ABSTRACT
RESUMEN Objetivo: Analizar la asociación entre el polimorfismo rs2291166 del gen TJP1 con los niveles de glucosaminoglucanos (GAGS) excretados en orina como marcador de las primeras etapas de la nefropatía. Material y métodos: Se analizaron 600 muestras de orina de sujetos recién diagnosticados con diabetes tipo 2, de las cuales se incluyeron 203. La detección de GAGS en orina directa se realizó mediante prueba de turbidez de albúmina ácida y precipitación con cetilpiridinio (CPC). Resultados: El 26,64% de los pacientes diabéticos se encuentran en estadios tempranos de nefropatía, lo que corresponde a pacientes con prueba GAG positiva, siendo los que tienen mayor excreción de GAGS, heterocigotos para el polimorfismo. Conclusión:Sugerimos que el polimorfismo de TJP1 rs2291166 influye en la mucopolisacariduria en pacientes diabéticos tipo 2 de la población mexicana; que podría usarse como un marcador genético/ bioquímico válido para las primeras etapas de la nefropatía diabética.
ABSTRACT Objective: To analyze the association between the polymorphism rs2291166 of TJP1 gene, with the urine-excreted levels of GAGS as a marker of early stages of nephropathy. Methods: A 600 urine samples from newly diagnosed subjects with type 2 diabetes were analyzed, of which 203 were included. The GAGS detection in direct urine (corresponding to the first urine of the morning), was performed by albumin turbidity test and precipitation with cetylpyridinium (CPC). Results: The present study shows that 26.64% of diabetic patients are in early stages of nephropathy, corresponding to patients with a positive GAG test, being those with the highest GAGS excretion, heterozygous for the polymorphism. Conclusion: We suggest that the TJP1 polymorphism rs2291166 influences mucopolysacchariduria in type 2 diabetic patients of the Mexican population, which could be used as a valid genetic/biochemical marker for the early stages of diabetic nephropathy.
ABSTRACT
PURPOSE: We describe the changes of rat glomerular epithelial cells when exposed to high levels of glucose and advanced glycosylation endproducts(AGE) in the in vitro diabetic condition. We expect morphological alteration of glomerular epithelial cells and permeability changes experimentally and we may correlate the results with a mechanism of proteinuria in DM. METHODS: We made 0.2 M glucose-6-phsphate solution mixed with PBS(pH 7.4) containing 50 mg/mL BSA and protease inhibitor for preparation of AGE. As control, we used BSA. We manufactured and symbolized five culture dishes as follows; B5 - normal glucose(5 mM) + BSA, B30 - high glucose(30 mM) + BSA, A5 - normal glucose(5 mM) + AGE, A30 - high glucose(30 mM) + AGE, A/B 25 - normal glucose(5 mM) + 25 mM of mannitol(osmotic control). After the incubation period of both two days and seven days, we measured the amount of heparan sulfate proteoglycan(HSPG) in each dish by ELISA and compared them with the B5 dish at 2nd and 7th incubation days. We observed the morphological changes of epithelial cells in each culture dish using scanning electron microscopy(SEM). We tried the permeability assay of glomerular epithelial cells using cellulose semi-permeable membrane measuring the amount of filtered BSA through the apical chamber for 2 hours by sandwich ELISA. RESULTS: On the 2nd incubation day, there was no significant difference in the amount of HSPG between the 5 culture dishes. But on the 7th incubation day, the amount of HSPG increased by 10% compared with the B5 dish on the 2nd day except the A30 dish(P0.05). In the osmotic control group (A/B 25) no significant correlation was observed. On the SEM, we could see the separated intercellular junction and fused microvilli of glomerular epithelial cells in the culture dishes where AGE was added. The permeability of BSA increased by 19% only in the A30 dish on the 7th day compared with B5 dish on the 7th day in the permeability assay(P<0.05). CONCLUSION: We observed not only the role of a high level of glucose and AGE in decreasing the production of HSPG of glomerular epithelial cells in vitro, but also their additive effect. However, the role of AGE is greater than that of glucose. These results seems to correlate with the defects in charge selective barrier. Morphological changes of the disruption of intercellular junction and fused microvilli of glomerular epithelial cells seem to correlate with the defects in size-selective barrier. Therefore, we can explain the increased permeability of glomerular epithelial units in the in vitro diabetic condition.
Subject(s)
Animals , Rats , Cellulose , Enzyme-Linked Immunosorbent Assay , Epithelial Cells , Glucose , Glycosylation , Heparan Sulfate Proteoglycans , Heparitin Sulfate , Intercellular Junctions , Membranes , Microvilli , Permeability , Protease Inhibitors , ProteinuriaABSTRACT
BACKGROUND: Fighter pilots are frequently exposed to high gravitational acceleration force acting along the body axis from the head to the feet (+GZ) and this gravitational force causes considerable strain on several organ systems, including cardiovascular system and kidneys. Proteinuria had been observed after +GZ stress but the characteristics of urinary protein and the mechanism of proteinuria are not closely investigated up to now. METHODS: A total of 44 student pilots were exposed to +6GZ for 30 seconds using Human Centrifuge and urine samples were collected before and after +GZ load. The amount of urinary protein was measured quantitatively and semiquantitatively with chemistry and dipstick, and the protein components were analysed with electrophoresis. RESULTS: After a total of 44 student pilots were exposed to +6GZ for 30 seconds without anti-G suit, 19 urine samples were positive in dipstick protein test and electrophoresis revealed that their major protein component was albumin. The amount of urinary protein excretion and urinary protein and creatinine ratios (UProt/UCr) were significantly increased to levels of 33.4+/-29.3 mg/dL and 0.239+/-0.203 in comparison with pre-G training levels of 8.8+/-4.3 mg/dL and 0.046+/-0.018, respectively. All 44 urine samples collected the next day of G training were negative in dipstick protein test and had protein levels of 6.8+/-3.0 mg/dL. Of 19 subjects showed proteinuria, 15 performed the same +GZ training again with anti-G suit and so only three urine samples were positive in dip stick protein test. CONCLUSIONS: These results indicates that transient proteinuria can be developed after high +GZ stress most possibly due to increased glomerular permeability of albumin and be effectively protected by the anti-G suit.