Hideo Mugishima

Mature adipocyte-derived dedifferentiated fat cells exhibit multilineage potential.

When mature adipocytes are subjected to an in vitro dedifferentiation strategy referred to as ceiling culture, these mature adipocytes can revert to a more primitive phenotype and gain cell proliferative ability. We refer to these cells as dedifferentiated fat (DFAT) cells. In the present study, we examined the multilineage differentiation potential of DFAT cells. DFAT cells obtained from adipose tissues of 18 donors exhibited a fibroblast‐like morphology and sustained high proliferative activity. Flow cytometric analysis revealed that DFAT cells comprised a highly homogeneous cell population compared with that of adipose‐derived stem/stromal cells (ASCs), although the cell‐surface antigen profile of DFAT cells was very similar to that of ASCs. DFAT cells lost expression of mature adipocytes marker genes but retained or gained expression of mesenchymal lineage‐committed marker genes such as peroxisome proliferator‐activated receptor gamma (PPARγ), RUNX2, and SOX9. In vitro differentiation analysis revealed that DFAT cells could differentiate into adipocytes, chondrocytes, and osteoblasts under appropriate culture conditions. DFAT cells also formed osteoid matrix when implanted subcutaneously into nude mice. In addition, clonally expanded porcine DFAT cells showed the ability to differentiate into multiple mesenchymal cell lineages. These results indicate that DFAT cells represent a type of multipotent progenitor cell. The accessibility and ease of culture of DFAT cells support their potential application for cell‐based therapies. J. Cell. Physiol. 215: 210–222, 2008.

VEGF receptor-2 Y951 signaling and a role for the adapter molecule TSAd in tumor angiogenesis

Vascular endothelial growth factor receptor‐2 (VEGFR‐2) activation by VEGF‐A is essential in vasculogenesis and angiogenesis. We have generated a pan‐phosphorylation site map of VEGFR‐2 and identified one major tyrosine phosphorylation site in the kinase insert (Y951), in addition to two major sites in the C‐terminal tail (Y1175 and Y1214). In developing vessels, phosphorylation of Y1175 and Y1214 was detected in all VEGFR‐2‐expressing endothelial cells, whereas phosphorylation of Y951 was identified in a subset of vessels. Phosphorylated Y951 bound the T‐cell‐specific adapter (TSAd), which was expressed in tumor vessels. Mutation of Y951 to F and introduction of phosphorylated Y951 peptide or TSAd siRNA into endothelial cells blocked VEGF‐A‐induced actin stress fibers and migration, but not mitogenesis. Tumor vascularization and growth was reduced in TSAd‐deficient mice, indicating a critical role of Y951‐TSAd signaling in pathological angiogenesis.

Umbilical cord milking reduces the need for red cell transfusions and improves neonatal adaptation in infants born at less than 29 weeks’ gestation: a randomised controlled trial

Objective: To investigate the effects of umbilical cord milking on the need for red blood cell (RBC) transfusion and morbidity in very preterm infants. Patients and Methods: 40 singleton infants born between 24 and 28 weeks’ gestation were randomly assigned to receive umbilical cord clamped either immediately (control group, n = 20) or after umbilical cord milking (milked group, n = 20). Primary outcome measures were the probability of not needing transfusion, determined by Kaplan–Meier analysis, and the total number of RBC transfusions. Secondary outcome variables were haemoglobin value and blood pressure at admission. Results: There were no significant differences in gestational age and birth weight between the two groups. The milked group was more likely not to have needed red cell transfusion (p = 0.02) and had a decreased number (mean (SD)) of RBC transfusions (milked group 1.7 (3.0) vs controls 4.0 (4.2); p = 0.02). The initial mean (SD) haemoglobin value was higher in the milked group (165 (14) g/l) than in the controls (141 (16) g/l); p<0.01). Mean (SD) blood pressure at admission was significantly higher in the milked group (34 (9) mm Hg) than in the controls 28 (8) mm Hg; p = 0.03). There was no significant difference in mortality between the groups. The milked group had a shorter duration of ventilation or supplemental oxygen than the control group. Conclusion: Milking the umbilical cord is a safe procedure, reducing the need for RBC transfusions, and the need for circulatory and respiratory support in very preterm infants.

