Metronidazole enhances steatosis-related early-stage hepatocarcinogenesis in high fat diet-fed rats through DNA double-strand breaks and modulation of autophagy.

Nonalcoholic fatty liver disease is a hepatic disorder with deposition of fat droplets and has a high risk of progression to steatosis-related hepatitis and irreversible hepatic cancer. Metronidazole (MNZ) is an antiprotozoal and antimicrobial agent widely used to treat patients infected with anaerobic bacteria and intestinal parasites; however, MNZ has also been shown to induce liver tumors in rodents. To investigate the effects of MNZ on steatosis-related early-stage hepatocarcinogenesis, male rats treated with N-nitrosodiethylamine following 2/3 hepatectomy at week 3 were received a control basal diet, high fat diet (HFD), or HFD containing 0.5% MNZ. The HFD induced obesity and steatosis in the liver, accompanied by altered expression of Pparg and Fasn, genes related to lipid metabolism. MNZ increased nuclear translocation of lipid metabolism-related transcription factor peroxisome proliferator-activated receptor gamma in hepatocytes, together with altered liver expression of lipid metabolism genes (Srebf1, Srebf2, Pnpla2). Furthermore, MNZ significantly increased the number of preneoplastic liver foci, accompanied by DNA double-strand breaks and late-stage autophagy inhibition, as reflected by increased levels of γ-H2AX, LC3, and p62. Therefore, MNZ could induce steatosis-related hepatocarcinogenesis by inducing DNA double-strand breaks and modulating autophagy in HFD-fed rats.

Clinical and pathological characteristics of acute myelogenous leukemia in a female koala with diabetes mellitus.

A female koala presented with hyperglycemia related to diabetes mellitus diagnosed at 9 years and treated with insulin. She presented with nasal hemorrhage, anemia, leukocytosis, and tachypnea at 10 years. A blood smear examination revealed scattered, atypical large myeloid cells and a clinical diagnosis of myelogenous leukemia was made. White blood cell count reached a maximum of 295 × 102/µl, with evidence of severe regenerative anemia and thrombocytopenia. Grossly, systemic lymph node enlargement, fragile liver with hemorrhage, and bloody ascites were observed. Histopathologically, atypical myeloid cells, including myelocytic and metamyelocytic cells, were scattered in the vasculature and surrounding tissues throughout the organs. The patient was infected with a koala retrovirus, which might have caused the myelogenous leukemia.

Subacute oral administration of folic acid elicits anti-inflammatory response in a mouse model of allergic dermatitis.

Folic acid (FA) deficiency is associated with several health problems, including megaloblastic anemia and fetal neural tube defects. Therefore, supplementation with FA is strongly recommended by governments worldwide. Recent published reports indicate that FA functions in immune system maintenance. The main objective of this study is to examine possible anti-inflammatory and antipruritic effects of FA using a mouse model of allergic dermatitis. The mouse model was developed by repetitive sensitization to the Th2-type hapten toluene-2,4-diisocyanate (TDI). During the development of allergic dermatitis, FA was orally administered to the mice at doses of 8, 160, 1000 or 10,000 µg/day for 5 weeks. The ear swelling response and scratching behavior were monitored after the TDI challenge. Serum, ear tissue and auricular lymph node samples were isolated for further analysis 24 h after the TDI challenge. The ear swelling response was reduced in a dose-dependent manner by FA administration, and a significant change was observed at a concentration of 10,000-µg/day group. Comparable results were obtained through histological evaluation and cytokine level measurement in the ear tissue samples. Oral administration of FA exhibited the inhibitory effect on T-cell infiltration and T-cell-related cytokine production in auricular lymph nodes. Scratching behavior was not altered by FA administration. The in vivo evidence was corroborated by in vitro results, which showed that FA treatment significantly interfered with T-cell proliferation in a dose-dependent manner. Our findings imply that subacute oral administration of FA elicits an anti-inflammatory response, mainly through inhibition of T-cell proliferation.

Involvement of estrogen receptor α in pro-pruritic and pro-inflammatory responses in a mouse model of allergic dermatitis.

