RESUMEN
Introducción: Existen 14 formas de lipofuscinosis. La de tipo 6, en su forma infantil tardía, comienza entre los 3 y 8 años con alteraciones motoras, mioclonos, disartria, ataxia, pérdida de la visión y las habilidades motoras, y muerte temprana. Ocurre por mutaciones en el gen CLN6. La mayoría de los pacientes presenta variantes en estado homocigoto, asociadas a consanguinidad o endogamia, y son poco frecuentes las variantes en estado heterocigoto compuesto. Casos clínicos: Hermanos con síntomas desde los 4 y 5 años, con marcha inestable, caídas frecuentes, posteriormente pérdida de la marcha, mioclonías, disfagia y alucinaciones visuales. En el examen físico presentaban atrofia del nervio óptico, Babinski y ataxia del tronco. El electroencefalograma mostraba brotes de ondas lentas generalizadas, sin respuesta fotoparoxística, y la resonancia magnética de cráneo, hiperintensidad de la sustancia blanca periventricular, y atrofia cerebelosa y cortical. El panel de lipofuscinosis reveló dos mutaciones nuevas en el gen CLN6, c.552del y c.244G>C (p.Gly82Arg), no descritas previamente. La madre resultó portadora de la deleción 552, y el padre y la abuela paterna, de la sustitución G>C (Gly82Arg). Conclusiones: El diagnóstico diferencial en los trastornos con neurorregresión se dificulta debido a que los signos clínicos son inespecíficos, similares a otras epilepsias mioclónicas progresivas. Presentamos los hallazgos clínicos en dos hermanos mexicanos con la variante infantil tardía de CLN6 por dos mutaciones heterocigotas nuevas que contribuyen al conocimiento de las mutaciones en la población mexicana y señalan la relevancia de realizar estudios genéticos aplicando la secuenciación de nueva generación para permitir un adecuado asesoramiento.(AU)
Introduction: There are 14 forms of lipofuscinosis, among them type 6 in its late childhood form is found, it starts between three and eight years with epilepsy, motor disorders, myoclonus, dysarthria, ataxia and neurological regression associated with vision loss and motor skills, and early death. It occurs from mutations in the CLN6 gene, most patients have homozygote variants associated with consanguinity, and rarely, with compound heterozygote variants. Case report: Siblings, started at 4 and 5 years each, with unstable gear, frequent falls and difficult running. Subsequently, loss of gait, myoclonus, dysphagia, and hallucinations. On physical examination, present optic nerve atrophy, Babinski and trunk ataxia. Electroencephalogram with widespread slow wave bursts during non-REM sleep, non photoparoxystic response, MRI with periventricular white substance hyperintensity, cerebellar atrophy and cortical. Panel of lipofuscinosis report two mutations, c.552del and c.244G>C, not described previously, in both patients. The mother was the carrier of the 552 deletion and the father and paternal grandmother of the G>C substitution (Gly82Arg). Conclusions: Differential diagnosis in neuroregression disorders is difficult because clinical signs are nonspecific, like many other neurodegenerative disorders with progressive myoclonic epilepsy. We report the clinical findings in two Mexican siblings with the late childhood variant of CLN6 with two new heterozygote mutations that contribute to the knowledge of mutations in the Mexican population and point out the relevance of performing next-generation genetic sequencing studies which will allow a better genetic counseling practice.(AU)
Asunto(s)
Humanos , Masculino , Niño , /diagnóstico , Ataxia , Enfermedad de Lafora , Enfermedades Neurodegenerativas , Hermanos , Neurología , Enfermedades del Sistema Nervioso , Pediatría , Pacientes Internos , Examen Físico , Evaluación de Síntomas , MéxicoRESUMEN
INTRODUCTION: There are 14 forms of lipofuscinosis, among them type 6 in its late childhood form is found, it starts between three and eight years with epilepsy, motor disorders, myoclonus, dysarthria, ataxia and neurological regression associated with vision loss and motor skills, and early death. It occurs from mutations in the CLN6 gene, most patients have homozygote variants associated with consanguinity, and rarely, with compound heterozygote variants. CASE REPORT: Siblings, started at 4 and 5 years each, with unstable gear, frequent falls and difficult running. Subsequently, loss of gait, myoclonus, dysphagia, and hallucinations. On physical examination, present optic nerve atrophy, Babinski and trunk ataxia. Electroencephalogram with widespread slow wave bursts during non-REM sleep, non photoparoxystic response, MRI with periventricular white substance hyperintensity, cerebellar atrophy and cortical. Panel of lipofuscinosis report two mutations, c.552del and c.244G>C, not described previously, in both patients. The mother was the carrier of the 552 deletion and the father and paternal grandmother of the G>C substitution (Gly82Arg). CONCLUSIONS: Differential diagnosis in neuroregression disorders is difficult because clinical signs are nonspecific, like many other neurodegenerative disorders with progressive myoclonic epilepsy. We report the clinical findings in two Mexican siblings with the late childhood variant of CLN6 with two new heterozygote mutations that contribute to the knowledge of mutations in the Mexican population and point out the relevance of performing next-generation genetic sequencing studies which will allow a better genetic counseling practice.
