Overexpression of membrane-type matrix metalloproteinase-1 gene induces mammary gland abnormalities and adenocarcinoma in transgenic mice.

To investigate the role of membrane-type matrix metalloproteinase-1 (MT1-MMP) in mammary gland development and tumorigenesis, transgenic mice overexpressing MT1-MMP in mammary gland under the control of the mouse mammary tumor virus long terminal repeat-promoter were generated. The mouse mammary tumor virus/MT1-MMP transgenic mice displayed abnormalities in 82% of female mammary glands. The abnormalities were verified as lymphocytic infiltration, fibrosis, hyperplasia, alveolar structure disruption, dysplasia, and adenocarcinoma. Northern and reverse transcription-PCR analyses demonstrated that MT1-MMP mRNA was overexpressed in mammary glands exhibiting abnormalities. Western blot analysis and immunohistochemical studies have revealed that the protein expression level was also increased in these glands. In addition, the beta-casein gene as a functional epithelial cell marker was poorly expressed in the mammary glands of transgenic mice exhibiting abnormalities. Gelatin zymography showed significantly increased MMP-2 activation in these mammary glands. These results showed that overexpression of MT1-MMP induced remodeling of the extracellular matrix and tumor formation in the mammary glands of transgenic mice. Therefore, we suggest that overexpression of MT1-MMP may play a key role in development and tumorigenesis in mammary glands.

Mizoribine-mediated apoptotic signaling pathway in human T-Cell line.

Mizoribine (MZR), an inhibitor of inosine monophosphate dehydrogenase, which depletes cellular guanadine triphosphate, is an immunosuppressive drug. The aim of this study was to evaluate the mechanism by which MZR exerts cytotoxic effects on human Jurkat T cells. Our study showed that MZR-induced apoptotic death of human Jurkat T cells is dose-dependent and time-dependent, as revealed by chromatin condensation and H2AX phosphorylation. Furthermore, MZR increased the catalytic activity of caspase family cysteine proteases, including caspase-3, caspase-8, and caspase-9, in human Jurkat T cells. In conclusion, MZR induces the apoptotic death of human Jurkat T cells via activation of caspase family proteases as well as by mitochondrial dysfunction.

Epidemiological characteristics of rabies in South Korea from 1993 to 2001.

In the nine years from 1993 to 2001, 210 cases of rabies were recorded in domestic animals in South Korea; 115 cattle, 94 dogs and one farmed deer were affected. The annual incidence of rabies cases increased to a peak of 64 in 1998, and then decreased to about 30 cases per year. The cases were confined to the northern part of Kyounggi and Kangwon provinces. One hundred and forty-six cases (69.5 per cent) occurred in Kyounggi and 64 cases (30.5 per cent) in Kangwon province, and about 82 per cent of them were confined to two counties in Kyounggi province (29 per cent in Paju and 28.1 per cent in Younchun) and to Chulwon county in Kangwon province (25.2 per cent). However, over several years the outbreaks gradually moved south and east in both Kyounggi and Kangwon provinces. There were more rabies cases in cattle than in dogs, suggesting that the disease is transmitted by the sylvatic cycle. To investigate the relationship between rabies in domestic animals and wild animals, 107 wild animals, including Korean raccoon dogs, badgers, weasels and feral cats, were tested for rabies; 21 of the 67 Korean raccoon dogs tested (31 per cent) were infected. The cases in domestic animals were most common in winter, from December to February, and least common in summer, from June to September.

Transforming growth factor-beta 1 inhibits human arterial smooth-muscle cell proliferation in a growth-rate-dependent manner.

