Impaired adipogenic capacity in induced pluripotent stem cells from lipodystrophic patients with BSCL2 mutations

OBJECTIVE

Congenital generalized lipodystrophy (CGL) is an autosomal recessive disorder characterized by marked scarcity of adipose tissue, extreme insulin resistance, hypertriglyceridemia, hepatic steatosis and early-onset diabetes. Mutation of the BSCL2/SEIPIN gene causes the most severe form of CGL. The aim of this study was to generate induced pluripotent stem (iPS) cells from patients with CGL harboring BSCL2/SEIPIN mutations.

METHODS

Skin biopsies were obtained from two Japanese patients with CGL harboring different nonsense mutations (E189X and R275X) in BSCL2/SEIPIN. The fibroblasts thus obtained were infected with retroviruses encoding OCT4, SOX2, c-MYC, and KLF4. The generated iPS cells were evaluated for pluripotency by examining the expression of pluripotency markers (alkaline phosphatase, SSEA-4, TRA-1-60, and NANOG) and their ability to differentiate to three germ layers in vitro by forming embryoid bodies, and to form teratomas in vivo. Adipogenic capacity of differentiated BSCL2-iPS cells was determined by oil red O and adipose differentiation-related protein (ADRP) staining. Rescue experiments were also performed using stable expression of wild-type BSCL2. A coimmunoprecipitation assay was conducted to investigate the interaction of SEIPIN with ADRP.

RESULTS

iPS cells were generated from fibroblasts of the two patients with CGL. Each of the patient-derived iPS (BSCL2-iPS) clones showed all of the hallmarks of pluripotency and could differentiate into derivatives of all three germ layers in vitro by forming embryoid bodies, and form teratomas after injection into mouse testes. BSCL2-iPS cells maintained the mutations in BSCL2 and lacked intact BSCL2. Upon adipogenic differentiation, BSCL2-iPS cells exhibited marked reduction of lipid droplet formation concomitant with diffuse cytoplasmic distribution of ADRP, compared with iPS cells from healthy individuals. Forced expression of BSCL2 not only rescued the lipid accumulation defects, but also restored cytoplasmic punctate localization of ADRP in BSCL2-iPS cells. Coimmunoprecipitation indicated SEIPIN interacted with ADRP.

CONCLUSION

BSCL2-iPS cells that recapitulate the lipodystrophic phenotypes in vitro could provide valuable models with which to study the physiology of lipid accumulation and the pathology of human lipodystrophy. We found that BSCL2 defines the localization of ADRP, which has a role in lipid accumulation and adipogenic differentiation.

Oncoplastic breast conserving surgery: Volume replacement vs. volume displacement

Oncoplastic breast conserving surgery (BCS) has emerged as a third option between conventional BCS and mastectomy. Oncoplastic BCS includes two fundamentally different approaches: volume replacement and volume displacement. The former involves partial mastectomy and immediate reconstruction of the breast with the transposition of autologous tissue from elsewhere, while the latter involves partial mastectomy and using the remaining breast tissue to fill the defect resulting from extirpation of the tumor. There are several benefits associated with oncoplastic BCS. First, it allows partial mastectomy without cosmetic penalties, and can achieve better cosmetic outcomes than total mastectomy with immediate breast reconstruction. Second, it avoids the need for total mastectomy in an increasing number of patients without compromising local control. Third, partial breast reconstruction is less extensive and has fewer complications than conventional procedures. Partial mastectomy and partial breast reconstruction can be carried out either simultaneously as a one-stage procedure, or using a two-stage approach. Although patients prefer a one-stage procedure, it requires intraoperative confirmation of complete tumor excision using frozen-section analysis. Moreover, oncoplastic BCS requires combined skills, knowledge, and understanding of both oncological and plastic surgeries, which may be optimally achieved by an oncoplastic surgeon.

