Research Bio
Dr. Schwartz' research interests are:
1) Molecular physiology of acid-base disturbances
2) Kidney tubular acidosis
3) Disorders of sodium, potassium, and magnesium transport
4) Carbonic anhydrase deficiency diseases
5) Assessment of kidney function (glomerular filtration rate)
The long term goal is to determine how intercalated cells of the kidney cortical collecting duct (CCD) sense a change in extracellular pH and adapt by reversing their polarity of H+/HCO3 transporters. After exposure to a 3 h incubation at pH 6.8, rabbit CCDs, which normally secrete HCO3, reverse polarity, secrete H+ and endocytically remove apical Cl/HCO3 exchangers to stop HCO3 secretion. The novel protein hensin is expressed in the extracellular matrix (ECM) surrounding adapting HCO3-secreting intercalated cells (B-ICs) and plays a key role in this adaptation.
Aim 1 determines the mechanisms by which polymerized hensin is deposited in the ECM and how hensin signals the adaptation of B-ICs during metabolic acidosis. Other proteins interacting with hensin include integrins, galectin 3, and cyclophilin A (cyp A); these proteins may be regulated by acid-base disturbances and hensin polymerization. Cyclosporin (CsA) causes renal tubular acidosis and inhibits cyp A peptidyl prolyl isomerase activity. To assess CsA's effect, cultured intercalated cells are plated at high density in the presence of CsA and examined for hensin polymerization in the media and ECM. A cyp A "knockdown" model using siRNAs will be examined similarly; to determine if hensin fails to polymerize without this isomerase activity.
Aim 2 examines the adaptation of CCD ICs to metabolic alkalosis regarding proteins of the hensin pathway and investigates if in vitro alkalosis can reverse the adaptation occurring in response to in vivo metabolic acidosis.
Aim 3 addresses early events in response to metabolic acidosis. Our data suggest that low cell pH is the signal to initiate the adaptation; the role of the adjacent principal cell in this signaling will be determined. We will show whether low pH stimulates endothelin-1 and nitric oxide, and whether they mediate changes in HCO3 transport during acidosis. The early steps of tyrosine phosphorylation and c-Src activation in response to low pH will also be examined.
These studies will illustrate how ICs respond to acid-base perturbations and change functional polarity.
| Listed in: Guide to America's Top Pediatricians |
2006 |
| Fellow of the American Society of Nephrology |
2004 - Present |
| Fellow of the American Heart Association (Inaugural fellow of the Council on the Kidney in Cardiovascular Disease) |
2003 - Present |
| Best Doctors, Inc. |
2002 - Present |
| Specialist in Clinical Hypertension | American Society of Hypertension |
1999 - Present |
| AMA Physician's Recognition Award |
1977 - 1980 |
| Magna Cum Laude | Colgate University |
1968 |
| Dana Scholar | Colgate University |
1968 |
| Phi Beta Kappa | Colgate University |
1968 |
| High Honors in Major (Chemistry) | Colgate University |
1968 |
| Honorary Journalism Society | Colgate University |
1966 - 1968 |
| Honorary Mathematics Society (KME) | Colgate University |
1966 - 1968 |
2013 Apr
Oleksyn D, Pulvino M, Zhao J, Misra R, Vosoughi A, Jenks S, Tipton C, Lund F, Schwartz G, Goldman B, Mohan C, Mehta K, Mehta M, Leitgets M, Sanz I, Chen L. "Protein kinase C? is required for lupus development in Sle mice." Arthritis and rheumatism. 2013 Apr 0; 65(4):1022-31. |
2013 Mar 5
Fuhrman DY, Maier PS, Schwartz GJ. "Rapid assessment of renal reserve in young adults by cystatin C." Scandinavian journal of clinical and laboratory investigation. 2013 Mar 5; Epub 2013 Mar 05. |
2013
Chambrey, R., Kurth, I, Peti-Peterdi, J., Houillier, P., Purkerson, J.M., Leviel, F., Hentschke, M., Zdebik, A.A., Schwartz, G.J., Hubner, C.A., Eladari, D.:. "Renal Intercalated Cells are Rather Energized by a Proton than a Sodium-pump." PNAS. Accepted for publication Apr 2013.. 2013; . |
2012 Jan
Wang E, Meier DJ, Sandoval RM, Von Hendy-Willson VE, Pressler BM, Bunch RM, Alloosh M, Sturek MS, Schwartz GJ, Molitoris BA. "A portable fiberoptic ratiometric fluorescence analyzer provides rapid point-of-care determination of glomerular filtration rate in large animals." Kidney international. 2012 Jan 0; 81(1):112-7. Epub 2011 Aug 31. |
2012
Alvarez, O.; Miller, ST.; Wang, WC.; Luo, Z.; McCarville, MB.; Schwartz, GJ.; Thompson, B; Howard, T.; Iyer, RV.; Rana, SR.; Rogers, ZR.; Sarnaik, SA.; Thornburg, CD.; Ware, RE.; the BABY HUG Investigators. "Effect of hydroxyurea treatment on renal function parameters: Results from the multicenter placebo-controlled BABY HUG clinical trial for infants with sickle cell anemia." Pediatr Blood Cancer. 2012; 59: 668-674. |
