Sensors for the mTORC1 pathway regulated by amino acids / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The mechanistic target of rapamycin complex 1 (mTORC1) controls cell growth and metabolism in response to various environmental inputs, especially amino acids. In fact, the activity of mTORC1 is highly sensitive to changes in amino acid levels. Over past decades, a variety of proteins have been identified as participating in the mTORC1 pathway regulated by amino acids. Classically, the Rag guanosine triphosphatases (GTPases), which reside on the lysosome, transmit amino acid availability to the mTORC1 pathway and recruit mTORC1 to the lysosome upon amino acid sufficiency. Recently, several sensors of leucine, arginine, and S-adenosylmethionine for the amino acid-stimulated mTORC1 pathway have been coming to light. Characterization of these sensors is requisite for understanding how cells adjust amino acid sensing pathways to their different needs. In this review, we summarize recent advances in amino acid sensing mechanisms that regulate mTORC1 activity and highlight these identified sensors that accurately transmit specific amino acid signals to the mTORC1 pathway.

Evaluation of protein undernourishment on the condylar process of the Wistar rat mandible correlation with insulin receptor expression

The mandible condylar process cartilage (CP) of Wistar rats is a secondary cartilage and acts as a mandibular growth site. This phenomenon depends on adequate proteins intake and hormone actions, including insulin. Objectives The present study evaluated the morphological aspects and the expression of the insulin receptor (IR) in the cartilage of the condylar process (CP) of rats subjected to protein undernourishment. Material and Methods The nourished group received a 20% casein diet, while the undernourished group (U) received a 5% casein diet. The re-nourished groups, R and RR, were used to assess the effects of re-nutrition during puberty and adulthood, respectively. CPs were processed and stained with picro-sirius red, safranin-O and azocarmine. Scanning electron microscopy and immunohistochemistry were also performed. Results The area of the CP cartilage and the number of cells in the chondroblastic layer decreased in the U group, as did the thickness of the CP layer in the joint and hypertrophic layer. Renourishment during the pubertal stage, but not during the adult phase, restored these parameters. The cell number was restored when re-nutrition occurred in the pubertal stage, but not in the adult phase. The extracellular matrix also decreased in the U group, but was restored by re-nutrition during the pubertal stage and further increased in the adult phase. IR expression was observed in all CPs, being higher in the chondroblastic and hypertrophic cartilage layers. The lowest expression was found in the U and RR groups. Conclusions Protein malnutrition altered the cellularity, the area, and the fibrous cartilage complex, as well as the expression of the IRs. .

"El hecho de que sean más mujeres, no garantiza nada": feminización y experiencias de las mujeres en la ginecobstetricia en México / "The fact that there are more women doesn't guarantee anything": The feminization of obstetrics and gynecology and the experiences of female medical professionals in Mexico

En el marco de la creciente feminización de la profesión médica en México, el artículo indaga sobre las características de este proceso para el caso de la ginecobstetricia. Considerando la feminización como un proceso de cambio, que se analiza cuantitativa y cualitativamente, el artículo se detiene en especial en las experiencias de las mujeres ginecobstetras, experiencias que se dan en el seno de una especialidad que, desde sus orígenes, funcionó como un dispositivo de control del cuerpo de las mujeres. Basado en una investigación etnográfica, el artículo combina fuentes estadísticas, de archivo y de observación de campo. El material que surge de las entrevistas muestra las experiencias y tensiones que viven las ginecobstetras en este contexto.

In the framework of an increasing feminization of the medical profession in Mexico, this article explores the characteristics of this process in the obstetrics and gynecology specialty. Understanding feminization as a process of change to be analyzed both quantitatively and qualitatively, the article focuses special attention on the experiences of female obstetrician-gynecologists within a medical specialty that has since its origins functioned as a mechanism of control over women's bodies. Based on ethnographic research, the article combines statistical and archival sources and field observation. The interviews reveal the experiences and tensions women obstetrician-gynecologists encounter in this context.

Adhesión a dentina radicular tratada con arginina utilizando sistemas de auto-grabado / Adhesion to arginine-treated root dentin using self-etching bonding systems

El objetivo de este estudio fue evaluar, comparativamente, la resistencia de la unión adhesiva de resinas compuestas a dentina radicular, previamente tratada con arginina (AR) y otras técnicas, utilizando un sistema de auto-grabado (SAG). Se seleccionaron ocho terceros molares libres de caries y de reciente extracción, de los cuales se utilizó la dentina radicular. Se asignaron cuatro grupos de acuerdo al tratamiento realizado: A) AA (acondicionamiento ácido) + AR; B) AA; C) AA + piedra pómez (PP) (control); D) PP (control absoluto). Seguidamente, las superficies fueron tratadas con un SAG y cargadas con un composite. Las probetas fueron sometidas a cargas traccionales utilizando una máquina Instron. A partir de los valores registrados, se obtuvieron los resultados de resistencia de la unión adhesiva, que fueron analizados mediante análisis de varianza de 1 vía y p rueba de comparaciones múltiples de Bonferroni. Se encontraron diferencias estadísticamente significativas (P<0,05) entre los grupos C y B y entre los grupos A y B, concluyendo que AR no interfirió en la resistencia adhesiva en relación a los grupos control.

Actividad microbiana en suelos de sabanas de los Llanos Orientales de Venezuela convertidas en pasturas / Microbial activity in Eastern Venezuelan savannas turned into grasslands

We studied the effects of season and management practices on chemical properties and biochemical parameters in a typical Ultisol soil of native and introduced pastures of the Eastern savannas of Venezuela. Sseason, soil management, and their interaction, significantly affected chemical properties and biochemical parameters. The total carbon and the water soluble carbon experienced a significant decrease during the wet period. The basal respiration, the arginine ammonification (AA) and the fluoriscein diacetate hydrolysis showed a relatively low microbial activity. The transformation of native savannas to pastures systems of B. brizantha and S. capitata increased the organic matter content in soil. The AA and the basal respiration were sensible indicators to estimate changes in soil quality and also reflected the interaction of temporal changes and management practices.

Se determinó el efecto de la variabilidad temporal y de las prácticas de manejo agrícola sobre las propiedades químicas y parámetros bioquímicos en un típico suelo Ultisol de pasturas nativas e introducidas de las sabanas orientales de los Llanos de Venezuela. La variabilidad temporal, el manejo agrícola y el efecto interactivo de ambos factores, afectaron las propiedades químicas y los parámetros bioquímicos. El carbono orgánico total e hidrosoluble experimentaron una significativa disminución durante la estación lluviosa. La respiración basal, la amonificación de la arginina (AA) y la hidrólisis del diacetato de fluorisceína (DAF) mostraron que en esas sabanas existe una baja actividad microbiana. La transformación de sabanas nativas a sistemas de pasturas de B. brizantha y S. capitata, incrementaron el contenido de materia orgánica en el suelo. La AA, y la respiración basal fueron indicadores sensibles, con los cuales se pueden estimar cambios en la calidad del suelo y reflejar el efecto causado por la interacción de los cambios temporales y las prácticas de manejo.

Molecular characterization of hair cuticle and its extracted proteins in seven mammalian species

Hair is an of the epidermis in mammals and consists of two large groups of human hair proteins. One is hard -keratins and the other is matrix proteins. The present investigation aimed to compare the ultrastructural of the hair scale using the scanning electron microscope, and the proteins and amino acids content of the keratin in seven mammalian species. The values of the hair thickness, x/y feret and hair pattern of the species in the present study confirm the presence of species-specific characteristics and ultra structural variation. The situation in man differs from the wild mammals due to damage of hair cuticle caused by mechanical abuse, exposure to ultraviolet radiation and chemical over processing. The maximum amount of extracted proteins from hair keratin was analyzed by SDS-PAGE. The electrophoretic patterns showed an overall degree of similarity. However, differences exist between species in the intensity of stain. Quantitatively, the electrophoretic patterns scanned and analyzed using gel protein analyzer. The results showed no difference between the molecular mass of some species, but different in molecular mass distribution. Amino acid composition of keratin of mammalian hair species of the present study showed some variation, especially for methionine, isoleucine, lysine and arginine. The other amino acids studied are significantly present in most hair. One of the later amino acid is cysteine. Cysteine is a very important due to the presence of disulfate cross-links

A Korean Family of Hypokalemic Periodic Paralysis with Mutation in a Voltage-gated Calcium Channel (R1239G)

Hypokalemic periodic paralysis (HOPP) is a rare disease characterized by reversible attacks of muscle weakness accompanied by episodic hypokalemia. Recent molecular work has revealed that the majority of familial HOPP is due to mutations in a skeletal muscle voltage-dependent calcium-channel: the dihydropyridine receptor. We report a 13-yr old boy with HOPP from a family in which 6 members are affected in three generations. Genetic examination identified a nucleotide 3705 C to G mutation in exon 30 of the calcium channel gene, CACNA1S. This mutation predicts a codon change from arginine to glycine at the amino acid position #1239 (R1239G). Among the three known mutations of the CACNA1S gene, the R1239G mutation was rarely reported. This boy and the other family members who did not respond to acetazolamide, showed a marked improvement of the paralytic symptoms after spironolactone treatment.

X-linked Severe Combined Immunodeficiency Syndrome: The First Korean Case with gamma c Chain Gene Mutation and Subsequent Genetic Counseling

X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the gamma c chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for gamma c chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the gamma c chain gene is useful for definite diagnosis and genetic counseling for X-SCID.

A Korean Family with Arg1448Cys Mutation of SCN4A Channel Causing Paramyotonia Congenita: Electrophysiologic, Histopathologic, and Molecular Genetic Studies

A family with paramyotonia congenita (PC) is presented. At least 10 family members were affected in an autosomal dominant inheritance pattern. The proband had cold-sensitive muscle stiffness, paradoxical myotonia, and intermittent muscle weakness since childhood. The serum level of creatine kinase was mildly elevated and short exercise test with cooling revealed a drastic reduction of compound muscle action potentials with repetitive discharges. Muscle biopsy revealed marked variation in the fiber size and increased internal nuclei. The molecular biological study revealed a common missense mutation (Arg1448Cys) at the voltage-gated sodium channel gene (SCN4A). The repetitive CMAP discharges during short exercise test with cooling observed in the proband has not been reported previously. This observation needs to be confirmed among PC patients with different mutations. This is the first report on a PC family confirmed by the molecular biological technique in Korea.

Purification and characterization of an invertase produced by Aspergillus ochraceus TS.

Purification and characterization of an extracellular invertase produced by Aspergillus ochraceus TS are reported. The enzyme was purified (42-fold) from culture filtrate by salt precipitation, ion-exchange and gel filtration. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme showed a single band of molecular mass 66 kDa. The molecular mass of the native enzyme was found to be 130 kDa by gel filtration. The purity of the protein was also checked against its antiserum raised in rabbits by two-dimensional immunodiffusion in agarose gel and Western blot that showed a single band. It is a glycoprotein with mannose as its carbohydrate residue. The enzyme showed high affinity for sucrose with a Km of 3.5 mM. The amino acid analysis revealed a high proportion of acidic residues but it had a low content of cysteine, histidine and arginine comparable to other fungal invertases.

Effect of arginine modifying reagents on pigeon liver fatty acid synthetase: evidence for the presence of essential arginine residues at the beta-ketoacyl reductase and enoyl-CoA reductase domain.

Pigeon liver fatty acid synthetase was inactivated by arginine modifying reagent, phenylglyoxal and 2,3-butanedione. The inactivation of overall fatty acid synthetase was accompanied by the loss of beta-ketoacyl reductase and enoyl-CoA reductase activity. The inactivation followed a pseudo-first order kinetics and sum of the second order rate constants for the two reductase reactions equaled that for the synthetase reaction. Inactivation of all three activities was prevented by NADPH or its analogs 2',5'-ADP and 2'-AMP but not by the corresponding nucleotides containing the 5'-phosphate. These results suggest that binding of NADPH to fatty acid synthetase involves specific interaction of the 2'-phosphate with the guanidino group of arginine residues at the active site of the two reductases. pH-Dependent inactivation by phenylglyoxal indicated that a group with a pka 7.5 is involved in the loss of enzyme activity. Stoichiometric results showed that 4 out of 164 arginine residues per enzyme molecule were essential for the enzyme activity.

Memorias: inmunomodulacion / Memories: immunomodulation

La arginina tiene efectos inmunoestimulatorios, anabolicos y antitumorales. Sus efectos se deben a sintesis de proteinas, poliaminas, nitrogeno, secrecion hormonal y estimulacion de linfocitos T4