[Inhibition of gap junctional intercellular communication protects astrocytes from hypoxia/reoxygenation injury].

OBJECTIVE: To investigate the effects of inhibiting gap junctional intercellular communication on hypoxia/reoxygenation injury in astrocytes. METHODS: Primary cultured cerebral cortical astrocytes of neonate rats were divided into normal control group, hypoxia reoxygenation injury group and 18-α-glycyrrhetinic acid and oleamide (gap junctional intercellular channel inhibitors) group. The gap junction intercellular communication was determined by Parachute assay. The viability of astrocyes was detected by MTT assay. The apoptosis of astrocytes were detected with annexin V/PI and Hoechst 33258 staining. RESULTS: Compared with the normal control group, the gap junctional function of astrocytes was increased significantly in ischemia/reperfusion group (P<0.01), the surviving fraction of astrocytes decreased significantly (P<0.01) and its cell apoptosis ratio increased significantly (P<0.01). Compared with the ischemia/reperfusion group, the gap junctional function of astrocytes in18-α-glycyrrhetinic acid and oleamide group decreased significantly (P<0.01), the viability of astrocytes increased significantly (P<0.01), while cell apoptosis decreased significantly (P<0.01). CONCLUSION: Inhibition of intercellular gap junction has protective effect against hypoxia/reoxygenation injury in astrocytes.

[Total flavonoids of litsea coreana decreases the cytotoxicity of oxaliplatin in TM3 Leydig cells via enhancing the function of gap junction].

OBJECTIVE: To investigate the effects of total flavonoids of Litsea Coreana (TFLC) on the gap junction (GJ) intercellular communication in TM3 testicular Leydig cells and whether TFLC can reduce the cytotoxicity of oxaliplatin (OHP) in vitro. METHODS: We detected the effect of TFLC on the dye spread of the in vitro cultured TM3 cells by parachute assay, observed changes in the expression of connexin 43 (Cx43) total protein in the TFLC-treated TM3 cells by Western blot, and determined the effects of TFLC on the expression of Cx43 on the membrane of the TM3 cells by immunofluorescence assay and on the cytotoxicity of OHP by MTT assay. RESULTS: TFLC obviously enhanced the GJ function with the increasing of the TFLC concentration in the TM3 cells. Western blot and immunofluorescence assay confirmed that TFLC significantly enhanced the expression of Cx43 total protein and Cx43 expression on the membrane of the TM3 cells. MTT assay showed that at a high cell density (confluent with GJ formation), 20 microg/ml TFLC enhanced the GJ function of the TM3 cells and reduced the cytotoxicity of OHP (P < 0.05), while at a low density (preconfluent with no GJ formation), TFLC exhibited no effect on the cytotoxicity of OHP (P > 0.05). CONCLUSION: TFLC increases the Cx43 expression and GJ function in normal TM3 Leydig cells, and the enhancement of GJ function reduces the cytotoxicity of OHP.

Ethanol-Induced Changes in Brain of Transgenic Mice Overexpressing DYRK1A.

Alcoholism is a chronic relapsing disorder defined by loss of control over excessive consumption of ethanol despite damaging effects on the liver and brain. We previously showed that the overexpression in mice of Dyrk1A (TgDyrk1A, for dual-specificity tyrosine (Y) phosphorylation-regulated kinase 1A) reduces the severity of alcohol mediated liver injury. Ethanol consumption has also been associated with increased brain glutamate concentration that led to therapies targeting glutamatergic receptors and normalization of glutamatergic neurotransmission. Interestingly, mice overexpressing Dyrk1A (TgDyrk1A mice) present a reduction of glutamatergic brain transmission, which we propose could be protective against alcohol intake. To answer this question, we investigated the ethanol preference in TgDyrk1A mice using a two-bottle choice paradigm. TgDyrk1A mice showed a non-significant decrease of voluntary ethanol intake and ethanol preference compared with wild-type mice. At the peripheral level, mice overexpressing Dyrk1A show lower ethanol plasma levels, indicating a faster ethanol metabolism. At the end of the protocol, lasting 21 days, brains were extracted for protein analysis. Ethanol reduced levels of the synaptic protein PSD-95 and increased the glutamate decarboxylase GAD65, specifically in the cortex of TgDyrk1A mice. Our results suggest that overexpression of DYRK1A may cause different ethanol-induced changes in the brain.

Haploidentical in utero hematopoietic cell transplantation improves phenotype and can induce tolerance for postnatal same-donor transplants in the canine leukocyte adhesion deficiency model.

