Advanced search
Start date

Molecular and functional study of membrane transporters

Grant number: 13/23087-4
Support type:Research Projects - Thematic Grants
Duration: May 01, 2014 - October 31, 2018
Field of knowledge:Health Sciences - Medicine
Principal Investigator:Gerhard Malnic
Grantee:Gerhard Malnic
Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Co-Principal Investigators:Margarida de Mello Aires
Assoc. researchers:Antonio Carlos Cassola ; Deise Carla Almeida Leite Dellova ; Margarida de Mello Aires ; Maria Oliveira de Souza ; Nancy Amaral Reboucas ; Raif Musa Aziz ; Regiane Cardoso Castelo Branco


The sub-projects outlined in the present Thematic Project proposal all involve studying the transport of ions through cell membranes. With the exception of two that analyze 1) other aspects of glomerular cells and 2) the transport of the neutral molecule NH3 through cells involved with ammonia ammonia (NH3/NH4+) homeostasis or transport, such as the hepatocytes and collecting duct cells. These projects also focus on ion transport in the renal tubule or stem cells, with a particular interest in H+, Na+ and K+ coupled transporters. These projects include the study of the renin-angiotensin-aldosterone system (RAAS). In the glomerulus, the interactions of leptin and endothelin with the RAAS will be evaluated by using mesangial and podocyte cell lines. Another interest is to elucidate functional aspects of these interactions among angiotensin II (Ang II) receptor AT1R, ATRAP (AT1R Associated Protein), and HSC70 (Heat Shock Protein 70). The interaction between ATRAP and CAML (Ca2+ modulating cyclophilin ligand) is involved in activating the transcription factors NFATs via AngII. RdgB² (Retinal degenation type B²) - a phosphatidyl inositol (PI) transfer protein - will be also evaluated in proximal tubule and in Human Embrionic Kidney cells (HEK). The modulation of activity and expression of WNK1 and WNK4 - members of the WNK (With No lysine-K) kinase family - will be investigated in distal convoluted tubule and collecting duct cells. WNK 1 and 4 have been shown to be important regulators of Na+ and K+ transport in distal nephron, by AngII activating the AT1R/ATRAP/CAML/NFAT pathway. It is also important to evaluate the effect that calcineurin inhibitors have on immune-suppressors largely used in renal transplanted patients. The effects of Ang1-7 on the transport in proximal tubules, and the non-genomic effects of aldosterone will be investigated in isolated tubules and in the whole kidney. Finally, the effects of AngII and vasopressin on the transport of solutes and fluid in rat renal proximal tubules with water restriction will be investigated, with a focus on Na+/H+ exchanger NHE3.Another important aspect of the included sub-projects is to study the effect of simvastatin, sildenafil, and GLP-1 peptide - an incretin secreted by intestinal cells in postprandial period - on the activity and expression of NHE3 in proximal tubules. Another pharmacological approach is to determine the effect of phenylkenes on isoforms of a voltage sensitive potassium channel in stem cells. These projects have direct clinical interest, which is a new focus of our group. The methods proposed in these projects include measuring H+ and K+ activity using micropuncture techniques. Intracellular H+ and Ca2+ measurements will be determined using fluorescent probes in isolated tubules and in cultured cells using confocal or wide field fluorescence microscopes. The patch clamp technique will be used for the analysis of single channels. Analysis of tissue structure and protein immune-localization will be analyzed by optic microscopy and chemical or fluorescence techniques, respectively. We will also use molecular biology techniques to overexpress recombinant proteins, introduce mutations, induce gene silencing, study promoters with reporter genes, co-immune precipitation and western blot to study protein interactions, and RT-PCR for gene expression analysis. To analyze protein interactions, resonance energy transfer (RET) techniques will be employed, using yellow and cyan fluorescent proteins, for FRET, and Renilla luciferase and YFP, for BRET. The sub project involving the transport of ammonia is designed to understand how NH3 moves through channels, and, at a more integrated level, the physiological importance of gas channels. The oocyte NH3 permeability will be analyzed using microelectrodes to monitor changes in cell surface pH (pHS) caused by the influx of NH3 between extra and intracellular space of Rana oocytes after exposure of specific solutions. (AU)

