Hwa g Youn

Transplantation of CTLA4Ig gene-transduced adipose tissue-derived mesenchymal stem cells reduces inflammatory immune response and improves Th1/Th2 balance in experimental autoimmune thyroiditis.

Autoimmune thyroiditis is one of common organ‐specific autoimmune disease. The aim of this study was to observe the effect of adipose tissue derived mesenchymal stem cells (ATMSC) and CTLA4Ig gene‐transduced ATMSC on autoimmune thyroiditis.

Prevalence of Bartonella henselae and Bartonella clarridgeiae in cats and dogs in Korea.

Blood, saliva, and nail samples were collected from 54 dogs and 151 cats and analyzed for the presence of Bartonella henselae with a novel nested polymerase chain reaction (PCR) method. Bartonella (B.) henselae was detected in feral cat blood (41.8%), saliva (44.1%), and nail (42.7%) samples. B. henselae was also detected in pet cat blood (33.3%), saliva (43.5%), and nail (29.5%) samples and in pet dog blood (16.6%), saliva (18.5%), and nail (29.6%) samples. Nine samples were infected with B. clarridgeiae and 2 were co-infected with B. henselae and B. clarridgeiae of blood samples of dogs. This report is the first to investigate the prevalence of B. henselae and B. clarridgeiae in dogs and cats in Korea, and suggests that dogs and cats may serve as potential Bartonella reservoirs.

Detection of betanodaviruses in apparently healthy aquarium fishes and invertebrates.

Betanodaviruses are the causative agents of viral nervous necrosis (VNN) in cultured marine fish. A total of 237 apparently healthy aquarium fish, marine (65 species) and freshwater (12 species) fishes and marine invertebrates (4 species), which were stocked in a commercial aquarium in Seoul, South Korea, were collected from November 2005 to February 2006. The brains of the fish and other tissues of the invertebrates were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR to detect betanodavirus. Positive nested PCR results were obtained from the brains of 8 marine fish species (shrimp fish Aeoliscus strigatus, milkfish Chanos chanos, three spot damsel Dascyllus trimaculatus, Japanese anchovy Engraulis japonicus, pinecone fish Monocentris japonica, blue ribbon eel Rhinomuraena quaesita, look down fish Selene vomer, yellow tang Zebrasoma flavesenes), 1 marine invertebrate species (spiny lobster Pamulirus versicolor), and 2 freshwater fish species (South American leaf fish Monocirrhus polyacanthus and red piranha Pygocentrus nattereri). The detection rate in nested PCR was 11/237 (4.64%). These subclinically infected aquarium fish and invertebrates may constitute an inoculum source of betanodaviruses for cultured fishes in the Korean Peninsula.

Pyridoxine induced neuropathy by subcutaneous administration in dogs.

To construct a sensory neuropathy model, excess pyridoxine (150 mg/kg s.i.d.) was injected subcutaneously in dogs over a period of 7 days. During the administrations period, the dogs experienced body weight reduction and proprioceptive loss involving the hindquarters. After pyridoxine administration was completed, electrophysiological recordings showed that the M wave remained at a normal state, but the H-reflex of the treated dogs disappeared at 7 days. The dorsal funiculus of L4 was disrupted irregularly in the axons and myelin with vacuolation. The dorsal root ganglia of L4, and sciatic and tibial nerves showed degenerative changes and vacuolation. However, the lateral and ventral funiculi of L4 showed a normal histopathologic pattern. Although this subcutaneous administration method did not cause systemic toxicity and effectively induced sensory neuropathy, this study confirmed the possibility of producing a pyridoxine-induced sensory neuropathy model in dogs with short-term administration.