In the murine model, in utero hematopoietic cell transplantation (IUHCT) has been shown to achieve low levels of allogeneic chimerism and associated donor-specific tolerance permitting minimal conditioning postnatal hematopoietic stem cell transplantation (HSCT). In this pilot study, we investigated IUHCT in the canine leukocyte adhesion deficiency (CLAD) model. Haploidentical IUHCT resulted in stable low-level donor cell chimerism in all dogs that could be analyzed by sensitive detection methodology (4 of 10) through 18 months of follow-up. In the 2 CLAD recipients, low-level chimerism resulted in amelioration and complete reversal of the CLAD phenotype, respectively. Six recipients of IUHCT (5 carriers and 1 CLAD) subsequently received postnatal HSCT from the same haploidentical prenatal donor after minimal conditioning with busulfan 10 mg/kg. Chimerism in 2 of 5 CLAD carriers that underwent HSCT increased from < 1% pre-HSCT to sustained levels of 35% to 45%. Control animals undergoing postnatal haploidentical HSCT without IUHCT had no detectable donor chimerism. These results demonstrate that haploidentical IUHCT in the CLAD model can result in low-level donor chimerism that can prevent the lethal phenotype in CLAD dogs, and can result in donor-specific tolerance that can facilitate postnatal minimal conditioning HSCT.

Nonmyeloablative hematopoietic stem cell transplantation corrects the disease phenotype in the canine model of leukocyte adhesion deficiency.

OBJECTIVE: The aim of this study was to test a nonmyeloablative hematopoietic stem cell transplant regimen applicable to children with leukocyte adhesion deficiency (LAD) who have a histocompatible sibling donor by using the canine model of LAD, namely canine leukocyte adhesion deficiency or CLAD. METHODS: Thirteen CLAD pups received a hematopoietic stem cell transplant from a dog leukocyte antigen (DLA)-matched littermate donor after pretransplant nonmyeloablative conditioning with 200 cGy total-body irradiation and posttransplant immunosuppression with cyclosporine and mycophenolate mofetil. Donor chimerism following transplant was assessed by flow cytometry for the presence of donor CD18 peripheral blood leukocytes and leukocyte subsets. RESULTS: Eleven of the 13 transplanted animals achieved stable mixed donor chimerism and reversal of the severe CLAD phenotype without graft-vs-host disease. The level of donor chimerism ranged from 3.9 to 95.5% at 1 year following transplant. There was one early death 3 weeks after transplant from thrombocytopenia and hemorrhage, and one dog with donor microchimerism (0.5% CD18+ donor leukocytes) who had attenuation of the CLAD phenotype. CONCLUSION: These results demonstrate that a nonmyeloablative transplant regimen from a DLA-matched littermate donor leads to mixed chimerism and reversal of the severe disease phenotype in dogs with CLAD, and provides support for the use of this approach in children with LAD who possess a histocompatible sibling donor.

MiR-146a-5p inhibits cell proliferation and cell cycle progression in NSCLC cell lines by targeting CCND1 and CCND2.

Previous studies have indicated that miR-146a-5p acts as an oncogene in several types of cancer, yet a tumor suppressor gene in others. In non-small cell lung cancer (NSCLC), one report showed that it was downregulated and played the role of tumor suppressor. However, another study showed that miR-146a-5p was overexpressed in the serum of NSCLC patients compared to healthy controls. Therefore, it is obvious that further study of the function of miR-146a-5p in NSCLC is necessary to fully understand its importance. Herein, we have verified that miR- 146a- 5p acts as a tumor suppressor in NSCLC. Our data revealed that the expression level of miR-146a-5p was significantly decreased in several human NSCLC cell lines, and also less abundant in human NSCLC tissues, when compared with controls. Moreover, we observed that miR-146a-5p could suppress cell proliferation, both in vitro and in vivo. Our results also showed that miR-146a-5p directly targeted the 3'-UTR of CCND1 and CCND2 mRNAs as well as decreased their expression at both mRNA and protein levels, causing cell cycle arrest at the G0/G1 phase. Furthermore, siRNA-mediated downregulation of CCND1 or CCND2 yielded the same effects on proliferation and cell cycle arrest as miR-146a-5p upregulation did in the NSCLC cell lines. We confirmed that the expression of miR-146a-5p had negative relationship with CCND1 or CCND2. Besides, we also found that miR-146a-5p could inhibit tumor growth in xengroft mouse models, and CCND1 and CCND2 were downregulated in miR-146a-5p overexpressed xengroft tumor tissues. In summary, our results demonstrated that miR-146a-5p could suppress the proliferation and cell cycle progression in NSCLC cells by inhibiting the expression of CCND1 and CCND2.

