Kirsten H Limesand
Assistant Dean, Graduate Education
Professor, BIO5 Institute
Professor, Cancer Biology - GIDP
Professor, Nutritional Sciences
Professor, Physiological Sciences - GIDP
Primary Department
Department Affiliations
(520) 626-4517
Work Summary
Kirsten Limesand's research program has its foundation in radiation-induced salivary gland dysfunction; mechanisms of damage, clinical prevention measures, and restoration therapies. They utilize a number of techniques including: genetically engineered mouse models, real-time RT/PCR, immunoblotting, immunohistochemistry, primary cultures, siRNA transfections, and procedures to quantitate salivary gland physiology and integrate this information in order to understand the complete system.
Research Interest
Public Relevance Statement: Can you imagine having a mouthful of canker sores and cavities? Thousands of head and neck cancer patients suffer these consequences from radiation treatment. The Limesand lab works to prevent these side effects thereby improving patients' quality of life. Clinical Relevance: Radiation therapy for head and neck cancer causes adverse secondary side effects in the normal salivary gland including xerostomia, oral mucositis, malnutrition, and increase oral infections. Although improvements have been made in targeting radiation treatment to the tumor, the salivary glands are often in close proximity to the treatment site. The significant destruction of the oral cavity following radiation therapy results in diminished quality of life and in some cases interruptions in cancer treatment schedules. Research Interests: My research program has its foundation in radiation-induced gland dysfunction; mechanisms of damage, clinical prevention measures, and restoration therapies. Evidence suggests that salivary acinar function is compromised due to apoptosis induced by these treatments and temporary suppression of apoptotic events in salivary glands would have significant benefits to oral health. We utilize a number of techniques in my laboratory including: genetically engineered mouse models, real-time RT/PCR, immunoblotting, immunohistochemistry, primary cultures, siRNA transfections, irradiation, and procedures to quantitate salivary gland physiology. Current project areas: 1. Radiation-induced apoptosis 2. Mechanisms of preserving salivary gland function 3. Identifying the radiosensitivity of salivary gland progenitor cells 4. Restoration of salivary gland function 5. Role of autophagy in radiation-induced loss of function

Publications

Goldberg, E. L., Romero-Aleshire, M. J., Renkema, K. R., Ventevogel, M. S., Chew, W. M., Uhrlaub, J. L., Smithey, M. J., Limesand, K. H., Sempowski, G. D., Brooks, H. L., & Nikolich-Žugich, J. (2015). Lifespan-extending caloric restriction or mTOR inhibition impair adaptive immunity of old mice by distinct mechanisms. Aging cell, 14(1), 130-8.
BIO5 Collaborators
Heddwen L Brooks, Kirsten H Limesand

Aging of the world population and a concomitant increase in age-related diseases and disabilities mandates the search for strategies to increase healthspan, the length of time an individual lives healthy and productively. Due to the age-related decline of the immune system, infectious diseases remain among the top 5-10 causes of mortality and morbidity in the elderly, and improving immune function during aging remains an important aspect of healthspan extension. Calorie restriction (CR) and more recently rapamycin (rapa) feeding have both been used to extend lifespan in mice. Preciously few studies have actually investigated the impact of each of these interventions upon in vivo immune defense against relevant microbial challenge in old organisms. We tested how rapa and CR each impacted the immune system in adult and old mice. We report that each intervention differentially altered T-cell development in the thymus, peripheral T-cell maintenance, T-cell function and host survival after West Nile virus infection, inducing distinct but deleterious consequences to the aging immune system. We conclude that neither rapa feeding nor CR, in the current form/administration regimen, may be optimal strategies for extending healthy immune function and, with it, lifespan.

Morgan-Bathke, M., Harris, Z. I., Arnett, D. G., Klein, R. R., Burd, R., Ann, D. K., & Limesand, K. H. (2014). The Rapalogue, CCI-779, improves salivary gland function following radiation. PloS one, 9(12), e113183.