Anti-Tumor Effect of Adipose Tissue Derived-Mesenchymal Stem Cells Expressing Interferon-β and Treatment with Cisplatin in a Xenograft Mouse Model for Canine Melanoma

Adipose tissue-derived mesenchymal stem cells (AT-MSCs) are attractive cell-therapy vehicles for the delivery of anti-tumor molecules into the tumor microenvironment. The innate tropism of AT-MSCs for tumors has important implications for effective cellular delivery of anti-tumor molecules, including cytokines, interferon, and pro-drugs. The present study was designed to determine the possibility that the combination of stem cell-based gene therapy with low-dose cisplatin would improve therapeutic efficacy against canine melanoma. The IFN-β transduced canine AT-MSCs (cAT-MSC-IFN-β) inhibited the growth of LMeC canine melanoma cells in direct and indirect in vitro co-culture systems. In animal experiments using BALB/c nude mouse xenografts, which developed by injecting LMeC cells, the combination treatment of cAT-MSC-IFN-β and low-dose cisplatin significantly reduced tumor volume compared with the other treatment groups. Fluorescent microscopic analysis with a TUNEL (terminal deoxynucleotidyl transferase-mediated nick-end labeling) assay of tumor section provided evidence for homing of cAT-MSC-IFN-β to the tumor site and revealed that the combination treatment of cAT-MSC-IFN-β with low-dose cisplatin induced high levels of cell apoptosis. These findings may prove useful in further explorations of the application of these combined approaches to the treatment of malignant melanoma and other tumors.

Hormonal change and cytokine mRNA expression in peripheral blood mononuclear cells during the development of canine autoimmune thyroiditis.

To elucidate the hormonal change and alteration in cytokine expression in peripheral blood mononuclear cells (PBMC) during the early stage of autoimmune thyroiditis, we have developed a canine model of this disease, in which normal dogs were immunized with bovine thyroglobulin (Tg) and/or canine thyroid extract. Serum samples were collected weekly, anti‐canine Tg antibody was measured by enzyme‐linked immunosorbent assay (ELISA) and thyroid stimulating hormone (TSH) and total T4 levels by radioimmunoassay. We also assayed T lymphocyte proliferation in response to Tg, as well as measuring cytokine mRNA by semiquantitative reverse transcription–polymerase chain reaction (RT–PCR). All six dogs immunized with bovine Tg had both canine Tg autoantibody and anti‐T4 antibody. When the sample from the highest TgAA titre time‐point was compared with baseline the expression of mRNA encoding the Th1‐type cytokine such as interferon (IFN)‐γ, interleukin (IL)‐18 and IL‐15 was increased during the development of autoimmune thyroiditis. Expression of the Th2‐type cytokine, IL‐6 showed minimal change and IL‐4 expression was not detected in any of the samples. Expression of the T suppressive cytokine, IL‐10 and transforming growth factor (TGF)‐β was increased in the presence of antigen stimulation. These findings suggest that, although autoimmune thyroiditis is an organ‐specific autoimmune disease, systemic cytokine mRNA expression is also changed.

Therapeutic effects of hepatocyte growth factor-overexpressing human umbilical cord blood-derived mesenchymal stem cells on liver fibrosis in rats

Fibrosis is a common end stage for a variety of liver diseases, including most chronic liver diseases, and results from an imbalance between collagen deposition and degradation. Mesenchymal stem cells (MSCs) have the ability to migrate into fibrotic livers and differentiate into hepatocytes. Hepatocyte growth factor (HGF) has potent anti‐apoptotic and mitogenic effects on hepatocytes during liver injury and plays an essential role in the development and regeneration of the liver. In this study, human HGF‐overexpressing human umbilical cord blood‐derived MSCs (hHGF‐HUCB‐MSCs) were prepared using the pMEX Expression System, and the upregulation of hHGF expression was confirmed by RT‐PCR and ELISA. HGF expressed by hHGF‐HUCB‐MSCs exerted a stimulatory effect on hepatocyte proliferation in vitro. hHGF‐HUCB‐MSCs were transplanted to investigate the therapeutic effects of these cells on carbon tetrachloride (CCL4)‐induced liver fibrosis in a rat model. After 4 weeks of cell treatment once per week with 2 × 106 cells, biochemical analysis of the serum and histopathological analysis of the liver tissue were performed. The results of the biochemical analysis of the serum show that the hHGF‐HUCB‐MSC‐treated group had higher levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase, indicating the improvement of liver function. Histopathology showed that the hHGF‐HUCB‐MSC‐treated group had reduction in the density of collagen fibres. Thus hHGF‐HUCB‐MSCs can enhance liver regeneration and could be useful for the treatment of patients with liver fibrosis or cirrhosis.

