Weakly nonlinear focused ultrasound in viscoelastic media containing multiple bubbles

To facilitate practical medical applications such as cancer treatment utilizing focused ultrasound and bubbles, a mathematical model that can describe the soft viscoelasticity of human body, the nonlinear propagation of focused ultrasound, and the nonlinear oscillations of multiple bubbles is theoretically derived and numerically solved. The Zener viscoelastic model and Keller-Miksis bubble equation, which have been used for analyses of single or few bubbles in viscoelastic liquid, are used to model the liquid containing multiple bubbles. From the theoretical analysis based on the perturbation expansion with the multiple-scales method, the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, which has been used as a mathematical model of weakly nonlinear propagation in single phase liquid, is extended to viscoelastic liquid containing multiple bubbles. The results show that liquid elasticity decreases the magnitudes of the nonlinearity, dissipation, and dispersion of ultrasound and increases the phase velocity of the ultrasound and linear natural frequency of the bubble oscillation. From the numerical calculation of resultant KZK equation, the spatial distribution of the liquid pressure fluctuation for the focused ultrasound is obtained for cases in which the liquid is water or liver tissue. In addition, frequency analysis is carried out using the fast Fourier transform, and the generation of higher harmonic components is compared for water and liver tissue. The elasticity supresses the generation of higher harmonic components and promotes the remnant of the fundamental frequency components. This indicates that the elasticity of liquid suppresses shock wave formation in practical applications.

Weakly nonlinear propagation of focused ultrasound in bubbly liquids with a thermal effect: Derivation of two cases of Khokolov-Zabolotskaya-Kuznetsoz equations

A physico-mathematical model composed of a single equation that consistently describes nonlinear focused ultrasound, bubble oscillations, and temperature fluctuations is theoretically proposed for microbubble-enhanced medical applications. The Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation that has been widely used as a simplified model for nonlinear propagation of focused ultrasound in pure liquid is extended to that in liquid containing many spherical microbubbles, by applying the method of multiple scales to the volumetric averaged basic equations for bubbly liquids. As a result, for two-dimensional and three-dimensional cases, KZK equations composed of the linear combination of nonlinear, dissipation, dispersion, and focusing terms are derived. Especially, the dissipation term depends on three factors, i.e., interfacial liquid viscosity, liquid compressibility, and thermal conductivity of gas inside bubbles; the thermal conduction is evaluated by using four types of temperature gradient models. Finally, we numerically solve the derived KZK equation and show a moderate temperature rise appropriate to medical applications.

17β-Estradiol induces proliferation of endometrial NK cells (CD56+) in postmenopausal women

OBJECTIVE

The aim of this report was to evaluate the impact of hormone replacement therapy (HRT) on lymphocytic infiltration of the endometrium in postmenopausal women.

METHOD

This study included 58 Japanese patients who had undergone hysterectomy at the University Hospital of Occupational and Environmental Health, Japan. Before surgery, nine patients had received 17β-estradiol (E2), 0.72 mg transdermally for 2-8 weeks (E2 group); 16 patients had received an Estra-1,3,5(10)-triene-3,16α, 17β-triol (E3) vaginal tablet 0.5 mg per month five times (E3 group); and 19 patients had received 17β-estradiol, 0.62 mg, and norethindrone acetate (P), 2.70 mg for 3-16 weeks (E2 + P group). Fourteen patients received no HRT (control group). We examined uterine tissue specimens immunohistochemically for CD45+, CD3+, CD4+, CD8+, CD20+, CD56+, and Ki67 antigen-positive cells.

RESULTS

The numbers of CD56 + cells were significantly increased in the E2 group compared with all other groups (E2 vs. E3: 7.0 vs. 0.75, p = 0.017; E2 vs. E2 + P: 7.0 vs. 0.58, p = 0.009; E2 vs.

CONTROL

7.0 vs. 0.43, p = 0.010). The numbers of CD3+ cells were significantly increased in the E2 group compared with the control group (149.3 vs. 42.6, p = 0.008).

CONCLUSION

17β-Estradiol induced the proliferation of endometrial uterine natural killer cells (CD56+) in postmenopausal women.

D-Amino acid oxidase-induced oxidative stress, 3-bromopyruvate and citrate inhibit angiogenesis, exhibiting potent anticancer effects

Angiogenesis is critical for cancer growth and metastasis. Steps of angiogenesis are energy consuming, while vascular endothelial cells are highly glycolytic. Glioblastoma multiforme (GBM) is a highly vascular tumor and this enhances its aggressiveness. D-amino acid oxidase (DAO) is a promising therapeutic protein that induces oxidative stress upon acting on its substrates. Oxidative stress-energy depletion (OSED) therapy was recently reported (El Sayed et al., Cancer Gene Ther, 19, 1-18, 2012). OSED combines DAO-induced oxidative stress with energy depletion caused by glycolytic inhibitors such as 3-bromopyruvate (3BP), a hexokinase II inhibitor that depleted ATP in cancer cells and induced production of hydrogen peroxide. 3BP disturbs the Warburg effect and antagonizes effects of lactate and pyruvate (El Sayed et al., J Bioenerg Biomembr, 44, 61-79, 2012). Citrate is a natural organic acid capable of inhibiting glycolysis by targeting phosphofructokinase. Here, we report that DAO, 3BP and citrate significantly inhibited angiogenesis, decreased the number of vascular branching points and shortened the length of vascular tubules. OSED delayed the growth of C6/DAO glioma cells. 3BP combined with citrate delayed the growth of C6 glioma cells and decreased significantly the number and size of C6 glioma colonies in soft agar. Human GBM cells (U373MG) were resistant to chemotherapy e.g. cisplatin and cytosine arabinoside, while 3BP was effective in decreasing the viability and disturbing the morphology of U373MG cells.

Prognostic significance of BAF57 expression in patients with endometrial carcinoma

This study was conducted to elucidate the prognostic significance of BAF57 in patients with endometrial carcinoma. We investigated the relationship between the immunohistochemical expression of BAF57 and various clinicopathological variables in 111 endometrial carcinomas. Both univariate and multivariate regression analyses were performed. The correlations between the BAF57 expression and the other variables including estrogen receptor (ER) and p53 were examined. The high nuclear BAF57 expression was detected in 42 (37.8%) endometrial carcinomas, and 69 (62.2%) endometrial carcinomas were defined as having low nuclear BAF57 expression. The BAF57 expression was significantly associated with the surgical stage, grade of the tumor, myometrial invasion, lympho-vascular space invasion (LVSI) and lymph node metastasis. The 10-year overall survival rates of patients with low and high BAF57 expression were 96.9% and 58.2%, respectively (p<0.001). A multivariate analysis identified BAF57 expression as an independent prognostic factor. The BAF57 expression was significantly correlated with p53 expression (r=0.312, P=0.001), but was not correlated with ER expression (r= -0.141, P=0.14). The high BAF57 expression is an independent marker of poor prognosis of the patients in endometrial carcinomas. The inhibition of BAF57 activity may be one of the candidates for endometrial cancer therapy, especially therapy for aggressive tumors showing overexpression of p53.