Development of gene silencing pyrrole-imidazole polyamide targeting the TGF-beta1 promoter for treatment of progressive renal diseases.

Pyrrole-imidazole (Py-Im) polyamides are nuclease-resistant novel compounds that inhibit gene expression by binding to the minor groove of DNA. A Py-Im polyamide that targets rat TGF-beta1 was designed as a gene-silencing agent for progressive renal diseases, and the distribution and the effects of this polyamide on renal injury were examined in Dahl-salt sensitive (Dahl-S) rats. For identification of transcription factor binding elements for activation of the rat TGF-beta1 gene, recombinant TGF-beta1 reporter plasmids were transfected into HEK-293 cells, and promoter activity was measured. Py-Im polyamide was designed to the activator protein-1 binding site of the rat TGF-beta1 promoter. This Py-Im polyamide showed strong, fast, and specific binding to the target DNA in gel mobility shift and Biacore assays. Py-Im polyamide significantly inhibited TGF-beta1 promoter activity and expression of TGF-beta1 mRNA and protein in rat mesangial cells. Intravenously administered fluorescein-labeled polyamide distributed to the kidney of rats. Py-Im polyamide significantly inhibited expression of TGF-beta1 mRNA and protein in the renal cortex of Dahl-S rats and reduced the increase in urinary protein and albumin in Dahl-S rats independent of changes in blood pressure. These results indicate that Py-Im polyamide that targets TGF-beta1 will be a novel gene-silencing agent for the TGF-beta1-associated diseases, including progressive renal diseases.

Intensified chemotherapy increases the survival rates in patients with stage 4 neuroblastoma with MYCN amplification.

Purpose Patients with high-risk neuroblastoma who have multiple copies of MYCN fare much worse than do those without MYCN amplification; however, it has not been clarified whether intensified chemotherapy with or without blood stem cell transplantation can alter the extremely poor prognosis of patients with amplified MYCN. Methods and Results Between 1985 and 1999, 301 patients older than age 12 months with stage 4 neuroblastoma were treated. From January 1985 to February 1991, 80 patients with stage 4 neuroblastoma with and without MYCN amplification uniformly received induction chemotherapy with regimen A1 (cyclophosphamide 1,200 mg/m2 and vincristine 1.5 mg/m2 on day 1, tetra-hydropyranyl [THP]-Adriamycin 40 mg/m2 on day 3, and cisplatin 90 mg/m2 on day 5). Among 22 patients with MYCN amplification, nine (40.9%) achieved a complete remission and seven (31.8%) underwent stem cell transplantation. Of 58 patients without MYCN amplification, 43 (74.1%) achieved a complete remission and 14 (24.1%) underwent stem cell transplantation. The 5-year relapse-free survival rates were 23.2% for stage 4 patients with MYCN amplification and 33.3% for those without MYCN amplification (P = 0.029); the 5-year overall survival rates were 32.8% for stage 4 patients with MYCN amplification and 42.8% for those without MYCN amplification (P > 0.05). From March 1991 to June 1998, patients with stage 4 neuroblastoma who had 10 or more copies of MYCN were treated with regimen A3 (cyclophosphamide 1,200 mg/m2 per day on days 1 and 2, THP-Adriamycin 40 mg/m2 on day 3, etoposide 100 mg/m2 per day on days 1 to 5, and cisplatin 25 mg/m2 per day on days 1 to 5); those with fewer than 10 copies of MYCN received regimen new A1 (cyclophosphamide 1,200 mg/m2 on day 1, THP-Adriamycin 40 mg/m2 on day 3, etoposide 100 mg/m2 per day on days 1 to 5, and cisplatin 90 mg/m2 on day 5), which is similar in intensity to regimen A1. Among 88 patients with MYCN amplification, 63 (71.6%) achieved a complete remission and 63 (71.68%) underwent stem cell transplantation. Of 133 patients without MYCN amplification, 93 (69.9%) achieved a complete remission and 71 (53.4%) underwent stem cell transplantation. The 5-year relapse-free survival rates were 36.0% for stage 4 patients with MYCN amplification and 32.2% for those without MYCN amplification (P > 0.05), the 5-year overall survival rates were 34.0% for stage 4 patients with MYCN amplification and 38.9% for those without MYCN amplification (P > 0.05). The difference in relapse-free survival rates was significantly different (P = 0.003) between patients with MYCN-amplified tumor treated before (regimen A1) versus after 1991 (regimen A3). Conclusions With the use of the more intensive induction regimen A3 plus blood stem cell transplantation for MYCN-amplified patients, survival curves for those with or without MYCN amplification now appear similar. Higher doses of chemotherapy may ameliorate the effect of MYCN amplification in patients with high-risk neuroblastoma.

