Brain from bone: efficient "meta-differentiation" of marrow stroma-derived mature osteoblasts to neurons with Noggin or a demethylating agent

Bone marrow stromal cells are able to differentiate into adipogenic, chondrogenic, myogenic, osteogenic, and cardiomyogenic lineages, all of which are limited to a mesoderm-derived origin. In this study, we showed that neurons, which are of an ectoderm-origin, could be generated from marrow-derived stromal cells by specific inducers, fibronectin/ornithine coating, and neurosphere formation. The neurons generated from marrow stroma formed neurites, expressed neuron-specific markers and genes, and started to respond to depolarizing stimuli as functional mature neurons. Among stromal cells, isolated mature osteoblasts which had strong in vivo osteogenic activity could be efficiently converted into functional neurons. This transdifferentiation or meta-differentiation was enhanced by Noggin, an inhibitor of bone morphogenetic proteins, in comparison with 5-azacytidine, a demethylating agent capable of altering the gene expression pattern. Marrow stroma is therefore a potential source of cells for neural cell transplantation.

In vivo cardiovasculogenesis by direct injection of isolated adult mesenchymal stem cells

The characterization of mesenchymal stem cells (MSCs) is of biological and clinical interest. We demonstrate that isolated MSCs, defined by CD34(low) c-kit(+) CD140a(+) Sca-1(high), are able to differentiate into cardiomyocytes, endothelial cells, and pericytes or smooth muscle cells by direct injection into adult heart. In skeletal muscle and lung, they also contributed to formation of the vasculature. MSCs did not transform into malignant cells or form excess extracellular matrix. This study suggests that MSCs may supply an ideal donor source of cardiovascular cells in patients with cardiopulmonary diseases.

High-dose porcine hematopoietic cell transplantation combined with CD40 ligand blockade in baboons prevents an induced anti-pig humoral response

BACKGROUND

In pig-to-primate organ transplantation, hyperacute rejection can be prevented, but the organ is rejected within days by acute vascular rejection, in which induced high-affinity anti-Gal alpha1-3Gal (alphaGal) IgG and possibly antibodies directed against new porcine (non-alphaGal) antigenic determinants are considered to play a major role. We have explored the role of an anti-CD40L monoclonal antibody in modifying the humoral response to porcine hematopoietic cells in baboons pretreated with a nonmyeloablative regimen.

METHODS

Porcine peripheral blood mobilized progenitor cells obtained by leukapheresis from both major histocompatibility complex-inbred miniature swine (n=7) and human decay-accelerating factor pigs (n=3) were transplanted into baboons. Group 1 baboons (n=3) underwent whole body (300 cGy) and thymic (700 cGy) irradiation, T cell depletion with ATG, complement depletion with cobra venom factor, short courses of cyclosporine, mycophenolate mofetil, porcine hematopoietic growth factors, and anti-alphaGal antibody depletion by immunoadsorption before transplantation of high doses (2-4 x 10(10)/cells/kg) of peripheral blood mobilized progenitor cells. In group 2 (n=5), cyclosporine was replaced by eight doses of anti-CD40L monoclonal antibodies over 14 days. The group 3 baboons (n=2) received the group 1 regimen plus 2 doses of anti-CD40L monoclonal antibodies (on days 0 and 2).

RESULTS

In group 1, sensitization to alphaGal (with increases in IgM and IgG of 3- to 6-fold and 100-fold, respectively) and the development of antibodies to new non-alphaGal porcine antigens occurred within 20 days. In group 2, no sensitization to alphaGal or non-alphaGal determinants was seen, but alphaGal-reactive antibodies did return to their pre- peripheral blood mobilized progenitor cells transplant levels. In group 3, attenuated sensitization to alphaGal antigens was seen after cessation of cyclosporine and mycophenolate mofetil therapy at 30 days (IgM 4-fold, IgG 8-30-fold), but no antibodies developed against new porcine determinants. In no baboon did anti-CD40L monoclonal antibodies prevent sensitization to its own murine antigens.

CONCLUSIONS

We believe these studies are the first to consistently demonstrate prevention of a secondary humoral response after cell or organ transplantation in a pig-to-primate model. The development of sensitization to the murine elements of the anti-CD40L monoclonal antibodies suggests that nonresponsiveness to cell membrane-bound antigen (e.g., alphaGal) is a specific phenomenon and not a general manifestation of immunological unresponsiveness. T cell costimulatory blockade may facilitate induction of mixed hematopoietic chimerism and, consequently, of tolerance to pig organs and tissues.