Neuroradiological and neurofunctional examinations for patients with 22q11.2 deletion

Since the neuroradiological features of patients with 22q11.2 deletion syndrome are not well-understood, examinations using functional imaging were performed in this study. Brain magnetic resonance imaging (MRI) and 1H-magnetic resonance spectroscopy (MRS) were performed using a clinical 3-Tesla MR imager in 4 patients with 22q11.2 deletion syndrome (2 boys and 2 girls; aged 2-6 years.) and 20 age- and sex-matched healthy control subjects. Furthermore, interictal 123I-iomazenil (IMZ) single photon emission computed tomography (SPECT) was examined in 2 of the 4 patients. Among the 4 patients with 22q11.2 deletion syndrome, 2 patients showed polymicrogyria and 1 patient showed agyria. Those patients with brain malformations also showed abnormal brain artery patterns and decreased accumulation of IMZ in 123I-IMZ SPECT. Although all 4 patients showed epileptic discharges in their electroencephalograms (EEG), one patient with polymicrogyria had no seizure episodes. Decreases in γ-aminobutyric acid (GABA) corresponding to the areas of polymicrogyria and/or epileptic discharges in EEG were shown in all patients except for the patient with agyria. Although consistent evidence was not seen in patients with 22q11.2 deletion syndrome in this study, brain malformations and disturbances of the GABAergic nervous system would be underlying mechanisms of the neurodevelopmental abnormalities in this syndrome.

D-amino acid oxidase gene therapy sensitizes glioma cells to the antiglycolytic effect of 3-bromopyruvate

Glioma tumors are refractory to conventional treatment. Glioblastoma multiforme is the most aggressive type of primary brain tumors in humans. In this study, we introduce oxidative stress-energy depletion (OSED) therapy as a new suggested treatment for glioblastoma. OSED utilizes D-amino acid oxidase (DAO), which is a promising therapeutic protein that induces oxidative stress and apoptosis through generating hydrogen peroxide (H2O2). OSED combines DAO with 3-bromopyruvate (3BP), a hexokinase II (HK II) inhibitor that interferes with Warburg effect, a metabolic alteration of most tumor cells that is characterized by enhanced aerobic glycolysis. Our data revealed that 3BP induced depletion of energetic capabilities of glioma cells. 3BP induced H2O2 production as a novel mechanism of its action. C6 glioma transfected with DAO and treated with D-serine together with 3BP-sensitized glioma cells to 3BP and decreased markedly proliferation, clonogenic power and viability in a three-dimensional tumor model with lesser effect on normal astrocytes. DAO gene therapy using atelocollagen as an in vivo transfection agent proved effective in a glioma tumor model in Sprague-Dawley (SD) rats, especially after combination with 3BP. OSED treatment was safe and tolerable in SD rats. OSED therapy may be a promising therapeutic modality for glioma.

Online Walking Control System for Humanoids with Short Cycle Pattern Generation

The present paper presents an online walking control system that frequently generates and updates dynamically stable motion patterns with a cycle time of 20 ms. We show that frequently updating the motion pattern contributes to maintaining long-term balance while performing online walking control. In addition, the system enables a robot to respond quickly to changes in the commanded walking direction. Using preview control theory, we generate dynamically stable walking patterns. We propose a method to adjust the future desired zero moment point (ZMP) by modifying the foot landing position in order to maintain the dynamic balance of the generated motion pattern. This technique can be used to filter input commands that would result in sudden changes to the foot landing position, which would result in dynamic instability. The method is also used to compensate for errors between the actual and desired ZMP due to disturbances encountered while walking. We also present an extension of the short cycle pattern generation method that can accommodate external forces measured online. Experimental results for activities such as pushing a table are demonstrated on the full-size humanoid HRP-2 to evaluate the performance of the proposed walking control system.

Increase of integrin-linked kinase activity in cultured podocytes upon stimulation with plasma from patients with recurrent FSGS

Recurrent focal segmental glomerulosclerosis (FSGS) is a major challenge in the field of transplantation. Integrin-linked kinase (ILK) has emerged as a key mediator of podocyte-glomerular basement membrane (GBM) interactions. To clarify the involvement of plasma factors in FSGS recurrence, we examined the effects of plasma from FSGS patients with or without posttransplant recurrence on cultured podocytes, focusing particularly on ILK activity. Podocytes from a conditionally immortalized mouse podocyte cell line were treated with plasma from 11 FSGS patients, and ILK activity was determined using an immune complex kinase assay. Treatment with plasma from three patients with recurrence induced an increase in ILK activity. In contrast, no increase in ILK activity was observed in cultured podocytes treated with plasma from the remaining three patients with recurrence and five patients without recurrence. Cultured podocytes treated with plasma that induced ILK activity showed alterations of focal contact and detachment from the laminin matrix. In conclusion, this preliminary study provides experimental evidence suggesting the possible presence of circulating toxic factors in the plasma of some patients with recurrent FSGS, which induce an increase in podocyte ILK activity that may lead to the detachment of podocytes from the GBM.

Sézary syndrome treated with narrowband ultraviolet B: time-course measurement of serum levels of CCL17/CCL27

We describe a patient with Sézary syndrome (SS) who was successfully treated with topical steroid and narrowband UVB. Sézary cells in peripheral blood correlated with severity of skin lesions. In addition, serum levels of CCL17 and CCL27 decreased as disease activity improved. These chemokines may be important for the pathogenesis of SS.

Analysis of GM-CSF gene polymorphisms (3606T/C and 3928C/T) in Japanese patients with atopic dermatitis

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is thought to play an important role in the pathogenesis of atopic dermatitis. To examine whether GM-CSF single nucleotide polymorphisms (SNPs) are associated with susceptibility to atopic dermatitis, we investigated the genotype and allele frequencies of the SNPs 3606T/C and 3928C/T of the GM-CSF gene in 181 Japanese patients with atopic dermatitis and 100 controls, using a PCR restriction fragment length polymorphism method. A strong linkage disequilibrium existed between the polymorphisms 3606 and 3928, suggesting two common GM-CSF haplotypes, 3606*T-3928*C and 3606*C-3928*T. However, there was no significant difference in genotype or allele frequencies between patients with atopic dermatitis and controls for either of the two polymorphisms, thus GM-CSF SNPs do not appear to be associated with susceptibility to atopic dermatitis in Japanese patients. A large-scale study is necessary to confirm these findings.

Peripheral blood stem cell mobilization by granulocyte colony-stimulating factor alone and engraftment kinetics following autologous transplantation in children and adolescents with solid tumor

In 56 pediatric and adolescent patients (median age 7 years, range 1-21) with various solid tumors, peripheral blood stem cells (PBSC) were mobilized with granulocyte colony-stimulating factor (G-CSF) alone, and the yields of PBSC and engraftment kinetics following autologous peripheral blood stem cell transplantation (PBSCT) were evaluated retrospectively. Granulocyte colony-stimulating factor (10 microg/kg) was injected subcutaneously for mobilization when patients showed no influence of previous chemotherapy, and administration was continued for 5 days. The peaks of CD34+ cells and colony-forming units-granulocyte/macrophage in the blood were observed on days 4 through 6 of G-CSF administration in all patients. Peripheral blood stem cell harvest was commenced on day 5 of G-CSF treatment. Compared to the results in patients mobilized by chemotherapy plus G-CSF (N=18), the progenitor cell yields were lower in patients mobilized with G-CSF alone. However, there were no significant differences in WBC and ANC engraftment compared to the chemotherapy plus G-CSF mobilization group. Platelet recovery following autologous PBSCT was delayed in patients mobilized with G-CSF alone. The median time taken for ANC and platelet counts to reach 0.5 x 10(9) and 20 x 10(9)/l was 12 days (range: 9-28) and 15 days (8-55), respectively, in all patients who received PBSC mobilized by G-CSF alone. In summary, mobilization with G-CSF alone can mobilize sufficient CD34+ cells for successful autografting and sustained hematological reconstitution in pediatric and adolescent patients with solid tumors, and even in heavily pre-treated patients.

