Background: Radiotherapy or accidental exposure to ionizing radiation causes severe damage of healthy intestinal tissues. Intestinal barrier function is highly sensitive to ionizing radiation, and loss of epithelial integrity results in mucosal inflammation, bacterial translocation, and endotoxemia. Few studies have of epithelial integrity as a therapeutic target to treat radiation toxicity. Here, we examined the effects of pravastatin (PS) and the molecular mechanisms underlying epithelial integrity on radiation-induced enteropathy.
Methods: The radio-mitigative effects of PS were evaluated in a minipig model by quantifying clinical symptoms, and performing histological and serological analyses and mRNA sequencing in intestinal tissues. To evaluate the role of intercellular junctions on radiation damage, we used tight junction regulator and metallothionein 2 (MT2) as treatments in a mouse model of radiation-induced enteropathy. Caco-2 monolayers were used to examine functional epithelial integrityand intercellular junction expression.
Finding: Using a minipig model of pharmaceutical oral bioavailability, we found that PS mitigated acute radiation-induced enteropathy. PS-treated irradiated minipigs had mild clinical symptoms, lower intestinal inflammation and endotoxin levels, and improved gastrointestinal integrity, compared with control group animals. The results of mRNA sequencing analysis indicated that PS treatment markedly influenced intercellular junctions by inhibiting p38 MAPK signaling in the irradiated intestinal epithelium. The PS-regulated gene MT2 improved the epithelial barrier via enhancement of intercellular junctions in radiation-induced enteropathy.
Interpretation: PS regulated epithelial integrity by modulating MT2 in radiation-damaged epithelial cells. These findings suggested that maintenance of epithelial integrity is a novel therapeutic target for treatment of radiation-induced gastrointestinal damage.
Funding: As stated in the Acknowledgments.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8546423 | PMC |
http://dx.doi.org/10.1016/j.ebiom.2021.103641 | DOI Listing |
Front Neurol
December 2024
Department of Surgical Sciences, Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden.
Background: There still exists controversy about whether the healthy human middle ear mucosa is sterile or if it may harbor a diverse microbiome. Considering the delicacy of the human round window membrane (RWM), different mechanisms may exist for avoiding inner ear pathogen invasion causing sensorineural deafness. We re-analyzed archival human RWMs using light and transmission electron microscopy after decalcification to determine if bacteria are present in clinically normal human middle ears.
View Article and Find Full Text PDFAm J Pathol
December 2024
Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA. Electronic address:
Tissue inhibitors of metalloproteinases (TIMPs) modulate extracellular matrix (ECM) remodeling for maintaining homeostasis and promoting cell migration and proliferation. Pathological conditions can alter TIMP homeostasis and aggravate disease progression. The roles of TIMPs have been studied in tissue-related disorders; however, their contributions to tissue repair during corneal injury are undefined.
View Article and Find Full Text PDFAm J Pathol
December 2024
International Ocular Surface Research Center, Key Laboratory for Regenerative Medicine, Institute of Ophthalmology, Jinan University, Guangzhou 510632, China; Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou 510630, China. Electronic address:
The gut microbiota plays a crucial regulatory role in various physiological processes, yet its impact on corneal homeostasis remains insufficiently understood. Here, we investigate the effects of antibiotic-induced gut dysbiosis (AIGD) and germ-free (GF) conditions on circadian gene expression, barrier integrity, nerve density, and immune cell activity in the corneas of mice. Through RNA sequencing, we found that both AIGD and GF conditions significantly disrupted the overall transcriptomic profile and circadian transcriptomic oscillations in the cornea.
View Article and Find Full Text PDFHum Cell
December 2024
Section of Oncopathology and Morphological Pathology, Department of Pathology, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miazaki, 889-1692, Japan.
Hepatocyte growth factor activator inhibitor type 1 (HAI-1), which is encoded by the SPINT1 gene, is a membrane-associated serine proteinase inhibitor abundantly expressed in epithelial tissues. We had previously demonstrated that HAI-1 is critical for placental development, epidermal keratinization, and maintenance of keratinocyte morphology by regulating cognate proteases, matriptase and prostasin. After performing ultrastructural analysis of Spint1-deleted skin tissues, our results showed that Spint1-deleted epidermis exhibited partially disrupted epidermal basement-membrane structures.
View Article and Find Full Text PDFCell Immunol
December 2024
Defence Institute of Physiology and Allied Sciences, Delhi 110054, India. Electronic address:
The gastrointestinal (GI) tract is susceptible to damage under high altitude hypoxic conditions, leading to gastrointestinal discomfort and intestinal barrier injury. Sodium butyrate, a short-chain fatty acid present as a metabolite in the gut, has emerged as a promising therapeutic agent due to its ability to act as an immunomodulatory agent and restore intestinal barrier integrity. This study aimed to explore the mechanism by which sodium butyrate exhibits anti inflammatory effect on intestinal epithelial cells.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!