Lysophosphatidic acid mediates fibrosis in injured joints by regulating collagen type I biosynthesis.

OBJECTIVE: Articular cartilage is a highly specialized tissue which forms the surfaces in synovial joints. Full-thickness cartilage defects caused by trauma or microfracture surgery heal via the formation of fibrotic tissue characterized by a high content of collagen I (COL I) and subsequent poor mechanical properties. The goal of this study is to investigate the molecular mechanisms underlying fibrosis after joint injury. DESIGN: Rat knee joint models were used to mimic cartilage defects after acute injury. Immunohistochemistry was performed to detect proteins related to fibrosis. Human fetal chondrocytes and bone marrow stromal cells (BMSCs) were used to study the influence of the lipid lysophosphatidic acid (LPA) on COL I synthesis. Quantitative PCR, ELISA and immunohistochemistry were performed to evaluate the production of COL I. Chemical inhibitors were used to block LPA signaling both in vitro and in vivo. RESULTS: After full-thickness cartilage injury in rat knee joints, stromal cells migrating to the injury expressed high levels of the LPA-producing enzyme autotaxin (ATX); intact articular cartilage in rat and humans expressed negligible levels of ATX despite expressing the LPA receptors LPAR1 and LPAR2. LPA-induced increases in COL I production by chondrocytes and BMSCs were mediated by the MAP kinase and PI3 Kinase signaling pathways. Inhibition of the ATX/LPA axis significantly reduced COL I-enriched fibrocartilage synthesis in full-thickness cartilage defects in rats in favor of the collagen II-enriched normal state. CONCLUSION: Taken together, these results identify an attractive target for intervention in reducing the progression of post-traumatic fibrosis and osteoarthritis.

Engraftment of gene-modified umbilical cord blood cells in neonates with adenosine deaminase deficiency.

Haematopoietic stem cells in umbilical cord blood are an attractive target for gene therapy of inborn errors of metabolism. Three neonates with severe combined immunodeficiency were treated by retroviral-mediated transduction of the CD34+ cells from their umbilical cord blood with a normal human adenosine deaminase complementary DNA followed by autologous transplantation. The continued presence and expression of the introduced gene in leukocytes from bone marrow and peripheral blood for 18 months demonstrates that umbilical cord blood cells may be genetically modified with retroviral vectors and engrafted in neonates for gene therapy.

T lymphocytes with a normal ADA gene accumulate after transplantation of transduced autologous umbilical cord blood CD34+ cells in ADA-deficient SCID neonates.

Adenosine deaminase-deficient severe combined immunodeficiency was the first disease investigated for gene therapy because of a postulated production or survival advantage for gene-corrected T lymphocytes, which may overcome inefficient gene transfer. Four years after three newborns with this disease were given infusions of transduced autologous umbilical cord blood CD34+ cells, the frequency of gene-containing T lymphocytes has risen to 1-10%, whereas the frequencies of other hematopoietic and lymphoid cells containing the gene remain at 0.01-0.1%. Cessation of polyethylene glycol-conjugated adenosine deaminase enzyme replacement in one subject led to a decline in immune function, despite the persistence of gene-containing T lymphocytes. Thus, despite the long-term engraftment of transduced stem cells and selective accumulation of gene-containing T lymphocytes, improved gene transfer and expression will be needed to attain a therapeutic effect.

Lentiviral vectors with amplified beta cell-specific gene expression.

An important goal of gene therapy is to be able to deliver genes, so that they express in a pattern that recapitulates the expression of an endogenous cellular gene. Although tissue-specific promoters confer selectivity, in a vector-based system, their activity may be too weak to mediate detectable levels in gene-expression studies. We have used a two-step transcriptional amplification system to amplify gene expression from lentiviral vectors using the human insulin promoter. In this system, the human insulin promoter drives expression of a potent synthetic transcription activator (the yeast GAL4 DNA-binding domain fused to the activation domain of the Herpes simplex virus-1 VP16 activator), which in turn activates a GAL4-responsive promoter, driving the enhanced green fluorescent protein reporter gene. Vectors carrying the human insulin promoter did not express in non-beta-cell lines, but expressed in murine insulinoma cell lines, indicating that the human insulin promoter was capable of conferring cell specificity of expression. The insulin-amplifiable vector was able to amplify gene expression five to nine times over a standard insulin-promoter vector. In primary human islets, gene expression from the insulin-promoted vectors was coincident with insulin staining. These vectors will be useful in gene-expression studies that require a detectable signal and tissue specificity.