Internalization of isolated functional mitochondria: involvement of macropinocytosis

In eukaryotic cells, mitochondrial dysfunction is associated with a variety of human diseases. Delivery of exogenous functional mitochondria into damaged cells has been proposed as a mechanism of cell transplant and physiological repair for damaged tissue. We here demonstrated that isolated mitochondria can be transferred into homogeneic and xenogeneic cells by simple co-incubation using genetically labelled mitochondria, and elucidated the mechanism and the effect of direct mitochondrial transfer. Intracellular localization of exogenous mitochondria was confirmed by PCR, real-time PCR, live fluorescence imaging, three-dimensional reconstruction imaging, continuous time-lapse microscopic observation, flow cytometric analysis and immunoelectron microscopy. Isolated homogeneic mitochondria were transferred into human uterine endometrial gland-derived mesenchymal cells in a dose-dependent manner. Moreover, mitochondrial transfer rescued the mitochondrial respiratory function and improved the cellular viability in mitochondrial DNA-depleted cells and these effects lasted several days. Finally, we discovered that mitochondrial internalization involves macropinocytosis. In conclusion, these data support direct transfer of exogenous mitochondria as a promising approach for the treatment of various diseases.

Coagulation and thrombotic disorders associated with pig organ and hematopoietic cell transplantation in nonhuman primates

BACKGROUND

Efforts to achieve tolerance to transplanted pig organs in nonhuman primates by the induction of a state of mixed hematopoietic chimerism have been associated with disorders of coagulation and thrombosis. Activation of recipient vascular endothelium and platelets by porcine hematopoietic cells and/or activation of donor organ vascular endothelium and/or molecular differences between the species may play roles. Irradiation or drug therapy could possibly potentiate endothelial cell activation and/or injury.

METHODS

We have investigated parameters of coagulation and platelet activation in nonhuman primates after (1) a regimen aimed at inducing mixed hematopoietic chimerism and tolerance (TIR that included total body irradiation, T cell depletion, and splenectomy; (2) pig bone marrow or pig peripheral blood mobilized progenitor cell transplantation (PCTx); and/or (3) pig organ transplantation (POTx). Five experimental groups were studied. Baboons were the recipient subjects in all groups except Group 1. Gp 1 Cynomolgus monkeys (n=6) underwent TIR + allotransplantation of hematopoietic cells and a kidney or heart or TIR + concordant xenotransplantation (using baboons as donors) of cells and a kidney; Gp 2 Baboons (n=4) underwent TIR with or without (+/-) autologous hematopoietic cell infusion; Gp 3 (n=12) PCTx+/-TIR; Gp 4 (n=5) POTx+/-TIR; Gp 5 (n=4) TIR + PCTx + POTx. Platelet counts, with plasma prothrombin time, partial thromboplastin time, fibrinogen levels, fibrin split products and/or D-dimer were measured.

RESULTS

In the absence of a discordant (porcine) cellular or organ transplant (Groups 1 and 2), TIR resulted in transient thrombocytopenia only, in keeping with bone marrow depression from irradiation. PCTx alone (Group 3) was associated with the rapid development of a thrombotic thrombocytopenic (TTP)-like microangiopathic state, that persisted longer when PCTx was combined with TIR. POTx (+/-TIR) (Group 4) was associated with a gradual fall (over several days) in platelet counts and fibrinogen with disseminated intravascular coagulation (DIC); after graft excision, the DIC generally resolved. When TIR, PCTx and POTx were combined (Group 5), an initial TTP-like state was superseded by a consumptive picture of DIC within the first week, necessitating graft removal.

CONCLUSIONS

Both PCTx and POTx lead to profound alterations in hemostasis and coagulation parameters that must be overcome if discordant xenotransplantation of hematopoietic cells and organs is to be fully successful. Disordered thromboregulation could exacerbate vascular damage and potentiate activation of coagulation pathways after exposure to xenogeneic cells or a vascularized xenograft.

Sonoporation using microbubble BR14 promotes pDNA/siRNA transduction to murine heart

Naked plasmid DNA (pDNA) and short interfering RNA (siRNA) duplexes were transduced into adult murine heart by means of sonoporation using the third-generation microbubble, BR14. Plasmid DNAs carrying luciferase, beta-galactosidase (beta-gal), or enhanced green fluorescent protein (EGFP) reporter genes were mixed with BR14 and injected percutaneously into the left ventricular (LV) cavity of C57BL/6 mice while exposed to transthoracic ultrasound at 1MHz for 60s. Sonoporation at an output intensity of 2.0W/cm(2) and a 50% pulse duty ratio resulted in the highest luciferase expression in the heart. Histological examinations revealed significant expression of the beta-gal and EGFP reporters in the subendocardial myocardium of LV. Intraventricular co-injection of siRNA-GFP and BR14 with concomitant ultrasonic exposure resulted in substantial reduction in EGFP expression in the coronary artery in EGFP transgenic mice. The present method may be applicable to gain-of-function and loss-of-function genetic engineering in vivo of adult murine heart.