The genetic immunodeficiency disease, leukocyte adhesion deficiency, in humans, dogs, cattle, and mice.

This review highlights the genotype-phenotype relationship of the genetic immunodeficiency disease leukocyte adhesion deficiency (LAD) in humans, dogs, cattle, and mice, and provides assessment of the opportunities that each animal species provides in the understanding of leukocyte biology and in developing new therapeutic approaches to LAD in humans. This comparison is important since animal models of genetic diseases in humans provide the opportunity to test new therapeutic approaches in an appropriate, disease-specific model. The success of this approach is dependent on the relationship of the phenotype in the animal to the phenotype of the disease in humans.

Human cord blood stem cell applications in cell therapy.

Human umbilical cord blood (UCB) is a valuable alternative source of ethically acceptable, clinically competent stem cells that is most likely closest to embryonic stem cells. Development of reliable methods for the expansion of cord blood stem cells is critical to ensure their clinical application. In the present article, advances in cord blood stem cell isolation, culture expansion methods through co-culture with human mesenchymal stem cells, culture optimization techniques with defined media and cord blood stem cell banking aspects have been reviewed. Refined methods of isolation as well as defined culture conditions of expansion that favor retention of stem cell phenotype and proper cryogenic storage can significantly increase the use of cord blood stem cells in human cell therapy applications.

Successful treatment of canine leukocyte adhesion deficiency by foamy virus vectors.

Recent successes in treating genetic immunodeficiencies have demonstrated the therapeutic potential of stem cell gene therapy. However, the use of gammaretroviral vectors in these trials led to insertional activation of nearby oncogenes and leukemias in some study subjects, prompting studies of modified or alternative vector systems. Here we describe the use of foamy virus vectors to treat canine leukocyte adhesion deficiency (CLAD). Four of five dogs with CLAD that received nonmyeloablative conditioning and infusion of autologous, CD34+ hematopoietic stem cells transduced by a foamy virus vector expressing canine CD18 had complete reversal of the CLAD phenotype, which was sustained more than 2 years after infusion. In vitro assays showed correction of the lymphocyte proliferation and neutrophil adhesion defects that characterize CLAD. There were no genotoxic complications, and integration site analysis showed polyclonality of transduced cells and a decreased risk of integration near oncogenes as compared to gammaretroviral vectors. These results represent the first successful use of a foamy virus vector to treat a genetic disease, to our knowledge, and suggest that foamy virus vectors will be effective in treating human hematopoietic diseases.

Correction of the disease phenotype in canine leukocyte adhesion deficiency using ex vivo hematopoietic stem cell gene therapy.

Canine leukocyte adhesion deficiency (CLAD) represents the canine counter-part of the human disease leukocyte adhesion deficiency (LAD). Defects in the leukocyte integrin CD18 adhesion molecule in both CLAD and LAD lead to recurrent, life-threatening bacterial infections. We evaluated ex vivo retroviral-mediated gene therapy in CLAD using 2 nonmyeloablative conditioning regimens--200 cGy total body irradiation (TBI) or 10 mg/kg busulfan--with or without posttransplantation immunosuppression. In 6 of 11 treated CLAD dogs, therapeutic levels of CD18(+) leukocytes were achieved. Conditioning with either TBI or busulfan allowed long-term engraftment, and immunosuppression was not required for efficacy. The percentage of CD18(+) leukocytes in the peripheral blood progressively increased over 6 to 8 months after infusion to levels ranging from 1.26% to 8.37% at 1-year follow-up in the 6 dogs. These levels resulted in reversal or moderation of the severe CLAD phenotype. Linear amplification-mediated polymerase chain reaction assays indicated polyclonality of insertion sites. These results describe ex vivo hematopoietic stem cell gene transfer in a disease-specific, large animal model using 2 clinically applicable conditioning regimens, and they provide support for the use of nonmyeloablative conditioning regimens in preclinical protocols of retroviral-mediated gene transfer for nonmalignant hematopoietic diseases such as LAD.

Nonmyeloablative conditioning with busulfan before matched littermate bone marrow transplantation results in reversal of the disease phenotype in canine leukocyte adhesion deficiency.

