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An Efficient Method to Obtain Dedifferentiated Fat Cells

Tissue engineering and cell therapy hold great promise clinically. In this regard, multipotent cells, such as mesenchymal stem cells (MSCs), may be used ...

Nihon University

During hemodialysis session, several adverse reactions can occur on platelets, which are attributable to bioincompatibility of the dialysis membrane. Glycoprotein IIb/IIIa (GPIIb/IIIa) is the receptor for fibrinogen, which mediates platelet aggregation and adhesion. Accordingly, we compared the influence of a cellulose triacetate (CTA) and polysulfone (PS) membrane on GPIIb/IIIa and platelet activation.

Comparison of the effects of cellulose triacetate and polysulfone membrane on GPIIb/IIIa and platelet activation.

Acetate-free biofiltration (AFB) is a special hemodiafiltration (HDF) modality performed with a base-free dialysate and simultaneous injection of non-pyrogenic sodium bicarbonate solution. The purpose of this study was to investigate the difference of cytokine production by conventional bicarbonate hemodialysis (BCD), standard HDF and AFB in the same patients. Eight stable hemodialysis patients were treated in random order with BCD, HDF and AFB every 4 weeks. The production of interleukin-1 beta (IL-1 beta) and interleukin-1 receptor antagonist (IL-1Ra) by peripheral blood mononuclear cells (PBMC) was investigated without stimulation and with stimulation by a small amount of endotoxin (ET)-contaminated beta 2-microglobulin (beta 2M) and lipopolysaccharide (LPS) before and after dialysis treatment in the last sessions during all periods. To serve as controls, 14 healthy volunteers participated in this study. In spontaneous IL-1Ra production, the values of before and after AFB were not significantly different from that of the controls, and the values of before and after BCD and before HDF were significantly higher than that of the controls. In LPS-stimulated PBMC, IL-1 beta production before and after AFB was not significantly different from that of the controls, and before and after BCD and HDF was significantly higher than that of the controls. In ET-contaminated beta 2M-stimulated PBMC, IL-1 beta production before and after AFB was not significantly different compared to the controls, and the production was significantly lower than that before and after BCD and HDF. In addition, IL-1Ra production after AFB was not significantly different from the controls, and the production was significantly lower than that before and after BCD and HDF. It was concluded that a lower cytokine production by AFB may have the effect of preventing dialysis-related complications.

A comparison of bicarbonate hemodialysis, hemodiafiltration, and acetate-free biofiltration on cytokine production.

We investigated whether or not uremic serum has an influence on IL-1beta and IL-1Ra production by normal peripheral blood mononuclear cells (PBMC). Four groups of subjects were divided into healthy controls and non-dialyzed patients with chronic renal failure (CRF), patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) patients. We examined cytokine concentrations and cytokine production by PBMC from a normal subject at the density of 2.5 x 10(6) cells/mL incubated with 25% serum in the medium and serum containing polymyxin-B or lipopolysaccharides (LPS). IL-1Ra concentrations in the serum of the uremic groups were significantly higher than those of the controls. In IL-1beta production by PBMC in medium with both serum and serum containing polymyxin-B, these values in the uremic groups were significantly higher than in the controls. In IL-1Ra production with serum containing polymyxin-B, these values in the uremic groups were significantly higher than in the controls. In contrast, in IL-1Ra production by PBMC in medium with serum containing LPS, these values in the uremic groups were significantly lower than in the controls. It was concluded that uremic serum not only contains nonendotoxemic cytokine-inducing substances, but also shows impaired cytokine production by PBMC in response to LPS.

The influence of uremic serum on interleukin-1beta and interleukin-1 receptor antagonist production by peripheral blood mononuclear cells.

Complications associated with atherosclerosis in dialysis patients are attracting attention. Fetuin-A, a circulating calcium-regulatory glycoprotein that inhibits vascular calcification, is associated with inflammation and outcome in dialysis patients. In this study, the relation between serum fetuin-A concentration and biochemical parameters in patients on hemodialysis was investigated.

Evaluation of serum fetuin-A relationships with biochemical parameters in patients on hemodialysis.

We evaluated the effects of the angiotensin II (Ang II) receptor blocker (ARB) losartan on the formation and number of endothelial progenitor cells (EPCs) in hypertensive rats. Wistar-Kyoto (WKY) rats and stroke-prone, spontaneously hypertensive rats (SHR-SP) were salt-loaded and then treated with losartan (10 mg/kg/day), trichlormethiazide (TCM; 1.6 mg/kg/day), or tempol (1 mmol/L) for 2 weeks. Peripheral blood mononuclear cells were isolated, subjected to flow cytometric analysis to determine the number of circulating EPCs, cultured to assay EPC colony formation, and subjected to a migration chamber assay to evaluate EPC migration. Oxidative stress in EPCs was evaluated by thiobarbituric acid reactive substance (TBARS) assay. The results showed that the number, colony formation, and migration of EPCs were markedly decreased in SHR-SP compared to those in WKY rats. The TBARS scores were significantly greater in SHR-SP than in WKY rats. Losartan and TCM decreased systolic blood pressure in SHR-SP to similar levels. Losartan and tempol increased the number of circulating EPCs and colony formation, and inhibited oxidation in SHR-SP. TCM did not affect the EPC number, colony formation, or oxidation. Both losartan and TCM stimulated EPC migration. Expression of gp91(phox), p22(phox), and p47(phox) mRNA in tissues was significantly decreased by losartan but not by TCM. These results indicate that the formation and function of EPCs are impaired by oxidative stress in SHR-SP. This is the first report to show that losartan improves the proliferation and function of EPCs in hypertension, suggesting that ARBs are useful to repair hypertensive vascular injuries.