TITLE: Lipofuscinosis ceroidea neuronal. Variante infantil tardía de tipo 6 en dos hermanos heterocigotos compuestos con mutaciones nuevas.Introducción. Existen 14 formas de lipofuscinosis. La de tipo 6, en su forma infantil tardía, comienza entre los 3 y 8 años con alteraciones motoras, mioclonos, disartria, ataxia, pérdida de la visión y las habilidades motoras, y muerte temprana. Ocurre por mutaciones en el gen CLN6. La mayoría de los pacientes presenta variantes en estado homocigoto, asociadas a consanguinidad o endogamia, y son poco frecuentes las variantes en estado heterocigoto compuesto. Casos clínicos. Hermanos con síntomas desde los 4 y 5 años, con marcha inestable, caídas frecuentes, posteriormente pérdida de la marcha, mioclonías, disfagia y alucinaciones visuales. En el examen físico presentaban atrofia del nervio óptico, Babinski y ataxia del tronco. El electroencefalograma mostraba brotes de ondas lentas generalizadas, sin respuesta fotoparoxística, y la resonancia magnética de cráneo, hiperintensidad de la sustancia blanca periventricular, y atrofia cerebelosa y cortical. El panel de lipofuscinosis reveló dos mutaciones nuevas en el gen CLN6, c.552del y c.244G>C (p.Gly82Arg), no descritas previamente. La madre resultó portadora de la deleción 552, y el padre y la abuela paterna, de la sustitución G>C (Gly82Arg). Conclusiones. El diagnóstico diferencial en los trastornos con neurorregresión se dificulta debido a que los signos clínicos son inespecíficos, similares a otras epilepsias mioclónicas progresivas. Presentamos los hallazgos clínicos en dos hermanos mexicanos con la variante infantil tardía de CLN6 por dos mutaciones heterocigotas nuevas que contribuyen al conocimiento de las mutaciones en la población mexicana y señalan la relevancia de realizar estudios genéticos aplicando la secuenciación de nueva generación para permitir un adecuado asesoramiento genético.
Asunto(s)
Mutación , Lipofuscinosis Ceroideas Neuronales/clasificación , Lipofuscinosis Ceroideas Neuronales/genética , Preescolar , Femenino , Heterocigoto , Humanos , Masculino , Lipofuscinosis Ceroideas Neuronales/diagnósticoRESUMEN
This study determined whether clinical salt-sensitive hypertension (cSSHT) results from the interaction between partial arterial baroreceptor impairment and a high-sodium (HNa) diet. In three series (S-I, S-II, S-III), mean arterial pressure (MAP) of conscious male Wistar ChR003 rats was measured once before (pdMAP) and twice after either sham (SHM) or bilateral aortic denervation (AD), following 7 days on a low-sodium (LNa) diet (LNaMAP) and then 21 days on a HNa diet (HNaMAP). The roles of plasma nitric oxide bioavailability (pNOB), renal medullary superoxide anion production (RMSAP), and mRNA expression of NAD(P)H oxidase and superoxide dismutase were also assessed. In SHM (n=11) and AD (n=15) groups of S-I, LNaMAP-pdMAP was 10.5±2.1 vs 23±2.1 mmHg (P<0.001), and the salt-sensitivity index (SSi; HNaMAP-LNaMAP) was 6.0±1.9 vs 12.7±1.9 mmHg (P=0.03), respectively. In the SHM group, all rats were normotensive, and 36% were salt sensitive (SSi≥10 mmHg), whereas in the AD group â¼50% showed cSSHT. A 45% reduction in pNOB (P≤0.004) was observed in both groups in dietary transit. RMSAP increased in the AD group on both diets but more so on the HNa diet (S-II, P<0.03) than on the LNa diet (S-III, P<0.04). MAP modeling in rats without a renal hypertensive genotype indicated that the AD*HNa diet interaction (P=0.008) increases the likelihood of developing cSSHT. Translationally, these findings help to explain why subjects with clinical salt-sensitive normotension may transition to cSSHT.