Dedifferentiated fat cells convert to cardiomyocyte phenotype and repair infarcted cardiac tissue in rats

Adipose tissue-derived stem cells have been demonstrated to differentiate into cardiomyocytes and vascular endothelial cells. Here we investigate whether mature adipocyte-derived dedifferentiated fat (DFAT) cells can differentiate to cardiomyocytes in vitro and in vivo by establishing DFAT cell lines via ceiling culture of mature adipocytes. DFAT cells were obtained by dedifferentiation of mature adipocytes from GFP-transgenic rats. We evaluated the differentiating ability of DFAT cells into cardiomyocytes by detection of the cardiac phenotype markers in immunocytochemical and RT-PCR analyses in vitro. We also examined effects of the transplantation of DFAT cells into the infarcted heart of rats on cardiomyocytes regeneration and angiogenesis. DFAT cells expressed cardiac phenotype markers when cocultured with cardiomyocytes and also when grown in MethoCult medium in the absence of cardiomyocytes, indicating that DFAT cells have the potential to differentiate to cardiomyocyte lineage. In a rat acute myocardial infarction model, transplanted DFAT cells were efficiently accumulated in infarcted myocardium and expressed cardiac sarcomeric actin at 8 weeks after the cell transplantation. The transplantation of DFAT cells significantly (p<0.05) increased capillary density in the infarcted area when compared with hearts from saline-injected control rats. We demonstrated that DFAT cells have the ability to differentiate to cardiomyocyte-like cells in vitro and in vivo. In addition, transplantation of DFAT cells led to neovascuralization in rats with myocardial infarction. We propose that DFAT cells represent a promising candidate cell source for cardiomyocyte regeneration in severe ischemic heart disease.

Mature, Adipocyte Derived, Dedifferentiated Fat Cells Can Differentiate Into Smooth Muscle-Like Cells and Contribute to Bladder Tissue Regeneration

PURPOSE We recently reported that mature, adipocyte derived, dedifferentiated fat cells show high proliferative activity and multilineage differentiation potential. In the current study we investigated whether such cells could differentiate into a smooth muscle cell lineage and contribute to bladder tissue regeneration in a mouse bladder injury model. MATERIALS AND METHODS Human adipocyte derived dedifferentiated fat cells were cultured for 1 week under conditions favorable for smooth muscle cell differentiation and immunostained for alpha-smooth muscle actin. The expression of smooth muscle cell marker genes for differentiating dedifferentiated fat cells was measured by real-time reverse transcription-polymerase chain reaction. Green fluorescence protein labeled dedifferentiated fat cells were injected into cryo-injured bladder walls in mice. The ability of the fat cells to regenerate smooth muscle tissue was examined immunohistochemically 14 and 30 days after transplantation. RESULTS Immunohistochemical analysis revealed that more than 50% of the fat cells were successfully differentiated into alpha-smooth muscle actin positive cells under the optimum culture condition of a medium containing 5% fetal bovine serum and 5 ng/ml transforming growth factor-beta1. Real-time reverse transcription-polymerase chain reaction revealed increased expression of SM22alpha, alpha-smooth muscle actin and smooth muscle-myosin heavy chain in dedifferentiated fat cells during week 1 of differentiation culture. Cells expressing alpha-smooth muscle actin plus green fluorescence protein were observed at the bladder wall injection sites in mice 14 and 30 days after transplantation. Alpha-smooth muscle actin positive areas in injured bladder tissue in mice with fat cell injection were significantly larger than those in saline injected control mice. CONCLUSIONS These findings suggest that dedifferentiated fat cells can differentiate into smooth muscle cell lineages and contribute to the regeneration of bladder smooth muscle tissue.

