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Walter Koltun, MD

Walter Koltun, MD

Peter and Marshia Carlino Chair in Inflammatory Bowel Disease, Department of Surgery
Chief, Division of Colon and Rectal Surgery
Disease Teams:
Cancer Institute, Gastrointestinal Cancer Team

Research Interests

  • Crohn Disease
  • Inflammatory Bowel Diseases
  • Ulcerative Colitis
  • Therapeutics
  • Genes
  • Single Nucleotide Polymorphism
  • Diverticulitis
  • Restorative Proctocolectomy
  • Neoplasms
  • Colitis
  • Colon
  • Permeability

Recent Publications


Ganapathy, AS, Saha, K, Wang, A, Arumugam, P, Dharmaprakash, V, Yochum, G, Koltun, W, Nighot, M, Perdew, G, Thompson, TA, Ma, T & Nighot, P 2023, 'Alpha-tocopherylquinone differentially modulates claudins to enhance intestinal epithelial tight junction barrier via AhR and Nrf2 pathways', Cell Reports, vol. 42, no. 7, 112705.
Saha, K, Subramenium Ganapathy, A, Wang, A, Michael Morris, N, Suchanec, E, Ding, W, Yochum, G, Koltun, W, Nighot, M, Ma, T & Nighot, P 2023, 'Autophagy Reduces the Degradation and Promotes Membrane Localization of Occludin to Enhance the Intestinal EpithelialTight Junction Barrier against Paracellular Macromolecule Flux', Journal of Crohn's and Colitis, vol. 17, no. 3, pp. 433-449.
Tom, CM, Mankarious, MM, Jeganathan, NA, Deutsch, M, Koltun, WA, Berg, AS & Scow, JS 2023, 'Characteristics and Outcomes of Right- Versus Left-Sided Early-Onset Colorectal Cancer', Diseases of the colon and rectum, vol. 66, no. 4, pp. 498-510.
Nighot, M, Liao, PL, Morris, N, McCarthy, D, Dharmaprakash, V, Ullah Khan, I, Dalessio, S, Saha, K, Ganapathy, AS, Wang, A, Ding, W, Yochum, G, Koltun, W, Nighot, P & Ma, T 2023, 'Long-Term Use of Proton Pump Inhibitors Disrupts Intestinal Tight Junction Barrier and Exaggerates Experimental Colitis', Journal of Crohn's and Colitis, vol. 17, no. 4, pp. 565-579.
King, CM, Marx, OM, Ding, W, Koltun, WA & Yochum, GS 2023, 'TCF7L1 Regulates LGR5 Expression in Colorectal Cancer Cells', Genes, vol. 14, no. 2, 481.
Portolese, AC, McMullen, BN, Baker, SK, Chen See, JR, Yochum, GS, Koltun, WA, Lamendella, R & Jeganathan, NA 2023, 'The Microbiome of Complicated Diverticulitis: An Imbalance of Sulfur-Metabolizing Bacteria', Diseases of the colon and rectum, vol. 66, no. 5, pp. 707-715.


Bogale, K, Maheshwari, P, Kang, M, Gorrepati, VS, Dalessio, S, Walter, V, Stuart, A, Koltun, W, Bernasko, N, Tinsley, A, Williams, ED, Clarke, K & Coates, MD 2022, 'Symptoms associated with healthcare resource utilization in the setting of inflammatory bowel disease', Scientific reports, vol. 12, no. 1, 10577.
Zhao, X, Yang, W, Yu, T, Yu, Y, Cui, X, Zhou, Z, Yang, H, Yu, Y, Bilotta, AJ, Yao, S, Xu, J, Zhou, J, Yochum, GS, Koltun, WA, Portolese, A, Zeng, D, Xie, J, Pinchuk, IV, Zhang, H & Cong, Y 2023, 'Th17 Cell-Derived Amphiregulin Promotes Colitis-Associated Intestinal Fibrosis Through Activation of mTOR and MEK in Intestinal Myofibroblasts', Gastroenterology, vol. 164, no. 1, pp. 89-102.
Marx, OM, Mankarious, MM, Eshelman, MA, Ding, W, Koltun, WA & Yochum, GS 2022, 'Transcriptome Analyses Identify Deregulated MYC in Early Onset Colorectal Cancer', Biomolecules, vol. 12, no. 9, 1223.