Factors associated with granulocyte colony-stimulating factor-induced peripheral blood stem cell yield in healthy donors

BACKGROUND AND OBJECTIVES

Poor collection results are a clinical problem in granulocyte-colony stimulating factor (G-CSF)-induced peripheral blood stem cell (PBSC) collection in healthy donors. It would be beneficial to be able to predict the PBSC yield from allogeneic donors before mobilization or harvesting.

MATERIALS AND METHODS

We examined the relationship between certain donor characteristics and the effectiveness of G-CSF-induced PBSC collection in 59 healthy family donors aged 3-63 years old (median 16 years). G-CSF was administered subcutaneously at 10 microg/kg for mobilization, daily for 5 days, and PBSC harvest using a continuous blood cell separator was started on day 5 of G-CSF treatment. Total cell yields were calculated as the number per unit of processed blood (l) per unit weight of the donor (kg).

RESULTS

In a univariate analysis, the donor's age, body mass index (BMI), white blood cell (WBC) count before mobilization, and platelet count before and during mobilization were significantly correlated with the yield of mononuclear cells (MNC), CD34(+) cells and granulocyte-macrophage colony-forming units (GM-CFU). Younger age (P < 0.001), a low BMI (P = 0.002), a high WBC count before mobilization (P = 0.004), a high platelet count before (P = 0.012) and during (P < 0.05) mobilization, and a low speed of withdrawal (P = 0.019) were associated with a higher CD34(+) cell yield. No significant correlation was found for gender, the type of G-CSF, the serum level of G-CSF, the type of cell separator, or the type of blood access. A multivariate forward and backward stepwise selection regression analysis showed that the factors associated with CD34(+) cell yield were age, platelet count before and during mobilization, and circulating CD34(+) cell concentration on day 2 of G-CSF treatment.

CONCLUSION

In this small preliminary study, we found that donor age is the most important factor in predicting G-CSF-induced PBSC yields. Old age and low platelet counts before mobilization might be useful indicators for identifying poor mobilizers. Further validation of these findings in a larger number of donors are needed to establish whether these findings apply to other populations.

Interleukin-4 and interleukin-13 enhance CCL26 production in a human keratinocyte cell line, HaCaT cells

Eotaxin-2/CCL24 and eotaxin-3/CCL26 are CC chemokines and their receptor, CC chemokine receptor 3 is preferentially expressed on eosinophils. It was reported that vascular endothelial cells and dermal fibroblasts produced CCL26. However, the regulation of CCL24 and CCL26 production in keratinocytes has not been well documented. We investigated the expression and production of CCL24 and CCL26 in the human keratinocyte cell line, HaCaT cells. Reverse transcription and polymerase chain reaction was performed using these cells and Enzyme-linked immunosorbent assay was carried out using supernatant of these cells. The production of CCL24 in HaCaT cells was slightly enhanced by IL-4 and that of CCL26 was strongly enhanced by IL-4 and IL-13. Furthermore, TNF-alpha generated a synergistic effect on IL-4 enhanced CCL26 production. Dexamethasone, IFN-gamma and the p38 mitogen-activated protein kinase inhibitor SB202190 inhibited IL-4 enhanced CCL26 production. IL-4 enhanced production of CCL26 was inhibited by leflunomide and JAK inhibitor 1, but not by JAK3 inhibitor, which indicates that it is mediated by JAK1-STAT6-dependent pathway. This result also strongly suggests the involvement of the type 2 IL-4 receptor in IL-4 enhanced production of CCL26. These results suggest that keratinocytes are involved in the migration of CC chemokine receptor 3 positive cells such as eosinophils in a Th2-dominant situation like atopic dermatitis.

Significant elevation of serum levels of eotaxin-3/CCL26, but not of eotaxin-2/CCL24, in patients with atopic dermatitis: serum eotaxin-3/CCL26 levels reflect the disease activity of atopic dermatitis

Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease characterized by the predominant infiltration of T cells, eosinophils and macrophages in lesional skin. Recently, eotaxin-2/CCL24 and eotaxin-3/CCL26 were identified as CC chemokines that signal exclusively via the CCR3 receptor and have eosinophil-selective chemoattractant activity, as does eotaxin/CCL11. We previously reported that serum levels of thymus and activation-regulated chemokine (TARC)/CCL17 and macrophage-derived chemokine (MDC)/CCL22 were correlated with the severity of AD. In this report, we investigated the participation of eotaxin-2/CCL24 and eotaxin-3/CCL26 in AD, first measuring the serum levels of eotaxin-2/CCL24 and eotaxin-3/CCL26 in 30 patients with AD, 20 patients with psoriasis vulgaris and 20 healthy controls. The serum levels of eotaxin-3/CCL26 (but not eotaxin-2/CCL24) were significantly higher in patients with AD than in either healthy controls or patients with psoriasis vulgaris; furthermore, the eotaxin-3/CCL26 levels in patients with moderate and severe AD were significantly higher than eotaxin-3/CCL26 levels in patients with mild AD. The serum eotaxin-3/CCL26 levels tended to decrease after treatment, but there was no significant difference between groups. Moreover, the serum eotaxin-3/CCL26 levels were significantly correlated with the serum TARC/CCL17 and MDC/CCL22 levels, eosinophil numbers in peripheral blood and the scoring AD (SCORAD) index. Our study strongly suggests that serum levels of eotaxin-3/CCL26, but not of eotaxin-2/CCL24, have a notable correlation with disease activity of AD and that eotaxin-3/CCL26, as well as TARC/CCL17 and MDC/CCL22, may be involved in the pathogenesis of AD.

Endothelin-1 is a potent stimulator of alpha1beta1 integrin-mediated collagen matrix remodeling by rat mesangial cells

Endothelin-1 (ET) is known to stimulate mesangial cell (MC) proliferation, extracellular matrix (ECM) synthesis, and thereby contribute to the progression of glomerulonephritis (GN). To clarify the molecular and cellular mechanisms of how ET is involved in the development of glomerular sclerosis, we investigated the influence of ET on the MC-alpha1beta1 integrin-mediated collagen matrix reorganization using a collagen gel contraction assay. ET enhanced MC-alpha1beta1 integrin-mediated gel contraction in a dose-dependent manner. Addition of the endothelin A (ETA) receptor antagonist, BQ123, into collagen gels abolished ET-induced gel contraction by MC. Cell behavior involved in ET-induced gel contraction was investigated in combination with function-blocking anti-alpha1-integrin antibody. Migration and adhesion assays revealed that ET stimulated alpha1beta1 integrin-mediated MC migration but did not influence cell adhesion to type I collagen (collagen I). Integrin-function blocking studies using anti-alpha1 integrin antibody indicated that MC-alpha1beta1 integrin is required not only for collagen-dependent migration, but also for gel contraction. Zymography showed that ET increased MC matrix metalloproteinase-2 (MMP-2) activity in a dose-dependent manner during MC-induced gel contraction process. Finally, flow cytometry analysis indicated that ET did not affect the cell surface expression of the MC-alpha1beta1 integrin within the collagen gel. These data suggested that ET promotes collagen matrix reorganization through the enhancement of MC-alpha1beta1 integrin-dependent migration and MMP-2 activity. We therefore conclude that ET is a potential molecule inducing pathological collagen matrix remodeling observed in progressive GN.

Vitamin D receptor gene polymorphism detected by digestion with Apa I influences the parathyroid response to extracellular calcium in Japanese chronic dialysis patients

BACKGROUND

To play its physiological role, 1,25(OH)2D3 must bind to a specific vitamin D receptor (VDR) in the nucleus. We have previously reported that VDR gene polymorphism influences the parathyroid function in patients with end-stage renal disease (ESRD). In the present study, we have investigated the relationship between the parathyroid responsiveness and VDR gene polymorphism, as detected by the Apa I restriction enzyme, by changing the concentration of Ca2+ in the dialysate.

