Fibrin patch influences the expression of hypoxia-inducible factor-1α and nuclear factor-κBp65 factors on ischemic intestinal anastomosis

Hypoxia signaling in the equine small intestine: Expression and distribution of hypoxia inducible factors during experimental ischemia

Introduction

Hypoxia inducible factors (HIF) are widely researched in human medicine for their role in different disease processes. The aim of this study was to investigate the expression and distribution of HIF in experimental small intestinal ischemia in the horse.

Methods

In 14 horses under general anesthesia, segmental jejunal ischemia with 90% reduction in blood flow was induced. The horses were randomly divided into two groups of seven horses, one subjected to ischemic postconditioning (IPoC) by delayed reperfusion, and a control group (group C) undergoing undelayed reperfusion. Intestinal samples were taken pre-ischemia, after ischemia and after reperfusion. Following immunohistochemical staining for HIF1α and -2α, the immunoreactivity pattern in the small intestine was evaluated by light microscopy, and the mucosal enterocyte and muscularis staining were semi-quantitatively scored. Additionally, mucosal HIF1α protein levels were determined by an Enzyme Linked Immunosorbent Assay (ELISA), and mRNA levels of HIF1α and its target genes by a two-step real-time Reverse Transcriptase Polymerase Chain Reaction. Statistical comparison was performed between the groups and time points using parametric and non-parametric tests (p < 0.05).

Results

All cell types exhibited cytoplasmic and nuclear immunoreactivity for HIF1α. After reperfusion, the cytoplasmic staining of the crypt and villus enterocytes as well as the villus nuclear staining significantly increased, whereas the perinuclear granules in the crypts decreased. The protein levels showed a significant decrease in group C at reperfusion, with lower HIF1α levels in group C compared to group IPoC during ischemia and reperfusion. No other group differences could be detected. In the HIF2α stained slides, mild to moderate cytoplasmic staining yet no nuclear immunoreactivity of the enterocytes was observed, and no significant changes over time were noted.

Discussion

the changes in HIF1α immunoreactivity pattern and expression over time suggest that this transcription factor plays a role in the intestinal response to ischemia in horses. However, the current study could not identify an effect of IPoC on HIF distribution or expression.

18β-Glycyrrhetinic acid suppresses allergic airway inflammation through NF-κB and Nrf2/HO-1 signaling pathways in asthma mice

18β-Glycyrrhetinic acid (18β-GA), the main bioactive component of Glycyrrhizae Radix, is considered a promising anti-inflammatory and antioxidant agent. Here, we evaluated the anti-inflammatory and antioxidant effects of 18β-GA in an ovalbumin (OVA)-induced asthma mouse model, and examined the role of NF-κB and Nrf2/HO-1 signaling pathways. The histopathological changes of lung tissue in mouse were assessed by histochemical staining and counting of inflammatory cells. The levels of IgE and inflammatory cytokines in the bronchoalveolar lavage fluid of mice were detected by ELISA. In OVA-induced asthmatic mice, 18β-GA treatment can significantly improve lung function and reduce lung inflammation including infiltration of inflammatory cells. In addition, 18β-GA reduced the OVA-induced NF-κB phosphorylation in lungs of mice while increasing the expression of Nrf2 and HO-1. These results indicate that 18β-GA protects OVA-induced allergic inflammation of airway by inhibiting phosphorylation of NF-κB and enhancing the Nrf2/HO-1 pathway, and serves as a potential treatment option for allergic inflammation of airway.

Double-layered Nanofibrous Patch for Prevention of Anastomotic Leakage and Peritoneal Adhesions, Experimental Study

BACKGROUND/AIM

Anastomotic leakage is a feared complication in colorectal surgery. Postoperative peritoneal adhesions can also cause life-threatening conditions. Nanofibrous materials showed their pro-healing properties in various studies. The aim of the study was to evaluate the impact of double-layered nanofibrous materials on anastomotic healing and peritoneal adhesions formation.

MATERIALS AND METHODS

Two versions of double-layered materials from polycaprolactone and polyvinyl alcohol were applied on defective anastomosis on the small intestine of healthy pigs. The control group remained with uncovered defect. Tissue specimens were subjected to histological analysis and adhesion scoring after 3 weeks of observation.

RESULTS

The wound healing was inferior in the experimental groups, however, no anastomotic leakage was observed and the applied material always kept covering the defect. The extent of adhesions was larger in the experimental groups.

CONCLUSION

Nanofibrous materials may prevent anastomotic leakage but delay healing.