Ganapathy, AS, Saha, K, Suchanec, E, Singh, V, Verma, A, Yochum, G, Koltun, W, Nighot, M, Ma, T & Nighot, P 2022, 'AP2M1 mediates autophagy-induced CLDN2 (claudin 2) degradation through endocytosis and interaction with LC3 and reduces intestinal epithelial tight junction permeability', Autophagy, vol. 18, no. 9, pp. 2086-2103.
Schieffer, KM, Emrich, SM, Yochum, GS & Koltun, WA 2021, 'CD163L1+CXCL10+ Macrophages are Enriched Within Colonic Lamina Propria of Diverticulitis Patients', Journal of Surgical Research, vol. 267, pp. 527-535.
Kline, BP, Yochum, GS, Brinton, DL, Schieffer, KM, Weaver, T, Harris, L, Deiling, S, Berg, AS & Koltun, WA 2021, 'COLQ and ARHGAP15 are associated with diverticular disease and are expressed in the colon', Journal of Surgical Research, vol. 267, pp. 397-403.
Kline, BP, Weaver, T, Brinton, DL, Harris, L, Yochum, GS, Berg, AS & Koltun, WA 2021, 'Clinical and Genetic Factors Impact Time to Surgical Recurrence After Ileocolectomy for Crohn's Disease', Annals of surgery, vol. 274, no. 2, pp. 346-351.
Grim, C, Noble, R, Uribe, G, Khanipov, K, Johnson, P, Koltun, WA, Watts, T, Fofanov, Y, Yochum, GS, Powell, DW, Beswick, EJ & Pinchuk, IV 2021, 'Impairment of Tissue-Resident Mesenchymal Stem Cells in Chronic Ulcerative Colitis and Crohn's Disease', Journal of Crohn's and Colitis, vol. 15, no. 8, pp. 1362-1375.
Bogale, K, Vrana, K, Konsavage, WR, Walter, V, Stuart, A, Dalessio, S, Koltun, W, Bernasko, N, Tinsley, A, Williams, E, Clarke, K & Coates, MD 2021, 'Polysubstance use in inflammatory bowel disease', Journal of Digestive Diseases, vol. 22, no. 12, pp. 706-713.
Jeganathan, NNA & Koltun, WA 2021, 'Special Considerations of Anastomotic Leaks in Crohn's Disease', Clinics in Colon and Rectal Surgery, vol. 34, no. 6, pp. 412-416.
Jeganathan, NA, Davenport, ER, Yochum, GS & Koltun, WA 2021, 'The microbiome of diverticulitis', Current Opinion in Physiology, vol. 22, 100452.


Gorrepati, VS, Soriano, C, Johri, A, Dalessio, S, Stuart, A, Koltun, W, Tinsley, A, Clarke, K, Williams, E & Coates, M 2020, 'Abdominal pain and anxious or depressed state are independently associated with weight loss in inflammatory bowel disease', Crohn's and Colitis 360, vol. 2, no. 2.
Coates, MD, Johri, A, Gorrepati, VS, Maheshwari, P, Dalessio, S, Walter, V, Stuart, A, Koltun, W, Bernasko, N, Tinsley, A, Williams, ED & Clarke, K 2021, 'Abdominal pain in quiescent inflammatory bowel disease', International Journal of Colorectal Disease, vol. 36, no. 1, pp. 93-102.
Kline, BP, Weaver, T, Brinton, DL, Deiling, S, Yochum, GS, Berg, AS & Koltun, WA 2020, 'Clinical and Genetic Factors Associated With Complications After Crohn's Ileocolectomy', Diseases of the colon and rectum, vol. 63, no. 3, pp. 357-364.
Pathak, T, Gueguinou, M, Walter, V, Delierneux, C, Johnson, MT, Zhang, X, Xin, P, Yoast, RE, Emrich, SM, Yochum, GS, Sekler, I, Koltun, WA, Gill, DL, Hempel, N & Trebak, M 2020, 'Dichotomous role of the human mitochondrial na+ /ca2+ /li+ exchanger nclx in colorectal cancer growth and metastasis', eLife, vol. 9, e59686, pp. 1-41.
Coates, MD, Soriano, C, Dalessio, S, Stuart, A, Walter, V, Koltun, W, Bernasko, N, Tinsley, A, Clarke, K & Williams, ED 2020, 'Gastrointestinal hypoalgesia in inflammatory bowel disease', Annals of Gastroenterology, vol. 33, no. 1, pp. 45-52.
Rawat, M, Nighot, M, Al-Sadi, R, Gupta, Y, Viszwapriya, D, Yochum, G, Koltun, W & Ma, TY 2020, 'IL1B Increases Intestinal Tight Junction Permeability by Up-regulation of MIR200C-3p, Which Degrades Occludin mRNA', Gastroenterology, vol. 159, no. 4, pp. 1375-1389.
Aguirre, JE, Beswick, EJ, Grim, C, Uribe, G, Tafoya, M, Palma, GC, Samedi, V, McKee, R, Villeger, R, Fofanov, Y, Cong, Y, Yochum, G, Koltun, W, Powell, D & Pinchuk, IV 2020, 'Matrix metalloproteinases cleave membrane-bound PD-L1 on CD90+ (myo-)fibroblasts in Crohn’s disease and regulate Th1/Th17 cell responses', International immunology, vol. 32, no. 1, pp. 57-68.
Kulaylat, AN, Kulaylat, AS, Schaefer, EW, Mirkin, K, Tinsley, A, Williams, E, Koltun, WA, Hollenbeak, CS & Messaris, E 2021, 'The Impact of Preoperative Anti-TNFα Therapy on Postoperative Outcomes Following Ileocolectomy in Crohn’s Disease', Journal of Gastrointestinal Surgery, vol. 25, no. 2, pp. 467-474.
Eshelman, MA, Harris, L, Deiling, S, Koltun, WA, Jeganathan, NA & Yochum, GS 2020, 'Transcriptomic analysis of ileal tissue from crohn’s disease patients identifies extracellular matrix genes that distinguish individuals by age at diagnosis', Physiological genomics, vol. 52, no. 10, pp. 478-484.


