome-wide study of peripheral leukocytes was conducted using the Illumina MethylationEPIC platform in sixteen subjects, eight diagnosed with periodontitis patients and eight age-matched and sex-matched periodontally healthy controls. A trained periodontist performed the clinical evaluation. Global DNA methylation was estimated using methylation-sensitive high-resolution melting in LINE1. Routine cell count cytometry and metabolic laboratory tests were also performed. The analysis of differentially methylated positions (DMPs) and differentially methylated regions (DMRs) was made using R/Bioconductor environment considering leukocyte populations assessed in both routine cell counts and using the FlowSorted.Blood.EPIC package. Finally, a DMP and DMR intersection analysis was performed. Functional enrichment analysis was carried out with the differentially methylated genes found in DMP. RESULTS: DMP analysis identified 81 differentially hypermethylated genes and 21 differentially hypomethylated genes. Importantly, the intersection analysis showed that zinc finger protein 718 (ZNF718) and homeobox A4 (HOXA4) were differentially hypermethylated and zinc finger protein 57 (ZFP57) was differentially hypomethylated in periodontitis. The functional enrichment analysis found clearly immune-related ontologies such as "detection of bacterium" and "antigen processing and presentation." CONCLUSION: The results of this study propose three new periodontitis-related genes: ZNF718, HOXA4, and ZFP57 but also evidence the suitability and relevance of studying leukocytes' DNA methylome for biological interpretation of systemic immune-related epigenetic patterns in periodontitis.

Global long interspersed nuclear element 1 DNA methylation in a Colombian sample of patients with late-onset Alzheimer's disease.

Alterations in DNA methylation have implicated as an epigenetic event in the pathogenesis of late-onset Alzheimer's disease (LOAD). The objective of this work was to evaluate global DNA methylation levels for long interspersed nuclear element 1 (LINE-1) repetitive sequences in Colombian patients with LOAD and controls. The LINE-1 DNA methylation levels in peripheral blood samples from 28 Colombian patients with LOAD and 30 healthy participants were assessed using a methylation-sensitive high-resolution melting (MS-HRM) quantitative assay. We did not find differences in LINE-1 methylation levels between patients with Alzheimer's disease (AD; median 76.2%, interquartile range [IQR]: 69.8-81.9) and control participants (median 79.8%, IQR: 73.2-83.8; P = .3). Additional stratified analyses did not show differences in LINE-1 methylation levels for male or female patients versus controls nor for apolipoprotein E4 carriers and noncarriers. This is the first report of LINE-1 methylation levels in patients with LOAD using the cost-effective MS-HRM technique, and this is the first global DNA methylation study in Latin American patients with AD.

Optimizing methodologies for PCR-based DNA methylation analysis.

Comprehensive analysis of DNA methylation patterns is critical for understanding the molecular basis of many human diseases. While hundreds of PCR-based DNA methylation studies are published every year, the selection and implementation of appropriate methods for these studies can be challenging for molecular genetics researchers not yet familiar with methylation analysis. Here we review the most commonly used PCR-based DNA methylation analysis techniques: bisulfite sequencing PCR (BSP), methylation specific PCR (MSP), MethyLight, and methylation-sensitive high resolution melting (MS-HRM). We provide critical analysis of the strengths and weaknesses of each approach as well as a series of guidelines to assist in selecting and implementing an appropriate method.

Functional Neurodissection in the First Episode of Schizophrenia: Time to Do It / Neurodisección funcional en el primer episodio de esquizofrenia: es hora de hacerla

Introduction: Current available knowledge does not delineate the relative contribution of cortical and/or subcortical mechanisms in the development of the various symptoms of schizophrenia. Methods: We propose here to employ a battery of functional neurological studies to be done in the earliest phase of manifest schizophrenia combining transcranial magnetic stimulation and brainstem reflex studies. The proposed battery would examine both cortical and subcortical mechanisms reasonably well-correlated with neurotransmitter abnormalities to differentiate GABAergic, cholinergic, and dopaminergic subgroups of patients and healthy controls. Conclusion: These investigations would lead towards a better neurophysiological subcategorization and could guide towards a more focused pharmacological intervention in early schizophrenia symptoms.