Can the life span of human marrow stromal cells be prolonged by bmi-1, E6, E7, and/or telomerase without affecting cardiomyogenic differentiation?

BACKGROUND

Cell transplantation has recently been challenged to improve cardiac function of severe heart failure. Human mesenchymal stem cells (hMSCs) are multipotent cells that can be isolated from adult marrow stroma, but because of their limited life span, it is difficult to study them further. To overcome this problem, we attempted to prolong the life span of hMSCs and investigate whether the hMSCs modified with cell-cycle-associated genes can differentiate into cardiomyocytes in vitro.

METHODS

We attempted to prolong the life span of hMSCs by infecting retrovirus encoding bmi-1, human papillomavirus E6 and E7, and/or human telomerase reverse transcriptase genes. To determine whether the hMSCs with an extended life span could differentiate into cardiomyocytes, 5-azacytidine-treated hMSCs were co-cultured with fetal cardiomyocytes in vitro.

RESULT

The established hMSCs proliferated over 150 population doublings. On day 3 of co-cultivation, the hMSCs became elongated, like myotubes, began spontaneously beating, and acquired automaticity. Their rhythm clearly differed from that of the surrounding fetal mouse cardiomyocytes. The number of beating cardiomyocytes increased until 3 weeks. hMSCs clearly exhibited differentiated cardiomyocyte phenotypes in vitro as revealed by immunocytochemistry, RT-PCR, and action potential recording.

CONCLUSIONS

The life span of hMSCs was prolonged without interfering with cardiomyogenic differentiation. hMSCs with an extended life span can be used to produce a good experimental model of cardiac cell transplantation and may serve as a highly useful cell source for cardiomyocytic transplantation.

Interleukin (IL)-21 and IL-15 genetic transfer synergistically augments therapeutic antitumor immunity and promotes regression of metastatic lymphoma

IL-21 supports proliferation of mature T and B cells and facilitates expansion and maturation of natural killer (NK) cells in synergy with IL-15. However, the biological implications of IL-21 in vivo have not been fully elucidated. IL-21 and IL-15 expression plasmids were intravenously injected under high pressure into the tail veins of mice, which were subsequently challenged by an intravenous injection of RLmale1 lymphoma cells. The IL15 gene transfection significantly reduced the numbers of metastatic tumor foci in the liver. In contrast, when IL21 and IL15 genes were cotransfected, complete regression was achieved in 80% of the mice. The cytokine gene therapy was also performed in mice that had been intravenously inoculated with the tumor cells. Forty percent of mice that received a single injection of a mixture of cytokine genes successfully rejected the preestablished metastatic lymphoma and showed tumor-free survival for more than 300 days. IL-21 significantly elevated the cytotoxic T lymphocyte activity in the spleens of tumor-inoculated mice, while the two cytokines augmented NK killing activity in a synergistic manner. These results strongly suggest that the codelivery of IL-21 and IL-15 elicits powerful antitumor immune responses, resulting in marked therapeutic efficacy against metastatic tumors.

Electrochemo-gene therapy of cancer: intratumoral delivery of interleukin-12 gene and bleomycin synergistically induced therapeutic immunity and suppressed subcutaneous and metastatic melanomas in mice

To treat established melanoma in mice, intratumoral transfer of bleomycin and/or an interleukin (IL)-12 expression vector was performed by means of electroporation. Although either bleomycin alone or the IL12 gene alone significantly suppressed the subcutaneous tumors, the combination therapy drastically improved the therapeutic outcome. Three of eight mice (37.5%) that received both bleomycin and the IL12 gene showed complete remission of the preestablished tumors and rejected subsequent rechallenge with the tumor cells. We also examined whether electrochemo-gene therapy for subcutaneous tumor mass induced suppression of pulmonary metastasis that had been established by intravenous inoculation of the melanoma cells. Although metastatic foci were significantly reduced in number in groups that were given IL12 gene alone or bleomycin plus IL12 gene, it was only the combination therapy that significantly prolonged the mean survival period of the tumor-bearing animals. Natural killer (NK) and cytotoxic T lymphocyte cytolytic activities were markedly enhanced in the mice that received the chemo-gene therapy, while IL12 gene therapy alone partially elevated the NK cytotoxicity. The present study suggests that the electroporation-mediated delivery of the IL12 gene and bleomycin synergistically elicits innate and adaptive anti-melanoma immune responses, resulting in marked suppression of the treated tumors as well as bystander metastatic lesions.