The standard of care for head and neck cancer typically includes surgical resection of the tumor followed by targeted head and neck radiation. However depending on tumor location and stage, some cases may not require surgical resection while others may be treated with chemoradiation. Unfortunately, these radiation treatments cause chronic negative side effects for patients. These side effects are associated with damage to surrounding normal salivary gland tissue and include xerostomia, changes in taste and malnutrition. The underlying mechanisms of chronic radiation-induced salivary gland dysfunction are unknown, however, in rodent models persistently elevated proliferation is correlated with reduced stimulated salivary flow. The rapalogue, CCI-779, has been used in other cell systems to induce autophagy and reduce proliferation, therefore the aim of this study was to determine if CCI-779 could be utilized to ameliorate chronic radiation-induced salivary gland dysfunction. Four to six week old Atg5f/f; Aqp5-Cre, Atg5+/+; Aqp5-Cre and FVB mice were treated with targeted head and neck radiation. FVB mice were treated with CCI-779, chloroquine, or DMSO post-radiation. Stimulated salivary flow rates were determined and parotid and submandibular salivary gland tissues were collected for analyses. Mice with a defect in autophagy, via a conditional knockout of Atg5 in the salivary glands, display increased compensatory proliferation in the acinar cell compartment and hypertrophy at 24-72 hours following radiation. FVB mice treated with post-therapy CCI-779 have significant improvements in salivary gland physiology as determined by stimulated salivary flow rates, proliferation indices and amylase production and secretion. Consequently, post-radiation use of CCI-779 allows for improvement of salivary gland function and reestablishment of glandular homeostasis. As CCI-779 is already FDA approved for other uses, it could have a secondary use to alleviate the chronic side effects in head and neck cancer patients who have completed anti-tumor therapy.

Limesand, K. H. (2017). Autophagic Reliance Promotes Metabolic Reprogramming in Oncogenic KRAS-driven Tumorigenesis. Autophagy.
Khalafalla, M. G., Woods, L. T., Camden, J. M., Khan, A. A., Limesand, K. H., Petris, M. J., Erb, L., & Weisman, G. A. (2017). P2X7 receptor antagonism prevents IL-1β release from salivary epithelial cells and reduces inflammation in a mouse model of autoimmune exocrinopathy. The Journal of biological chemistry, 292(40), 16626-16637.

Salivary gland inflammation is a hallmark of Sjögren's syndrome (SS), a common autoimmune disease characterized by lymphocytic infiltration of the salivary gland and loss of saliva secretion, predominantly in women. The P2X7 receptor (P2X7R) is an ATP-gated nonselective cation channel that induces inflammatory responses in cells and tissues, including salivary gland epithelium. In immune cells, P2X7R activation induces the production of proinflammatory cytokines, including IL-1β and IL-18, by inducing the oligomerization of the multiprotein complex NLRP3-type inflammasome. Here, our results show that in primary mouse submandibular gland (SMG) epithelial cells, P2X7R activation also induces the assembly of the NLRP3 inflammasome and the maturation and release of IL-1β, a response that is absent in SMG cells isolated from mice deficient in P2X7Rs (P2X7R-/-). P2X7R-mediated IL-1β release in SMG epithelial cells is dependent on transmembrane Na+ and/or K+ flux and the activation of heat shock protein 90 (HSP90), a protein required for the activation and stabilization of the NLRP3 inflammasome. Also, using the reactive oxygen species (ROS) scavengers N-acetyl cysteine and Mito-TEMPO, we determined that mitochondrial reactive oxygen species are required for P2X7R-mediated IL-1β release. Lastly, in vivo administration of the P2X7R antagonist A438079 in the CD28-/-, IFNγ-/-, NOD.H-2h4 mouse model of salivary gland exocrinopathy ameliorated salivary gland inflammation and enhanced carbachol-induced saliva secretion. These findings demonstrate that P2X7R antagonism in vivo represents a promising therapeutic strategy to limit salivary gland inflammation and improve secretory function.

Morgan-Bathke, M., Lin, H. H., Ann, D. K., & Limesand, K. H. (2015). The Role of Autophagy in Salivary Gland Homeostasis and Stress Responses. Journal of dental research, 94(8), 1035-40.

Autophagy is a catabolic process that has been shown to have a role in many cellular processes including the removal of excessive or damaged proteins and protein aggregates. The salivary glands play a critical role in oral health, and their secretory capacity may be critically intertwined with the autophagic process. This review describes the role of autophagy activation in normal salivary gland homeostasis and during the glandular stress responses of therapeutic radiation, ductal ligation, autoimmunity, and salivary gland adenoid cystic carcinoma.