CLAUDIA MARIA DE BARROS HELOU
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/12 - Laboratório de Pesquisa Básica em Doenças Renais, Hospital das Clínicas, Faculdade de Medicina
LIM/12 - Laboratório de Pesquisa Básica em Doenças Renais, Hospital das Clínicas, Faculdade de Medicina
3 resultados
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- CHRONIC NICOTINE EXPOSURE DOWNREGULATES RENAL KLOTHO EXPRESSION AND TRIGGERS DIFFERENT RENAL AND AUTONOMIC RESPONSES ACCORDING TO THE KLOTHO STATUS IN MICE(2015) COELHO, Fernanda O.; JORGE, Lecticia B.; BRAGANCA, Ana Carolina de; SANCHES, Talita R. C.; CANALE, Daniele; HELOU, Claudia M. B.; IRIGOYEN, Maria Claudia; KUROO, Makoto; ANDRADE, Lucia
- High Cholesterol Feeding May Induce Tubular Dysfunction Resulting in Hypomagnesemia(2012) FAVARO, Vanessa F.; OSHIRO-MONREAL, Fabiola M.; BRAGANCA, Ana Carolina de; ANDRADE, Lucia; SEGURO, Antonio Carlos; HELOU, Claudia M. B.Background/Aims: Hypomagnesemia may induce hypercholesterolemia, but the contrary has not been described yet. Thus, magnesium homeostasis was evaluated in rats fed a cholesterol-enriched diet for 8 days. This study has a relevant clinical application if hypomagnesemia, due to hypercholesterolemia, is confirmed in patients with long-term hypercholesterolemia. Methods: Both hypercholesterolemic (HC) and normocholesterolemic rats (NC) were divided into sets of experiments to measure hemodynamic parameters, physiological data, maximum capacity to dilute urine (C-H2O), variations (Delta) in [Ca2+](i) and the expression of transporter proteins. Results: HC developed hypomagnesemia and showed high magnesuria in the absence of hemodynamic abnormalities. However, the urinary sodium excretion and C-H2O in HC was similar to NC. On the other hand, the responses to angiotensin II by measuring Delta [Ca2+](i) were higher in the thick ascending limb of Henle's loop (TAL) of HC than NC. Moreover, high expression of the cotransporter NKCC2 was found in renal outer medulla fractions of HC. Taken together, the hypothesis of impairment in TAL was excluded. Actually, the expression of the epithelial Mg2+ channel in renal cortical membrane fractions was reduced in HC. Conclusion: Impairment in distal convoluted tubule induced by hypercholesterolemia explains high magnesuria and hypomagnesemia observed in HC.
- Chronic nicotine exposure reduces klotho expression and triggers different renal and hemodynamic responses in klotho-haploinsufficient mice(2018) COELHO, Fernanda Oliveira; JORGE, Lecticia Barbosa; VICIANA, Ana Carolina de Braganca; SANCHES, Talita R.; SANTOS, Fernando dos; HELOU, Claudia M. B.; IRIGOYEN, Maria Claudia; KURO-O, Makoto; ANDRADE, LuciaThe klotho gene, which encodes a single-pass transmembrane protein and a secreted protein, is expressed predominantly by the distal renal tubules and is related to calcium phosphorus metabolism, ion channel regulation, intracellular signaling pathways, and longevity. Klotho deficiency aggravates acute kidney injury and renal fibrosis. Exposure to nicotine also worsens kidney injury. Here, we investigated renal Klotho protein expression in a mouse model of chronic (28-day) nicotine exposure, in which mice received nicotine or vehicle (saccharine) in chinking water, comparing wild-type (WT) mice, klotho-haploinsufficient (kl/+) mice, and their respective controls, in terms of the effects of that exposure. Nicotine exposure was associated with a significant decline in renal Klotho expression in WT and kl/+ mice as well as a reduction in the glomerular filtration rate in WT mice. Although plasma electrolytes were similar among the groups, fractional excretion of sodium was reduced in both nicotine-exposed groups. The nicotine-WT mice presented augmented baroreflex sensitivity to nitroprusside and augmented sympathetic cardiac modulation. However, nicotine-kl/+ mice presented higher plasma levels of urea and aldosterone together with a higher alpha-index (spontaneous baroreflex) and higher peripheral sympathetic modulation, as evaluated by spectral analysis. We can conclude that nicotine downregulates Klotho expression as well as that renal and autonomic responses to nicotine exposure are modified in kl/+ mice.