Losartan improves the impaired function of endothelial progenitor cells in hypertension via an antioxidant effect.

Endothelial progenitor cells (EPCs) derived from bone marrow migrate to areas of endothelial damage and repair them. EPC function is impaired by oxidative stress. We examined the effects of an antioxidative beta1-adrenoceptor blocker on the number and function of EPCs in hypertensive rats.

Effects of the antioxidative beta-blocker celiprolol on endothelial progenitor cells in hypertensive rats.

We established dedifferentiated fat (DFAT) cells from mature adipocytes that differentiate to multiple lineages and have characteristics similar to those of mesenchymal stem cells. In this study, we evaluated the effect of implantation of DFAT cells on habu snake venom (HSV)-induced renal dysfunction in tenascin-C knockout (TC-KO) mice.

Implantation of dedifferentiated fat cells ameliorates habu snake venom-induced chronic renal dysfunction in tenascin-C-deficient mice.

Zinc-finger transcriptional factor Sall1 modulates gene expression and regulates organogenesis, including kidney development. Angiogenesis induced by vascular endothelial growth factor (VEGF) is also required for organogenesis. We investigated whether Sall1 induces angiogenesis through VEGF gene activation. Sall1 gene transfer induced marked neovascularization in rat cornea and in mouse embryoid bodies (EBs). The neovascularization in EBs was abolished by co-administration of anti-VEGF antibody. Sall1 gene transfer in Swiss 3T3 cells significantly increased the expression of VEGF-A mRNA but did not markedly increase the expression of fibroblast growth factor-2, epidermal growth factor, hepatocyte growth factor and ETS-1 mRNA. Sall1 gene transfer significantly increased VEGF-A protein levels in conditioned medium from cultured fibroblasts. Sall1 gene transfer significantly increased VEGF-A promoter activity in HEK293T cells as compared with cells transfected with mock vector or truncated Sall1. These results suggest that Sall1 induces angiogenesis by stimulating VEGF-A promoter activity.

Zinc-finger transcriptional factor Sall1 induces angiogenesis by activation of the gene for VEGF-A.

The pathogenesis of hypertension is dependent on tissue angiotensin (Ang) II, which induces cardiovascular and renal remodeling. The presence of label-retaining cells (LRCs) as renal stem cells has been reported in nephrotubulus. We examined effects of treatment with valsartan on endothelial progenitor cells (EPCs) and renal LRCs in stroke-prone spontaneously hypertensive rats (SHR-SP).

Treatment with valsartan stimulates endothelial progenitor cells and renal label-retaining cells in hypertensive rats.

Statins exert pleiotropic effects, including antioxidative and cellular protective effects. Endogenous adrenomedullin (AM) induces anti-inflammatory, anti-fibrotic and proangiogenic effects. We examined the effects of simvastatin on cardiac fibrosis and apoptosis in AM heterozygous knockout (AM(+/-)) mice treated with angiotensin (Ang) II and high salt loading. Seven-week-old AM(+/-) mice were infused with Ang II while on a high-salt diet with or without simvastatin for 2 weeks. Hearts were stained by hematoxylin-eosin or Masson's trichrome, and were immunostained with isolectin B(4) and α-smooth muscle actin antibodies. Expression of c-Kit and Sca-1 messenger RNA (mRNA) was evaluated by real-time PCR analysis. Apoptotic cells in hearts were identified by terminal deoxynucleotidyl transferase-mediated UTP end labeling (TUNEL) staining. Hearts from Ang II/salt loading AM(+/-) mice showed marked perivascular fibrosis around coronary arteries. Treatment with simvastatin significantly inhibited the fibrosis around coronary arteries in Ang II/salt-loading AM(+/-) mice. Expression of c-Kit and Sca-1 mRNAs in hearts from Ang II/salt-loading AM(+/-) mice was significantly lower than in hearts from wild-type mice. Treatment with simvastatin significantly increased the suppressed expression of c-Kit and Sca-1 mRNAs. In addition, treatment with simvastatin significantly increased the number of isolectin B(4)-positive capillary arteries in hearts from Ang II/salt-loading AM(+/-) mice. Ang II/high salt significantly increased apoptotic cells in hearts from AM(+/-) mice; this trend was reversed by treatment with simvastatin. Thus, statins have potent cardioprotective effects that may be associated with anti-fibrotic, proangiogenic and anti-apoptotic effects in Ang II/salt-loading AM(+/-) mice.

Chii Yamamoto

Division of Cell Regeneration and Transplantation,
School of Medicine,
Division of Cell Regeneration and Transplantation, School of Medicine

Nihon University

An Efficient Method to Obtain Dedifferentiated Fat Cells

Chii Yamamoto

Division of Cell Regeneration and Transplantation,School of Medicine,Division of Cell Regeneration and Transplantation, School of Medicine

Nihon University

An Efficient Method to Obtain Dedifferentiated Fat Cells

Division of Cell Regeneration and Transplantation,
School of Medicine,
Division of Cell Regeneration and Transplantation, School of Medicine