Abstract P2-11-04: Serum IgG response against prostate-related antigen revealed by personalized peptide vaccination in patients with metastatic recurrent breast cancer

Purpose: We have indicated that IgG and CTL boosting response could be a potential prognostic factor for overall survival (OS) and progression free survival (PFS) in metastatic recurrent breast cancer (mrBC) patients, who had received personalized selected peptide vaccine (PPV) therapy in our previously reported clinical phase II study. The aim of this study is to identify the prognostic role of serum value of IgG antibody against prostate related-antigen (PRA), including prostate-specific antigen (PSA), prostate specific membrane antigen (PSMA) and prostate acid phosphatase (PAP) in mrBC patients

Methods: Peripheral blood samples of 77 patients with mrBC were analyzed for serum anti-PRA IgG levels before and after 6th and 12th PPV therapy prospectively. Most of the peptides using for PPV are derived from cancer associated antigens expressing in various types of advanced cancers, but the peptides derived from PRAs were not used in this study.

Results: After PPV therapy, total serum levels of anti-PRA IgG were significantly increased in 31 mrBC patients (Group 1) whereas in remaining 46 rmBC patients (Group 2). Either serum anti-PSA, anti-PAP and/or anti-PMSA IgGs showed a significant increase in patients of Group 1 after 6th (p=0.045) and 12th PPV treatment (p < 0.001), irrespective of their intrinsic subtypes. The median PFS and median OS of Group 1 patients were 8.1 and 14.3 months, while those of Group 2 patients were 5.1 and 10.8 months, respectively. Anti-PRA IgG levels were significantly associated with PFS (p=0.0073; HR: 0.37) and OS (p=0.025; HR: 0.43) between these two groups, whereas no significant relation was found with age, clinical response rate and recurrent metastatic status.

Conclusions: The Group 1 patients with elevated anti-PRA IgG may have better prognosis compared to Group 2 patients who showed no IgG elevation after PPV treatment for rmBC. These results indicated a clinical significance between pre-and post- treatment measurement of serum anti-PRA IgGs in mrBC patients receiving PPV therapy, and may be a useful prognostic marker for monitoring the outcome to PPV treatment of breast cancer.

Citation Format: Toh U, Okabe M, Iwakuma N, Mishima M, Shichijo S, Yamada A, Noguchi M, Itoh K, Akagi Y. Serum IgG response against prostate-related antigen revealed by personalized peptide vaccination in patients with metastatic recurrent breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-04.

Positioning bedridden patients to reduce interface pressures over the sacrum and great trochanter

OBJECTIVE

In this study, we evaluated the effect of hip-joint rotation on the interface pressure over the sacrum and greater trochanter with a new protocol for positioning of bedridden elderly patients.

METHOD

The interface pressure values over the sacrum and greater trochanter in bedridden patients were evaluated. These were collected in the supine position, 90° lateral position, and 30° and 40° laterally inclined positions with external rotation or neutral positioning of the hip joint. Each interface pressure was assessed with a device measuring pressure distribution, after which, the peak pressure index (PPI) was calculated.

RESULTS

In the 17 patients examined, the PPI over the sacrum in the supine position was significantly greater than that in other positions. In the 30° and 40° laterally inclined positions, the PPIs over the greater trochanter were significantly lower in the neutral position of the hip joint compared with those in the external rotation position.

CONCLUSION

Our findings revealed the effects of hip-joint rotation on the interface pressure for the greater trochanter, possibly due to the increased distance between the greater trochanter and the sacrum caused by neutral position of the hip joint. The results demonstrate that it is to best place the hip joint in a neutral position when the legs are in contact with the bed in order to distribute the pressure over the greater trochanter in the 30° and 40° laterally inclined positions. These results can be applied to the clinical setting to improve patient positioning and decrease pressure ulcers.

DECLARATION OF INTEREST

The authors declare that they have no competing financial interests.

Real-time observation of irradiated HeLa-cell modified by fluorescent ubiquitination-based cell-cycle indicator using synchrotron X-ray microbeam

Fluorescent ubiquitination-based cell-cycle indicator (FUCCI) human cancer (HeLa) cells (red indicates G1; green, S/G2) were exposed to a synchrotron X-ray microbeam. Cells in either G1 or S/G2 were irradiated selectively according to their colour in the same microscopic field. Time-lapse micrographs of the irradiated cells were acquired for 24 h after irradiation. For fluorescent immunostaining, phosphorylated histone proteins (γ-H2AX) indicated the induction of DNA double-strand breaks. The cell cycle was arrested by irradiation at S/G2. In contrast, cells irradiated at G1 progressed to S/G2. The foci were induced in cells irradiated at both G1 and S/G2, suggesting that the G1-S (or S) checkpoint pathway does not function in HeLa cells due to the fact that the cells are functionally p53 deficient, even though X-ray microbeam irradiation significantly induces double-strand breaks. These results demonstrate that single FUCCI cell exposure and live cell imaging are powerful methods for studying the effects of radiation on the cell cycle.

