ABSTRACT
As indicated by the 2019 Global Burden of Disease Study, although women, on average, have a longer lifespan
than men, women typically experience worsened health outcomes as they age. Notably, postmenopausal women
have a higher incidence of knee osteoarthritis (KOA) and present with more severe disease progression over
time. However, it is still unclear whether these differences are genetic in nature, hormonal in nature, or a
combination of the two. Here, we propose to investigate whether and how changes in the chondrocyte
microenvironment—including soluble factors (Aim1) and extracellular matrix (ECM) stiffening (Aim2)—drive
KOA pathogenesis in a sex-, gender- and age-dependent manner. Specifically, in Aim 1, we will
mechanistically interrogate the direct role of soluble microenvironmental factors on the loss of cartilage
integrity with aging and according to sex. In Aim 2, we will interrogate the contribution of ECM biophysical
properties on the loss of cartilage integrity with aging and according to sex. We will accomplish these aims
using technically innovative approaches, including: (1) an in vitro and in vivo heterosex biofluid exchange
model, which will allow us to disentangle the multi-dimensional contribution of environmental factors on
chondrocyte health and cartilage integrity over time; (2) an advanced network medicine approach integrated
with machine learning algorithms to elucidate the sex chromosome- and sex hormone-dependent regulatory
landscape; and (3) a physiologically relevant model of female aging by which menopause is chemically-induced
in middle-aged mice. These conceptually and technically innovative studies will be carried out by an
interdisciplinary team comprising a stem cell biologist (PI), a computational biologist (co-PI), and a bioengineer
(co-I), the breadth of which enhances feasibility, impact, and likelihood for success. Successful completion of
the aims as proposed will provide mechanistic insights into how sex and gender profiles impact cartilage
physiology over time. Ultimately, we anticipate that the innovative research studies proposed will aid in the
development of effective interventions that consider sex- and gender-specific variables to the benefit of our
aging population.