Vascular smooth muscle cell kinetics: a new assay for studying patterns of cellular proliferation in vivo.

A new quantitative assay for studying the kinetics of vascular smooth muscle cells in vivo is reported. The assay was used to determine the specific activity of DNA from rabbit aortic smooth muscle cells stimulated to grow by removal of the endothelial layer. The specific activity of the DNA was correlated with the rate of tritiated thymidine incorporation as measured by autoradiography and with the rate of DNA synthesis as estimated by direct measurement of cellular proliferation. Smooth muscle cells exhibit a 24-hour latent period in vivo prior to DNA synthesis; the synthesis peaks at 48 hours and then rapidly declines. The decline in DNA synthesis is not related to endothelial regrowth, and may be of homeostatic significance in limiting luminal stenosis. The assay offers a rapid and reliable alternative to autoradiographic and morphometric techniques for evaluating growth kinetics and growth regulation in vivo.

Comment regarding "On the Crooks fluctuation theorem and the Jarzynski equality" [J. Chem. Phys. 129, 091101 (2008)] and "Nonequilibrium fluctuation-dissipation theorem of Brownian dynamics" [J. Chem. Phys. 129, 144113 (2008)].

The incongruous "unexpected inapplicability of the Crook's fluctuation theorem" is due to an inexplicable, inappropriate use of inconsistent expressions. The girding is secure.

The T-ALL related gene BCL11B regulates the initial stages of human T-cell differentiation.

The initial stages of T-cell differentiation are characterized by a progressive commitment to the T-cell lineage, a process that involves the loss of alternative (myelo-erythroid, NK, B) lineage potentials. Aberrant differentiation during these stages can result in T-cell acute lymphoblastic leukemia (T-ALL). However, the mechanisms regulating the initial stages of human T-cell differentiation are obscure. Through loss of function studies, we showed BCL11B, a transcription factor recurrently mutated T-ALL, is essential for T-lineage commitment, particularly the repression of NK and myeloid potentials, and the induction of T-lineage genes, during the initial stages of human T-cell differentiation. In gain of function studies, BCL11B inhibited growth of and induced a T-lineage transcriptional program in T-ALL cells. We found previously unknown differentiation stage-specific DNA binding of BCL11B at multiple T-lineage genes; target genes showed BCL11B-dependent expression, suggesting a transcriptional activator role for BCL11B at these genes. Transcriptional analyses revealed differences in the regulatory actions of BCL11B between human and murine thymopoiesis. Our studies show BCL11B is a key regulator of the initial stages of human T-cell differentiation and delineate the BCL11B transcriptional program, enabling the dissection of the underpinnings of normal T-cell differentiation and providing a resource for understanding dysregulations in T-ALL.

Erratum to: Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B3: Area 5).

[This corrects the article DOI: 10.1186/s13601-016-0116-9.].

Building Bridges for Innovation in Ageing: Synergies between Action Groups of the EIP on AHA.

The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).

Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B3: Area 5).

Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) focuses on the integrated care of chronic diseases. Area 5 (Care Pathways) was initiated using chronic respiratory diseases as a model. The chronic respiratory disease action plan includes (1) AIRWAYS integrated care pathways (ICPs), (2) the joint initiative between the Reference site MACVIA-LR (Contre les MAladies Chroniques pour un VIeillissement Actif) and ARIA (Allergic Rhinitis and its Impact on Asthma), (3) Commitments for Action to the European Innovation Partnership on Active and Healthy Ageing and the AIRWAYS ICPs network. It is deployed in collaboration with the World Health Organization Global Alliance against Chronic Respiratory Diseases (GARD). The European Innovation Partnership on Active and Healthy Ageing has proposed a 5-step framework for developing an individual scaling up strategy: (1) what to scale up: (1-a) databases of good practices, (1-b) assessment of viability of the scaling up of good practices, (1-c) classification of good practices for local replication and (2) how to scale up: (2-a) facilitating partnerships for scaling up, (2-b) implementation of key success factors and lessons learnt, including emerging technologies for individualised and predictive medicine. This strategy has already been applied to the chronic respiratory disease action plan of the European Innovation Partnership on Active and Healthy Ageing.

The AFT024 stromal cell line supports long-term ex vivo maintenance of engrafting multipotent human hematopoietic progenitors.