BACKGROUND: Proliferation of arterial smooth-muscle cells is central in the development of both atherosclerosis and intimal hyperplasia. The cytokine transforming growth factor-beta 1 (TGF-beta 1) is known to have variable effects on smooth-muscle cell proliferation. Using human arterial smooth-muscle cells, we sought (1) to define the serum concentrations required to maintain cellular proliferation; and (2) to define the effects of TGF-beta 1 on smooth-muscle cell proliferation. METHODS: Smooth-muscle cell cultures were established from the normal aorta of transplant donors. Cells were grown to subconfluent and confluent densities, then incubated in either serum-free media, or 1% or 10% fetal bovine serum (FBS) enhanced media. Cellular proliferation was assayed by cell counting at 24, 48, and 96 hours to establish growth rate. Identical experiments with the addition of recombinant human TGF-beta 1 (5 ng/mliters) were also performed. Studies were done in triplicate for each group, and results expressed as the mean +/- SE. Groups were compared by analysis of variance. RESULTS: In subconfluent cultures, only smooth-muscle cells in 10% FBS proliferated, whereas growth arrest occurred in serum-free media and 1% FBS. In confluent cultures, cells in all media conditions proliferated. TGF-beta 1 had an inhibitory effect in actively proliferating cultures. There was a positive correlation between the inhibitory effects of TGF-beta 1 and smooth-muscle cell growth rate (r = .65; P = 0.005). CONCLUSIONS: When confluent, human arterial smooth-muscle cells continue to proliferate after serum deprivation, suggesting that these cells are capable of conditioning their own medium. TGF-beta 1 inhibits smooth-muscle cell proliferation in a growth-rate-dependent manner. These data suggest that TGF-beta 1 may have a growth-regulatory role in vascular disease by counteracting states of arterial smooth-muscle cell proliferation.

Maintenance and characterization of multipotent mesenchymal stem cells isolated from canine umbilical cord matrix by collagenase digestion.

Multipotent mesenchymal stem cells have been considered as a novel clinical approach for cell therapy and regenerative medicine. In this study, mesenchymal stem cells (MSCs) were successfully isolated from canine umbilical cord matrix (cUCM; also referred to as Wharton's Jelly) by collagenase digestion and further characterized for multipotent properties associated with MSCs. Our cUCM-derived MSCs (cUCM-MSCs) were plastic adherent, spindle-shaped and fibroblast-like cells, maintaining expression of pluripotency markers such as Oct3/4, Nanog, Sox-2 and SSEA-4 as well as normal chromosomal number during a long-term proliferative culture. The cells expressed MSCs-specific surface markers, including CD44, CD90, CD105, and CD184, but did not CD29, CD33, CD34, and CD45. More importantly, cUCM-MSCs could differentiate into mesodermal (adipocyte, osteocyte and chondrocyte) and ectodermal (neuronal cell) cell lineages. These results imply that collagenase digestion would be a highly effective way to isolate multipotent MSCs in abundant amounts.

Mizoribine versus mycophenolate mofetil in combination therapy with tacrolimus for de novo kidney transplantation: evaluation of efficacy and safety.

The present study compared the efficacy and safety of mizoribine (MZR) with mycophenolate mofetil (MMF) in kidney transplantation. This multicenter, randomized clinical trial. Employed doses of study drug tailored to the immunosuppressive need. The primary efficacy outcome was the incidence of biopsy-proven acute rejection episodes (BPAR). The safety of the study drug was assessed using the incidences of adverse events, drug discontinuations, and abnormal laboratory results. The 7 (6.4%) BPARs above grade II were observed in the MZR group noninferior to the 2 (1.8%) in the MMF group (95% confidence interval, -0.007-0.097 > noninferiority limit [-0.2]). BPAR was significantly decreased in the MZR group after the dose change (17/41 [41.4%] vs 8/69 [11.6%]; P < .0001) and the incidence of BPAR was similar between the MZR and MMF groups after the dose change (P = .592). The uric acid level was significantly elevated in the MZR group (P = .002). In conclusion, the efficacy and safety of MZR were similar and statistically noninferior to MMF in combination therapy with tacrolimus.

Mucosal protective effect of PGI2 on canine small bowel auto-transplantation.