Redifferentiation of dedifferentiated chondrocytes and chondrogenesis of human bone marrow stromal cells via chondrosphere formation with expression profiling by large-scale cDNA analysis

Characterization of dedifferentiated chondrocytes (DECs) and mesenchymal stem cells capable of differentiating into chondrocytes is of biological and clinical interest. We isolated DECs and bone marrow stromal cells (BMSCs), H4-1 and H3-4, and demonstrated that the cells started to produce extracellular matrices, such as type II collagen and aggrecan, at an early stage of chondrosphere formation. Furthermore, cDNA sequencing of cDNA libraries constricted by the oligocapping method was performed to analyze difference in mRNA expression profiling between DECs and marrow stromal cells. Upon redifferentiation of DECs, cartilage-related extracellular matrix genes, such as those encoding leucine-rich small proteoglycans, cartilage oligomeric matrix protein, and chitinase 3-like 1 (cartilage glycoprotein-39), were highly expressed. Growth factors such as FGF7 and CTGF were detected at a high frequency in the growth stage of monolayer stromal cultures. By combining the expression profile and flow cytometry, we demonstrated that isolated stromal cells, defined by CD34(-), c-kit(-), and CD140alpha(- or low), have chondrogenic potential. The newly established human mesenchymal cells with expression profiling provide a powerful model for a study of chondrogenic differentiation and further understanding of cartilage regeneration in the means of redifferentiated DECs and BMSCs.

Use of isolated mature osteoblasts in abundance acts as desired-shaped bone regeneration in combination with a modified poly-DL-lactic-co-glycolic acid (PLGA)-collagen sponge

Controlled regeneration of bone or cartilage has recently begun to facilitate a host of novel clinical treatments. An osteoblast line, which we isolated is able to form new bone matrix in vivo within 2 days and exhibits a mature osteoblast phenotype both in vitro and in vivo. Using these cells, we show that cuboidal bones can be generated into a predesigned shaped-bone with high-density bone trabeculae when used in combination with a modified poly-DL-lactic-co-glycolic acid (PLGA)-collagen sponge. PLGA coated with collagen gel serves as a good scaffold for osteoblasts. These results indicate that mature osteoblasts, in combination with a scaffold such as PLGA-collagen sponge, show promise for use in a custom-shaped bone regeneration tool for both basic research into osteogenesis and for development of therapeutic applications.

Sequence-specific gene silencing in murine muscle induced by electroporation-mediated transfer of short interfering RNA

BACKGROUND

Post-genomic biomedical research requires efficient techniques for functional analyses of poorly characterized genes in living organisms. Sequence-specific gene silencing in mammalian organs may provide valuable information on the physiological and pathological roles of predicted genes in mammalian systems. Here, we attempted targeted gene knockdown in vivo in murine skeletal muscle through the electroporation-mediated transfer of short interfering RNA (siRNA).

METHODS

siRNA duplexes corresponding to the firefly luciferase (Luc), green fluorescent protein (GFP), or glyceraldehyde-3-phosphate dehydrogenase (GAPD) genes were delivered by electroporation into the tibial muscle of normal or enhanced GFP (EGFP) transgenic mice. Plasmid vectors carrying the Luc, hRluc or beta-galactosidase (beta-gal) reporter genes were also delivered. The Luc and hRluc activities in the muscle lysates were assayed. The EGFP and GAPD expression was detected by fluorescence microscopic observation and RT-PCR, respectively.

RESULTS

When Luc-specific siRNA was co-delivered with the Luc expression vector into the tibial muscle, the reporter gene expression was markedly suppressed (less than 1% of the control level) for 5 days. As little as 0.05 micro g of siRNA almost completely blocked the reporter gene expression from 10 micro g of the plasmid. To examine whether siRNA can also suppress expression of an endogenous gene, transgenic mice carrying the EGFP gene received intramuscular transfection of a mixture of beta-gal plasmid and GFP-specific siRNA. beta-Gal-positive cells failed to express detectable levels of EGFP, while EGFP expression was not inhibited in control mice that received nonspecific siRNA. Expression of GAPD was also suppressed by the specific siRNA.

CONCLUSIONS

The present system may provide a useful means of phenotypic analysis of genetic information in mammalian organs for basic research as well as therapeutic molecular targeting in the post-genomic era.

Plasma perfusion by apheresis through a Gal immunoaffinity column successfully depletes anti-Gal antibody: experience with 320 aphereses in baboons

BACKGROUND

Anti-Galalpha1-3Gal (Gal) antibodies (Gal Ab) contribute to the rejection of porcine organs transplanted into primates. Extracorporeal immunoadsorption (EIA) has been developed to eliminate Gal Ab from the circulation.

METHODS

Between 1995 and 1999 we performed 320 EIAs in baboons using a COBE-Spectra apheresis unit incorporating a synthetic Gal immunoaffinity column. Three plasma volumes were immunoadsorbed on each occasion. The 221 consecutive EIAs performed in 41 immunosuppressed baboons between January 1997 and April 1999 form the basis of this review. Of these 41 baboons, 29 underwent a series of three or four EIAs at daily intervals, seven had multiple series of three EIAs, and the remainder underwent single or double EIAs. Serum Gal Ab levels were monitored by ELISA before and at intervals after the course of EIA.