The immortalized murine stromal cell line AFT024 has been reported to maintain human hematopoietic progenitors in an undifferentiated state in vitro. In the current studies the beige/nude/xid (bnx) mouse in vivo xenograft model was used to examine the engraftment and multilineage generative potential of human hematopoietic progenitors after 2-3 weeks growth on AFT024 stroma, in comparison to primary stromal monolayers derived from post-natal human bone marrow. Eight to 12 months after transplantation of human CD34+CD38- cells from umbilical cord blood, cultured on AFT024 vs human stroma for 2-3 weeks, the murine bone marrow was harvested and analyzed for the presence of human myeloid and lymphoid cells. The mean percent engraftment of total human hematopoietic cells in the murine marrow was significantly higher after co-cultivation on AFT024 than on human stroma. Human myeloid and lymphoid lineage cells were detected in all mice. However, engraftment of myeloid lineage cells (CD33+), B lymphoid (CD19+), and T lymphoid cells (CD4+and CD8+) were significantly higher after co-cultivation of the human cells on AFT024 than on human stroma, prior to transplantation. Interestingly, the length of time in culture did not significantly affect the engraftment of the myeloid and T lymphoid lineage progenitors, but the percentage of B lymphoid lineage engraftment decreased significantly between 2 and 3 weeks of co-cultivation on both types of stroma. Cells with a primitive phenotype (CD45+/CD34-/CD38- and CD45+/CD34-/lin-) and cells with the capacity to generate secondary human CFU after recovery from the bnx bone marrow were maintained at significantly higher levels during culture on AFT024 stroma than on human stroma. The current studies demonstrate that the AFT024 murine stromal cell line supports the ex vivo survival and maintenance of human hematopoietic progenitors that are capable of long-term multilineage reconstitution for 2-3 weeks ex vivo, to levels superior to those that can be obtained using human stromal cells.

Clinical implications of Barrett's esophagus.

Barrett's esophagus is a medical condition in which the squamous mucosa that normally lines the distal esophagus is replaced by a columnar type of epithelium. Most definitions that have been used for inclusion of patients in studies have indicated that columnar mucosa must extend 3 cm or more above the gastroesophageal junction. The precise length refers to the distance above the manometrically defined lower esophageal sphincter. This measurement is somewhat cumbersome to make on a routine basis for all patients at the time of endoscopy and thus is generally not done. It is important to realize that the gastroesophageal junction can be visually identified at the area where the esophagus tapers, in the region of the lower esophageal sphincter. The tapering of the esophagus in the region of the lower esophageal sphincter may be difficult to determine when lower esophageal sphincter pressures are low; thus, we commonly say that Barrett's esophagus is defined as columnar mucosa 3 cm above the region where the gastric folds end.

Retroviral vector-mediated gene transfer into primitive human hematopoietic progenitor cells: effects of mast cell growth factor (MGF) combined with other cytokines.

Retroviral vector-mediated gene transfer into human hematopoietic stem cells may permit gene therapy of numerous genetic diseases. Stimulation of marrow with hematopoietic growth factors (HGFs) has been shown to increase the level of retroviral transduction. We have examined the effects of recombinant human mast cell growth factor (MGF), alone and in combination with other HGFs, on the efficiency of gene transfer into human hematopoietic progenitor cells. MGF acts in concert with interleukin 3 (IL-3) and interleukin 6 (IL-6) to increase the percentage of CD34+ progenitors transduced with a retroviral vector expressing the neo gene. The most potent combination of growth factors that we examined, interleukin 1 (IL-1)/IL-3/IL-6/MGF, resulted in the conferral of G418 resistance to 45% of progenitors and long-term culture-initiating cells. Extending the time of cocultivation of the marrow cells with the vector-producing cells did not further increase gene transfer frequency, suggesting that the amount of available vector is not limiting. To analyze the effects of the HGF on gene transfer into more primitive hematopoietic progenitors, CD34+ cells were isolated from marrow samples that were purged of committed progenitor cells by treatment with 4-hydroperoxycyclophosphamide (4-HC). Preculturing the CD34+ 4-HC-treated cells with the combination of four HGF (IL-1/IL-3/IL-6/MGF) permitted transduction of 20%-28% of the progenitors that formed colonies after 30 days in culture. These results demonstrate that MGF in combination with other HGFs enhances gene transduction of human hematopoietic progenitor cells.

The murine stromal cell line AFT024 acts specifically on human CD34+CD38- progenitors to maintain primitive function and immunophenotype in vitro.

