Biography

Karen LaShea Posey, PhD, is an associate professor in the Department of Pediatrics at McGovern Medical School at UTHealth Houston. She holds a PhD in Biochemistry from the University of Houston. Since joining UTHealth Houston in 2003, Dr. Posey has advanced through academic ranks, contributing significantly to both research and education.

Dr. Posey’s research focuses on skeletal dysplasias, particularly pseudoachondroplasia, and the molecular mechanisms underlying cartilage oligomeric matrix protein (COMP) pathology. She has served as principal investigator on numerous grants, including National Institutes of Health (NIH)-funded studies and industry-sponsored clinical research, and has authored more than 37 peer-reviewed publications. Her work has led to patented therapeutic innovations, including antisense technologies and nutraceutical formulations targeting ER stress-related conditions. Dr. Posey’s leadership extends to national scientific communities, where she serves as secretary/treasurer and board committee member of the American Society of Matrix Biology, promoting interdisciplinary collaboration and mentorship.

Beyond her research, Dr. Posey is deeply committed to education and service. She facilitates problem-based learning for medical students, mentors graduate and postdoctoral trainees, and contributes to university committees focused on ethics, safety, and scholarship. Her community engagement includes volunteer work with Habitat for Humanity, food banks, and outreach programs. Dr. Posey’s holistic approach to science, teaching, and service reflects her dedication to fostering compassionate health care professionals and advancing biomedical knowledge through collaborative and ethical inquiry.

Education

Graduate School
University of Houston, Houston, Texas, 2000
Postdoctoral Program
Texas A&M Institute of Biotechnology, Houston, Texas, 2000-2003

Areas of Interest

Research Interests

The goal of my research is to define the molecular mechanisms that contribute to cartilage-related conditions in order to develop therapeutics that improve cartilage and joint health to improve the quality of life of individuals with dwarfing conditions and osteoarthritis. I study pseudoachondroplasia (PSACH), a severe dwarfing condition associated with severe and osteoarthritis early-onset. Using our pseudoachondroplasia mouse model, we defined the mechanisms underlying chondrocyte dysfunction and loss, a self-perpetuating pathological loop between endoplasmic reticulum (ER) stress, inflammation and oxidative stress, which revealed drug targets. Understanding the pathological loop between ER stress, inflammation and oxidative stress is very exciting because there is growing evidence that this pathological mechanism may be involved in many other ER stress related conditions such as neurodegenerative disorders and diabetes and has provided a foundation for the development of the first therapies for pseudoachondroplasia. We have investigated readily-available and well-tolerated antioxidants and anti-inflammatory agents to dampen the intracellular ER retention chondrocyte pathology. This approach may work on many types of secretory cells (chondrocytes, neurons, islet cells, etc.) interrupting the ER stress-inflammation-oxidative stress loop pathology. If this type of inexpensive and well-tolerated therapy could be applied to the early stages of neurodegenerative disorders and metabolic syndrome, onset may be delayed or the pathology suppressed effecting a revolution in health care and the impact of these devastating conditions. Additionally, this pseudoachondroplasia mouse model has lead me to expand my work into the field of osteoarthritis because early-onset osteoarthritis is associated with this dwarfing condition. The inducible feature of the model allows the stimulation of ER stress in adult articular chondrocytes in order to assess the role that ER stress plays in osteoarthritis establishment and progression. Our findings suggest that ER stress may be a major component in idiopathic osteoarthritis.

Publications

Visit the PubMed profile page

Posey, K.L., Veerisetty, A.C., Liu, P., Wang, H.R., Poindexter, B.J., Bick, R., Alcorn, J. L., Hecht, J.T.: An inducible COMP mouse model recapitulates human PSACH phenotype. Am J Pathol 175(4):1555-63, 2009.

Posey, K.L., Liu, P., Wang, H.R., Veerisetty, A.C., Alcorn, J. L., Hecht, J.T.: RNAi Reduces Expression and Intracellular Retention of Mutant Cartilage Oligomeric Matrix Protein (COMP). Plos One  5(4):e10302, 2010.

Li H., Haudenschild D.R., Posey K.L., Hecht J.T., Di Cesare P.E., Yik J.H.: Comparative analysis with collagen type II distinguishes cartilage oligomeric matrix protein as a primary TGFβ-responsive gene. Osteoarthritis Cartilage. 19(10):1246-53, 2011.

Posey K.L., Coustry F., Veerisetty A.C., Liu P., Alcorn J.L., Hecht J.T.: Chop (Ddit3) is essential for D469del-COMP retention and cell death in chondrocytes in an inducible transgenic mouse model of pseudoachondroplasia. Am J Pathol 180(2):727-37, 2012.

Coustry F., Posey K.L., Liu P., Alcorn J.L., Hecht J.T.: D469del-COMP retention in chondrocytes stimulates caspase-independent necroptosis. Am J Pathol 180(2):738-48, 2012.

Posey K.L., Coustry F., Veerisetty A.C., Liu P., Alcorn J.L., Hecht J.T.: Chondrocyte-specific pathology during skeletal growth and therapeutics in a murine model of pseudoachondroplasia. J Bone Miner Res.;29(5):1258-68, 2014.

Posey K.L., Alcorn J.L., Hecht J.T.: Pseudoachondroplasia/COMP – translating from the bench to the bedside. Matrix Biol. 37C:167-173, 2014

Posey K.L., Coustry F., Veerisetty A.C., Hossain M., Alcorn J.L., Hecht J.T: Antioxidant and anti-inflammatory agents mitigate pathology in a mouse model of pseudoachondroplasia. Hum Mol Genet. 15;24(14):3918-28. 2015.