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l-Arginine alleviates heat stress-induced intestinal epithelial barrier damage by promoting expression of tight junction proteins via the AMPK pathway
- Source :
- Molecular Biology Reports. 46:6435-6451
- Publication Year :
- 2019
- Publisher :
- Springer Science and Business Media LLC, 2019.
-
Abstract
- Heat stress (HS) and secondary restricted blood flow to the intestines cause dysfunction of the intestinal epithelial barrier. Tight junctions (TJs) are essential to maintain intestinal integrity. l-Arginine has beneficial effects on gut functions. However, the underlying mechanisms remain largely unknown. This study tested the hypothesis that l-arginine regulates the TJ network by activating AMP-activated protein kinase (AMPK) signaling, which in turn improves intestinal barrier functions under HS. IEC-6 cells and rat small intestines were used as experiment models of heat stress. AICAR and dorsomorphin were used to activate and inhibit the AMPK pathway, respectively. Cell proliferation, apoptosis, differential gene expression and KEGG pathway analysis, intestinal paracellular permeability, intestinal morphology, and expression of HSP and TJ proteins, and p-AMPK were determined. l-Arginine promoted cell proliferation and reduced apoptosis after heat exposure at an optimal concentration of 5 mmol. Transcriptome sequencing analysis revealed that differentially expressed genes associated with the HSP family and TJs were elevated by l-arginine. According to KEGG pathway analysis, l-arginine activated the AMPK signaling pathway. In vivo, intestinal damage resulted in obvious morphological changes as well as apoptosis with TUNEL and caspase-3 staining under HS and dorsomorphin treatments. Furthermore, HS and dorsomorphin increased the serum D-lactate concentration, diamine oxidase activity, and mRNA expression level of MLCK (P l-arginine and AICAR treatments reduced intestinal injury, maintained intestinal permeability, and increased the villus/crypt ratio under hyperthermia. l-Arginine had the same effect as AICAR both in vitro and in vivo, namely increasing p-AMPK protein expression. l-Arginine and AICAR also upregulated the mRNA expression level of HSP70 and HSP90, and downregulated mRNA expression of MLCK (P l-arginine and AICAR. Our findings indicate that activation of AMPK signaling by l-arginine is associated with improved intestinal mucosal barrier functions by enhancing the expression of TJs in rat small intestines and IEC-6 cells during HS.
- Subjects :
- Male
0301 basic medicine
AMP-Activated Protein Kinases
Arginine
Permeability
Cell Line
03 medical and health sciences
0302 clinical medicine
Gene expression
Genetics
medicine
Animals
Intestinal Mucosa
Protein kinase A
Molecular Biology
Cell Proliferation
Tight Junction Proteins
Intestinal permeability
Tight junction
Chemistry
Gene Expression Profiling
Diamine oxidase activity
AMPK
General Medicine
medicine.disease
Rats
Hsp70
Cell biology
Pyrimidines
030104 developmental biology
Apoptosis
030220 oncology & carcinogenesis
Models, Animal
Pyrazoles
Heat-Shock Response
Signal Transduction
Subjects
Details
- ISSN :
- 15734978 and 03014851
- Volume :
- 46
- Database :
- OpenAIRE
- Journal :
- Molecular Biology Reports
- Accession number :
- edsair.doi.dedup.....75a5f8b5609d7ba852300d4241c0870e