A stromal cell line derived from murine fetal liver (AFT024) has been demonstrated to maintain long-term repopulating murine stem cells for up to 7 weeks in vitro. We evaluated the ability of AFT024 to maintain the immunophenotype and function of primitive human progenitors in vitro by comparing the cocultivation of CD34+CD38 cells on AFT024 with that on primary human stroma (HS). We have previously reported that within the CD34+CD38- population of bone marrow and cord blood, a highly primitive progenitor subpopulation can be identified functionally by its ability to generate colony forming unit-cells (CFU-Cs) in extended long-term culture (ELTC), that is, beyond 60 days of stromal cocultivation. Cocultivation of bone marrow and cord blood CD34+CD38-cells on AFT024 produced significantly greater cell expansion (p=0.0002) and CFU-C output (p=0.0007) during the ELTC period compared with culturing on HS. CFU-C production continued up to 9 weeks longer on AFT024 stroma. After 3 to 4 weeks of bulk culture on either AFT024 or HS, cells were replated in a limiting dilution to measure the number of cobblestone area-forming cells (CAFCs) maintained on each stroma. AFT024 maintained significantly more CAFCs than did HS (n=3, p=0.002). Fluorescence-activated cell sorter analysis of AFT024 and HS cocultures showed that both the frequency (p=0.018) and absolute number (p=0.027) of CD34+CD38- cells were significantly higher in cultures on AFT024 than in those on HS (n=9). The effects of AFT024 on preservation of primitive progenitors were not seen in transwell (noncontact) cultures. Thus, AFT024 acts by direct contact to maintain the phenotype and function of the most primitive and quiescent human progenitors currently identifiable by in vitro assays.

Differentiation of human CD34+CD38- cord blood stem cells into B cell progenitors in vitro.

Umbilical cord blood CD34+CD38- cells are a rare, quiescent, primitive progenitor subpopulation lacking expression of lymphoid and myeloid lineage specific antigens. Although myeloid, erythroid, and megakaryocytic differentiation from these cells has been described, B lineage differentiation has not been demonstrated previously. We report here that highly enriched human B cell progenitors can be consistently generated from CD34+CD38- cord blood cells using long-term culture on the murine stromal line, S17, in the absence of added cytokines. After 6-8 weeks, cell numbers increased up to 160-fold, and cultures contained > 80-90% CD10+CD19+ B progenitors. Consistent with previous reports describing delayed myeloid cell differentiation from CD34+CD38- cells, production of B cell progenitors from CD34+CD38- cord blood cells was delayed 2-4 weeks relative to cultures initiated with either CD34+CD38bright or CD34+CD38dim progenitors. Addition of Flt3 ligand to long-term cultures resulted in a 2-3-fold greater increase in the number of CD19+ cells generated after 4-8 weeks. The selective outgrowth of B cell progenitors using this culture model will be useful for a range of in vitro studies using primitive hematopoietic progenitors.

Toward gene therapy for Gaucher disease.

We are studying the transfer and expression by retroviral vectors of the human glucocerebrosidase (GC) gene into bone marrow cells as a model of gene therapy for genetic diseases of hematopoietic cells. A simple retroviral vector (G2) was developed that contains a normal human GC cDNA under the control of the Moloney murine leukemia virus long-terminal repeat (LTR) enhancer/promoter. Murine bone marrow was transduced with the G2 vector and maintained in long-term bone marrow culture (LTBMC). Expression of the human GC gene in the transduced murine LTBMC cells exceeded the level of endogenous murine GC mRNA. Murine bone marrow cells were also transduced with G2 and transplanted into irradiated syngeneic recipients. High levels of GC gene transfer and expression were seen in day-12 CFU-S foci, and to a lesser extent in the hematopoietic organs 4 months after gene transfer/bone marrow transplant (BMT). Human bone marrow, from a patient with Gaucher disease, was also used in studies of GC gene transduction. Gene transfer into 35-40% of the Gaucher hematopoietic progenitor cells was achieved, following prestimulation of the marrow with recombinant hematopoietic growth factors. Equal rates of gene transfer were obtained using either total marrow mononuclear cells or progenitor cells enriched 100-fold by immunomagnetic bead separation. GC gene transduction corrected the enzymatic deficiency of the Gaucher marrow. Our results demonstrate the potential utility of retroviral vector-mediated gene transfer for gene therapy of Gaucher disease. Current efforts are aimed at achieving more consistent in vivo GC expression in the murine BMT model and demonstrating transduction of pluripotent human hematopoietic stem cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Hematopoietic stem cell transplantation for primary lymphoid immunodeficiencies.