Visualisation of cell cycle modifications by X-ray irradiation of single HeLa cells using fluorescent ubiquitination-based cell cycle indicators

To explore the effects of X-ray irradiation on mammalian cell cycle dynamics, single cells using the fluorescent ubiquitination-based cell cycle indicator (Fucci) technique were tracked. HeLa cells expressing Fucci were used to visualise cell cycle modifications induced by irradiation. After cultured HeLa-Fucci cells were exposed to 5 Gy X-rays, fluorescent cell images were captured every 20 min for 48 h using a fluorescent microscope. Time dependence of the fluorescence intensity of S/G2 cells was analysed to examine the cell cycle dynamics of irradiated and non-irradiated control cells. The results showed that irradiated cells could be divided into two populations: one with similar cell cycle dynamics to that of non-irradiated cells, and another displaying a prolonged G2 phase. Based on these findings, it is proposed in this article that an underlying switch mechanism is involved in cell cycle regulation and the G2/M checkpoint of HeLa cells.

Live-cell imaging study of mitochondrial morphology in mammalian cells exposed to X-rays

Morphological changes in mitochondria induced by X-irradiation in normal murine mammary gland cells were studied with a live-cell microscopic imaging technique. Mitochondria were visualised by staining with a specific fluorescent probe in the cells, which express fluorescent ubiquitination-based cell-cycle indicator 2 (Fucci2) probes to visualise cell cycle. In unirradiated cells, the number of cells with fragmented mitochondria was about 20 % of the total cells through observation period (96 h). In irradiated cells, the population with fragmented mitochondria significantly increased depending on the absorbed dose. Particularly, for 8 Gy irradiation, the accumulation of fragmentation persists even in the cells whose cell cycle came to a stand (80 % in G1 (G0-like) phase). The fraction reached to a maximum at 96 h after irradiation. The kinetics of the fraction with fragmented mitochondria was similar to that for cells in S/G2/M phase (20 %) through the observation period (120 h). The evidences show that, in irradiated cells, some signals are continually released from a nucleus or cytoplasm even in the G0-like cells to operate some sort of protein machineries involved in mitochondrial fission. It is inferred that this delayed mitochondrial fragmentation is strongly related to their dysfunction, and hence might modulate radiobiological effects such as mutation or cell death.

FIVE CASES OF TICK BITE

Reported here are five cases of tick bite: in a 2-year-old boy, a 3-year-old girl, a 72-year-old woman, a 29-year-old woman, and a 51-year-old man. Four cases are thought to have occurred in a mountain area while one occurred in a city garden. None were accompanied with severe systemic symptoms or deuteropathies. The parasites were identified as the adult female tick Ixodes ovatus Neumann (3 cases) and Ixodes nipponensis Kitaoka et Saito (2 cases), which are commonly distributed in Japan.

Leptin restores the insulinotropic effect of exenatide in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet

Leptin may reduce pancreatic lipid deposition, which increases with progression of obesity and can impair β-cell function. The insulinotropic effect of glucagon-like peptide-1 (GLP-1) and the efficacy of GLP-1 receptor agonist are reduced associated with impaired β-cell function. In this study, we examined whether leptin could restore the efficacy of exenatide, a GLP-1 receptor agonist, in type 2 diabetes with increased adiposity. We chronically administered leptin (500 μg·kg⁻¹·day⁻¹) and/or exenatide (20 μg·kg⁻¹·day⁻¹) for 2 wk in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet (STZ/HFD mice). The STZ/HFD mice exhibited hyperglycemia, overweight, increased pancreatic triglyceride level, and reduced glucose-stimulated insulin secretion (GSIS); moreover, the insulinotropic effect of exenatide was reduced. However, leptin significantly reduced pancreatic triglyceride level, and adding leptin to exenatide (LEP/EX) remarkably enhanced GSIS. These results suggested that the leptin treatment restored the insulinotropic effect of exenatide in the mice. In addition, LEP/EX reduced food intake, body weight, and triglyceride levels in the skeletal muscle and liver, and corrected hyperglycemia to a greater extent than either monotherapy. The pair-feeding experiment indicated that the marked reduction of pancreatic triglyceride level and enhancement of GSIS by LEP/EX occurred via mechanisms other than calorie restriction. These results suggest that leptin treatment may restore the insulinotropic effect of exenatide associated with the reduction of pancreatic lipid deposition in type 2 diabetes with increased adiposity. Combination therapy with leptin and exenatide could be an effective treatment for patients with type 2 diabetes with increased adiposity.