Leukocyte adhesion deficiency (LAD)-1, a primary immunodeficiency disease caused by molecular defects in the leukocyte integrin CD18 molecule, is characterized by recurrent, life-threatening bacterial infections. Myeloablative hematopoietic stem cell transplantation is the only curative treatment for LAD-1. Recently, canine LAD (CLAD) has been shown to be a valuable animal model for the preclinical testing of nonmyeloablative transplantation regimens for the treatment of children with LAD-1. To develop new allogeneic transplantation approaches for LAD-1, we assessed a nonmyeloablative conditioning regimen consisting of busulfan as a single agent before matched littermate allogeneic bone marrow transplantation in CLAD. Three CLAD dogs received busulfan 10 mg/kg intravenously before infusion of matched littermate bone marrow, and all dogs received posttransplantation immunosuppression with cyclosporin A and mycophenolate mofetil. Initially, all 3 dogs became mixed chimeras, and levels of donor chimerism sufficient to reverse the CLAD phenotype persisted in 2 animals. The third dog maintained donor microchimerism with an attenuated CLAD phenotype. These 3 dogs have all been followed up for at least 1 year after transplantation. These results indicate that a nonmyeloablative conditioning regimen with chemotherapy alone is capable of generating stable mixed chimerism and reversal of the disease phenotype in CLAD.

Laminin isoform-specific promotion of adhesion and migration of human bone marrow progenitor cells.

Laminins are alphabetagamma heterotrimeric extracellular proteins that regulate cellular functions by adhesion to integrin and nonintegrin receptors. Laminins containing alpha4 and alpha5 chains are expressed in bone marrow, but their interactions with hematopoietic progenitors are unknown. We studied human bone marrow cell adhesion to laminin-10/11 (alpha5beta1gamma1/alpha5beta2gamma1), laminin-8 (alpha4beta1gamma1), laminin-1 (alpha1beta1gamma1), and fibronectin. About 35% to 40% of CD34(+) and CD34(+)CD38(-) stem and progenitor cells adhered to laminin-10/11, and 45% to 50% adhered to fibronectin, whereas they adhered less to laminin-8 and laminin-1. Adhesion of CD34(+)CD38(-) cells to laminin-10/11 was maximal without integrin activation, whereas adhesion to other proteins was dependent on protein kinase C activation by 12-tetradecanoyl phorbol-13-acetate (TPA). Fluorescence-activated cell-sorting (FACS) analysis showed expression of integrin alpha6 chain on most CD34(+) and CD34(+)CD38(-) cells. Integrin alpha6 and beta1 chains were involved in binding of both cell fractions to laminin-10/11 and laminin-8. Laminin-10/11 was highly adhesive to lineage-committed myelomonocytic and erythroid progenitor cells and most lymphoid and myeloid cell lines studied, whereas laminin-8 was less adhesive. In functional assays, both laminin-8 and laminin-10/11 facilitated stromal-derived factor-1alpha (SDF-1alpha)-stimulated transmigration of CD34(+) cells, by an integrin alpha6 receptor-mediated mechanism. In conclusion, we demonstrate laminin isoform-specific adhesive interactions with human bone marrow stem, progenitor, and more differentiated cells. The cell-adhesive laminins affected migration of hematopoietic progenitors, suggesting a physiologic role for laminins during hematopoiesis.

Leukocyte adhesion deficiency in children and Irish setter dogs.

Children with the genetic immunodeficiency disease leukocyte adhesion deficiency, or LAD, develop life-threatening bacterial infections as a result of the inability of their leukocytes to adhere to the vessel wall and migrate to the sites of infection. Recently, the canine counterpart to LAD, known as canine leukocyte adhesion deficiency, or CLAD, has been described in Irish setter dogs. This review describes how the clinical phenotype of dogs with CLAD closely parallels that of children with the severe deficiency phenotype of LAD, thus enabling the CLAD dog to provide a disease-specific, large-animal model for testing novel hematopoietic stem cell and gene therapy strategies before their translation to children with LAD.

Very low levels of donor CD18+ neutrophils following allogeneic hematopoietic stem cell transplantation reverse the disease phenotype in canine leukocyte adhesion deficiency.

Children with the severe phenotype of the genetic immunodeficiency disease leukocyte adhesion deficiency or LAD experience life-threatening bacterial infections because of molecular defects in the leukocyte integrin CD18 molecule and the resultant failure to express the CD11/CD18 adhesion molecules on the leukocyte surface. Hematopoietic stem cell transplantation remains the only definitive therapy for LAD; however, the degree of donor chimerism and particularly the number of CD18(+) donor-derived neutrophils required to reverse the disease phenotype are not known. We performed nonmyeloablative hematopoietic stem cell transplantations from healthy matched littermates in 9 dogs with the canine form of LAD known as CLAD and demonstrate that in the 3 dogs with the lowest level of donor chimerism, less than 500 CD18(+) donor-derived neutrophils/microL in the peripheral blood of the CLAD recipients resulted in reversal of the CLAD disease phenotype. These results demonstrate the value of a disease-specific, large-animal model for identifying the lowest therapeutic level required for successful cellular and gene therapy.