Hematopoietic stem cell (HSC) transplantation is curative therapy for many primary immunodeficiencies. All forms of severe combined immune deficiency (SCID) can be cured, but the extent of the immunologic correction is dependent on the pathophysiology of the primary defect. Defects involving lymphocyte differentiation are more easily corrected than defects in lymphocyte function because a selective advantage exists for the progeny of the normal donor HSC when the primary defect affects lymphocyte differentiation. T-cell-depleted (TCD), haploidentical-HSC transplantation can cure many forms of SCID, but not other primary immunodeficiencies like the Wiskott-Aldrich syndrome (WAS). Unrelated bone marrow and umbilical cord blood are alternative sources of HSC for patients who do not have histocompatible donors.

The number and generative capacity of human B lymphocyte progenitors, measured in vitro and in vivo, is higher in umbilical cord blood than in adult or pediatric bone marrow.

The lack of human B lymphocyte development in beige/nude/XID (bnx) mice is in sharp contrast to the robust development observed in another immune deficient strain, the NOD/SCID mouse. The ability to generate human B lymphocytes in the NOD/SCID, but not bnx mouse has been hypothesized to be caused by differences in the microenvironments or systemic cytokine concentrations. In the current studies we report that the differences in development can be primarily attributed to the source of the progenitors transplanted into the mice. The prior studies in bnx mice used cultured pediatric or adult bone marrow (BM) as the source of the CD34+ cells, whereas the NOD/SCID studies have predominantly used fresh or cultured umbilical cord blood (UCB). We have analyzed BM and UCB for the number of human CD34+/CD38- cells capable of in vitro B lymphocyte development, and have found a lower frequency of B lymphocyte generation in BM. The individual B lymphocyte clones that developed from bone marrow produced 100-fold fewer cells than the UCB-derived clones. In agreement with the in vitro studies, human B lymphocytes developed in bnx mice from both CD34+ and CD34+/CD38- cells isolated from human umbilical cord blood, but not from equivalent numbers of CD34+ and CD34+/CD38- progenitors from bone marrow. Therefore, the lower generative capacity, and frequency of B lymphocyte precursors in human marrow may be responsible for the previous results that showed a lack of B lymphocyte development in bnx mice.

N-methyl-D-aspartate antagonist D-APV selectively disrupts taste-potentiated odor aversion learning.

Two experiments examined the effects of the competitive N-methyl-D-aspartate (NMDA) antagonist D-APV (D-2-amino-5-phosphonovalerate) on rats' ability to acquire potentiated aversions to the odor element of a taste-odor compound. In Experiment 1, pretreatment with D-APV (2.5 micrograms/side icv) caused stereospecific deficits in potentiated odor aversion learning but left simple taste and odor aversion learning intact. In Experiment 2, pretreatment with D-APV had no effect on rats' acquisition of an illness-based odor discrimination task. These results parallel those previously obtained using a noncompetitive NMDA antagonist (Robinson, Crooks, Shinkman, & Gallagher, 1989) and show that interference with NMDA receptors can selectively impair potentiated odor aversion learning. These results suggest that NMDA receptors play a critical role in some, but not all, forms of learning and memory.

T cell depleted haploidentical bone marrow transplantation for the treatment of children with severe combined immunodeficiency.

Severe combined immunodeficiency (SCID) is fatal in early childhood if unrecognized and if not treated. The aim was to determine the efficacy of T cell depleted bone marrow transplantation (TCD BMT) in the treatment of children with SCID. Eleven children diagnosed with SCID received histocompatible related donor bone marrow transplantation--HRD BMT (group I). Thirty seven children diagnosed with SCID who did not have histocompatible donors were treated with TCD haploidentical parental bone marrow transplantation (BMT) (group II). TCD was performed by in vitro soybean lectin agglutination followed by E-rosette depletion. Patients were longitudinally assessed for the presence and function of T and B lymphocytes. In group I all children survived. The mean age of children in this group at the time of HRD BMT was 15.4 months. All surviving patients normalized their specific T cell function. Two out of 11 require treatment with intravenous immunoglobulin i.v. Ig. In group II 17 out of 37 (46%) children survived. At the time of TCD BMT the mean age of survivors was 7.5 months, vs. 11.4 months in patients who died. Death was caused most commonly by opportunistic infections, Epstein-Barr virus induced lymphoproliferative disease (EBV-LPD), and graft versus host disease (GvHD). Seventeen out of 17 surviving patients recovered normal numbers of CD3+ cells and antigen specific T cell function. Five out of 17 never recovered their B cell function and require i.v. Ig injections. Early diagnosis, prevention or treatment of opportunistic infections, and enhancement of immune recovery will be necessary to improve survival in patients with SCID treated with TCD BMT.