RESUMO
Amyotrophic lateral sclerosis (ALS) is the third most common neurodegenerative disorder and is sometimes associated with frontotemporal dementia. Charcot-Marie-Tooth disease (CMT) is one of the most commonly inherited peripheral neuropathies causing the slow progression of sensory and distal muscle defects. Of note, the severity and progression of CMT symptoms markedly vary. The phenotypic heterogeneity of ALS and CMT suggests the existence of modifiers that determine disease characteristics. Epigenetic regulation of biological functions via gene expression without alterations in the DNA sequence may be an important factor. The methylation of DNA, noncoding RNA, and post-translational modification of histones are the major epigenetic mechanisms. Currently, Drosophila is emerging as a useful ALS and CMT model. In this review, we summarize recent studies linking ALS and CMT to epigenetic regulation with a strong emphasis on approaches using Drosophila models.
Assuntos
Esclerose Lateral Amiotrófica/patologia , Doença de Charcot-Marie-Tooth/patologia , Epigênese Genética , Esclerose Lateral Amiotrófica/genética , Animais , Doença de Charcot-Marie-Tooth/genética , Metilação de DNA , Modelos Animais de Doenças , Drosophila , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , RNA Longo não Codificante/metabolismoRESUMO
An accumulation of protein-bound uremic toxins (PBUTs) is one of major reasons for development of uremia-related complications. We examined the PBUT removal ability of a hexadecyl-immobilized cellulose bead (HICB)-containing column for patients undergoing hemodialysis. Adsorption of indoxyl sulfate (IS), a representative PBUT, to HICBs was examined in vitro. The HICB column was used in patients undergoing hemodialysis for direct hemoperfusion with a regular hemodialyzer. The serum IS, indole acetic acid (IAA), phenyl sulfate (PhS), and p-cresyl sulfate (PCS) levels were measured before and after passing the column. HICBs adsorbed protein-free (free) IS in a dose- and time-dependent manner in vitro (55.4 ± 1.4% adsorption of 1 millimolar, 251 µg/mL, IS for 1 h). In clinical studies, passing the HICB-containing column decreased the serum level of free IS, IAA, PhS, and PCS levels significantly (by 34.4 ± 30.0%, 34.8 ± 25.4%, 28.4 ± 18.0%, and 34.9 ± 22.1%, respectively), but not protein-bound toxins in maintenance hemodialysis patients. HICBs absorbed some amount of free PBUTs, but the clinical trial to use HICB column did not show effect to reduce serum PBUTs level in hemodialysis patients. Adsorption treatment by means of direct hemoperfusion with regular hemodialysis may become an attractive blood purification treatment to increase PBUT removal when more effective materials to adsorb PBUTs selectively will be developed.
Assuntos
Celulose/química , Hemoperfusão/métodos , Falência Renal Crônica/terapia , Diálise Renal/métodos , Toxinas Biológicas/química , Uremia/terapia , Adsorção , Idoso , Proteínas Sanguíneas/metabolismo , Cresóis/sangue , Cresóis/química , Cresóis/metabolismo , Cresóis/toxicidade , Estudos de Viabilidade , Feminino , Hemoperfusão/instrumentação , Humanos , Indicã/sangue , Indicã/química , Indicã/metabolismo , Indicã/toxicidade , Ácidos Indolacéticos/sangue , Ácidos Indolacéticos/química , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/toxicidade , Falência Renal Crônica/sangue , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Porosidade , Ligação Proteica , Diálise Renal/instrumentação , Albumina Sérica , Ésteres do Ácido Sulfúrico/sangue , Ésteres do Ácido Sulfúrico/química , Ésteres do Ácido Sulfúrico/metabolismo , Ésteres do Ácido Sulfúrico/toxicidade , Toxinas Biológicas/sangue , Toxinas Biológicas/metabolismo , Toxinas Biológicas/toxicidade , Uremia/sangue , Uremia/etiologiaRESUMO
BACKGROUND: Dialysis-related amyloidosis (DRA) is a severe complication in end-stage kidney disease (ESKD) patients undergoing long-term dialysis treatment, characterized by the deposition of ß2-microglobulin-related amyloids (Aß2M amyloid). To inhibit DRA progression, hexadecyl-immobilized cellulose bead (HICB) columns are employed to adsorb circulating ß2-microglobulin (ß2M). However, it is possible that the HICB also adsorbs other molecules involved in amyloidogenesis. METHODS: We enrolled 14 ESKD patients using HICB columns for DRA treatment; proteins were extracted from HICBs following treatment and identified using liquid chromatography-linked mass spectrometry. We measured the removal rate of these proteins and examined the effect of those molecules on Aß2M amyloid fibril formation in vitro. RESULTS: We identified 200 proteins adsorbed by HICBs. Of these, 21 were also detected in the amyloid deposits in the carpal tunnels of patients with DRA. After passing through the HICB column and hemodialyzer, the serum levels of proteins such as ß2M, lysozyme, angiogenin, complement factor D and matrix Gla protein were reduced. These proteins acted in the Aß2M amyloid fibril formation. CONCLUSIONS: HICBs adsorbed diverse proteins in ESKD patients with DRA, including those detected in amyloid lesions. Direct hemoperfusion utilizing HICBs may play a role in acting Aß2M amyloidogenesis by reducing the amyloid-related proteins.