Inhibition of histone deacetylase 6 restores intestinal tight junction in hemorrhagic shock.

Abstract

BACKGROUND:

We recently discovered that Tubastatin-A, a histone deacetylase (HDAC6) inhibitor, can improve survival in a rodent model of hemorrhagic shock (HS), but mechanisms remain poorly defined. In this study, we investigated whether Tubastatin-A could protect intestinal tight junction (TJ) in HS.

METHODS:

In an in-vivo study with Wistar-Kyoto rats, the rats underwent HS (40% blood loss) followed by Tubastatin-A (70 mg/kg) treatment, without fluid resuscitation. The experimental groups were (1) sham (no hemorrhage, no treatment), (2) control (hemorrhage, without treatment), and (3) treatment (hemorrhage with Tubastatin-A administration). Six hours after hemorrhage, ileum was harvested. Whole cell lysate were analyzed for acetylated α-tubulin (Ac-tubulin), total tubulin, acetylated histone 3 at lysine 9 (Ac-H3K9), β-actin, claudin-3 and zonula occludens 1 (ZO-1) proteins by Western blot. Histological effects of Tubastatin-A on small bowel were examined. In an in-vitro study, human intestinal epithelial cells (Caco-2) were divided into three groups: (1) sham (normoxia), (2) control (anoxia, no treatment), and (3) treatment (anoxia, treatment with Tubastatin-A). After 12 hours in an anoxia chamber, the cells were examined for Ac-tubulin and Ac-H3K9, cellular viability, cytotoxicity, claudin-3 and ZO-1 protein expression, and transwell permeability study.

RESULTS:

Tubastatin-A treatment significantly attenuated HS-induced decreases of Ac-tubulin, Ac-H3K9, ZO-1 and claudin-3 proteins in small bowel in-vivo (p < 0.05). In cultured Caco-2 cells, anoxia significantly decreased cellular viability (p < 0.001) and increased cytotoxicity (p < 0.001) compared to the sham group, while Tubastatin-A treatment offered significant protection (p < 0.0001). Moreover, expression of claudin-3 was markedly decreased in vitro compared to the sham group, whereas this was significantly attenuated by Tubastatin-A (p < 0.05). Finally, anoxia markedly increased the permeability of Caco-2 monolayer cells (p < 0.05), while Tubastatin-A significantly attenuated the alteration (p < 0.05).

CONCLUSION:

Inhibition of HDAC6 can induce Ac-tubulin and Ac-H3K9, promote cellular viability, and prevent the loss of intestinal tight junction proteins during HS and anoxia.

• Authors: Zhigang Chang, Yongqing Li, Wei He, Baoling Liu, Xiuzhen Duan, Ihab Halaweish, Ted Bambakidis, Baihong Pan, Yingjian Liang, Vahagn C Nikolian, Patrick Georgoff, Hasan B Alam
• Journal: The journal of trauma and acute care surgery (J Trauma Acute Care Surg) Vol. 81 Issue 3 Pg. 512-9 (09 2016) ISSN: 2163-0763 [Electronic] United States
• PMID: 27257709 (Publication Type: Journal Article)

Chemical References

• Histone Deacetylase Inhibitors
• Hydroxamic Acids
• Indoles
• tubastatin A

Topics

• Animals
• Blotting, Western
• Disease Models, Animal
• Histone Deacetylase Inhibitors (pharmacology)
• Hydroxamic Acids (pharmacology)
• Ilium (drug effects)
• Indoles (pharmacology)
• Male
• Rats
• Rats, Wistar
• Shock, Hemorrhagic (drug therapy)
• Tight Junctions (drug effects)