Prohibitin is a highly conserved protein that has pleiotropic functions depending on the cell and tissue type in which it is expressed. Little is known regarding the expression and function of prohibitin in the intestine. During my postdoctoral fellowship I demonstrated that 1) prohibitin is expressed by native human colonic epithelia as well as model intestinal epithelial cells, 2) in resting intestinal epithelial cells, prohibitin localizes to the mitochondria and protects against oxidative stress, 3) prohibitin is downregulated during oxidant stress, during active human inflammatory bowel disease (IBD) and experimental colitis, and 4) prohibitin transgenic mice are protected from DSS- and Salmonella typhimurium-induced colitis and oxidative stress. In assessing the mechanism by which prohibitin modulates inflammation, our preliminary data demonstrate that prohibitin is a potent activator of Nrf2, a master transcriptional regulator that activates a battery of anti-oxidant genes. In addition, our recent in vitro data demonstrate that prohibitin inhibits TNF(-induced NF-(B activation and barrier dysfunction. Based on these data, the central hypothesis of this proposal is that prohibitin functions as an epithelial defense against oxidative stress and inflammation-induced barrier dysfunction and decreased levels of prohibitin in IBD contribute to tissue injury and inflammation. The overall objective of the proposal is to determine the mechanism underlying the protective role of prohibitin in colitis. Our interrelated yet independently achievable aims based on our hypothesis and supported by preliminary data are i) to determine the role and mechanism by which prohibitin modulates Nrf2, ii) to address the mechanism of prohibitin in inhibiting NF-(B signaling and its downstream effects, and iii) to determine the in vivo mechanism by which prohibitin ameliorates colitis Together, these studies will elucidate the function and mechanism of action of prohibitin as an activator of anti-oxidants and as an anti-inflammatory molecule in intestinal epithelial cells. The training in protein biochemistry and electrophysiology the candidate will learn from executing the proposed studies will improve potential for transition to an independent IBD researcher.
This study proposes to define the function and mechanism of prohibitin in protecting against oxidative stress, NF-(B activation and barrier dysfunction, which are hallmarks of intestinal inflammation. These studies are designed to provide evidence for prohibitin as a potential therapeutic target to prevent the consequences of intestinal inflammation.
|Han, Jie; Yu, Chunhua; Souza, Rhonda F et al. (2014) Prohibitin 1 modulates mitochondrial function of Stat3. Cell Signal 26:2086-95|
|Han, Jie; Theiss, Arianne L (2014) Stat3: friend or foe in colitis and colitis-associated cancer? Inflamm Bowel Dis 20:2405-11|
|Theiss, Arianne L (2013) Sphingosine-1-phosphate: Driver of NFÎºB and STAT3 persistent activation in chronic intestinal inflammation and colitis-associated cancer. JAKSTAT 2:e24150|
|Kathiria, Arwa S; Butcher, Mackenzie A; Hansen, Jason M et al. (2013) Nrf2 is not required for epithelial prohibitin-dependent attenuation of experimental colitis. Am J Physiol Gastrointest Liver Physiol 304:G885-96|
|Kathiria, Arwa S; Neumann, William L; Rhees, Jennifer et al. (2012) Prohibitin attenuates colitis-associated tumorigenesis in mice by modulating p53 and STAT3 apoptotic responses. Cancer Res 72:5778-89|
|Kathiria, Arwa S; Butcher, Lindsay D; Feagins, Linda A et al. (2012) Prohibitin 1 modulates mitochondrial stress-related autophagy in human colonic epithelial cells. PLoS One 7:e31231|
|Theiss, Arianne L; Sitaraman, Shanthi V (2011) The role and therapeutic potential of prohibitin in disease. Biochim Biophys Acta 1813:1137-43|
|Theiss, Arianne L; Laroui, Hamed; Obertone, Tracy S et al. (2011) Nanoparticle-based therapeutic delivery of prohibitin to the colonic epithelial cells ameliorates acute murine colitis. Inflamm Bowel Dis 17:1163-76|
|Laroui, Hamed; Theiss, Arianne L; Yan, Yutao et al. (2011) Functional TNFÎ± gene silencing mediated by polyethyleneimine/TNFÎ± siRNA nanocomplexes in inflamed colon. Biomaterials 32:1218-28|
|Theiss, Arianne L; Jenkins, Aaron K; Okoro, Ngozi I et al. (2009) Prohibitin inhibits tumor necrosis factor alpha-induced nuclear factor-kappa B nuclear translocation via the novel mechanism of decreasing importin alpha3 expression. Mol Biol Cell 20:4412-23|