It has been reported that endogenous or exogenous estrogens can affect the immune system, resulting in immune disorders; however, their direct involvement in such conditions remains to be demonstrated. The purpose of this study was to investigate whether estrogen receptors (ER) are directly implicated in pro-pruritic and pro-inflammatory reactions in cutaneous allergy. Initially, enhancement of the pro-inflammatory response by several ER agonists [methoxychlor (MXC), ß-estradiol (E2), propylpyrazoletriol (PPT; an ERα agonist), and diarylpropionitrile (DPN; an ERß agonist)] was examined in vivo using a male BALB/c mouse model of allergic dermatitis induced by toluene-2,4-diisocyanate administration. The ear swelling response, itch response, and local cytokine secretion were measured. Subsequently, the mechanism underlying the development of such allergic reactions was analyzed in vitro using human epidermal keratinocytes, murine bone marrow-derived dendritic cells (mBMDCs), and the mixed leucocyte reaction assay. Activated cells were exposed to each ER agonist for 24 h, and cytokine secretion and cell proliferation were measured. Our in vivo experiments indicated significant upregulation of pro-inflammatory and pro-pruritic responses in the E2-, MXC-, and PPT-treated groups compared to the control group; however, no change was observed in the DPN-treated group. Levels of cytokines expressed by keratinocytes, such as TSLP and IL-33, were particularly increased by exposure to E2, MXC, or PPT. These in vivo results were confirmed in vitro in keratinocytes, but not mBMDCs or T cells. Our findings imply that ERα is involved in pro-inflammatory and pro-pruritic responses in cutaneous allergy through activation of keratinocytes.

Oral Administration of Bisphenol A Directly Exacerbates Allergic Airway Inflammation but Not Allergic Skin Inflammation in Mice.

Bisphenol A (BPA) is used in various areas of daily life as a major component of plastic products. However, it is also known as a strong endocrine disruptor that affects the human immune system. Studies have indicated that BPA possibly exacerbates allergic diseases such as atopic dermatitis and asthma. The main aim of this study was to elucidate whether BPA is directly involved in the exacerbation of allergic inflammation. Initially, in vivo experiments with mouse models of allergic inflammation induced by Th2 type hapten toluene-2, 4-diisocyanate (TDI) was performed. Mice were subjected to oral administration of BPA 48, 24, and 4 h before challenge with TDI. Dermal challenge of TDI onto the ear auricle was performed for the allergic dermatitis model, and intratracheal challenge of TDI was performed for the allergic airway inflammation model. In the allergic dermatitis model, ear-swelling response was significantly downregulated by high doses of BPA. The opposite reaction was observed in the allergic airway inflammation model, including significant exacerbation of red coloration in the lung, local cytokine levels, and total IgE levels in serum by BPA administration. To confirm the in vivo results, in vitro experiments with human epidermal keratinocytes (HEKs) and bronchial epithelial (BEAS-2B) cells were carried out. Significant enhancement of cytokine release from BEAS-2B cells but not HEKs in the BPA-treated group supported the in vivo observations. Our results imply that exposure to BPA directly exacerbates allergic airway inflammation but not allergic dermatitis.

Spironolactone in Combination with α-glycosyl Isoquercitrin Prevents Steatosis-related Early Hepatocarcinogenesis in Rats through the Observed NADPH Oxidase Modulation.

Administration of the diuretic, spironolactone (SR), can inhibit chronic liver diseases. We determined the effects of SR alone or in combination with the antioxidant α-glycosyl isoquercitrin (AGIQ) on hyperlipidemia- and steatosis-related precancerous lesions in high-fat diet (HFD)-fed rats subjected to a two-stage hepatocarcinogenesis model. Rats were fed with control basal diet or HFD, which was administered with SR alone or in combination with an antioxidant AGIQ in drinking water. An HFD increased body weight, intra-abdominal fat (adipose) tissue weight, and plasma lipids, which were reduced by coadministration of SR and AGIQ. SR and AGIQ coadministration also reduced hepatic steatosis and preneoplastic glutathione S-transferase placental form-positive foci, in association with decrease in NADPH oxidase (NOX) subunit p22phox-positive cells and an increase in active-caspase-3-positive cells in the foci. Hepatic gene expression analysis revealed that the coadministration of SR and AGIQ altered mRNA levels of lipogenic enzymes ( Scd1 and Fasn), antioxidant-related enzymes ( Catalase), NOX component ( P67phox), and anti-inflammatory transcriptional factor ( Pparg). Our results indicated that SR in combination with AGIQ had the potential of suppressing hyperlipidemia- and steatosis-related early hepatocarcinogenesis through the reduced expression of NOX subunits.