Takahiro Tabata

Monocyte chemoattractant protein-1 induces scavenger receptor expression and monocyte differentiation into foam cells.

Accumulation of monocytes and the entrapment of oxidized-low-density lipoprotein (ox-LDL) in monocytes are important in the differentiation into foam macrophages and the pathogenesis of atherosclerosis. We investigated the role of monocyte chemoattractant protein-1 (MCP-1) in the expression of scavenger receptor (SCR) by using resting monocytes prepared by counterflow centrifugal elutriation. Our results showed that: (1) MCP-1 increased the expression of CD36 SCR by flow cytometric analysis. (2) MCP-1 increased incorporation of 125I-labeled ox-LDL and oil red O staining. (3) MCP-1 and ox-LDL enhanced in vitro transendothelial monocyte migration. (4) These functions were mediated at least in part via extracellular signal-regulated kinase (ERK) pathway. (5) MCP-1 and ox-LDL did not induce monocyte proliferation. Our results imply that MCP-1 is involved in the inflammatory process of atherosclerosis through the induction of SCR expression via the ERK pathway and differentiation of monocytes into foam macrophages, as well as induction of monocyte migration.

Hepatocyte growth factor enhances adhesion of breast cancer cells to endothelial cells in vitro through up-regulation of CD44

For cancer metastasis, tumor cells present in the circulation must first adhere to the endothelium. Integrins play a central role in leukocyte adhesion to the endothelium and subsequent migration into tissues. The majority of tumor cells derived from solid cancers, including breast cancer, do not express integrins. We investigated the mechanisms of adhesion and transendothelial migration of cancer cells using breast carcinoma cell lines. Our results showed the following features of breast cancer cells: (1) HGF stimulated breast cancer cells by up-regulating CD44 expression in a concentration-dependent manner. (2) the maximum level of HGF-induced CD44 up-regulation on breast cancer cell lines occurred within 3 h. (3) HGF-induced up-regulation of CD44 was mediated by the tyrosine kinase signaling pathway. (4) HGF induced CD44-mediated adhesion of tumor cell lines to bone marrow-derived endothelial cells. (5) HGF did not change rolling of breast cancer cell lines on bone marrow-derived endothelial cells, but enhanced firm adhesion of cancer cells on endothelial cells under shear stress conditions. (6) HGF increased transendothelial migration of cancer cells. Our results indicate that HGF stimulates CD44-mediated adhesion of breast cancer cells to bone marrow-derived endothelial cells, which subsequently results in transendothelial migration of tumor cells. These results suggest that CD44 may confer the metastatic properties of breast cancer cells and, therefore, could be used as a target in future molecular cancer therapy.

Oxidized low density lipoprotein-induced LFA-1-dependent adhesion and transendothelial migration of monocytes via the protein kinase C pathway

Inflammatory and immune responses are highly relevant processes in the pathogenesis of atherosclerosis, as illustrated by the central event of monocyte accumulation in atherosclerotic plaques. Integrin LFA-1-mediated adhesion of circulating monocytes to the endothelium is a prerequisite for recruitment of monocytes to these areas. Integrin-mediated adhesion is tightly regulated and integrins are only functional in response to particular monocyte activation stimuli. We investigated the role of oxidized low-density lipoprotein (LDL) in adhesion of resting monocytes prepared by elutriation from endothelium. Our results showed that: (1) oxidized LDL (and MCP-1) induced both LFA-1-mediated adhesion of monocytes to endothelial cells and transendothelial migration of monocytes; (2) oxidized LDL functionally transformed monocyte LFA-1 to an activated form; (3) oxidized LDL induced F-actin polymerization and cytoskeletal rearrangement within seconds; and (4) the LDL-associated antioxidant, alpha-tocopherol, but not beta-tocopherol, inhibited both F-actin polymerization and LFA-1-mediated adhesion of monocytes, which paralleled the effect of protein kinase C (PKC) inhibitors. Our results indicate that oxidized LDL plays a pivotal role in triggering LFA-1 activation and LFA-1-mediated adhesion and transmigration of monocytes to sites of atherosclerotic plaques, via the PKC pathway.

Management of symptoms in step‐down therapy of gastroesophageal reflux disease

Objective:u2002 Majority of studies on gastroesophageal reflux disease (GERD) that include patients with or without erosive disease have documented the efficacy of proton pump inhibitors (PPIs) as well as their superiority to H2‐receptor antagonist (H2‐RA). The purpose of this study was to clarify the difference in quality of GERD treatment with PPIs and H2‐RA in step‐down protocol using lansoprazole.

Reduced Progression to Type 2 Diabetes From Impaired Glucose Tolerance After a 2-Day In-Hospital Diabetes Educational Program : The Joetsu Diabetes Prevention Trial

OBJECTIVE—We assessed the effects of a 2-day in-hospital diabetes educational program in preventing or delaying progression of impaired glucose tolerance (IGT) to type 2 diabetes, including analysis of changes in serum lipids, body weight, and blood pressure after the program. RESEARCH DESIGN AND METHODS—A total of 426 subjects (51 ± 9 years, BMI 24.6 ± 3.9 kg/m2) with newly diagnosed IGT were randomly assigned to three groups, 143 as the short-term hospitalization with diabetes education and support (STH) group, 141 as the nonhospitalization but diabetes education and support (DES) group, and 142 as the neither hospitalization nor education (control) group. RESULTS—The average follow-up was 3.1 years. The incidence of diabetes was 8.0, 10.7, and 13.2 cases per 100 person-years for STH, DES, and control groups, respectively. The incidence of diabetes was 42% lower (95% CI 33–51%) in the STH group and 27% lower (15–37%) in the DES group than in the control group. The incidence of diabetes was 21% lower (10–31%) in the STH group than in the DES group. CONCLUSIONS—The 2-day in-hospital program with diabetes education and support every 3 months was more effective in preventing or delaying the progression from IGT to diabetes than only diabetes education and support every 3 months.

Ultrasonographic evaluation of lansoprazole-induced improvement of submucosal injury in patients with gastroesophageal reflux.

OBJECTIVE:Endoscopic ultrasonographic (EUS) changes in gastroesophageal reflux disease (GERD) after treatment with proton pump inhibitor have been poorly evaluated. We conducted a randomized, double-blind 12-wk clinical trial to compare the EUS effects of lansoprazole to histamine H2-receptor antagonist therapy in GERD.METHODS:Seventeen patients with reflux-related symptoms received 40 mg of famotidine for 6 wk or 30 mg of lansoprazole for 6 wk followed by 40 mg of famotidine or 30 mg of lansoprazole for another 6 wk, respectively. Patients underwent EUS before and at 6 and 12 wk after treatment.RESULTS:Before treatment, a variable degree of wall thickening was noted on EUS in the lower esophagus, compared with 20 normal subjects. After 6 wk of therapy, esophageal wall was significantly thicker in the famotidine group compared with the lansoprazole group (p < 0.01). Surprisingly, thickening of esophageal wall and abnormal architecture were also detected in endoscopically negative reflux disease. Lansoprazole was superior to famotidine in reducing the thickness of esophageal wall.CONCLUSIONS:EUS was very useful for evaluation of submucosal injury in patients with GERD. EUS showed that a 6-wk course of lansoprazole therapy reduced thickening of esophageal wall, which was resistant to histamine H2-receptor antagonist therapy. Our results also suggest that inflammatory damage to the submucosal and muscle layers of the lower esophagus is the underlying mechanism of heartburn and associated symptoms in patients with endoscopically negative reflux disease.

Reduced expression of platelet endothelial cell adhesion molecule-1 in bone marrow cells in mice after skeletal unloading

One week of tail suspension significantly decreased the expression of PECAM‐1 in mouse tibial bone marrow cells but not those of a number of other vascular factors. Anti‐PECAM‐1 antibody suppressed both ALP+ CFU‐f formation and ALP production under co‐culture of the osteoblastic cell line and the PECAM‐1+ endothelial cell line. This study suggests that the reduced ALP activity after skeletal unloading is related to downregulation of PECAM‐1 expression in bone marrow cells in mice.

Increased esophageal mucosal/submucosal blood flow in patients with gastroesophageal reflux disease : Normalization by treatment with a proton pump inhibitor

Background and Aim:u2002 Mucosal injury caused by gastroesophageal reflux may result in changes in esophageal mucosal blood flow. Little is known about esophageal mucosal blood flow in patients with gastroesophageal reflux disease (GERD). Here we examined esophageal mucosal blood flow and the effects of treatment in patients with GERD.