RESULTS

There were two fatal complications, one from a respiratory mishap (unrelated to the EIA) and one from persistent hypotension unresponsive to therapeutic interventions. Seven procedures (3%) were terminated early owing to technical difficulties and/or persistent hypotension. Mean pre-EIA Gal Ab levels in naive baboons were 33.1 microg/ml (IgM) and 14.5 microg/ml (IgG). Immediately after three consecutive EIAs, IgM was depleted by a mean of 97.3% and IgG by 99.4%. By 18 to 24 h later, Gal Ab was returning but depletion remained at 80.1% (IgM) and 84.7% (IgG). The subsequent rate of return of Gal Ab depended on the immunomodulatory protocol used.

CONCLUSIONS

(1) With appropriate monitoring, EIA is an acceptably safe procedure, even in small (<10 kg) baboons. (2) Three consecutive EIAs are effective in removing >97% of Gal Ab. (3) In the majority of cases, return of Gal Ab begins within 24 h, irrespective of the immunomodulatory protocol.

Transfer of swine major histocompatibility complex class II genes into autologous bone marrow cells of baboons for the induction of tolerance across xenogeneic barriers

BACKGROUND

The present study examined the potential role of gene therapy in the induction of tolerance to anti-porcine major histocompatibility complex (SLA) class II-mediated responses after porcine renal or skin xenografts.

METHODS

Baboons were treated with a non-myeloablative or a myeloablative preparative regimen before bone marrow transplantation with autologous bone marrow cells retrovirally transduced to express both SLA class II DR and neomycin phosphotransferase (NeoR) genes, or the NeoR gene alone. Four months or more after bone marrow transplantation, the immunological response to a porcine kidney or skin xenograft was examined. Both the renal and skin xenografts were SLA DR-matched to the transgene, and recipients were conditioned by combinations of complement inhibitors, adsorption of natural antibodies, immunosuppressive therapy, and splenectomy.

RESULTS

Although the long-term presence of the SLA transgene was detected in the peripheral blood and/or bone marrow cells of all baboons, the transcription of the transgene was transient. Autopsy tissues were available from one animal and demonstrated expression of the SLA DR transgene in lymphohematopoietic tissues. After kidney and skin transplantation, xenografts were rejected after 8-22 days. Long-term follow-up of control animals demonstrated that high levels of induced IgG antibodies to new non-alphaGal epitopes developed after organ rejection. In contrast, induced non-alphaGal IgG antibody responses were minimal in the SLA DR-transduced baboons.

CONCLUSIONS

Transfer and expression of xenogeneic class II DR transgenes can be achieved in baboons. This therapy may prevent late T cell-dependent responses to porcine xenografts, which include induced non-alphaGal IgG antibody responses.

Waon Therapy for Managing Chronic Heart Failure - Results From a Multicenter Prospective Randomized WAON-CHF Study

BACKGROUND

Waon therapy improves heart failure (HF) symptoms, but further evidence in patients with advanced HF remains uncertain.

METHODS AND RESULTS

In 19 institutes, we prospectively enrolled hospitalized patients with advanced HF, who had plasma levels of B-type natriuretic peptide (BNP) >500 pg/ml on admission and BNP >300 pg/ml regardless of more than 1 week of medical therapy. Enrolled patients were randomized into Waon therapy or control groups. Waon therapy was performed once daily for 10 days with a far infrared-ray dry sauna maintained at 60℃ for 15 min, followed by bed rest for 30 min covered with a blanket. The primary endpoint was the ratio of BNP before and after treatment. In total, 76 Waon therapy and 73 control patients (mean age 66 years, men 61%, mean plasma BNP 777 pg/ml) were studied. The groups differed only in body mass index and the frequency of diabetes. The plasma BNP, NYHA classification, 6-min walk distance (6MWD), and cardiothoracic ratio significantly improved only in the Waon therapy group. Improvements in NYHA classification, 6MWD, and cardiothoracic ratio were significant in the Waon therapy group, although the change in plasma BNP did not reach statistical significance. No serious adverse events were observed in either group.

CONCLUSIONS

Waon therapy, a holistic soothing warmth therapy, showed clinical advantages in safety and efficacy among patients with advanced HF.