Scientific publications (8)
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
GONCALVES, GUILHERME LOPES; COSTA-PESSOA, JULIANA MARTINS; THIEME, KARINA; LINS, BRUNA BEZERRA; OLIVEIRA-SOUZA, MARIA. Intracellular albumin overload elicits endoplasmic reticulum stress and PKC-delta/p38 MAPK pathway activation to induce podocyte apoptosis. SCIENTIFIC REPORTS, v. 8, DEC 20 2018. Web of Science Citations: 0.
LEITE-DELLOVA, DEISE C. A.; SZRIBER, SHIRLEY J.; MERIGHE, GIOVANA K. F.; POLIDORO, JULIANO Z.; REBOUCAS, NANCY A.; OLIVEIRA-SOUZA, MARIA; DE MELLO-AIRES, MARGARIDA. Signaling pathways involved in the rapid biphasic effect of aldosterone on Na+/H(+)exchanger in rat proximal tubule cells. JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY, v. 182, p. 87-94, SEP 2018. Web of Science Citations: 2.
CARDOSO, VANESSA GEROLDE; GONCALVES, GUILHERME LOPES; COSTA-PESSOA, JULIANA MARTINS; THIEME, KARINA; LINS, BRUNA BEZERRA; MALAVAZZI CASARE, FERNANDO AUGUSTO; DE PONTE, MARIANA CHARLEAUX; SARAIVA CAMARA, NIELS OLSEN; OLIVEIRA-SOUZA, MARIA. Angiotensin II-induced podocyte apoptosis is mediated by endoplasmic reticulum stress/PKC-delta/p38 MAPK pathway activation and trough increased Na+/H+ exchanger isoform 1 activity. BMC Nephrology, v. 19, JUL 13 2018. Web of Science Citations: 6.
KABUTOMORI, JESSICA; BELOTO-SILVA, OLIVIA; GEYER, R. RYAN; MUSA-AZIZ, RAIF. Lithobates catesbeianus (American Bullfrog) oocytes: a novel heterologous expression system for aquaporins. BIOLOGY OPEN, v. 7, n. 4 APR 2018. Web of Science Citations: 0.
DE PONTE, MARIANA CHARLEAUX; MALAVAZZI CASARE, FERNANDO AUGUSTO; COSTA-PESSOA, JULIANA MARTINS; CARDOSO, VANESSA GEROLDE; MALNIC, GERHARD; MELLO-AIRES, MARGARIDA; VOLPINI, RILDO APARECIDO; THIEME, KARINA; OLIVEIRA-SOUZA, MARIA. The Role of beta-Adrenergic Overstimulation in the Early Stages of Renal Injury. Kidney & Blood Pressure Research, v. 42, n. 6, p. 1277-1289, 2017. Web of Science Citations: 1.
NERI, ELIDA ADALGISA; ALVES BEZERRA, CAMILA NOGUEIRA; QUEIROZ-LEITE, GABRIELLA DUARTE; POLIDORO, JULIANO ZEQUINI; REBOUCAS, NANCY AMARAL. Parathyroid hormone inhibition of Na+/H+ exchanger 3 transcription: Intracellular signaling pathways and transcription factor expression. Biochemical and Biophysical Research Communications, v. 461, n. 4, p. 582-588, JUN 12 2015. Web of Science Citations: 1.
THIEME, KARINA; OLIVEIRA-SOUZA, MARIA. Renal Hemodynamic and Morphological Changes after 7 and 28 Days of Leptin Treatment: The Participation of Angiotensin II via the AT(1) Receptor. PLoS One, v. 10, n. 3 MAR 20 2015. Web of Science Citations: 10.

Please report errors in scientific publications list by writing to: