Tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) activity and/or expression are upregulated in hypercholesterolemia. Despite extensive research on anti-thrombotic effect of statins, little is known about their effects on TF and PAI-1 expression in glomerular mesangial cells under hypercholesterolemic condition. Male rabbits were fed on either normal or high-cholesterol diet for 8 weeks. Then cholesterol-fed rabbits were randomly assigned to simvastatin or starch. At the end of 12 weeks, glomerular mesangial cells were collected. The concentrations of TF and PAI-1 mRNA were detected by RT-PCR. The plasma activities of TF and PAI-1 were determined with enzyme linked immunosorbent assay (ELISA) and chromogenic substrate method, respectively. The atherogenic diet caused a consistent increase in serum concentrations of total cholesterol (TC) and serum triglyceride (TG) (p < 0.05), increased TF and PAI-1 mRNA expression in glomerular mesangial cells and plasma activities as compared to the normal diet (p < 0.01). Four-week simvastatin treatment resulted in significant decrease of mesangial TF and PAI-1 mRNA (p < 0.01), and also of the plasma activities of TF (p < 0.05) and PAI-1 (p < 0.01). These results suggest that simvastatin might protect kidney from the formation of microthrombus under hypercholesterolemic condition and might be a possible pathogenesis of obesity-related glomerulopathy.
The effects of 20 μg/mL exogenous prostaglandin A2 (PGA2) were determined on Bax, Bcl-2 and proliferating cell nuclear antigen (PCNA) expression levels in MCF-7 cells. Flow cytometric analysis indicated a pronounced increase in the S phase and a decrease in the G1 phase, whereas a significant increase in the DNA content preceding the G0/G1 peak was also observed after 48 h of exposure to PGA2. Confirmation of apoptosis was determined after 12 h, 36 h and 48 h of PGA2 exposure employing the mitosensor reagent that detects potential changes in the mitochondrial membrane. Twenty-eight percent of PGA2-exposed cells were in apoptosis when compared to the 7.1% vehicle-treated cells after 48 h. PGA2 exposure led to statistically significant increase (1.25-fold) over vehicle-treated controls in Bax expression levels. Decreases in Bcl-2 (0.79-fold), as well as PCNA (0.69-fold) expression levels over vehicle-treated controls were observed. The Bax/Bcl-2 ratio for PGA2-exposed cells was 2.7. The present study suggests that an accumulation in the S phase, a decrease in expression levels of PCNA, as well as an altered ratio in favor of Bax, could lead to the induction of apoptosis in these cells.
We examined the relationship between the Arg16Gly polymorphism of β2-adrenoceptor (ADRB2) and the efficacy of tricyclic antidepressant therapy in patients with interstitial cystitis (IC). We studied 55 IC patients and 113 controls. The IC patients were treated with imipramine hydrochloride, and the efficacy of treatment was categorized by patients' satisfaction (no change, fair, or good). Genomic DNA was extracted from the controls and IC patients, and the Arg16Gly polymorphism of ADRB2 was analyzed. The Arg16Gly polymorphism showed a significant difference in prevalence between IC patients and controls, and Arg/Arg was associated with increase in the risk of IC than Arg/Gly or Gly/Gly. Regarding the tricyclic antidepressant therapy, there was a significant difference in the prevalence of this polymorphism between IC patients with no change or a fair response to treatment and controls, and Arg/Arg was associated with decrease in the response rate to tricyclic antidepressant therapy than Arg/Gly or Gly/Gly. Therefore, these results suggest that the Arg16Gly polymorphism of ADRB2 is related to down-regulation of ADRB2 expression in the detrusor muscle, so that the response of IC to tricyclic antidepressant therapy depends on the Arg16Gly polymorphism.