METHODS

58 Japanese ESRD patients undergoing renal replacement therapy in our institution were evaluated. Genomic DNA was extracted from peripheral leukocytes and digested at the intron between exon 8 and exon 9 of the VDR gene using Apa I enzyme. Then alleles were classified into genotype A (undigested allele) and genotype a (digested allele). Extracellular ionized calcium ([Ca2+]e), serum phosphate, and intact parathyroid hormone (PTH) were measured before and after each hemodialysis (HD) session with dialysates having different concentrations of Ca2+ (1.5 or 1.25 mmol/l). The significance of differences in statistical analyses was defined within confidence limits of 5.0%.

RESULTS

The AA, Aa, and aa genotypes were observed in 7/58 patients (12.1%), 23/58 patients (39.6%), and 28/58 patients (48.3%), respectively. The PTH reduction after HD with the 1.5-mmol/l Ca dialysate did not differ significantly between group AA+Aa and group aa. On the other hand, the PTH increase was significantly higher in group aa than in group AA+Aa after HD with the 1.25-mmol/l Ca dialysate (p = 0.0107), despite a similar PTH level before HD. Similarly, the percent increase of PTH after HD with the 1.25-mmol/l Ca dialysate was significantly higher (p = 0.0112) in group aa (50.2 +/- 9.4%) than in group AA+Aa (19.7 +/- 7.2%). There were no significant differences between the two groups in [Ca2+]e nor in serum phosphorus (Pi) before and after HD with either dialysate. Group AA+Aa and group aa did not show statistically significant differences in age, female/male ratio, ratio of diabetic nephropathy, or dialysis period.

CONCLUSIONS

The study results showed that the patients in group aa were more sensitive to changes in [Ca2+]e than those in group AA+Aa. Moreover, they suggested that the VDR gene polymorphism may affect parathyroid responsiveness to changes in [Ca2+]e, which in turn may influence onset and progression of hyperparathyroidism in ESRD patients.

[The role of hyperphosphatemia in the pathogenesis of secondary hyperparathyroidism]

Renal phosphate handling plays key role in phosphate metabolism. Kidney dysfunction induced hyperphosphatemia. The phosphatemia with renal insufficiency, especially uremia, indirectly progresses into secondary hyperparathyroidism via suppression of vitamin D/Ca system. This indirect effect on parathyroid is called "Trade-off theory". Recently, the direct effect of hyperphosphatemia on parathyroid has been reported independent of vitamin D/Ca system in renal failure. The control of serum phosphate is certainly important by restriction of phosphate intake in renal failure patients.

Requirement for tyrosine kinase-ERK1/2 signaling in alpha 1 beta 1 integrin-mediated collagen matrix remodeling by rat mesangial cells

Abnormal mesangial extracellular matrix remodeling by mesangial cells (MCs) is the hallmark of progressive glomerulonephritis (GN). We recently showed, using a type I collagen gel contraction assay, that alpha 1 beta 1 integrin-dependent MC adhesion and migration are necessary cell behaviors for collagen matrix remodeling. To further determine the mechanism of alpha 1 beta 1 integrin-mediated collagen remodeling, we studied the signaling pathways of MCs that participate in the regulation of collagen gel contraction. Immunoprecipitation and phosphotyrosine detection revealed that gel contraction is associated with the enhanced activity and phosphorylation of ERK1/2 by MCs. The tyrosine kinase inhibitors herbimycin and genistein inhibited collagen gel contraction dose dependently. Furthermore, targeting ERK1/2 activity with a MEK inhibitor, PD98059, and antisense ERK1/2 hindered gel contraction in a dose-dependent manner. Similar inhibitory effects on gel contraction and ERK1/2 phosphorylation were observed when MC-mediated gel contraction was performed in the presence of function-blocking anti-alpha1 or anti-beta1 integrin antibodies. However, cell adhesion and migration assays indicated that PD98059 and antisense ERK1/2 blocked alpha 1 beta 1 integrin-dependent MC migration, but did not interfere with collagen adhesion, although there was a marked decrease in ERK1/2 phosphorylation and ERK1/2 protein expression in cell adhesion on type I collagen. None of the above could affect membrane expression of alpha 1 beta 1 integrin. These results suggested that ERK1/2 activation is critical for the alpha 1 beta 1 integrin-dependent MC migration necessary for collagen matrix reorganization. We therefore conclude that ERK1/2 may serve as a possible target for pharmacological inhibition of pathological collagen matrix formation in GN.

Mutation of DNASE1 in people with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a highly prevalent human autoimmune diseases that causes progressive glomerulonephritis, arthritis and an erythematoid rash. Mice deficient in deoxyribonuclease I (Dnase1) develop an SLE-like syndrome. Here we describe two patients with a heterozygous nonsense mutation in exon 2 of DNASE1, decreased DNASE1 activity and an extremely high immunoglobulin G titer against nucleosomal antigens. These data are consistent with the hypothesis that a direct connection exists between low activity of DNASE1 and progression of human SLE.

Inhibition of azoxymethane-induced colon carcinogenesis in male F344 rats by the citrus limonoids obacunone and limonin

The modifying effects of dietary administration of the citrus limonoids obacunone and limonin on azoxymethane (AOM)-induced colon tumorigenesis were investigated in two experiments in male F344 rats. In a pilot study, we examined the modifying effects of obacunone and limonin on AOM-induced (20 mg/kg body wt, once a week for 2 weeks) formation of aberrant crypt foci (ACF). Dietary feeding of both compounds at dose levels of 200 and 500 p.p.m. during AOM exposure for 4 weeks ('initiation' feeding) or after AOM treatment for 4 weeks ('post-initiation' feeding) significantly inhibited ACF formation (55-65% reduction by 'initiation' feeding, P < 0.001; 28-42% reduction by 'post-initiation' feeding, P < 0.05-0.002). In a long-term study designed to confirm the protective effects of obacunone and limonin on ACF development, one group was treated with AOM alone and another four groups received the carcinogen treatment plus diets containing 500 p.p.m. test compounds for 3 weeks (initiation phase) or 29 weeks (post-initiation phase). Two groups were treated with obacunone or limonin alone (500 p.p.m. in diet) and one group was maintained on the basal diet. At the termination of the study, dietary exposure to obacunone or limonin during the initiation phase was found to have significantly reduced the incidence of colonic adenocarcinoma (72 versus 25 or 6%, P = 0.004 or 0.00003). Obacunone or limonin feeding during the post-initiation phase also reduced the frequency of colonic adenocarcinoma (72 versus 13%, P = 0.0002). Our results suggest that the citrus limonoids obacunone and limonin might be useful for the prevention of human colon cancers.

Effect of endothelin-1(1-31) on p38 mitogen-activated protein kinase in cultured human mesangial cells

It was reported that human chymase cleaves big endothelins (ETs) at the Tyr31-Gly32 bond and produces 31-amino acid ETs(1-31). In this study, we investigated the effect of ET-1(1-31) on p38 mitogen-activated protein kinase (p38-MAPK) activity in human mesangial cells (HMCs). By measuring the kinase activity, we demonstrated that ET-1 (1-31) activated the p38-MAPK dose-dependently (10(-9) M to 10(-7) M), which was inhibited by SB203580. The p38-MAPK activation induced by ET-1(1-31) peaked at 10 minutes. BQ123 almost abolished ET-1(1-31)-induced p38-MAPK activation, whereas BQ788 failed to inhibit it. These findings suggest that the stimulatory effect of ET-1(1-31) on p38-MAPK activation is mediated through ET(A) or ET(A)-like receptor. In conclusion, ET-1(1-31) induced increase in p38-MAPK activation in cultured HMCs.