Hypoglycemic effects of vanadium on alloxan monohydrate induced diabetic dogs.

The hypoglycemic effects after oral administration of vanadium have been studied previously in many species such as rats, mice and even humans. However, there has been no prior report on the glucose lowering effect of vanadium on diabetic dogs. Therefore, the purpose of this study was to evaluate the hypoglycemic effects of oral vanadium on diabetic dogs. Diabetes mellitus in the dogs studied was induced by alloxan monohydrate intravenous injection. The dogs were divided into two groups, one was the diabetic control (DC) group (n = 4) and the other was the vanadium treated (DV) group (n = 6). Fresh water was supplied to the dogs in the DC group, but sodium metavanadate solution (0.1~0.2 mg/ml) was given to the dogs in DV group from one week after the alloxan injection. The fasting glucose levels, fructosamine and serum chemistry profiles were compared between the two groups weekly for three weeks. The fasting blood glucose levels in DV group were significantly lower than those in the DC group (p < 0.01). Fructosamine levels in the DV group were also lower than those in the DC group (p < 0.05). The serum chemistry profiles were not significantly different in comparisons between the two groups. However, the cholesterol levels were significantly lower in the DV group compared to the DC group (p < 0.05). Our findings showed that oral vanadium administration had a hypoglycemic effect on chemically induced diabetic dogs.

Epitheliotropic cutaneous lymphoma (mycosis fungoides) in a dog.

A seven-year-old castrated male Yorkshire terrier dog was presented for a recurrent skin disease. Erythematous skin during the first visit progressed from multiple plaques to patch lesions and exudative erosion in the oral mucosa membrane. Biopsy samples were taken from erythematous skin and were diagnosed with epitheliotropic T cell cutaneous lymphoma by histopathology and immunochemical stain. In serum chemistry, the dog had a hypercalcemia (15.7 mg/dl) and mild increased alkaline phosphatase (417 U/l). Immunohistochemistry was performed to detect parathyroid hormone-related peptide (PTH-rP) in epitheliotropic cutaneous lymphoma tissues but the neoplastic cells were not labeled with anti-PTH-rP antibodies. The patient was treated with prednisolone and isotretinoin. However, the dog died unexpectedly.

Genistein inhibits pro‑inflammatory cytokines in human mast cell activation through the inhibition of the ERK pathway

Anaphylaxis is a rapidly occurring allergic reaction to any foreign substance, including venom from insects, foods and medications, which may cause fatalities. To prevent anaphylaxis, these triggers must be avoided. However, avoidance of numerous triggers is difficult. For this reason, the development of immunotherapeutic adjuvants that suppress the allergic response is important for anaphylaxis control. Mast cells are one of the major inflammatory cells involved in the inflammatory response, which secrete several inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β, and recruits other immune cells. Mast cells are also involved in a number of diseases, such as sinusitis, rheumatoid arthritis and asthma. Genistein, a phytoestrogen, has been reported to have anti-oxidative and anti-inflammatory activities. However, the effects of genistein on the anti-inflammatory response of mast cells remain unknown. In the present study, the anti-inflammatory effects of genistein on mast cells were investigated. Genistein significantly decreased IL-6 and IL-1β mRNA levels, as well as IL-6 production in PMA/A23187-induced mast cells activation. In addition, genistein inhibited the phosphorylation of ERK 1/2 in PMA/A23187-induced mast cell activation. However, phosphorylation of p38 was not altered. Thus, these findings indicate that genistein inhibited the inflammatory status of mast cells through inhibition of the ERK pathway.