Coelomic fluid (CF) and lysenin from the earthworm Eisenia foetida induced heavy epidermal exfoliation in the larvae of Bufo japonicus formosus at developmental stages from hatching (stage 22) to operculum completion (stage 34). In experiments with Xenopus laevis, we observed that exfoliated cells were not stained by trypan blue. Thus, it appeared that these cells were still alive. It is likely, therefore, that both CF and lysenin might disrupt the adhesion between epidermal cells of larvae prior to stage 34. Since it is known that lysenin exerts its toxic effects through its specific binding to sphingomyelin (SM), SM might be involved in such adhesion. This hypothesis was supported by the observations that CF and lysenin which had been incubated with SM-liposomes lost their exfoliative activity. In larvae after stage 34, the mechanism of adhesion between epidermal cells seemed to change and the adhesion was no longer disrupted by CF and lysenin. In larvae at around stage 34, a collagen layer started to form beneath the basement membrane of the epidermis. Furthermore, larvae at around this stage started to eat solid food. The developing collagen layer and food intake might be related indirectly to the chemical change in epidermal adhesion. The induction of exfoliation by CF and lysenin was also observed in other amphibian species. In Bufo larvae, defecation was induced both by CF and by lysenin but this effect was independent of exfoliation.
Catchlike property is the force enhancement produced when a brief, high-frequency burst of pulses is added to a constant low-frequency stimulation. In functional electrical stimulation, constant low-frequency stimulation of approximately 20 Hz has primarily been used to reduce muscle fatigue. The purpose of this study was to investigate the effects of catchlike-inducing intermittent stimulation on muscle fatigue in relation to continuous intermittent low-frequency stimulation. Twenty-two adult male Wistar ST rats were randomly assigned into the constant frequency stimulation (CFS) group or the catchlike-inducing stimulation (CIS) group. In the CFS group, constant low-frequency stimulation of 20 Hz was applied intermittently (4 seconds “ON”/15 seconds “OFF”). In the CIS group, a single electrical burst of 100 Hz was applied at the start of the every 4-second period of stimulation. The muscle fatigue test lasted for 16 min and isometric muscle force, muscle fatigue, and muscular workload were evaluated. CIS significantly increased the maximum muscular force (under fatigued condition) and workload, and significantly decreased muscle fatigue (p < 0.05). The results of this study suggest that catchlike-inducing intermittent electrical stimulation is useful in the clinical administration of functional electrical stimulation.
Growth hormone (GH) replacement therapy has been shown to have beneficial effects on linear growth enhancement in GH-deficient children over the past few decades. SMP-140 is a sterile liquid formation containing rhGH that is expected to improve patient compliance and accuracy of dosing, compared with the commercially available lyophilized form of GH. However, since there are no data showing that SMP-140 influences body elongation in animal models, we studied the effects of SMP-140 on body length in hypophysectomized (HPX) rats, which are used as animal models of GH deficiency. Consistent with the main feature of GH-deficient children, the body length of HPX rats was significantly shorter than that of sham-operated rats at the start of the study. SMP-140 (0.2, 1 and 5 mg/kg) was administered once daily to HPX rats for seven days, and resulted in a dose-dependent increase in body length and in the width of the growth plate cartilage. These results show that SMP-140 administration increases body length in an animal model of GH deficiency, and suggest that SMP-140 will be a useful agent for the treatment of growth-retarded children.
Oncostatin M (OSM) is a multifunctional regulator of cell growth and differentiation. It inhibits the growth of many types of tumor cells, but its role in metastasis is unknown. We studied the human OSM expressed and purified from reconstructed E. Coli on its activity of inhibiting metastasis of tumor cells by a series of assays in vitro and in vivo. Clone formation assay in soft agar was used to measure the inhibition activity of OSM on the proliferation of high metastatic human lung cancer cells 95-D. Cell attachment assay, cell migration assay and cell invasion assay were used to evaluate inhibition by OSM on 95-D cells of the adhesion ability, the migration ability, and the ability of cells to cross tissue barriers, respectively. Inhibition of OSM on secretion of MMP-2 and -9 secretion in 95-D cells was determined by Western blot. The in vivo inhibitory effect of OSM on metastasis of murine melanoma cells B16BL6 was examined in the pulmonary metastasis model. In vitro studies showed that OSM inhibited the proliferation of 95-D cells at low concentration. OSM also reduced the adhesion and invasion ability of 95-D cells and inhibited the secretion of MMP-2 and MMP-9 in OSM treated cells. In vivo results showed that OSM (20 μg/kg/d for 7 days) inhibited pulmonary metastasis at a rate of 20.7%. There were no differences in animal weights among the groups. These results suggest that OSM has the potential of being a clinical inhibitor on metastasis of some cancer cells.