[Analyses of factors prolonging the length of hospital stay in elderly patients beginning hemodialysis]

The aim of the present study is to clarify the factors causing prolongation of the length of hospital stay in elderly patients beginning hemodialysis. Patients aged over 60 years who had newly started hemodialysis (98 cases) were studied. These were 59 men and 39 women. The age was 73 +/- 7 years (mean +/- standard deviation). In each patient, the cause of renal failure (non-diabetes/diabetes), body mass index, comorbid conditions (cerebrovascular disease, ischemic heart disease, etc.), ambulation, cognitive function, urgency of the initiation of dialysis, occurrence of access failure, marital status, younger cohabitants, and the length of stay after initiation of dialysis were surveyed. The median and the mean of the length of stay were 37 and 49 days. Because of this disparity, a normal distribution of the length of stay could not be obtained. However, the distribution was transformed to close to normal by logarithmic conversion of the number of days. We used the log-converted value as the length of stay for statistical analyses. We investigated the influence of the differences of each factor on the length of stay. The subjects were divided into two groups for each factor. The mean and standard deviation of the length of stay was calculated respectively. Comparisons were carried out by unpaired t-test. Multiple regression analysis was also performed using background factors as explanatory variables, and the length of stay as a dependent variable. The factors presented by the nominal scale were converted to dummy variables. Eight variables in the unpaired t-test and seven variables in multiple regression analysis were statistically significant. All but one variable were common to both analyses. The gender was statistically significant only in the unpaired t-test. It could be explained by close correlation of gender with marital status. Access failure and urgent initiation of dialysis were dominant factors for the prolongation of the length of stay. Ischemic heart disease, diabetes, inability to walk, impaired cognitive function, and absence of a partner also prolonged the length of stay.

Suppression of azoxymethane-induced colon carcinogenesis in male F344 rats by mandarin juices rich in beta-cryptoxanthin and hesperidin

We have reported protective effects of dietary administration of a powder "CHRP" containing high amounts of beta-cryptoxanthin and hesperidin prepared from a Satsuma mandarin (Citrus unshiu Marc.) juice on azoxymethane (AOM)-induced rat aberrant crypt foci through suppression of crypt cell proliferation and/or induction of detoxifying enzymes. In the present study, we investigated the modifying effects of a commercial Satsuma mandarin (Citrus unshiu Marc.) juice (MJ) and those of MJ2 and MJ5, which were prepared from MJ and are richer in beta-cryptoxanthin and hesperidin than MJ, on the occurrence of colonic tumors induced by AOM in male F344 rats. Rats were given 2 weekly s.c. injections of AOM (20 mg/kg body weight) to induce colonic neoplasms. They also received MJ, MJ2, or MJ5 as a drinking water at night for 36 weeks, starting 1 week after the last dosing of AOM. AOM exposure produced colonic adenocarcinoma with an incidence of 69% and a multiplicity of 0.76 +/- 0.57/rat at week 38. MJ, MJ2, and MJ5 administration significantly reduced the frequency of colonic carcinoma [MJ: 35% (49% reduction), p < 0.02; MJ2: 20% (64% reduction), p = 0.0028; and MJ5: 15% (78% reduction), p < 0.00021] and multiplicity [MJ: 0.40 +/- 0.58 (47% reduction), p < 0.05; MJ2: 0.25 +/- 0.43 (67% reduction), p < 0.005; and MJ5: 0.15 +/- 0.36 (80% reduction), p < 0.001]. Also, the numbers of cancer cells positive for proliferative cell nuclear antigen (PCNA) and cyclin D1 in colonic tumors were lowered by these treatments. In addition, treatment with MJ, MJ2, or MJ5 significantly increased apoptotic index in colonic adenocarcinoma. These findings might suggest effective chemopreventive ability of MJs, especially MJ5, in colon tumorigenesis.

Effect of endothelin-1 (1-31) on human mesangial cell proliferation

It was previously found that human chymase cleaves big endothelins (ETs) at the Tyr31-Gly32 bond and produces 31-amino acid ETs (1-31). In the present study, human plasma concentrations of ET-1 (1-31) and ET-1 were examined and the effect of synthetic ET-1 (1-31) on the proliferation of cultured human mesangial cells (HMCs) was investigated. The proliferative effect of ET-1 (1-31) was evaluated from the [3H]-thymidine uptake. The activity of extracellular signal-regulated kinase (ERK) and DNA binding activity of activator protein-1 were determined by using an in-gel kinase assay and gel mobility shift assay, respectively. Immunoreactive ET-1 (1-31) was detectable in plasma, but the level was slightly lower than that of ET-1. ET-1 (1-31) increased [3H]-thymidine incorporation in HMCs to a degree similar to that induced by ET-1. ET-1 (1-31) also activated ERK1/2. Inhibition of protein kinase C and ERK kinase caused a reduction of ET-1 (1-31)-induced ERK1/2 activation. The ERK1/2 activation was followed by an increase in transcription factor activator protein-1 DNA binding activity. These findings suggest that ET-1 (1-31) is a bioactive peptide in humans and ET-1 (1-31) itself stimulates HMC proliferation.

Overexpression of alpha1beta1 integrin directly affects rat mesangial cell behavior

BACKGROUND

Glomerular mesangial cell (MC) proliferation, hypertrophy, and abnormal matrix remodeling characterized by increased expression of fibronectin, laminin and collagen type IV, and neoexpression of collagen I and III are the main biological features of progressive glomerulonephritis (GN). Especially, persistent pathological matrix remodeling may lead to glomerular scar formation (glomerular scarring). We reported recently that alpha1beta1 integrin, a major collagen receptor for MCs, may be a potential adhesion molecule for MC-mediated pathological collagen matrix remodeling in GN.

METHODS

To address further the direct role of alpha1beta1 integrin in MC behavior, such as cell growth and matrix remodeling, alpha1beta1 integrin was overexpressed in MCs by transfecting an expression vector containing a full-length rat alpha1 integrin cDNA. Flow cytometry and immunoprecipitation analysis were applied for selection of transfectants with a stable expression of the alpha1 integrin subunit. The effect of alpha1beta1 integrin overexpression on MC biology was examined with a 3H-thymidine incorporation assay, flow cytometric analysis of cell size and DNA content, Western blot analysis of a cyclin-dependent-kinase inhibitor, p27Kip1, alpha-smooth muscle actin expression, and a collagen gel contraction assay.

RESULTS

The alpha1 transfectants displayed a dramatic inhibition of 3H-thymidine incorporation as compared with the mock transfectants. Increased expression of the alpha1 subunit inversely correlated with cell cycle progression and paralleled the expression of p27Kip1 and alpha-smooth muscle actin, as well as the cell size in MCs. In addition, the alpha1-transfectants were able to enhance collagen matrix reorganization effectively.

CONCLUSION

These results indicate that MC-alpha1beta1 integrin expression is a critical determinant of MC phenotypes, including cell growth, cell size, and collagen matrix remodeling ability, and thereby contributes to scar matrix remodeling (sclerosis) in GN.