Gonzalez-Lopez, E, Kawasawa-Imamura, Y, Zhang, L, Huang, X, Koltun, WA, Coates, MD & Vrana, KE 2019, 'A single nucleotide polymorphism in dopamine beta hydroxylase (rs6271(C>T)) is over-represented in inflammatory bowel disease patients and reduces circulating enzyme', PloS one, vol. 14, no. 2, e0210175.
Denson, LA, Curran, M, McGovern, DPB, Koltun, WA, Duerr, RH, Kim, SC, Sartor, RB, Sylvester, FA, Abraham, C, de Zoeten, EF, Siegel, CA, Burns, RM, Dobes, AM, Shtraizent, N, Honig, G, Heller, CA, Hurtado-Lorenzo, A & Cho, JH 2019, 'Challenges in IBD Research: Precision Medicine', Inflammatory bowel diseases, vol. 25, pp. S31-S39.
Eshelman, MA, Jeganathan, NA, Schieffer, KM, Kline, BP, Mendenhall, M, Deiling, S, Harris, L, Koltun, WA & Yochum, GS 2019, 'Elevated colonic mucin expression correlates with extended time to surgery for ulcerative colitis patients', Journal of Gastrointestinal and Liver Diseases, vol. 28, no. 4, pp. 405-413.
Coates, MD, Kim, JS, Carkaci-Salli, N, Vrana, KE, Koltun, WA, Puhl, HL, Adhikary, SD, Janicki, PK & Ruiz-Velasco, V 2019, 'Impact of the NaV1.8 variant, A1073V, on post-sigmoidectomy pain and electrophysiological function in rat sympathetic neurons', Journal of neurophysiology, vol. 122, no. 6, pp. 2591-2600.
Gorrepati, VS, Stuart, A, Deiling, S, Koltun, W, Tinsley, A, Williams, ED & Coates, MD 2019, 'Response to the letter to the editor from dai et al, regarding "smoking and the risk of pouchitis in ulcerative colitis patients with ileal pouch anal anastomosis"', Inflammatory bowel diseases, vol. 25, no. 4, pp. E43.
Matthews, SM, Eshelman, MA, Berg, AS, Koltun, WA & Yochum, GS 2019, 'The Crohn’s disease associated SNP rs6651252 impacts MYC gene expression in human colonic epithelial cells', PloS one, vol. 14, no. 2, e0212850.
Eshelman, MA, Matthews, SM, Schleicher, EM, Fleeman, RM, Kawasawa, YI, Stumpo, DJ, Blackshear, PJ, Koltun, WA, Ishmael, FT & Yochum, GS 2019, 'Tristetraprolin targets Nos2 expression in the colonic epithelium', Scientific reports, vol. 9, no. 1, 14413.