Protooncogene TCL1b functions as an Akt kinase co-activator that exhibits oncogenic potency in vivo

Protooncogene T-cell leukemia 1 (TCL1), which is implicated in human T-cell prolymphocytic leukemia (T-PLL), interacts with Akt and enhances its kinase activity, functioning as an Akt kinase co-activator. Two major isoforms of TCL1 Protooncogenes (TCL1 and TCL1b) are present adjacent to each other on human chromosome 14q.32. In human T-PLL, both TCL1 and TCL1b are activated by chromosomal translocation. Moreover, TCL1b-transgenic mice have never been created. Therefore, it remains unclear whether TCL1b itself, independent of TCL1, exhibits oncogenicity. In co-immunoprecipitation assays, both ectopic and endogenous TCL1b interacted with Akt. In in vitro Akt kinase assays, TCL1b enhanced Akt kinase activity in dose- and time-dependent manners. Bioinformatics approaches utilizing multiregression analysis, cluster analysis, KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway mapping, Venn diagrams and Gene Ontology (GO) demonstrated that TCL1b showed highly homologous gene-induction signatures similar to Myr-Akt or TCL1. TCL1b exhibited oncogenicity in in vitro colony-transformation assay. Further, two independent lines of β-actin promoter-driven TCL1b-transgenic mice developed angiosarcoma on the intestinal tract. Angiosarcoma is a rare form of cancer in humans with poor prognosis. Using immunohistochemistry, 11 out of 13 human angiosarcoma samples were positively stained with both anti-TCL1b and anti-phospho-Akt antibodies. Consistently, in various cancer tissues, 69 out of 146 samples were positively stained with anti-TCL1b, out of which 46 were positively stained with anti-phospho-Akt antibodies. Moreover, TCL1b structure-based inhibitor 'TCL1b-Akt-in' inhibited Akt kinase activity in in vitro kinase assays and PDGF (platelet-derived growth factor)-induced Akt kinase activities-in turn, 'TCL1b-Akt-in' inhibited cellular proliferation of sarcoma. The current study disclosed TCL1b bears oncogenicity and hence serves as a novel therapeutic target for human neoplastic diseases.

In vitro characterization and engraftment of adipocytes derived from human induced pluripotent stem cells and embryonic stem cells

Human induced pluripotent stem (iPS) and embryonic stem (ES) cells can differentiate into a variety of cell types. We reported on adipogenic potential of human iPS and ES cells in vitro. In the present study, we investigate the survival and maintenance of adipocytes differentiated in vitro from human iPS and ES cells after transplantation. Following adipogenic induction in vitro, the differentiated cells exhibited functional properties of adipocytes such as lipid storage, lipolysis, and insulin responsiveness. Subsequently, Matrigel containing the differentiated human iPS and ES cells was transplanted into the subcutaneous tissue of nude mice. After 1-4 weeks, the cells with adipocyte-like features were observed in transplanted Matrigel by histological analysis. The human origin of the cells, their lipid accumulation, and gene expression of adipocyte markers in transplanted cells were then confirmed, suggesting the presence of adipocytes in transplanted Matrigel. When the relative areas of these cells were calculated by dividing the adipocyte areas by the total Matrigel areas, we found that they peaked at 2 weeks after transplantation, and that the adipocytes persisted at 4 weeks. The present study demonstrates that human iPS and ES cells can differentiate into adipocytes with functional properties and that adipocytes derived from human iPS and ES cells can survive and maintain the differentiated properties of adipocytes for at least 4 weeks after transplantation. Adipocytes derived from human iPS and ES cells thus have the potential to open new avenues for stem cell-based research into metabolic diseases and future therapeutic applications.