The gastrointestinal (GI) syndrome component of acute radiation syndrome (ARS) results from depletion of immature parenchymal stem cells after high dose irradiation and contributes significantly to early mortality. It is associated with severe, irreparable damage in the GI tract and extremely low survival. There is a need for the development of viable mitigators of whole body irradiation (WBI) due to the possibility of unexpected high level radiation exposure from nuclear accidents or attacks. We therefore examined the effect of recombinant human milk fat globule-EGF factor 8 (rhMFG-E8) in mitigating damage after WBI. Male Sprague-Dawley rats were exposed to 10 Gy WBI using Cesium-137 as the radiation source. The animals in the treatment group received rhMFG-E8 (166 µg/kg BW) subcutaneously once a day with the first dose given 6 h after WBI. Blood and tissue samples from the ileum were collected after 3 days of treatment. A separate cohort of animals was treated for 7 days and the 21 day mortality rate was determined. Treatment with rhMFG-E8 significantly improved the survival from 31% to 75% over 21 days. Furthermore, rhMFG-E8 treatment resulted in a 36% reduction in the radiation injury intestinal mucosal damage score, corresponding to visible histological changes. MFG-E8 gene expression was significantly decreased in WBI-induced animals as compared to sham controls. Treatment with rhMFG-E8 increased p53 and p21 expression by 207% and 84% compared to untreated controls. This was accompanied by an 80% increase in the expression of anti-apoptotic cell regulator Bcl-2. p53 and p21 levels correlate with improved survival after radiation injury. These cell regulators arrest the cell after DNA damage and enable DNA repair as well as optimize cell survival. Taken together, these results indicate that rhMFG-E8 ameliorates the GI syndrome and improves survival after WBI by minimizing intestinal cell damage and optimizing recovery.

Alcohol-induced liver disease is associated with unacceptable morbidity and mortality. When activated, Kupffer cells (KCs), the resident macrophages in the liver, release proinflammatory cytokine TNF-α, a key mediator of hepatic damage. Although chronic alcohol causes increase in norepinephrine (NE) release leading to hepatic dysfunction, the mechanism of NE-induced hepatic injury in chronic alcohol exposure has not been elucidated. This study was conducted to determine whether chronic alcohol exposure increases NE and upregulates KC α2A-adrenoceptors (α2A-AR) to cause TNF-α release. We also examined the role of mitogen activated protein kinase (MAPK) phosphatase-1 (MKP-1) in this process. Male adult rats were fed the Lieber-DeCarli liquid diet containing alcohol as 36% of total calories. The animals were sacrificed after 6 weeks and blood and liver samples were harvested for further analysis. KCs from healthy male rats were cultured with alcohol for 7 days, and cells then harvested for RNA and protein analyses. Chronic alcohol exposure resulted in hepatic damage. Alcohol caused a 276% increase in circulating NE and 86% increase in TNF-α in the liver. There was a 75% and 62% decrease in MKP-1 mRNA and protein levels in the liver, respectively. In-vitro experiments revealed 121% and 98% increase in TNF-α and α2A-AR mRNA levels with alcohol exposure, respectively, and a 32% decrease in MKP-1 mRNA compared to controls. In summary, chronic alcohol exposure elevates NE and upregulates KC α2A-AR to release TNF-α. Alcohol induced downregulation of MKP-1 leads to further release of TNF-α and hepatic injury.

Cutaneous wound continues to cause significant morbidity and mortality in the setting of diseases such as diabetes and cardiovascular diseases. Despite advances in wound care management, there is still an unmet medical need exists for efficient therapy for cutaneous wound. Combined treatment of adrenomedullin (AM) and its binding protein-1 (AMBP-1) is protective in various disease conditions. To examine the effect of the combination treatment of AM and AMBP-1 on cutaneous wound healing, full-thickness 2.0-cm diameter circular excision wounds were surgically created on the dorsum of rats, saline (vehicle) or AM/AMBP-1 (96/320 μg kg BW) was topically applied to the wound daily and wound size measured. At days 3, 7, and 14, skin samples were collected from the wound sites. AM/AMBP-1 treated group had significantly smaller wound surface area than the vehicle group over the 14-day time course. At day 3, AM/AMBP-1 promoted neutrophil infiltration (MPO), increased cytokine levels (IL-6 and TNF-α), angiogenesis (CD31, VEGF and TGFβ-1) and cell proliferation (Ki67). By day 7 and 14, AM/AMBP-1 treatment decreased MPO, followed by a rapid resolution of inflammation characterized by a decrease in cytokines. At the matured stage, AM/AMBP-1 treatment increased the alpha smooth muscle actin expression (mature blood vessels) and Masson-Trichrome staining (collagen deposition) along the granulation area, and increased MMP-9 and decreased MMP-2 mRNA expressions. TGFβ-1 mRNA levels in AM/AMBP-1 group were 5.3 times lower than those in the vehicle group. AM/AMBP-1 accelerated wound healing by promoting angiogenesis, collagen deposition and remodeling. Treatment also shortened the days to reach plateau for wound closure. Thus, AM/AMBP-1 may be further developed as a therapeutic for cutaneous wound healing.

Abstract. Alcoholic liver disease accounts for 12,000 deaths per year in the United States and is the second leading indication for liver transplantation. It covers a spectrum of disease conditions ranging from steatosis and cirrhosis to hepatic malignancies. Epidemiological data clearly show a strong correlation between alcohol consumption and liver diseases. A large body of evidence has accumulated over the years in determining the molecular mediators of alcohol-induced liver injury. In this review, we provide an overview of such mediators, which include alcohol metabolites and reactive oxygen/ nitrogen species, endotoxin via bacterial translocation from the gut and TNF-α, and highlight the role of the sympathetic nervous stimuli, norepinephrine and the α 2A -adrenergic receptors in contributing to the deleterious effect observed in alcohol-induced hepatic dysfunction.