RESUMEN
This study determined whether clinical salt-sensitive hypertension (cSSHT) results from the interaction between partial arterial baroreceptor impairment and a high-sodium (HNa) diet. In three series (S-I, S-II, S-III), mean arterial pressure (MAP) of conscious male Wistar ChR003 rats was measured once before (pdMAP) and twice after either sham (SHM) or bilateral aortic denervation (AD), following 7 days on a low-sodium (LNa) diet (LNaMAP) and then 21 days on a HNa diet (HNaMAP). The roles of plasma nitric oxide bioavailability (pNOB), renal medullary superoxide anion production (RMSAP), and mRNA expression of NAD(P)H oxidase and superoxide dismutase were also assessed. In SHM (n=11) and AD (n=15) groups of S-I, LNaMAP-pdMAP was 10.5±2.1 vs 23±2.1 mmHg (P<0.001), and the salt-sensitivity index (SSi; HNaMAP−LNaMAP) was 6.0±1.9 vs 12.7±1.9 mmHg (P=0.03), respectively. In the SHM group, all rats were normotensive, and 36% were salt sensitive (SSi≥10 mmHg), whereas in the AD group ∼50% showed cSSHT. A 45% reduction in pNOB (P≤0.004) was observed in both groups in dietary transit. RMSAP increased in the AD group on both diets but more so on the HNa diet (S-II, P<0.03) than on the LNa diet (S-III, P<0.04). MAP modeling in rats without a renal hypertensive genotype indicated that the AD*HNa diet interaction (P=0.008) increases the likelihood of developing cSSHT. Translationally, these findings help to explain why subjects with clinical salt-sensitive normotension may transition to cSSHT.
Asunto(s)
ATPasas Transportadoras de Calcio/genética , Músculo Liso/fisiología , Intercambiador de Sodio-Calcio/genética , ATPasa Intercambiadora de Sodio-Potasio/genética , Tráquea/fisiología , Transcripción Genética , Animales , Cobayas , Humanos , Isoformas de Proteínas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The aim of this work was to investigate the effect of cadmium, lead and arsenic on the apoptosis of human immune cells. Peripheral blood mononuclear cells (MNC) were incubated with increasing concentrations of these metals and then cellular apoptosis was determined by flow cytometry and by DNA electrophoresis. We found that arsenic induced a significant level of apoptosis at 15 microM after 48h of incubation. Cadmium had a similar effect, but at higher concentrations (65 microM). In addition, cadmium exerted a cytotoxic effect on MNC that seemed to be independent of the induction of apoptosis. In contrast, concentrations of lead as high as 500 microM were nontoxic and did not induce a significant degree of apoptosis. Additional experiments showed that arsenic at concentrations as low as 1.0 microM had a significant pro-apoptotic effect when cells were cultured in the presence of this pollutant for more than 72. Non-T cells were more susceptible than T lymphocytes to the effect of arsenic and cadmium. Interestingly, MNC from children chronically exposed to arsenic showed a high basal rate of apoptosis and a diminished in vitro sensibility to this metalloid. Our results indicate that both arsenic and cadmium are able to induce apoptosis of lymphoid cells, and suggest that this phenomenon may contribute to their immunotoxic effect in vivo.
