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Effect of Perinatal Low Protein Diet on the Expression of Renal Organic Cation Transporters in Adult Rats. Paulina Nguyen HHMI Recipient Mentor: Dr. Ganesh Cherala Lab: OSU-College of Pharmacy. Low Birth Weight ( LBW ).
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Effect of Perinatal Low Protein Diet on the Expression of Renal Organic Cation Transporters in Adult Rats Paulina Nguyen HHMI Recipient Mentor: Dr. Ganesh Cherala Lab: OSU-College of Pharmacy
Low Birth Weight (LBW) • About 1 in every 12 babies in the United States is born with low birth weight • Increased risk for serious health problems such as lasting disabilities and even death. • Stunted growth • Higher incidence of diseases
Fetal Programming and Low Birth Weight (LBW) • Poor conditions in the womb • Greater susceptibility to diseases in adult life (Barker’s Hypothesis) • Low protein diet (LPD)–Rodent model for LBW • Similar to human epidemiological findings • LPD in rodent model can be manipulated in laboratory conditions
Consequences of LBW • Altered tissue development leads to altered development of organs such as in kidney and liver • Affect renal organic transporter functionality • Affects drug transport and excretion in and out of the body • LBW individuals will need different drug dosages
LPD Low Birth Weight Morphological Physiological Various Organs Kidney Liver Heart, etc.
Drug Transport & Pharmacokinetics Pharmacokinetics (PK) Study of how drug travels through the body Absorption Distribution Metabolism Excretion Drug Metabolism and Transport Renal Excretion A D M E
PROXIMAL TUBULE PROXIMAL TUBULE Blood LUMEN Basolateral Membrane • Transporters • OAT • OCT • PGP • PEPT • MRP
Renal Organic Cation Transporters (OCT) • 5 Organic Cation Transporters found in rat models • OCT1 • OCT2 • OCT3 • OCTN1 • OCTN2 OCT2 OCTN1 OCTN2
Hypothesis • Low birth weight, as a result of altered perinatal environment, leads to permanent alterations in the expression of renal OCT transporters. • Specific Aims • To quantify mRNA expression of renal OCT2, OCTN1, and OCTN2 at various ages • To quantify protein expression of renal OCT2 at various ages
Control Study Design Low Protein (LP) Weaned onto regular diet Birth weights noted; litters culled Gestation 3 weeks Day 28 Day 65 Day 150 Lactation 4 weeks
Sample Analysis • Measure the mRNA level of OCT2, OCTN1, and OCTN2 expression in male and female offspring in both LP and Control groups using RT-PCR • Measure the protein expression of OCT2 in male and female offspring in both LP and Control groups using western blotting
RT-PCR Day 150 * * *
RT-PCR Summary * * * * Statistically Significant
Tissue Homogenize Tissue Homogenate 1000 G Supernatant • Pellet • Nuclei • Cell Debris 35000 G Pellet - Mitochondria - Plasma Membrane Supernatant 100000 G Pellet - Microsomes Supernatant - Cytosol
Results – Discussion • 27 fold decrease in expression of OCT2 in Day 150 LP females relative to control (regular diet) females • Effect of LP diet seen in later life
Discussion - Regulation of OCT2? • Sex hormone regulation of OCT2 a possible reason for 27 fold difference in LP Day 150 females • Sex hormone regulation of OCT2 • Testosterone up-regulates expression of OCT2 • Estrogen down-regulates expression of OCT2
Acknowledgements • Howard Hughes Medical Institute • Cripps Funding • Cherala Lab • Dr. GaneshCherala • BarentDuBois • Jacob Pearson • Dr. ShobanaGanesan • TahirMahmood • Shawn Mahmood • AlexandruCioara • OSU-College of Pharmacy • Dr. Kevin Ahern
Works Cited • Cherala G, Shapiro BH, and D'mello AP (2006) Two low protein diets differentially affect food consumption and reproductive performance in pregnant and lactating rats and long-term growth in their offspring. J Nutr 136: 2827–2833 • Kathleen M. Giacomini, et al. (2010) Membrane transporters in drug development Nature Reviews Drug Discovery , 215-236 • Hagenbuch, B (2010) Drug Uptake Systems in Liver and Kidney: A Historic Perspective Clinical Pharmacology & Therapeutics87 1, 39–47