Novel detergent for whole organ tissue engineering

Whole organ tissue engineering for various organs, including the heart, lung, liver, and kidney, has demonstrated promising results for end-stage organ failure. However, the sodium dodecyl sulfate (SDS)-based protocol for standard decellularization has drawbacks such as clot formation in vascularized transplantation and poor cell engraftment in recellularization procedures. Preservation of the surface milieu of extracellular matrices (ECMs) might be crucial for organ generation based on decellularization/recellularization engineering. We examined a novel detergent, sodium lauryl ether sulfate (SLES), to determine whether it could overcome the drawbacks associated with SDS using rat heart and kidney. Both organs were perfused in an antegrade fashion with either SLES or SDS. Although immunohistochemistry for collagen I, IV, laminin, and fibronectin showed similar preservation in both detergents, morphological analysis using scanning electron microscopy and an assay of glycosaminoglycan content on ECMs showed that SLES-treated tissues had better-preserved ECMs than SDS-treated tissues. Mesenteric transplantation revealed SLES did not induce significant inflammation, as opposed to SDS. Platelet adhesion to decellularized tissues was significantly reduced with SLES. Overall, SLES could replace older detergents such as SDS in the decellularization process for generation of transplantable recellularized organs.

TAT-dextran-mediated mitochondrial transfer enhances recovery from models of reperfusion injury in cultured cardiomyocytes

Acute myocardial infarction is a leading cause of death among single organ diseases. Despite successful reperfusion therapy, ischaemia reperfusion injury (IRI) can induce oxidative stress (OS), cardiomyocyte apoptosis, autophagy and release of inflammatory cytokines, resulting in increased infarct size. In IRI, mitochondrial dysfunction is a key factor, which involves the production of reactive oxygen species, activation of inflammatory signalling cascades or innate immune responses, and apoptosis. Therefore, intercellular mitochondrial transfer could be considered as a promising treatment strategy for ischaemic heart disease. However, low transfer efficiency is a challenge in clinical settings. We previously reported uptake of isolated exogenous mitochondria into cultured cells through co‐incubation, mediated by macropinocytosis. Here, we report the use of transactivator of transcription dextran complexes (TAT‐dextran) to enhance cellular uptake of exogenous mitochondria and improve the protective effect of mitochondrial replenishment in neonatal rat cardiomyocytes (NRCMs) against OS. TAT‐dextran–modified mitochondria (TAT‐Mito) showed a significantly higher level of cellular uptake. Mitochondrial transfer into NRCMs resulted in anti‐apoptotic capability and prevented the suppression of oxidative phosphorylation in mitochondria after OS. Furthermore, TAT‐Mito significantly reduced the apoptotic rates of cardiomyocytes after OS, compared to simple mitochondrial transfer. These results indicate the potential of mitochondrial replenishment therapy in OS‐induced myocardial IRI.

A novel polymorphism in the promoter region for the human osteocalcin gene: the possibility of a correlation with bone mineral density in postmenopausal Japanese women

We present a polymorphism of the human osteocalcin gene (also known as BGP, for bone Gla protein) due to a 1 base pair (bp) substitution from cytosine to thymine at position 298 nucleotides (nt), which is at position 198 nt upstream from the BGP exon 1. This mutation was detected by single-strand conformation polymorphism analysis after polymerase chain reaction for the osteocalcin gene fragment (326 bp) and sequencing analysis. The cytosine/thymine polymorphism can be defined by restriction fragment length polymorphism analysis using a modified primer pair and the restriction endonuclease HindIII. The osteocalcin genotype was determined in 160 postmenopausal Japanese women (age 48-80 years). Osteocalcin alleles were designated according to the absence (H) or presence (h) of the HindIII restriction site. There were 12 HH, 49 Hh, and 99 hh individuals, and the allele frequencies were 22.8% for H and 77.2% for h. To determine if genetic variation influences bone mineral density (BMD) and thus can be a determinant of susceptibility to osteoporosis in older women, we examined the association of BMD with the osteocalcin genotypes found in the present study. The subjects with genotype HH had the smallest BMD and those with hh had the greatest BMD among subjects, but these differences did not reach statistical significance. The HindIII genotype showed a significant effect on the prevalence of osteopenia in the subjects, that is, women with genotype HH had a 5.74 times greater risk for osteopenia (p < 0.05) and those with genotype Hh had a 1.59 times greater risk than women with genotype hh. We identified the osteocalcin gene polymorphism, detected with the HindIII genotype, which was suggested to influence bone density and is a possible genetic marker for bone metabolism.

N- and O-glycan cell surface protein modifications associated with cellular senescence and human aging

Background

Glycans play essential roles in biological functions such as differentiation and cancer. Recently, glycans have been considered as biomarkers for physiological aging. However, details regarding the specific glycans involved are limited. Here, we investigated cellular senescence- and human aging-dependent glycan changes in human diploid fibroblasts derived from differently aged skin donors using a lectin microarray.

Results

We found that α2-6sialylated glycans in particular differed between elderly- and fetus-derived cells at early passage. However, both cell types exhibited sequentially decreasing α2-3sialylated O-glycan structures during the cellular senescence process and showed similar overall glycan profiles.