PURPOSE: We designed this experimental study to assess the mucosal protective effects of continuous prostaglandin I2 (PGI2) infusion after canine small bowel autotransplantation. MATERIALS AND METHODS: Six Mongrel dogs were randomly divided two groups: PGI2 (n = 3) and control (n = 3). The small bowel from jejunum to ileum was obtained, including the mesenteric vascular pedicle. After cold flushing ex vivo, the harvested segment was preserved in an icebox for 3 hours. Thereafter we reimplanted the harvested intestinal segment. While completing the anastomosis, PGI2 (50 µg) was slowly infused through the mesenteric artery in the PGI2 group versus the same volume of saline in the control group. At 1, 3 and 6 days after autotransplantation, we obtained blood samples, and at 6 days, small bowel segments. Endotoxin and interleukin 6 (IL-6) levels were measured and all histologic specimens stained with hematoxylin-eosin H-E were reviewed by a pathologist to grade mucosal damage as: mild (1 point), moderate (2 points), or severe (3 points) change. RESULTS: Mean basal serum endotoxin levels were similar in both groups the PGI2 groups versus control group were 0.216 ± 0.018 versus 0.223 ± 0.040 EU/mL, respectively. However, on day 3 after the operation, the PGI2 group showed much decreased levels of serum endotoxin compared to control levels: 0.349 ± 0.196 versus 0.842 ± 0.446 EU/mL. The mean concentration of serum IL-6 on day 1 after operation among the PGI2 versus control group were 32.13 ± 7.13 pg/mL versus 36.96 ± 3.65 pg/mL. The histologic scores at 6 days after the operation were PGI2 group versus control group: 1.33 versus 1.66 (P = NS). CONCLUSION: Continuous infusions of PGI2 through the mesenteric artery after the canine small bowel autotransplantation may protect the small bowel mucosal barrier.

Platelet-derived growth factor is a cofactor in the induction of 1 alpha(I) procollagen expression by transforming growth factor-beta 1 in smooth muscle cells.

PURPOSE: Depending on the derivation of vascular smooth muscle cells (SMC), transforming growth factor-beta 1 (TGF-beta 1) has variable effects on proliferation and expression of extracellular matrix. Relatively little is known about TGF-beta 1's effects on human arterial SMC. Therefore, we sought to determine the effects of TGF-beta 1 on human arterial SMC proliferation and 1 alpha(I) procollagen expression. The mechanisms by which TGF-beta 1 regulate type I procollagen expression were also investigated. METHODS: SMC cultures were established from the aorta of transplant donors. Serial doses of TGF-beta 1 were applied, and cellular proliferation assessed by cell counting and tritiated thymidine incorporation. Total cellular ribonucleic acid (RNA) was analyzed by reverse transcription-polymerase chain reaction and Northern blot for changes in 1 alpha(I) procollagen and platelet-derived growth factor (PDGF)-A transcripts. RESULTS: In a dose-dependent manner, TGF-beta 1 inhibited SMC proliferation despite early induction of PDGF-A mRNA. After a delay of 24 hours, TGF-beta 1 increased 1 alpha(I) procollagen expression by 36% compared with control. PDGF-neutralizing antibodies blocked the TGF-beta 1-mediated upregulation of type I procollagen, although PDGF alone had no effect on matrix expression. CONCLUSION: The results indicate that TGF-beta 1 is a potent inhibitor of human arterial SMC proliferation that has a moderate effect on 1 alpha(I) procollagen transcripts. Despite inducing PDGF-A gene expression, TGF-beta 1 is not a mitogen in adult human arterial SMC. TGF-beta 1 regulates SMC type I procollagen expression partly by inducing PDGF-A as a co-factor.

Macrophage products inhibit human aortic smooth muscle cell proliferation and alter 1 alpha (I) procollagen expression.

While the role of the foam cell in early atherogenesis has been well characterized, much less is known about the interaction between infiltrating macrophages and medial smooth muscle cells (SMC) in chronic atherosclerosis. Our purpose was to determine the effects of soluble macrophage mediators on normal human aortic SMC proliferation and matrix expression. Human aortic SMC in subconfluent culture were exposed to supernatants from activated lipopolysaccharide (LPS) and nonactivated macrophages. SMC proliferation and type-I procollagen expression were determined. Both activated and nonactivated macrophage supernatants exhibited a potent growth inhibitory effect which became apparent at 48 hours. While nonactivated macrophage supernatant had no effect on procollagen expression, activated supernatant inhibited its expression. (33%; p < 0.05) These findings are consistent with the loss of medial SMC and matrix proteins associated with chronic atherosclerosis.