Anticancer activity of IRAK-4 inhibitors against canine lymphoid malignancies.

The interleukin-1 receptor-related kinase 4 (IRAK4), downstream of myd88, plays an essential role in hyperactive TLR signalling seen in some B-cell lymphomas. In particular, efficient IRAK4 inhibitors of activated B-cell subtype of human diffuse large B-Cell lymphoma (DLBCL) are being developed. However, the anticancer effect of IRAK-4 inhibitors in veterinary medicine has not been elucidated. It is therefore explored in this study involving the GL-1 and CL-1 canine lymphoma cell lines in vitro. MyD88 expression was analysed using polymerase chain reaction. GL-1 and CL-1 cells were subjected to concentration- and time-dependent treatment with an IRAK-4 inhibitor and assessed for viability, TLR signalling association and apoptosis using a cell counting Kit-8 assay, Western blotting and flow cytometry. The GL-1 and CL-1 cells exhibited enhanced MyD88 expression, however, canine peripheral blood mononuclear cells (cPBMCs) did not. The IRAK-4 inhibitor reduced cell viability in a dose- and time-dependent manner, significantly reduced the phosphorylation of molecules associated with TLR signalling at IC50 such as IRAK1, IRAK4, NF-κB and STAT3, and induced apoptosis in GL-1 and CL-1 cells. The anticancer effect of the IRAK-4 inhibitor on canine lymphoma cells is mediated by apoptosis via downregulation of TLR signalling.

Safety evaluation of FM101, an A3 adenosine receptor modulator, in rat, for developing as therapeutics of glaucoma and hepatitis.

Adenosine is a critical regulator of inflammation and fibrosis, it affects endogenous cell signaling via binding to the A3 adenosine receptor. FM101 is a potent, highly selective A3 adenosine receptor modulator that has been developed as a treatment for glaucoma and hepatitis. We determined that FM101 is a biased ligand with functional activities both as a G protein agonist and a ß-arrestin antagonist. The safety of FM101 was evaluated by administering an acute dose in rats, the results indicated that the approximate lethal dose was greater than 2000 mg/kg. In a subchronic toxicity study, FM101 was administered orally once per day to rats at doses of 250, 500, and 1000 mg/kg/day over a period of 28 days. Abnormal posture, irregular respiration, decreased movement, and ear flushing were observed during the early phase of dosing, and loose stools were observed sporadically among the animals that received 500 and 1000 mg/kg/day. Body weight and food consumption were decreased in one male and one female rat in the 1000 mg/kg/day group during the first 2 weeks of observation. However, there were no test substance-related changes or adverse effects observed during our ophthalmological, clinical chemistry, urine, organ weight, and histopathological analysis. These findings indicate that no observed adverse effect level of FM101 was 1000 mg/kg/day in male and female rats.

Correlation study between A3 adenosine receptor binding affinity and anti-renal interstitial fibrosis activity of truncated adenosine derivatives.

Truncated 4'-thionucleosides 1-4 and 4'-oxonucleosides 5-8 as potent and selective A3AR antagonists were synthesized from D-mannose and D-erythronic acid γ-lactone, respectively. These nucleosides were evaluated for their anti-fibrotic renoprotective activity in TGF-ß1-treated murine proximal tubular (mProx) cells. Their antagonistic activities for A3AR were proportional to their inhibitory activities against TGF-ß1-induced collagen I upregulation in mProx cells. This result suggests that the binding affinity of A3AR antagonists is closely correlated with their anti-fibrotic activity. Thus, A3AR antagonists might be novel therapeutic candidates for treating chronic kidney disease.

Pro-apoptotic and Growth-inhibitory Effect of IFN-ß-Overexpressing Canine Adipose Tissue-derived Mesenchymal Stem Cells Against Melanoma Cells.

BACKGROUND: Canine melanoma is the most common type of tumor in dogs. We investigated the effects of canine interferon-beta (cIFN-ß)-overexpressing adipose tissue-derived mesenchymal stem cells (cATMSCs) on apoptosis and proliferation of canine melanoma cells. MATERIALS AND METHODS: Expression of IFN-ß in cATMSCs was confirmed using reverse transcription-polymerase chain reaction and enzyme linked immunosorbent assays. Flow cytometry was performed for cell-cycle analysis and apoptotic cell quantification of LMeC (melanoma) cells. Protein expression of cyclin D1, procaspase-3, activated caspase-3, and Bcl-2 homologous antagonist killer (Bak) was evaluated by western blot analysis. RESULTS: Decreased proportions of cells in S- and G0/G1 phases were observed in parallel with decreased cyclin D1 expression in LMeC cells treated with cIFN-ß-cATMSC-conditioned media. Protein expression of active forms of caspase 3 and Bak increased in response to treatment with cIFN-ß-cATMSC-conditioned media. CONCLUSION: IFN-ß overexpression by cATMSCs was associated with pro-apoptotic and growth-inhibitory effects on canine melanoma cells. The antitumor effects of these cells have therapeutic potential for the treatment of canine melanoma.

Acute and 28-Day Subacute Toxicity Studies of Hexane Extracts of the Roots of Lithospermum erythrorhizon in Sprague-Dawley Rats.

Lithospermum erythrorhizon has long been used as a traditional oriental medicine. In this study, the acute and 28-day subacute oral dose toxicity studies of hexane extracts of the roots of L. erythrorhizon (LEH) were performed in Sprague-Dawley rats. In the acute toxicity study, LEH was administered once orally to 5 male and 5 female rats at dose levels of 500, 1,000, and 2,000 mg/kg. Mortality, clinical signs, and body weight changes were monitored for 14 days. Salivation, soft stool, soiled perineal region, compound-colored stool, chromaturia and a decrease in body weight were observed in the extract-treated groups, and no deaths occurred during the study. Therefore, the approximate lethal dose (ALD) of LEH in male and female rats was higher than 2,000 mg/kg. In the subacute toxicity study, LEH was administered orally to male and female rats for 28 days at dose levels of 25, 100, and 400 mg/kg/day. There was no LEH-related toxic effect in the body weight, food consumption, ophthalmology, hematology, clinical chemistry and organ weights. Compound-colored (black) stool, chromaturia and increased protein, ketone bodies, bilirubin and occult blood in urine were observed in the male and female rats treated with the test substance. In addition, the necropsy revealed dark red discoloration of the kidneys, and the histopathological examination showed presence of red brown pigment or increased hyaline droplets in the renal tubules of the renal cortex. However, there were no test substance-related toxic effects in the hematology and clinical chemistry, and no morphological changes were observed in the histopathological examination of the kidneys. Therefore, it was determined that there was no significant toxicity because the changes observed were caused by the intrinsic color of the test substance. These results suggest that the no-observed-adverse-effect Level (NOAEL) of LEH is greater than 400 mg/kg/day in both sexes.