Conclusions

We observed a senescence-associated decrease in sialylation and increase in galactose exposure. Therefore, glycan profiling using lectin microarrays might be useful for the characterization of biomarkers of aging.

Electronic supplementary material

The online version of this article (doi:10.1186/s13578-016-0079-5) contains supplementary material, which is available to authorized users.

Large-scale cell production of stem cells for clinical application using the automated cell processing machine

BACKGROUND

Cell-based regeneration therapies have great potential for application in new areas in clinical medicine, although some obstacles still remain to be overcome for a wide range of clinical applications. One major impediment is the difficulty in large-scale production of cells of interest with reproducibility. Current protocols of cell therapy require a time-consuming and laborious manual process. To solve this problem, we focused on the robotics of an automated and high-throughput cell culture system. Automated robotic cultivation of stem or progenitor cells in clinical trials has not been reported till date. The system AutoCulture used in this study can automatically replace the culture medium, centrifuge cells, split cells, and take photographs for morphological assessment. We examined the feasibility of this system in a clinical setting.

RESULTS

We observed similar characteristics by both the culture methods in terms of the growth rate, gene expression profile, cell surface profile by fluorescence-activated cell sorting, surface glycan profile, and genomic DNA stability. These results indicate that AutoCulture is a feasible method for the cultivation of human cells for regenerative medicine.

CONCLUSIONS

An automated cell-processing machine will play important roles in cell therapy and have widespread use from application in multicenter trials to provision of off-the-shelf cell products.

Direct human mitochondrial transfer: a novel concept based on the endosymbiotic theory

Mitochondria play an essential role in eukaryotes, and mitochondrial dysfunction is implicated in several diseases. Therefore, intercellular mitochondrial transfer has been proposed as a mechanism for cell-based therapy. In addition, internalization of isolated mitochondria cells by simple coincubation was reported to improve mitochondrial function in the recipient cells. However, substantial evidence for internalization of isolated mitochondria is still lacking, and its precise mechanism remains elusive. We tested whether enriched mitochondria can be internalized into cultured human cells by simple coincubation using fluorescence microscopy and flow cytometry. Mitochondria were isolated from endometrial gland-derived mesenchymal cells (EMCs) or EMCs stably expressing mitochondrial-targeted red fluorescent protein (EMCs-DsRed-mito), and enriched by anti-mitochondrial antibody-conjugated microbeads. They were coincubated with isogeneic EMCs stably expressing green fluorescent protein (GFP). Live fluorescence imaging clearly showed that DsRed-labeled mitochondria accumulated in the cytoplasm of EMCs stably expressing GFP around the nucleus. Flow cytometry confirmed the presence of a distinct population of GFP and DsRed double-positive cells within the recipient cells. In addition, transfer efficiency depended on mitochondrial concentration, indicating that human cells may possess the inherent ability to internalize mitochondria. Therefore, this study supports the application of direct transfer of isogeneic mitochondria as a novel approach for the treatment of diseases associated with mitochondrial dysfunction.

Single-cell-derived mesenchymal stem cells overexpressing Csx/Nkx2.5 and GATA4 undergo the stochastic cardiomyogenic fate and behave like transient amplifying cells

Bone marrow-derived stromal cells can give rise to cardiomyocytes as well as adipocytes, osteocytes, and chondrocytes in vitro. The existence of mesenchymal stem cells has been proposed, but it remains unclear if a single-cell-derived stem cell stochastically commits toward a cardiac lineage. By single-cell marking, we performed a follow-up study of individual cells during the differentiation of 9-15c mesenchymal stromal cells derived from bone marrow cells. Three types of cells, i.e., cardiac myoblasts, cardiac progenitors and multipotent stem cells were differentiated from a single cell, implying that cardiomyocytes are generated stochastically from a single-cell-derived stem cell. We also demonstrated that overexpression of Csx/Nkx2.5 and GATA4, precardiac mesodermal transcription factors, enhanced cardiomyogenic differentiation of 9-15c cells, and the frequency of cardiomyogenic differentiation was increased by co-culturing with fetal cardiomyocytes. Single-cell-derived mesenchymal stem cells overexpressing Csx/Nkx2.5 and GATA4 behaved like cardiac transient amplifying cells, and still retained their plasticity in vivo.

