Cell Nuclear Antigen-positive Nuclei Research Articles

Dipeptidyl-peptidase-4 inhibitor, alogliptin, attenuates arterial inflammation and neointimal formation after injury in low-density lipoprotein (LDL) receptor-deficient mice.

BackgroundThe results of recent studies suggest that dipeptidyl‐peptidase‐4 inhibitors have antiatherogenic effects. However, whether or not dipeptidyl‐peptidase‐4 inhibitors could suppress arterial inflammation and intimal hyperplasia after injury remains undetermined. The present study aims to clarify the anti‐inflammatory effects of the dipeptidyl‐peptidase‐4 inhibitor, alogliptin (AGP), on the arteries of atherogenic low‐density lipoprotein receptor‐deficient (LKO) mice.Methods and ResultsWe compared intimal hyperplasia in LKO mice 2 weeks after femoral artery injury using an external vascular cuff model. All mice received oral injection of AGP (20 mg/kg per day) or normal saline (control) once daily for 14 days. Fasting blood sugar levels, serum cholesterol levels, or blood pressure did not significantly differ between the 2 groups. Plasma levels of active glucagon‐like peptide‐1 were higher in the AGP than in the control LKO mice (22.2±1.9 versus 15.6±0.9 pg/mL; P<0.05). Compared with saline, AGP significantly reduced intimal hyperplasia (1087±127 versus 1896±140 μm2; P<0.001) as well as the intima/media ratio (0.08±0.01 versus 0.16±0.02; P<0.001). Immunostaining showed that AGP reduced proliferating cells (proliferating cell nuclear antigen–positive nuclei; P<0.001), percent smooth‐muscle cell area (α‐SMA‐positive cells; P<0.001), inflammatory cells infiltration (lymphocyte antigen 6 complex–positive cells; P<0.05), tumor necrosis factor‐α expression (P<0.05), and percent phospho‐NF‐κB‐positive cell compared with saline. Levels of tumor necrosis factor ‐α (0.5‐fold P<0.05), monocyte chemoattractant protein 1 (0.3‐fold P<0.01), and interleukin‐1β (0.2‐fold P<0.05) mRNA were lower in the injured arteries of the AGP than in the control group.ConclusionsAGP appeared to suppress neointimal formation by inhibiting inflammation, independently of its effects on glucose or cholesterol metabolism in atherogenic LKO mice.

Intervention of ginger or propolis ameliorates methotrexate-induced ileum toxicity.

The long-term clinical use of methotrexate (MTX) is restricted due to its severe intestinal toxicity. The protective effect of ginger or propolis on the toxicity induced by MTX is relatively less understood, so the possible protective effect of ginger or propolis, used separately, was investigated. A total of 60 male albino rats were divided into six groups as follows: (1) control group; (2) ginger group; (3) propolis group; (4) MTX group; (5) ginger + MTX group; and (6) propolis + MTX group. The present results show that MTX caused ileum injury, including shortening and fusion of the villi, inflammatory cell infiltration and goblet cell depletion. Administration of ginger or propolis ameliorated the MTX-induced ileum injury as shown by histological, immunohistochemical and ultrastructural investigations and statistical analysis. This is revealed by intact villi, which shows marked increase in brown colouration of proliferating cell nuclear antigen positive nuclei in the crypts region, improvement in the number of goblet cells and brush border length of ileum. The current results conclude the efficacy and safety of ginger and propolis, which may be due to their antioxidant properties.

Suppression of Right Ventricular Hypertrophy After Extensive Pulmonary Resection in Rats by Granulocyte Colony-Stimulating Factor

The objective of the present study was to investigate the effects of granulocyte colony-stimulating factor (G-CSF) on right ventricular hypertrophy following extensive pulmonary resection in rats. Adult rats were divided into four groups: (1) Group S (right thoracotomy only); (2) Group L (right three lobectomy); (3) Group LG10 (Group L+G-CSF [10microg/kg/d]); and (4) Group LG100 (Group L+G-CSF [100microg/kg/d]). At postoperative day 21, weight ratio of the right ventricular to the left ventricle plus septum (RV/LV+S, indicator of right ventricular hypertrophy) were measured, and a histopathological study was conducted to determine percentage wall thickness of peripheral pulmonary arteries and proliferating cell nuclear antigen labeling index (indicator of oxidative DNA damage) of right ventricles. Mean RV/LV+S for Group S was 0.27+/-0.02, significantly smaller than that for the lobectomy groups (Group L, LG10, LG100; 0.47+/-0.05, 0.35+/-0.02, 0.38+/-0.05). G-CSF significantly suppressed right ventricular hypertrophy. Mean medial wall thickness of peripheral pulmonary arteries for Group S was 13.6% +/- 4.9%, significantly smaller than that for Group L (22.9% +/- 9.6%). Compared with Group L, G-CSF reduced medial wall thickness (LG10, 17.6% +/- 9.5%; LG100, 18.0% +/- 11.2%). Incidence of proliferating cell nuclear antigen positive nuclei for Group S was 1.07% +/- 0.49%, significantly smaller than that for Group L (13.77% +/- 5.87%). G-CSF significantly reduced the incidence of proliferating cell nuclear antigen positive nuclei (LG10, 4.04% +/- 2.14%; LG100, 3.18% +/- 1.66%). G-CSF administration not only reduce medial wall thickness of peripheral pulmonary arteries but also directly protect cardiomyocytes of the right ventricle, thus suppressing right ventricular hypertrophy. These results suggest that low-dose G-CSF administration can prevent right heart failure following extensive pulmonary resection.

