Aristolochia manshuriensis Kom ethyl acetate extract protects against high-fat diet-induced non-alcoholic steatohepatitis by regulating kinase phosphorylation in mouse

Aristolochia manshuriensis Kom (AMK) is an herb used as a traditional medicine; however, it causes side effects such as nephrotoxicity and carcinogenicity. Nevertheless, AMK can be applied in specific ways medicinally, including via ingestion of low doses for short periods of time. Non-alcoholic steatohepatitis (NASH) induced the hepatocyte injury and inflammation. The protective effects of AMK against NASH are unclear; therefore, in this study, the protective effects of AMK ethyl acetate extract were investigated in a high-fat diet (HFD)-induced NASH model. We found decreased hepatic steatosis and inflammation, as well as increased levels of lipoproteins during AMK extract treatment. We also observed decreased hepatic lipid peroxidation and triglycerides, as well as suppressed hepatic expression of lipogenic genes in extract-treated livers. Treatment with extract decreased the activation of c-jun N-terminal kinase 1/2 (JNK1/2) and increased the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). These results demonstrate that the protective effect of the extract against HFD-induced NASH occurred via reductions in reactive oxygen species production, inflammation suppression, and apoptosis related to the suppression of JNK1/2 activation and increased ERK1/2 phosphorylation. Taken together, these results indicate that that ethyl acetate extract of AMK has potential therapeutic effects in the HFD-induced NASH mouse model.

Chemopreventive effect of alpha-viniferin in azoxymethane-induced mouse colorectal tumor and Caco-2 cells / 동물의과학연구지

alpha-Viniferin (AVF), a trimer of resveratrol, is known to have an anti-inflammatory effect via inhibition of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). It has been reported that up-regulated COX-2 and iNOS are expressed in colon cancer tissues of humans and rodents as well as pre-neoplastic aberrant crypt foci (ACF) of rodents. In this study, chemopreventive effects of AVF were assessed in Caco-2 cells as well as azoxymethane (AOM)-induced colorectal tumorigenesis in mice. Anti-tumor effect of AVF with regards to apoptotic induction was assessed by TUNEL and caspase-3 expression in human colon cancer Caco-2 cells. For development of ACF, AOM was administered with to mice intraperitoneally at a dose of 10 mg/kg once a week for 3 weeks. To induce colitis-related colon cancer, mice were administered a single dose of AOM (10 mg/kg) and 2% dextran sodium sulfate in drinking water. Mice treated with 0.05 and/or 0.1 mg of AVF by gavage showed significantly reduced development of ACF and colorectal tumors. Immunofluorescence detection in Caco-2 cells showed reduced COX-2 and iNOS expression, whereas cleavage of caspase-3 and apoptotic cell numbers increased upon AVF treatment. Immunostaining showed reduced expression levels of COX-2 and iNOS expression along with increased cleaved caspase-3 expression increased upon AVF treatment. These results suggest that AVF has chemopreventive effects on colorectal cancer via anti-inflammatory potential and pro-apoptotic activity.

Erratum

No abstract available.

Human leukocytes regulate ganglioside expression in cultured micro-pig aortic endothelial cells / 한국실험동물학회지

Gangliosides are ubiquitous components of the membranes of mammalian cells that are thought to play important roles in various cell functions such as cell-cell interaction, cell adhesion, cell differentiation, growth control, and signaling. However, the role that gangliosides play in the immune rejection response after xenotransplantation is not yet clearly understood. In this study, the regulatory effects of human leukocytes on ganglioside expression in primary cultured micro-pig aortic endothelial cells (PAECs) were investigated. To determine the impact of human leukocytes on the expression of gangliosides in PAECs, we performed high-performance thin layer chromatography (HPTLC) in PAECs incubated with FBS, FBS containing human leukocytes, human serum containing human leukocytes, and FBS containing TNF-alpha. Both HPTLC and immunohistochemistry analyses revealed that PAECs incubated with FBS predominantly express the gangliosides GM3, GM1, and GD3. However, the expression of GM1 significantly decreased in PAECs incubated for 5 h with TNF-alpha (10 ng/mL), 10% human serum containing human leukocytes, and 10% FBS containing human leukocytes. Taken together, these results suggest that human leukocytes induced changes in the expression profile of ganglioside GM1 similar to those seen upon treatment of PAECs with TNF-alpha. This finding may be relevant for designing future therapeutic strategies intended to prolong xenograft survival.