Long-term efficacy of hematopoietic stem cell transplantation on brain involvement in patients with mucopolysaccharidosis type II: a nationwide survey in Japan.

Hematopoietic stem cell transplantation (HSCT) has not been indicated for patients with mucopolysaccharidosis II (MPS II, Hunter syndrome), while it is indicated for mucopolysaccharidosis I (MPS I) patients <2 years of age and an intelligence quotient (IQ) of ≥ 70. Even after the approval of enzyme replacement therapy for both of MPS I and II, HSCT is still indicated for patients with MPS I severe form (Hurler syndrome). To evaluate the efficacy and benefit of HSCT in MPS II patients, we carried out a nationwide retrospective study in Japan. Activities of daily living (ADL), IQ, brain magnetic resonance image (MRI) lesions, cardiac valvular regurgitation, and urinary glycosaminoglycan (GAG) were analyzed at baseline and at the most recent visit. We also performed a questionnaire analysis about ADL for an HSCT-treated cohort and an untreated cohort (natural history). Records of 21 patients were collected from eight hospitals. The follow-up period in the retrospective study was 9.6 ± 3.5 years. ADL was maintained around baseline levels. Cribriform changes and ventricular dilatation on brain MRI were improved in 9/17 and 4/17 patients, respectively. Stabilization of brain atrophy was shown in 11/17 patients. Cardiac valvular regurgitation was diminished in 20/63 valves. Urinary GAG concentration was remarkably lower in HSCT-treated patients than age-matched untreated patients. In the questionnaire analysis, speech deterioration was observed in 12/19 patients in the untreated cohort and 1/7 patient in HSCT-treated cohort. HSCT showed effectiveness towards brain or heart involvement, when performed before signs of brain atrophy or valvular regurgitation appear. We consider HSCT is worthwhile in early stages of the disease for patients with MPS II.

Humanized NOD/SCID/IL2Rγnull Mice Transplanted with Hematopoietic Stem Cells under Nonmyeloablative Conditions Show Prolonged Life Spans and Allow Detailed Analysis of Human Immunodeficiency Virus Type 1 Pathogenesis

ABSTRACT In a previous study, we demonstrated that humanized NOD/SCID/IL2Rγnull (hNOG) mice constructed with human hematopoietic stem cells (HSCs) allow efficient human immunodeficiency virus type 1 (HIV-1) infection. However, HIV-1 infection could be monitored for only 43 days in the animals due to their short life spans. By transplanting HSCs without any myeloablation methods, the mice successfully survived longer than 300 days with stable engraftment of human cells. The mice showed high viremia state for more than the 3 months examined, with systemic HIV-1 infection and gradual decrease of CD4+ T cells analogous to that in humans. These capacities of the hNOG mice are very attractive for modeling mechanisms of AIDS progression and therapeutic strategy.

The Earliest Thymic Progenitors in Adults Are Restricted to T, NK, and Dendritic Cell Lineage and Have a Potential to Form More Diverse TCRβ Chains than Fetal Progenitors

T cell progenitors in the adult thymus (AT) are not well characterized. In the present study, we show that the earliest progenitors in the murine AT are, like those in fetal thymus (FT), unable to generate B or myeloid cells, but still retain the ability to generate NK cells and dendritic cells. However, AT progenitors are distinct from those in FT or fetal liver, in that they are able to produce ∼100 times larger numbers of T cells than progenitors in fetuses. Such a capability to generate a large number of T cells was mainly attributed to their potential to extensively proliferate before the TCRβ chain gene rearrangement. We propose that the AT is colonized by T/NK/dendritic cell tripotential progenitors with much higher potential to form diversity in TCRβ chains than FT progenitors.