[Analyses of factors preventing returning home in elderly patients on dialysis]

A significant number of elderly patients who begin dialysis are not able to return home even after attaining stable dialysis. The aim of the present study is to clarify the factors preventing returning home. Patients aged over 60 years who had newly started dialysis (103 cases) were studied. These were 58 men and 45 women. The age was 73 +/- 7 years (mean +/- standard deviation). In each patient, the cause of renal failure (non-diabetes/diabetes), nutritional state, complications, ambulation, cognitive function, urgency of the initiation into dialysis therapy, occurrence of access failure, presence or absence of the partner, presence or absence of members of the younger generation living in the same house, and the outcome (returning home or prolonged hospitalization) were surveyed. Of the 103 patients, 80 could return home, and 23 could not. First, we investigated the influence of the differences in each factor on the outcome. The subjects were divided into two groups by two categories in each factor. The numbers of patients who could not return home was calculated respectively. Comparisons were carried out by the chi 2 test. Statistically significant factors were ambulation (p < 0.0001), cognitive function (p < 0.0001), and cause of renal failure (p: 0.049). Multivariant logistic regression analysis was also performed using back-ground factors as explanatory variables and the outcome as a dependent variable. The factors presented by the nominal scale were converted to dummy variables. Statistically significant factors were ambulation (p < 0.0001), cognitive function (p: 0.001), and presence or absence of a partner (p: 0.012). Inability to walk, impaired cognitive function, and absence of a partner were the factors preventing returning home.

Suppressing effects of dietary supplementation of the organoselenium 1,4-phenylenebis(methylene)selenocyanate and the Citrus antioxidant auraptene on lung metastasis of melanoma cells in mice

The modifying effects of the organoselenium 1,4-phenylenebis(methylene)selenocyanate (p-XSC) and the Citrus antioxidant auraptene as dietary supplements on experimental pulmonary metastasis of B16BL6 murine melanoma cells were investigated in an i.v. injection model in mice. Seven groups of male C57BL/6 mice were fed a basal diet (control group) or the basal diet supplemented with p-XSC (4, 8, or 15 mg/kg) or auraptene (250, 500, or 1000 mg/kg). All mice were fed their respective diet for 2 weeks before and after i.v. injection of 1 x 10(5) viable melanoma cells. At termination of the study, the incidence of lung metastatic tumors was determined. Cross-sectional areas and tumor volumes were analyzed morphometrically. In addition, apoptotic indices of lung metastatic tumors of all groups were counted. The incidences of lung metastasis in mice fed the diet mixed with 8 or 15 mg p-XSC/kg were significantly smaller than that in mice fed the basal diet. The mean numbers of metastatic lung tumors were significantly lower in mice fed p-XSC (4, 8, and 15 mg/kg) and auraptene (500 and 1000 mg/kg) than in controls. Cross-sectional areas and volumes of the tumors were also significantly decreased in mice given p-XSC (8 or 15 mg/kg) and auraptene (500 mg/kg). Apoptotic indices in mice fed the diets mixed with p-XSC (4, 8, or 15 mg/kg) and auraptene (500 and 1000 mg/kg) were significantly greater than those in the control group. These results indicate that in mice, diet supplementation with p-XSC and auraptene reduces pulmonary metastasis of B16BL6 melanoma cells and inhibits the growth of these metastatic tumors in lung, in part, by inducing apoptosis. We suggest that these agents, especially p-XSC, may be valuable in preventing metastatic diseases in future studies in the clinic.

Prevention of colonic aberrant crypt foci by dietary feeding of garcinol in male F344 rats

The modifying effects of dietary feeding of a polyisoprenylated benzophenone, garcinol, isolated from Garcinia indica fruit rind on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in male F344 rats. We also assessed the effects of garcinol on proliferating cell nuclear antigen (PCNA) index in ACF and activities of detoxifying enzymes of glutathione S-transferase (GST) and quinone reductase (QR) in liver. In addition, we examined the effects of garcinol on 12-O-tetradecanoylphorbol-13-acetate-induced O(2)(-) generation in differentiated human promyelocytic HL-60 cells and lipopolysaccharide (LPS)- and interferon (IFN)-gamma-induced nitric oxide (NO) generation in mouse macrophage RAW 264.7 cells. Western blotting analysis of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression was done in LPS- and IFN-gamma-treated mouse macrophage RAW 264.7 cells. Rats were given subcutaneous injections of AOM (15 mg/kg body wt) once a week for 3 weeks to induce ACF. They also received the experimental diet containing 0.01 or 0.05% garcinol for 5 weeks, starting 1 week before the first dosing of AOM. AOM exposure produced 97 +/- 15 ACF/rat at the end of the study (week 5). Dietary administration of garcinol caused significant reduction in the frequency of ACF: 72 +/- 15 (26% reduction, P < 0.01) at a dose of 0.01% and 58 +/- 8 (40% reduction, P < 0.001) at a dose of 0.05%. Garcinol administration significantly lowered PCNA index in ACF. Feeding of garcinol significantly elevated liver GST and QR activities. In addition, garcinol could suppress O(2)(-) and NO generation and expression of iNOS and COX-2 proteins. These findings might suggest possible chemopreventive ability of garcinol, through induction of liver GST and QR, inhibition of O(2)(-) and NO generation and/or suppression of iNOS and COX-2 expression, on colon tumorigenesis.

Colitis-related rat colon carcinogenesis induced by 1-hydroxy-anthraquinone and methylazoxymethanol acetate (Review)

Patients with long-standing ulcerative colitis (UC) have an increased risk for developing colorectal cancer (CRC) compared to the general population. For investigation of the mechanisms and prevention of UC and UC-related CRC, establishment of a promising animal model for such disease is important. 1-hydroxyanthraquinone (1-HAQ) present in certain medicinal plants such as Rubia tinctorum L. is a genotoxic and rodent colon carcinogen. Long-term feeding of 1-HAQ induced hyper-cell proliferation in rat colonic crypts with ulcerative changes, crypt abscess, severe inflammation and erosion before the occurrence of tumors, which are similar to those found in human UC. In addition, 1-HAQ has a synergistic effect with methylazoxymethaol (MAM) acetate on colon carcinogenesis. The polymerase chain reaction-single strand conformation polymorphism analysis revealed no mutations in Ki-ras and p53 in colonic neoplasms induced by MAM acetate + 1-HAQ, MAM acetate alone or 1-HAQ alone. Also, no mutations of APC were found in these tumors. These findings are similar to those found in human ulcerative colitis-associated colon cancer in contrast with sporadic colon cancers. A previous study revealed that induced colonic tumors had beta-catenin mutation with high frequency, suggesting tumor development by activation of the beta-catenin-Tcf signaling pathway. Increased expression in TNF-alpha and IL-1alpha was found in these induced colonic neoplasms, and the expression was more remarkable in colonic mucosa of rats exposed to MAM acetate + 1-HAQ, MAM acetate or 1-HAQ when compared with that in untreated rats. Thus, these cytokines may act as growth factors in rat colon carcinogenesis by MAM acetate and 1-HAQ and the synergistic effect of 1-HAQ with MAM acetate might be related to the biological effects of the cytokines expressed in the inflammatory conditions induced by 1-HAQ.

[Homologous carcinosarcoma of the uterine corpus--report of a case and review of the literature in Japan]

A 59-year-old woman with leukorrhea. Aspiration smears were obtained from the uterine cavity. The dominant cellular components were fibrogenic sarcomatous cells, which had ill-defined lacy cytoplasm and a single nucleus with finely granular chromatin. There were occasional naked giant cells, and intracytoplasmic eosinophilic granules. Another infrequent cellular component was adenocarcinoma cells. Histopathologically, adenocarcinoma and spindle cell sarcoma were equivalently identified. Twenty-two cases of homologous carcinosarcoma of the uterine corpus were reviewed cytologically in Japan. Cytodiagnosis before treatment was positive for malignancy of carcinosarcoma in 28.6%. Characteristic cytological findings of this case were the presence of flat sheets of atypical cells with broad cytoplasm. These findings suggest epithelial features. However, the finely granular chromatin pattern and smooth nuclear membrane indicate sarcomatous cells.