Relationship between ganglioside expression and anti-cancer effects of the monoclonal antibody against epithelial cell adhesion molecule in colon cancer

The human colorectal carcinoma-associated GA733 antigen epithelial cell adhesion molecule (EpCAM) was initially described as a cell surface protein selectively expressed in some myeloid cancers. Gangliosides are sialic acid-containing glycosphingolipids involved in inflammation and oncogenesis. We have demonstrated that treatment with anti-EpCAM mAb and RAW264.7 cells significant inhibited the cell growth in SW620 cancer cells, but neither anti-EpCAM mAb nor RAW264.7 cells alone induced cytotoxicity. The relationship between ganglioside expression and the anti-cancer effects of anti-EpCAM mAb and RAW264.7 was investigated by high-performance thin-layer chromatography. The results demonstrated that expression of GM1 and GD1a significantly increased in the ability of anti-EpCAM to inhibit cell growth in SW620 cells. Anti-EpCAM mAb treatment increased the expression of anti-apoptotic proteins such as Bcl-2, but the expression of pro-apoptotic proteins Bax, TNF-alpha, caspase-3, cleaved caspase-3, and cleaved caspase-8 were unaltered. We observed that anti-EpCAM mAb significantly inhibited the growth of colon tumors, as determined by a decrease in tumor volume and weight. The expression of anti-apoptotic protein was inhibited by treatment with anti-EpCAM mAb, whereas the expression of pro-apoptotic proteins was increased. These results suggest that GD1a and GM1 were closely related to anticancer effects of anti-EpCAM mAb. In light of these results, further clinical investigation should be conducted on anti-EpCAM mAb to determine its possible chemopreventive and/or therapeutic efficacy against human colon cancer.

Roles of gangliosides in mouse embryogenesis and embryonic stem cell differentiation

Gangliosides have been suggested to play important roles in various functions such as adhesion, cell differentiation, growth control, and signaling. Mouse follicular development, ovulation, and luteinization during the estrous cycle are regulated by several hormones and cell-cell interactions. In addition, spermatogenesis in seminiferous tubules of adult testes is also regulated by several hormones, including follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and cell-cell interactions. The regulation of these processes by hormones and cell-cell interactions provides evidence for the importance of surface membrane components, including gangliosides. During preimplantation embryo development, a mammalian embryo undergoes a series of cleavage divisions whereby a zygote is converted into a blastocyst that is sufficiently competent to be implanted in the maternal uterus and continue its development. Mouse embryonic stem (mES) cells are pluripotent cells derived from mouse embryo, specifically, from the inner cell mass of blastocysts. Differentiated neuronal cells are derived from mES cells through the formation of embryonic bodies (EBs). EBs recapitulate many aspects of lineage-specific differentiation and temporal and spatial gene expression patterns during early embryogenesis. Previous studies on ganglioside expression during mouse embryonic development (including during in vitro fertilization, ovulation, spermatogenesis, and embryogenesis) reported that gangliosides were expressed in both undifferentiated and differentiated (or differentiating) mES cells. In this review, we summarize some of the advances in our understanding of the functional roles of gangliosides during the stages of mouse embryonic development, including ovulation, spermatogenesis, and embryogenesis, focusing on undifferentiated and differentiated mES cells (neuronal cells).