Introducción: El conocimiento actual que tenemos de la esquizofrenia no permite conocer la contribución de los mecanismos corticales o subcorticales que llevan al establecimiento clínico de los diferentes síntomas de la esquizofrenia. Métodos: Se propone emplear una batería de evaluaciones neurológicas funcionales que se deberán hacer en la fase más temprana de la enfermedad, y así combinar la estimulación magnética transcraneal y los refl ejos del tallo cerebral. Esta batería de estudios permitiría investigar el funcionamiento de los mecanismos corticales y subcorticales y su correlación con anormalidades en diferentes neurotransmisores, incluidos los gabaérgicos, los colinérgicos y los dopaminérgicos. Este último hecho llevaría a diferenciar clínicamente los diferentes subgrupos de pacientes y entre estos e individuos normales. Conclusión: Estas evaluaciones llevarían hacia una mejor subcategorización neurofi siológica clínica y guiaría hacia una intervención más efectiva en los estados iniciales de la esquizofrenia.

Two Babinski signs in seropositive (HAM) and seronegative tropical spastic paraparesis.

Tropical spastic paraparesis (TSP) may or may not be associated to HTLV-I antibodies and is usually characterized by clinical and pathological spinal cord abnormalities at thoracic levels. We present here five Brazilian patients who had typical chronic idiopathic spastic paraparesis; two of them were HTLV-I seropositive (HAM) and three HTLV-I seronegative (TSP) -associated-myelopathy. Three out of these five patients also displayed clinical supraspinal involvement, indeed, platysma muscle hypotrophy or atrophy (the Babinski plus sign). These findings support the view that clinical involvement in HAM and TSP is wider than the spinal cord abnormalities usually considered. Possible non-infectious co-factors (e.g., mycotoxins) may be involved in disease pathogenesis in a multistep process of viruses, toxins and environment which may account for serological differences found in this group of patients.

Two Babinski signs in seropositive (HAM) and seronegative tropical spastic paraparesis / Dos signos de Babinski en pacientes con paraparesia espástica tropical seropositiva (HAM) y seronegativa

Tropical spastic paraparesis (TSP) may or may not be associated to HTLV-I antibodies and is usually characterized by clinical and pathological spinal cord abnormalities at thoracic levels. We present here five Brazilian patients who had typical chronic idiopatic spastic paraparesis; two of them were HTLV-I seropositive (HAM) and three HTLV-I seronegative (TSP) - associated-myelopathy. Three out of these five patients also displayed clinical supraspinal involvement, indeed, platysma muscle hypotrophy or atrophy (the Babinski plus sign). These findings support the view that clinical involvement in HAM and TSP is wider than the spinal cord abnormalities usually considered. Possible non-infectious co-factors (e.g., mycotoxins) may be involved in disease pathogenesis in a multistep process of viruses, toxins and environment which may account for serological differences found in this group of patients.

La paraparesia espástica tropical (PET), puede o no estar asociada con anticuerpos contra el HTLV-I y se caracteriza, usualmente, por alteraciones clínicas y patológicas a nivel de region dorso-lumbar de la medula espinal. Presentamos cinco pacientes brasileros, quienes tuvieron hallazgos típicos de paraparesia espástica crónica idiopática; dos de ellos tuvieron (HAM) y tres no tuvieron (TSP) anticuerpos, en el suero, contra el HTLV-I. En tres pacientes se encontró hipotrofia o atrofia del músculo platisma (signo de Babinski plus), demostrando que el compromiso clínico en pacientes con HAM y TSP se extiende más allá de la médula espinal torácica. Cofactores (por ejemplo, micotoxinas) podrían estar involucrados en la patogénesis de esta enfermedad, en una interacción compleja de virus, toxinas y medio ambiente, lo cual explicaría las diferencias serológicas encontradas en este grupo de pacientes.

Abnormal tactile discrimination and somatosensory plasticity in familial primary hyperhidrosis.

Abnormal sensory processing seems to be involved in hyperhidrosis. To test this hypothesis, we investigated tactile acuity and cortical plastic changes in patients with primary hyperhidrosis (PH) and their asymptomatic relatives. We studied thirteen subjects belonging to two families with PH and thirteen age-matched healthy controls using Johnson-Van Boven-Phillips domes before and after 45min of transient visual deafferentation. Spatial discrimination thresholds (SDTs) were lower in controls than in the familial group (1.08+/-0.25 vs 1.59+/-0.71; p=0.0032). After 45min of light deprivation and blindfolding, SDTs decreased significantly in controls (0.83+/-0.3; p=0.003), but not in patients (1.4+/-0.62; p=0.108). Interestingly, two subjects without clinical complaints of hyperhidrosis had abnormal SDTs behavior after short term visual deprivation. This study demonstrates that sensory processing is abnormal in PH, with a lack of plastic cortical somatosensory changes regardless of clinical condition. These modulatory abnormalities would affect gating processes in the somatosensory cortex which may play a role in maintaining hyperhidrosis.