Alpha1beta1 integrin-mediated collagen matrix remodeling by rat mesangial cells is differentially regulated by transforming growth factor-beta and platelet-derived growth factor-BB

Pathologic remodeling of mesangial matrix after glomerular injury is the central biologic feature of glomerular scarring (sclerosis). Transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF)-BB have been implicated in the development of glomerular scarring in rat and human glomerulonephritis. To clarify molecular and cellular mechanisms involved in abnormal mesangial remodeling, this study focused on the role of alpha1beta1 integrin, a collagen/laminin receptor, in rat mesangial cells, using collagen gel contraction as an experimental model of in vivo collagen matrix remodeling and scar formation. In addition, the influence of TGF-beta and PDGF-BB on mesangial cell (MC)-mediated collagen gel contraction in association with the alpha1beta1 integrin expression was evaluated. Integrin function blocking studies using anti-alpha1, beta1 subunit antibodies indicated that MC-alpha1beta1 integrin is essentially required not only for collagen-dependent adhesion/migration, but also for gel contraction. Protein synthesis and mRNA analysis experiments demonstrated that TGF-beta, but not PDGF-BB, increases the expression of alpha1beta1 integrin in mesangial cells cultured on plastic surface and in collagen gels. The upregulation of alpha1beta1 integrin expression by TGF-beta correlated with increases in gel contraction and collagen-dependent adhesion but not migration of mesangial cells. On the other hand, PDGF-BB enhanced MC-mediated gel contraction and migration without affecting cell adhesion to collagen I. Growth factor-induced collagen-dependent adhesion, migration, and gel contraction were significantly attenuated by incubation with anti-alpha1, beta1 subunit antibodies. Thus, these data indicate that alpha1beta1 integrin-mediated collagen matrix remodeling can be modulated by TGF-beta and PDGF-BB via different mechanisms. Alpha1 integrin-mediated mesangial matrix remodeling induced by TGF-beta or PDGF-BB may be a pathogenic mechanism leading to glomerular scarring.

Selective inhibition of the bacterial peptidoglycan biosynthesis by the new types of liposidomycins

We examined the inhibitory activity against bacterial peptidoglycan biosynthesis, mammalian glycoprotein biosynthesis and growth of BALB/3T3 cells of four different types of liposidomycins which have the structure with or without sulfate and/or 3-methylglutaric acid moieties. Liposidomycins inhibited peptidoglycan biosynthesis about 30 to 500 times more effectively than tunicamycin, whereas liposidomycins inhibited mammalian glycoprotein biosynthesis about 30 to 300 times less effectively than tunicamycin. When the cytotoxic effect of liposidomycins and tunicamycin on the growth of mammalian cells were compared, liposidomycins did not show toxicity against BALB/3T3 cell at 25 microg/ml, though tunicamycin inhibited cell growth by 50% at 0.05 microg/ml. On the basis of these results, it is concluded that liposidomycins are selective antibiotics showing highly specific inhibition toward bacterial peptidoglycan biosynthesis.

Collagen type I modulates the platelet-derived growth factor (PDGF) regulation of the growth and expression of beta1 integrins by rat mesangial cells

Mesangial cell (MC) proliferation and the deposition of collagen type I (collagen I) are the major pathological features in many types of glomerulonephritis (GN). Recent work suggested that beta-integrins play a critical role in the cell proliferation and extracellular matrix (ECM) remodeling observed in tissue repair after injury. To examine the involvement of beta-integrins in MC proliferation in association with the interaction of MCs with pathological collagen I, we investigated the effect of a prominent mitogen, platelet-derived growth factor-BB (PDGF-BB) on the growth and expression of beta-integrins by MCs cultured on plastic or in a three-dimensional collagen I gel. Immunoprecipitation using 35S-metabolic labeling, flow cytometry and a 3H-thymidine-uptake analysis demonstrated that PDGF-BB stimulated the cell mitogenicity and the expression of alpha5beta1 integrin (a fibronectin receptor), but not alpha1beta1 integrin (a collagen and laminin receptor) of MCs on plastic, in a dose-dependent manner. In contrast, MCs in the collagen I gels showed no significant changes in mitogenicity or alpha1beta1 and alpha5beta1 integrin expression, but increased alpha1beta1 integrin-mediated gel contraction was observed after PDGF-BB stimulation. Thus, the parallel up-regulation of MC-mitogenicity and alpha5beta1 integrin expression by PDGF-BB suggested that alpha5beta1 integrin is an important ECM receptor involved in the proliferative phenotype of MC. A spatial interaction between MCs and pathological collagen I in GN may influence the PDGF regulation of the MC phenotype regarding the cell growth and the expression of beta1 integrins.

Effect of endothelin-1 (1-31) on extracellular signal-regulated kinase and proliferation of human coronary artery smooth muscle cells

1. We have previously found that human chymase cleaves big endothelins (ETs) at the Tyr31-Gly32 bond and produces 31-amino acid ETs (1-31), without any further degradation products. In this study, we investigated the effect of synthetic ET-1 (1-31) on the proliferation of cultured human coronary artery smooth muscle cells (HCASMCs). 2. ET-1 (1-31) increased [3H]-thymidine incorporation and cell numbers to a similar extent as ET-1 at 100 nM. This ET-1 (1-31)-induced [3H]-thymidine uptake was not affected by phosphoramidon, an inhibitor of ET-converting enzyme. It was, however, inhibited by BQ123, an endothelin ET(A) receptor antagonist, but not by BQ788, an endothelin ET(B) receptor antagonist. 3. By using an in-gel kinase assay, we demonstrated that ET-1 (1-31) activated extracellular signal-regulated kinase 1/2 (ERK1/2) in a concentration-dependent manner (100 pM to 1 microM) in HCASMCs. ET-1 (1-31)-induced ERK1/2 activation was inhibited by BQ123, but not by BQ788 and phosphoramidon. Inhibition of protein kinase C (PKC) and ERK kinase also caused a reduction of ET-1 (1-31)-induced ERK1/2 activation, whereas tyrosine kinase inhibition had little effect. 4. Gel-mobility shift analysis revealed that the ERK1/2 activation was followed by an increase in transcription factor activator protein-1 DNA binding activity in HCASMCs. 5. Our results strongly suggest that ET-1 (1-31) itself stimulates HCASMC proliferation probably through endothelin ET(A) or ET(A)-like receptors. The underlining mechanism of cell growth by ET-1 (1-31) may be explained in part by PKC-dependent ERK1/2 activation. Since human chymase has been proposed to play a role in atherosclerosis, ET-1 (1-31) may be one of the mediators.

New types of liposidomycins that inhibit bacterial peptidoglycan synthesis and are produced by Streptomyces. I. Producing organism and medium components

Liposidomycins are atypical lipid-bearing nucleoside antibiotics that inhibit bacterial peptidoglycan synthesis. A producing strain was identified as a Streptomyces sp. from its cultural characteristics and physiological properties. It produced new types of liposidomycins that lacked sulfate and/or 3-methylglutaric acid moieties present in known liposidomycins by changing medium components. Sucrose and malt extract were particularly suitable sources for specific production of the new types of liposidomycins.

New types of liposidomycins that inhibit bacterial peptidoglycan synthesis and are produced by Streptomyces. II. Isolation and structure elucidation

Various new liposidomycins were isolated from a culture of the strain Streptomyces sp. SN-1061M by changing medium components and they were classified into four types (I-IV) based on their structures. They were purified by butanol extraction, silica gel and LH-20 column chromatographies, and high performance liquid chromatography on ODS columns. Type (I) has the original structure which has sulfate and 3-methylglutaric acid moieties. Type (II) has no 3-methylglutaric acid moiety and type (III) has no sulfate moiety. Type (IV) has neither moiety. Type (III) and (IV) compounds, which have no sulfate moiety, exhibited more potent antimicrobial activity.