Porcine hematopoietic cell xenotransplantation in nonhuman primates is complicated by thrombotic microangiopathy

Thrombotic microangiopathy (TM) is a serious complication of bone marrow transplantation (BMT) that resembles thrombotic thrombocytopenic purpura (TTP). In attempting to achieve hematopoietic cell chimerism in the pig-to-baboon model, we have observed TM following infusion of high doses (>10(10) cells/kg) of porcine peripheral blood mobilized progenitor cells (PBPC) into baboons. We performed investigations to analyze the pathobiology of this TM and to test therapeutic interventions to ameliorate it. PBPC were obtained by leukapheresis of cytokine-stimulated swine. The initial observations were made in two baboons that underwent a non-myeloablative regimen (NMR) prior to PBPC transplantation (TX) (group 1). We then studied three experimental groups. Group 2 (n = 2) received NMR without PBPC TX. Group 3 (n = 2) received PBPC TX alone. Group 4 (n = 6) received NMR + PBPC TX combined with prostacyclin, low-dose heparin, methylprednisolone, and cyclosporine was replaced by anti-CD40L mAb in five cases. Baboons in groups 1 and 3 developed severe thrombocytopenia (<10,000/mm3), intravascular hemolysis with schistocytosis (>10/high powered field (hpf)), increase in plasma lactate dehydrogenase (LDH) (2500-9000 U/l), transient neurologic changes, renal insufficiency, and purpura. Autopsy on two baboons confirmed extensive platelet thrombi in the microcirculation, and, similar to clinical BMT-associated TM/TTP, no unusually large vWF multimers or changes in vWF protease activity were observed in the plasma of baboons with TM. In group 2, self-limited thrombocytopenia occurred for 10-15 days following NMR. Group 4 baboons developed thrombocytopenia (<20,000/mm3) rarely requiring platelet transfusion, minimal schistocytosis (<3/hpf), minor increase in LDH (<1000 U/l), with no clinical sequelae. We conclude that high-dose porcine PBPC infusion into baboons induces a microangiopathic state with vWF biochemical parameters resembling clinical BMT-associated TM/TTP and that administration of antithrombotic and anti-inflammatory agents can ameliorate this complication.

Sexual dimorphisms of mRNA and miRNA in human/murine heart disease

BACKGROUND

Sexual dimorphisms are well recognized in various cardiac diseases such as ischemic cardiomyopathy (ICM), hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Thorough understanding of the underlying genetic programs is crucial to optimize treatment strategies specified for each gender. By performing meta-analysis and microarray analysis, we sought to comprehensively characterize the sexual dimorphisms in the healthy and diseased heart at the level of both mRNA and miRNA transcriptome.

RESULTS

Existing mRNA microarray data of both mouse and human heart were integrated, identifying dozens/ hundreds of sexually dimorphic genes in healthy heart, ICM, HCM, and DCM. These sexually dimorphic genes overrepresented gene ontologies (GOs) important for cardiac homeostasis. Further, microarray of miRNA, isolated from mouse sham left ventricle (LV) (n = 6 & n = 5 for male & female) and chronic MI LV (n = 19 & n = 19) and from human normal LV (n = 6 & n = 6) and ICM LV (n = 4 & n = 5), was conducted. This revealed that 13 mouse miRNAs are sexually dimorphic in MI and 6 in normal heart. In human, 3 miRNAs were sexually dimorphic in ICM and 15 in normal heart. These data revealed miRNA-mRNA networks that operate in a sexually-biased fashion.

CONCLUSIONS

mRNA and miRNA transcriptome of normal and disease heart show significant sex differences, which might impact the cardiac homeostasis. Together this study provides the first comprehensive picture of the genome-wide program underlying the heart sexual dimorphisms, laying the foundation for gender specific treatment strategies.

Epithelial regeneration and preservation of tracheal cartilage after tracheal replacement with cryopreserved allograft in the rat

OBJECTIVE

We investigated the origin of the epithelium in transplanted cryopreserved tracheal allografts in rats and tried to clarify the mechanism by which immunogenicity is reduced in this procedure.

METHODS

Tracheal transplantation was performed with PVG rats (allele at the RT1 locus: c) used as donors and ACI rats (allele at the RT1 locus: a) as recipients. After resection of a 5-ring segment of the cervical trachea of an ACI rat, the trachea was reconstructed with the cryopreserved tracheal segment of a PVG rat (n = 6). No immunosuppressive agents or steroids were given. Histologic changes were determined and immunohistochemical staining was performed to investigate major histocompatibility complex class I antigens of the transplanted tracheal segment.

RESULTS

Two months after tracheal transplantation, 6 surviving ACI rats were killed. Histologically, the epithelium and tracheal cartilage of the transplanted cryopreserved segment displayed normal structure. Immunohistochemical staining showed that the major histocompatibility complex class I antigen of the ACI rat was expressed in the epithelium of the transplanted segment and that the class I antigen of the PVG rat was expressed in the cartilage of the transplanted segment.

CONCLUSIONS

After transplantation of the cryopreserved trachea, the epithelium of the transplanted cryopreserved segment originated from the recipient epithelium whereas the cartilage retained the structure of the donor trachea. We hypothesize that transplantation of a cryopreserved trachea leads to the growth of the recipient's epithelium over the donor trachea, thereby reducing the antigenicity of the transplant.