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  • Mice that lack matrix metalloproteinase-9 display delayed wound healing associated with delayed reepithelization and disordered collagen fibrillogenesis. 19379668

    Matrix metalloproteinase- (MMP-9) is involved in processes that occur during cutaneous wound healing such as inflammation, matrix remodeling, and epithelialization, To investigate its role in healing, full thickness skin wounds were made in the dorsal region of MMP-9-null and control mice and harvested up to 14 days post wounding. Gross examination and histological and immunohistochemical analysis indicated delayed healing in MMP-9-null mice. Specifically, MMP-9-null wounds displayed compromised reepithelialization and reduced clearance of fibrin clots. In addition, they exhibited abnormal matrix deposition, as evidenced by the irregular alignment of immature collagen fibers. Despite the presence of matrix abnormalities, MMP-9-null wounds displayed normal tensile strength. Ultrastructural analysis of wounds revealed the presence of large collagen fibrils, some with irregular shape. Keratinocyte proliferation, inflammation, and angiogenesis were found to be normal in MMP-9-null wounds. In addition, VEGF levels were similar in control and MMP-9-null wound extracts. To investigate the importance of MMP-9 in wound reepithelialization we tested human and murine keratinocytes in a wound migration assay and found that antibody-based blockade of MMP-9 function or MMP-9 deficiency retarded migration. Collectively, our observations reveal defective healing in MMP-9-null mice and suggest that MMP-9 is required for normal progression of wound closure.
    Document Type:
    Reference
    Product Catalog Number:
    MAB13415
    Product Catalog Name:
    Anti-MMP-9 Antibody, clone GE-213

  • The lack of chromosomal protein Hmg1 does not disrupt cell growth but causes lethal hypoglycaemia in newborn mice. 10391216

    High mobility group 1 (HMG1) protein is an abundant component of all mammalian nuclei, and related proteins exist in all eukaryotes. HMG1 binds linear DNA with moderate affinity and no sequence specificity, but bends the double helix significantly on binding through the minor groove. It binds with high affinity to DNA that is already sharply bent, such as linker DNA at the entry and exit of nucleosomes; thus, it is considered a structural protein of chromatin. HMG1 is also recruited to DNA by interactions with proteins required for basal and regulated transcriptions and V(D)J recombination. Here we generate mice harbouring deleted Hmg1. Hmg1-/- pups are born alive, but die within 24 hours due to hypoglycaemia. Hmg1-deficient mice survive for several days if given glucose parenterally, then waste away with pleiotropic defects (but no alteration in the immune repertoire). Cell lines lacking Hmg1 grow normally, but the activation of gene expression by the glucocorticoid receptor (GR, encoded by the gene Grl1) is impaired. Thus, Hmg1 is not essential for the overall organization of chromatin in the cell nucleus, but is critical for proper transcriptional control by specific transcription factors.
    Document Type:
    Reference
    Product Catalog Number:
    07-584

  • Lack of association between serum adiponectin levels and the Pro12Ala polymorphism in Asian Indians. 17335469

    AIMS: The aim of the study was to investigate the association of serum adiponectin levels with the Pro12Ala polymorphism of the peroxisome proliferator activated receptor-gamma (PPARG) gene in Asian Indians. METHODS: We selected 400 diabetic subjects, 200 with the Pro12Pro genotype (100 male and 100 female) and 200 with the Pro12Ala genotype (100 male and 100 female) and 400 age- and sex-matched normal glucose tolerance subjects with similar genotype profiles from the Chennai Urban Rural Epidemiology Study. Fasting serum adiponection levels were measured using radioimmunoassay. The Pro12Ala polymorphism was genotyped by PCR-restriction fragment length polymorphism using BstUI. RESULTS: All clinical and biochemical parameters were similar in the subjects with the Pro12Pro and Pro12Ala genotypes. There was no significant difference in serum adiponectin values between subjects with the Pro12Pro and Pro12Ala genotypes (males 5.4 vs. 5.8 microg/ml, P = 0.546; females 6.9 vs. 7.2 microg/ml, P = 0.748). Adiponectin values did not differ among these two genotypes even when categorized based on their diabetes status (normal glucose tolerance Pro12Pro 7.9 vs. Pro12Ala 7.7 microg/ml, P = 0.994; diabetes Pro12Pro 4.7 vs. Pro12Ala 5.4 microg/ml, P = 0.622). CONCLUSION: The Pro12Ala polymorphism of the PPARG gene is not associated with serum adiponectin levels in Asian Indians.
    Document Type:
    Reference
    Product Catalog Number:
    HADP-61HK
    Product Catalog Name:
    Human Adiponectin RIA

  • Lack of axonal sprouting of spared propriospinal fibers caudal to spinal contusion injury is attributed to chronic axonopathy. 19645528