Expression of beta 1-integrins on activated mesangial cells in human glomerulonephritis

beta 1-integrins, a family of cell-surface receptors, mediate cell-matrix interactions that play a critical role in tissue development and tissue remodeling after injury. In this study, to clarify the importance of beta 1-integrins in human glomerulonephritis (GN), the relationship among the glomerular expression of beta 1-integrins, their ligand matrix components, alpha-smooth muscle actin (alpha-SM actin) as a marker of activated mesangial cells (MC), transforming growth factor-beta (TGF-beta), and glomerular cellularity in two normal kidneys, ten minimal change nephrotic syndrome, 23 immunoglobulin A (IgA) GN, 13 lupus GN, and four membranous GN kidneys were studied. Immunostaining was performed on frozen sections, using monoclonal anti-alpha-SM actin antibody and polyclonal antibodies against fibronectin, collagen type IV, laminin, each subunit of alpha 1 beta 1 (collagen/laminin receptor), alpha 5 beta 1 (fibronectin receptor) and TGF-beta. Quantitation of staining indicated that the glomerular expression of alpha 1 beta 1 and alpha 5 beta 1 integrins correlated with the mesangial amounts of their ligands, collagen type IV, laminin and fibronectin (P < 0.01), alpha-SM actin (P < 0.01), and TGF-beta (P < 0.01). In addition, a correlation was observed between an increased expression of alpha 1 beta 1 and alpha 5 beta 1 integrins and the degree of glomerular cell proliferation (P < 0.01). Double immunostaining showed that activated MC expressing alpha-SM actin strongly expressed alpha 1 beta 1 and alpha 5 beta 1 integrins, and these MC phenotypic alterations paralleled the level of glomerular TGF-beta staining (P < 0.01). In conclusion, enhanced expression of beta 1-integrins by activated MC may contribute to the pathological mesangial remodeling characterized by MC proliferation and matrix deposition in human GN. Increased glomerular TGF-beta appears to be involved in these MC phenotypic changes.

Dual effects of angiotensin II on the plasminogen/plasmin system in rat mesangial cells

Previous studies indicate that angiotensin II (Ang II) stimulates extracellular matrix synthesis through induction of transforming growth factor-beta (TGF-beta) expression. Here we investigate Ang II effects on the plasmin protease system. Plasmin both degrades extracellular matrix itself and activates metalloproteinases which then degrade collagens. Plasmin production is determined by the balance between plasminogen activators (PA) and their inhibitors (PAI-1,2). The data presented here indicate that Ang II treatment of mesangial cells in culture markedly increases PAI-1 gene transcription and PAI-1 mRNA levels but does not change the half life of PAI-1 mRNA. Increased PAI-1 protein was detected 24 hours after Ang II stimulation with a concomitant decrease of PA activity. To determine whether these effects were mediated by TGF-beta, cells were coincubated with Ang II and neutralizing antibody to TGF-beta. Induction of PAI-1 at four hours was not altered but the prolonged effect of Ang II on PAI-1 protein synthesis was markedly diminished. Thus, Ang II acts both through rapid, direct transcriptional up-regulation of the PAI-1 gene and through induction of TGF-beta, providing sustained changes in the PAI-1/PA system, which would favor extracellular matrix accumulation by inhibiting turnover. These data provide further evidence that Ang II can act as a potent fibrogenic molecule independent of its effects on blood pressure.

A monoclonal antibody (1F3) to human glomerular epithelial cells: a new marker for renal epithelial cell injury

In order to identify a new cell surface antigen as a potential marker of renal epithelial cell injury, we produced a monoclonal antibody (Mab), 1F3, by immunizing mice with cultured human glomerular cells. Immunofluorescence (IF) and immunoelectron microscopy (IEM) studies demonstrated that 1F3-recognizing antigen (1F3 antigen) was strongly expressed on the cell surface of glomerular podocytes and very weakly on parietal epithelial cells. 1F3 antigen was not expressed in any other cells in the normal kidney. Immunoprecipitation analysis using metabolically labeled glomeruli revealed that 1F3 recognized a 125-kD protein under reducing conditions. IF studies of biopsy specimens from patients with a variety of glomerular and tubulointerstitial diseases showed that 1F3 antigen was almost negative in cellular crescents but was strongly expressed in fibrocellular crescents. When glomerular sclerosis appeared, the expression of 1F3 antigen decreased in sclerotic areas of glomeruli. 1F3 antigen became positive in atrophic tubules that were seen in diseased kidneys. Severity of tubular atrophy correlated well with the extent of tubular expression of 1F3 antigen. These results indicate that Mab, 1F3 marks phenotypic changes of renal epithelial cells under disease conditions and may be a useful marker for progressive kidney diseases.

Transforming growth factor-beta (TGF-beta) stimulates the expression of beta1 integrins and adhesion by rat mesangial cells

Transforming growth factor-beta (TGF-beta) has been implicated in the pathogenesis of mesangial matrix (MM) accumulation in human and experimental glomerulonephritis. To clarify molecular mechanisms responsible for pathological MM deposition, we examined the effect of TGF-beta on the production of beta1 integrins and on adhesion function of rat mesangial cells (MC). In immunoprecipitation experiments using [35S]methionine-labeled MC, stimulation of MC with TGF-beta for 48 h resulted in an increase in the synthesis of alpha1beta1 (collagen/laminin receptor) and alpha5beta1 (fibronectin receptor) integrins accompanied by increases in the synthesis of their ligands, collagen type I (collagen I), and fibronectin. A time-dependent increase in beta1, alpha1 integrin subunit mRNA peaking 48 h after exposure to TGF-beta was shown by Northern blot analysis. After 48 h of treatment with TGF-beta, MC displayed significant increases in adhesion to fibronectin, collagen I, and laminin as compared to untreated MC. Anti-beta1 antiserum significantly inhibits MC adhesion to fibronectin, collagen I, and laminin. Anti-alpha1 subunit antibody very strongly inhibited adhesion to collagen I and laminin, but not to fibronectin. Synthetic peptides containing RGD sequences specifically blocked adhesion to fibronectin. These data suggest that TGF-beta may promote MM deposition by increasing MC synthesis of both matrix proteins and beta1 integrins which facilitate binding of these proteins to the MC surface and thus enhance their incorporation into MM.

Possible role for a polysaccharide antigen shared between Streptococcus pyogenes and S. mutans in the pathogenesis of poststreptococcal glomerulonephritis

Streptococcus mutans has been shown to share a polysaccharide (PS) antigen with S. pyogenes strains isolated from patients with acute poststreptococcal glomerulonephritis (PSGN), using a monoclonal antibody f-77 reactive with the PS. To investigate the pathogenetic role of the shared PS in PSNG, experimental nephritis was induced in animals. Rats were immunized thrice with heat-killed cells of S. mutans or S. pyogenes, followed by an intravenous injection of live cells of S. pyogenes. Histologic examination showed that both animal groups had comparable degrees of diffuse proliferative nephritis characterized by immune deposits. The shared PS antigen was detected in glomeruli of all nephritic rats by immunofluorescence using monoclonal antibody f-77. Furthermore, all nephritic rats had an elevated antibody titer to the shared PS antigen. These results suggest that prior sensitization (infections such as dental caries) to S. mutans modulates immune responses to subsequent S. pyogenes infections and induces immune-complex disease (PSGN) through the shared PS antigen.