PPARgamma Inhibits Inflammation through the Suppression of ERK1/2 Kinase Activity in Human Gingival Fibroblasts

Periodontal disease is a major oral disorder and comprises a group of infections that lead to inflammation of the gingiva and the destruction of periodontal tissues. PPARgamma plays an important role in the regulation of several metabolic pathways and has recently been implicated in inflammatory response pathways. However, its effects on periodontal inflammation have yet to be clarified. In our current study, we evaluated the anti-inflammatory effects of PPARgamma on periodontal disease. Human gingival fibroblasts (HGFs) treated with lipopolysaccharide (LPS) showed high levels of intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), matrix metalloproteinase-2 (MMP-2), and -9 (MMP-9). Moreover, these cells also showed upregulated activities for extracellular signal regulated kinase (ERK1/2), inducible nitric oxide synthase (iNOS) and cyclooxygnase-2. However, cells treated with Ad/PPARgamma and rosiglitazone in same culture system showed reduced ICAM-1, VCAM-1, MMP-2, -9 and COX-2. Finally, the anti-inflammatory effects of PPARgamma appear to be mediated via the suppression of the ERK1/2 pathway and consequent inhibition of NF-kB translocation. Our present findings thus suggest that PPARgamma indeed has a pivotal role in gingival inflammation and may be a putative molecular target for future therapeutic strategies to control chronic periodontal disease.

Dynamic changes of gangliosides expression during the differentiation of embryonic and mesenchymal stem cells into neural cells

Stem cells are used for the investigation of developmental processes at both cellular and organism levels and offer tremendous potentials for clinical applications as an unlimited source for transplantation. Gangliosides, sialic acid-conjugated glycosphingolipids, play important regulatory roles in cell proliferation and differentiation. However, their expression patterns in stem cells and during neuronal differentiation are not known. Here, we investigated expression of gangliosides during the growth of mouse embryonic stem cells (mESCs), mesenchymal stem cells (MSCs) and differentiated neuronal cells by using high-performance thin-layer chromatography (HPTLC). Monosialoganglioside 1 (GM1) was expressed in mESCs and MSCs, while GM3 and GD3 were expressed in embryonic bodies. In the 9-day old differentiated neuronal cells from mESCs cells and MSCs, GM1 and GT1b were expressed. Results from immunostaining were consistent with those observed by HPTLC assay. These suggest that gangliosides are specifically expressed according to differentiation of mESCs and MSCs into neuronal cells and expressional difference of gangliosides may be a useful marker to identify differentiation of mESCs and MSCs into neuronal cells.

The Influence of Changes in Preload on Tei index

BACKGROUND: Tei index is a Doppler-derived index of combined systolic and diastolic myocardial performance proposed to be a promising noninvasive measurement of overall cardiac function, calculated as the sum of isovolumic contraction (ICT) and isovolumic relaxation times (IRT) divided by ejection time (ET). This study aimed to investigate the effect of changes in preload on Tei index. SUBJECTS AND METHOD: The study population was 10 patients with chronic renal failure who are on regular hemodialysis (HD). They were 3 men and 7 women with a mean age of 45.3+/-12.4 years old. The complete 2-dimensional and Doppler echocardiography including recordings of mitral inflow and left ventricular outflow were performed using HP SONOS 1500 equipment before and after HD. Body weight was measured using electric scale before and after HD. Blood pressure and pulse rate were measured by an automated cuff measurement every 1 hour throughout HD. Hematocrit was monitored noninvasively and continuously using the Crit-Line instrument (In-Line Diagnostics, Riverdale, UT, USA) during HD. RESULTS: There were no significant changes in systolic and diastolic blood pressure, RR interval, left ventricular end-diastolic and end-systolic dimension, left atrial dimension, and left ventricular ejection fraction during HD. The mean body weight loss during HD was 2.1+/-0.65 kg. The percentage of reduction of body weight was 4.1+/-1.56%. Changes in total blood volume at the end of HD were compared with that of baseline -11.79+/-5.51%. The percent change in total blood volume during the HD correlated significantly with the amount of change in body weight (r=0.678, p<0.05) and percent change in body weight (r=0.835, p<0.01), respectively. ICT before HD and at the end of HD were 39+/-13.0, 42+/-24.1 msec (p=NS). IRT before HD and at the end of HD were 76+/-29.1, 95+/-28.5 msec (p<0.01) and , ET before HD and at the end of HD were 317+/-18.1, 289+/-9.0 msec (p<0.01), respectively. Tei index before HD was 0.36+/-0.10, and the index at the end of HD were 0.47+/-0.13 (p<0.001). CONCLUSION: When there is a change in preload during a short period, it seems that the effect of change in preload should be considered when using Tei index to assess ventricular function.