Ivy Xiong, Ph.D.
Postdoctoral Fellow
Integrative Biology and Physiology
Quantitative and Computational Biosciences
University of California, Los Angeles
Seminar Information
Age-related decline in renal function is faster in males than in females, manifesting as increased susceptibility to both chronic and acute kidney diseases among males, in humans and rodents. Single-cell analysis on the mouse kidney demonstrated that sexually dimorphic gene activity maps predominantly to proximal tubule (PT) segments, where male-biased lipid metabolism implies exacerbated energy demands for reabsorption. Using intravital microscopy on mouse kidneys, we captured spontaneous metabolic oscillations in individual PT cells and real-time single-nephron glomerular filtration rate (GFR) oscillations, revealing a functional coupling between cell-level metabolism and tissue-level fluid flow in vivo. GFR is tightly regulated by tubuloglomerular feedback (TGF) within renal tubules to optimize filtration of plasma and re-uptake of essential molecules.
We found that TGF-mediated GFR oscillations also show sex-biased characteristics, with males exhibiting higher frequencies. Mathematical modeling of TGF indicates that differential metabolic states in renal tubules can account for sex differences in GFR dynamics. Male kidneys are more prone to loss of TGF-mediated auto-regulation, thus explaining male-female differences in renal aging and diseases.
Graduated from the University of Hong Kong (B.Sc.) and the University of Oxford (D.Phil.), Ivy Xiong is currently a postdoc fellow at the University of California Los Angeles. She studies dynamics in physiology, cancer and aging, with a special interest in the role of oscillatory processes in health and disease. By applying techniques from nonlinear dynamics, quantitative imaging, and computational biology, her research aims to explain the spatiotemporal nature of biological rhythms across scales.