Asunto(s)
Apoptosis/efectos de los fármacos , Arsénico/efectos adversos , Cadmio/efectos adversos , Contaminantes Ambientales/efectos adversos , Plomo/efectos adversos , Leucocitos Mononucleares/efectos de los fármacos , Adulto , Arsénico/orina , Arsenitos/farmacología , Arsenitos/toxicidad , Cloruro de Cadmio/farmacología , Cloruro de Cadmio/toxicidad , Células Cultivadas/efectos de los fármacos , Niño , Creatinina/orina , Relación Dosis-Respuesta a Droga , Exposición a Riesgos Ambientales , Humanos , Síndromes de Inmunodeficiencia/inducido químicamente , Leucocitos Mononucleares/citología , México , Minería , Compuestos Organometálicos/farmacología , Compuestos Organometálicos/toxicidad , Formación de Roseta , Compuestos de Sodio/farmacología , Compuestos de Sodio/toxicidad , Linfocitos T/citología , Linfocitos T/efectos de los fármacosRESUMEN
Most nuclearly encoded mitochondrial proteins are synthesized with an amino-terminal leader peptide that is cleaved by the mitochondrial processing peptidase (MPP). Purified rat liver MPP, like the Neurospora and yeast enzymes, consists of two nonidentical subunits, alpha (55 kDa) and beta (50 kDa). To confirm the functional authenticity of the recently cloned and sequenced cDNAs for the alpha- and beta-MPP subunits from rat liver and to study each subunit's participation in MPP activity, we have subcloned and expressed separately in Escherichia coli the mature sequence of each subunit as a fusion protein with the maltose-binding protein. After induction, about 80% of each expressed fusion protein was insoluble in aggregates or inclusion bodies, and 20% remained soluble in the supernatant. The fusion proteins in the soluble fraction were purified by affinity chromatography and treated with factor Xa, and the MPP subunits were purified to homogeneity. When mixed together, these subunits showed no activity, suggesting that they might be misfolded. Therefore, a reconstitution protocol was developed which consisted of denaturation in urea, dithiothreitol, and 2-mercaptoethanol, followed by renaturation by dilution and dialysis under reducing conditions. With this procedure, active MPP was recovered from the mixed subunits, and it could be demonstrated that both alpha- and beta-MPP subunits were necessary for activity. Reconstituted recombinant MPP resembled the native rat liver enzyme as judged by its molecular weight, its inhibition by EDTA, and its ability to process a variety of mitochondrial precursor proteins appropriately to either an intermediate or a mature form.
Asunto(s)
Metaloendopeptidasas/metabolismo , Mitocondrias Hepáticas/enzimología , Precursores de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Cartilla de ADN/química , Metaloendopeptidasas/química , Metaloendopeptidasas/genética , Datos de Secuencia Molecular , Peso Molecular , Ratas , Proteínas Recombinantes/metabolismo , Peptidasa de Procesamiento MitocondrialRESUMEN
Expression of the C-terminal third of chicken gizzard caldesmon in Escherichia coli, using the Nagai vector (Nagai, K., and Thøgersen, H.V. (1987) Methods Enzmol. 153, 461-481), produces a cII-caldesmon fusion protein (27 kDa) with caldesmon sequence beginning at Lys579. Degradation during purification yields five peptides with molecular masses of 24, 22, 19 (two peptides), and 15 kDa. The 24-kDa peptide begins at Phe581; the 22-kDa peptide begins at Leu597, the two 19-kDa peptides begin at Phe581 and Val629, respectively; the 15-kDa peptide also begins at Val629. We estimate that the 15-kDa and one of the 19-kDa peptides end near Leu710. Site-directed mutagenesis was used to produce truncated peptides with known C termini; one peptide (17 kDa) terminates at Asn675. Digestion of the fragments with chymotrypsin generates a second 15-kDa fragment that begins at Ser666 (15K'). All of the peptides, with the exception of 15K', bind Ca(2+)-calmodulin-Sepharose and share a common 37-amino acid peptide between Val629 and Ser666, suggesting this contains the calmodulin binding site. Comparison with published sequences (Takagi, T., Yazawa, M., Ueno, T., Suzuki, S., and Yagi, K. (1989) J. Biochem. (Tokyo) 106, 778-783 and Bartegi, A., Fattoum, A., Derancourt, J., and Kassab, R. (1990) J. Biol. Chem. 265, 15231-15238) for other calmodulin-binding fragments further restricts the binding site to 7 residues, Trp-Glu-Lys-Gly-Asn-Val-Phe, between Trp659 and Ser666. All of the fragments, except the two 15-kDa peptides, co-sediment with F-actin, indicating that there are two segments in the C-terminal third of caldesmon that can interact with F-actin: one between Leu597 and Val629, the other between Arg711 and Pro756. Although separated in the primary sequence, these domains may interact with the calmodulin-binding region in the folded structure.