Hematopoietic stem cells mobilized by granulocyte colony-stimulating factor partly contribute to liver graft regeneration after partial orthotopic liver transplantation

On the basis of the recently recognized potential of hematopoietic stem cells (HSCs) to give rise to hepatocytes, we investigated whether HSCs mobilized by granulocyte colony-stimulating factor (G-CSF) or G-CSF per se could contribute to faster recovery and promote tissue reparation after rats' (cross-sex) partial orthotopic liver transplantation (PLTx). Sex-mismatched (female to male) syngeneic rat PLTx was established. The recipients were repeatedly administrated recombinant G-CSF for 5 consecutive days before (G-CSF + PLTx group) and after PLTx (PLTx + G-CSF group). Compared with those in PLTx group, CD34+ cells in peripheral blood and portal tract region increased from day 1 to 7 after transplantation in G-CSF + PLTx group and from day 3 to 14 after transplantation in PLTx + G-CSF group, respectively, which suggested that CD34+ HSCs were mobilized and migrated into liver graft. Compared with that in G-CSF + PLTx and PLTx groups, there was a higher survival rate in the PLTx + G-CSF group. On day 3 after surgery, the level of aspartate aminotransferase and alanine aminotransferase were lower, whereas the mitosis index, proliferating cell nuclear antigen-positive nuclei, bromodeoxyuridine (BrdU) incorporation, and graft-to-recipient weight ratio were higher in the PLTx + G-CSF group. In contrast, these parameters had no significant difference between G-CSF + PLTx and PLTx groups. To define the origin of proliferating cells reconstituting liver after injury, sry+ (sex-determining region for Y chromosome) and sry+/cytokeratin 19+ (CK19) cells were quantitated. Higher percentage of sry+ and sry+/CK19+ cells in PLTx + G-CSF was detected than in G-CSF + PLTx groups on day 14 after surgery, although the liver engraftment rate still remained rather low. Some of the sry+/CK19+ cells in the portal tract areas were similar to hepatic oval cells/cholangiocytes. In conclusion, G-CSF administration after PLTx greatly improved survival rate and liver regeneration of partial graft, partly by its mobilizing HSCs into the injured liver to differentiate into hepatocytes through hepatic oval cells'/cholangiocytes' engraftment.

Endothelin-1 is involved in the growth promotion of vascular smooth muscle cells by hyaluronic acid

Proliferation of vascular smooth muscle cells (VSMC) is crucial to the progression of arteriosclerosis. In this study, we examined the role that interactions among endothelin-1 (ET-1), CD44, and hyaluronic acid (HA) play in VSMC proliferation. Co-localization of ET-1, CD44 and HA positive areas, as well as proliferating cell nuclear antigen positive nuclei, were observed in mouse neointima induced by endothelial injury. As found in intimal VSMC, cultured mouse VSMC secreted ET-1. The endothelin-converting enzyme (ECE) inhibitor, phosphoramidon, and endothelin type-A (ETA) receptor antagonist BQ-123 reduced expression of CD44 in VSMC. ET-1 reversed the reduction of CD44 expression by phosphoramidon. Because CD44 is a receptor for HA, we investigated the effects of phosphoramidon, BQ-123 or ET-1 on the mitogenic activity of HA in VSMC. Among the different molecular weights of this polysaccharide, oligosaccharides of HA (oHA) stimulated VSMC proliferation most effectively. Phosphoramidon and BQ-123 inhibited this oHA-induced DNA synthesis in VSMC. ET-1 reversed the suppression of oHA-induced proliferation by phosphoramidon. In conclusion, endogenously secreted ET-1 enhances oHA-stimulated VSMC growth via the ETA receptor in an autocrine manner. Thus it is suggested that the CD44-inducing activity of ET-1 is responsible for its stimulating effect on oHA-dependent growth of VSMC. These findings support the hypothesis that the interactions among ET-1, CD44 and HA promote the progression of arteriosclerosis.

Mesangial Cell Proliferation in Long-Term Streptozotocin-Induced Diabetes mellitus in the Rat and the Renoprotective Activity of Heparin

At present, it is not clear whether mesangial proliferation underlies mesangial expansion in diabetic nephropathy. To address this issue and the relationship between heparin’s renoprotective and antimitogenic activities, we studied three streptozotocin-induced diabetic rat groups 5 and 12 months after diabetes induction: two groups were administered a modified heparin, each with a different protocol, and two healthy rat groups, one of which was treated with the same heparin, served as controls. Untreated diabetic animals developed clear evidence of nephropathy, namely expansion of the glomerular extracellular matrix, as expressed by glomerular basement membrane thickening, and increased mesangial deposition of type IV collagen. These alterations were prevented/cured by heparin treatment. Kidney sections were processed immunohistochemically for proliferating cell nuclear antigen and smooth muscle α-actin which is expressed only by proliferating mesangial cells. The number of proliferating cell nuclear antigen positive nuclei and α-actin-positive cells per glomerulus did not differ between groups at both 5 and 12 months. In conclusion, there is no evidence that mesangial proliferation is increased in late experimental diabetic nephropathy, and heparin seems to be renoprotective through mechanisms other than antiproliferation.