    We have previously shown that a small percentage of long descending propriospinal tract (LDPT) axons are spared, whereas few short thoracic propriospinal (TPS) fibers survive 2 weeks following severe (50 mm weight drop) low thoracic spinal cord contusion injury (SCI). Here, we extended those findings to a moderate (25 mm weight drop) T9 SCI and assessed the effects of this lesion severity on propriospinal tract fibers at different time periods after injury. We anterogradely labeled fibers with fluororuby (FR) or WGA-HRP to determine their location and number 2, 4, 6, and 16 weeks post-SCI. Findings were compared with non-injured controls. At chronic time points, surviving FR-labeled LDPT fibers rostral to the injury remained as reactive endings or as putative regenerative sprouts. Caudal to the injury, spared LDPT fibers ran along a rim of lateral and ventral white matter, and ended as small abnormal-appearing putative terminal boutons or reactive endings within the intermediate gray matter of lumbosacral cord, with little axonal arborization and no evidence of injury-induced sprouting. One striking difference in the WGA-HRP experimental operates was the increased density of labeling of spared axons within the white matter caudal to the injury compared to controls. This labeling pattern was reminiscent of the labeling found after axotomy in studies by others, and raises a question as to contusion injury-induced impaired axonal transport. We hypothesize that axonal sprouting of axons after partial spinal cord injury seen in previous investigations was not found in the present investigation because of the additional pathological effects of contusion injury, similar to what is observed after traumatic brain injury.
    Document Type:
    Reference
    Product Catalog Number:
    MAB347
    Product Catalog Name:
    Anti-Growth Associated Protein 43 Antibody, clone 9-1E12

  • Lack of regulation of aromatic L-amino acid decarboxylase in intact bovine chromaffin cells. 12065667

    Aromatic l-amino acid decarboxylase (AADC) is the second enzyme in the catecholamine biosynthetic pathway, and its activity is generally considered not to be limiting, and therefore not involved, in regulating flux through this pathway. Recent studies showing that its activity can be regulated in vivo and that the enzyme can be phosphorylated and activated in vitro have raised the possibility that AADC may play more than an obligatory role in catecholamine biosynthesis. In the present study, the phosphorylation and activity of AADC was evaluated relative to that of tyrosine hydroxylase (TH; the first and rate-limiting enzyme in the pathway) in intact bovine chromaffin cells. Treatment of chromaffin cells with elevated potassium, acetylcholine, phorbol dibutyrate, forskolin, or okadaic acid each increased 32P incorporation into TH (after metabolic labeling of ATP pools with 32P(i)) and TH activity. In contrast, as measured in matched samples, 32P incorporation into AADC was not detected and none of the treatments altered AADC activity. Thus, that AADC can be phosphorylated and activated in vitro has questionable physiological significance.
    Document Type:
    Reference
    Product Catalog Number:
    AB1569
    Product Catalog Name:
    Anti-Dopa Decarboxylase Antibody

  • Lack or inhibition of dopaminergic stimulation induces a development increase of striatal tyrosine hydroxylase-positive interneurons. 23028485

    We examined the role of endogenous dopamine (DA) in regulating the number of intrinsic tyrosine hydroxylase-positive (TH(+)) striatal neurons using mice at postnatal day (PND) 4 to 8, a period that corresponds to the developmental peak in the number of these neurons. We adopted the strategy of depleting endogenous DA by a 2-day treatment with α-methyl-p-tyrosine (αMpT, 150 mg/kg, i.p.). This treatment markedly increased the number of striatal TH(+) neurons, assessed by stereological counting, and the increase was highly correlated to the extent of DA loss. Interestingly, TH(+) neurons were found closer to the clusters of DA fibers after DA depletion, indicating that the concentration gradient of extracellular DA critically regulates the distribution of striatal TH(+) neurons. A single i.p. injection of the D1 receptor antagonist, SCH23390 (0.1 mg/kg), the D2/D3 receptor antagonist, raclopride (0.1 mg/kg), or the D4 receptor antagonist, L-745,870 (5 mg/kg) in mice at PND4 also increased the number of TH(+) neurons after 4 days. Treatment with the D1-like receptor agonist SKF38393 (10 mg/kg) or with the D2-like receptor agonist, quinpirole (1 mg/kg) did not change the number of TH(+) neurons. At least the effects of SCH23390 were prevented by a combined treatment with SKF38393. Immunohistochemical analysis indicated that striatal TH(+) neurons expressed D2 and D4 receptors, but not D1 receptors. Moreover, treatment with the α4β2 receptor antagonist dihydro-β-erythroidine (DHβE) (3.2 mg/kg) also increased the number of TH(+) neurons. The evidence that DHβE mimicked the action of SCH23390 in increasing the number of TH(+) neurons supports the hypothesis that activation of D1 receptors controls the number of striatal TH(+) neurons by enhancing the release of acetylcholine. These data demonstrate for the first time that endogenous DA negatively regulates the number of striatal TH(+) neurons by direct and indirect mechanisms mediated by multiple DA receptor subtypes.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple

  • Lack of transforming growth factor-β signaling promotes collective cancer cell invasion through tumor-stromal crosstalk. 22748014

    Transforming growth factor beta (TGF-β) has a dual role during tumor progression, initially as a suppressor and then as a promoter. Epithelial TGF-β signaling regulates fibroblast recruitment and activation. Concurrently, TGF-β signaling in stromal fibroblasts suppresses tumorigenesis in adjacent epithelia, while its ablation potentiates tumor formation. Much is known about the contribution of TGF-β signaling to tumorigenesis, yet the role of TGF-β in epithelial-stromal migration during tumor progression is poorly understood. We hypothesize that TGF-β is a critical regulator of tumor-stromal interactions that promote mammary tumor cell migration and invasion.Fluorescently labeled murine mammary carcinoma cells, isolated from either MMTV-PyVmT transforming growth factor-beta receptor II knockout (TβRII KO) or TβRIIfl/fl control mice, were combined with mammary fibroblasts and xenografted onto the chicken embryo chorioallantoic membrane. These combinatorial xenografts were used as a model to study epithelial-stromal crosstalk. Intravital imaging of migration was monitored ex ovo, and metastasis was investigated in ovo. Epithelial RNA from in ovo tumors was isolated by laser capture microdissection and analyzed to identify gene expression changes in response to TGF-β signaling loss.Intravital microscopy of xenografts revealed that mammary fibroblasts promoted two migratory phenotypes dependent on epithelial TGF-β signaling: single cell/strand migration or collective migration. At epithelial-stromal boundaries, single cell/strand migration of TβRIIfl/fl carcinoma cells was characterized by expression of α-smooth muscle actin and vimentin, while collective migration of TβRII KO carcinoma cells was identified by E-cadherin+/p120+/β-catenin+ clusters. TβRII KO tumors also exhibited a twofold greater metastasis than TβRIIfl/fl tumors, attributed to enhanced extravasation ability. In TβRII KO tumor epithelium compared with TβRIIfl/fl epithelium, Igfbp4 and Tspan13 expression was upregulated while Col1α2, Bmp7, Gng11, Vcan, Tmeff1, and Dsc2 expression was downregulated. Immunoblotting and quantitative PCR analyses on cultured cells validated these targets and correlated Tmeff1 expression with disease progression of TGF-β-insensitive mammary cancer.Fibroblast-stimulated carcinoma cells utilize TGF-β signaling to drive single cell/strand migration but migrate collectively in the absence of TGF-β signaling. These migration patterns involve the signaling regulation of several epithelial-to-mesenchymal transition pathways. Our findings concerning TGF-β signaling in epithelial-stromal interactions are important in identifying migratory mechanisms that can be targeted as recourse for breast cancer treatment.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple

  • Lack of tumor necrosis factor-related apoptosis-inducing ligand but presence of its receptors in the human brain. 11844843

    Apoptosis mediated by members of the tumor necrosis factor (TNF)-nerve growth factor superfamily plays a crucial role in the interaction of the nervous and the immune system. On the one hand, it is involved in the defense mechanisms of the brain, the immune privilege. On the other hand, it is involved in the induction of glial-neuronal cell death in neuroinflammatory diseases. Here, we show that in contrast to the other known death ligands, TNF-related apoptosis-inducing ligand (TRAIL) is not constitutively expressed in the human brain, whereas both apoptosis-mediating and apoptosis-blocking TRAIL receptors are found on neurons, astrocytes, and oligodendrocytes. Thus, the brain differs from other immune-privileged organs, such as the placenta, with the TRAIL receptor-TRAIL system not being part of the immune privilege of the brain. Conversely, this death receptor-ligand system might well play an important role in T cell-mediated autoimmune diseases of the CNS such as multiple sclerosis.
    Document Type:
    Reference
    Product Catalog Number:
    AB16943

  • Lack of correlation between serum levels of E- and P-cadherin fragments and the presence of breast cancer. 10987257

    Breast cancers often show reduced expression of the transmembrane cell-cell adhesion protein, E-cadherin. In addition, approximately half of breast carcinomas express P-cadherin, which correlates with poor survival. A large fragment of the E-cadherin extracellular domain can be detected in serum, and it has been proposed that an increase in serum E-cadherin can denote the presence of a tumor. In this study, we tested the possibility that serum E- or P-cadherin levels might be useful diagnostic or prognostic indicators in breast cancer. However, we found no indication that the level of serum E-cadherin correlated with the presence of breast cancer. In addition, although we successfully detected a fragment of P-cadherin in serum, we found that its level was considerably lower than that of E-cadherin and did not correlate with the presence of P-cadherin-positive breast cancer.
    Document Type:
    Reference
    Product Catalog Number:
    05-916
    Product Catalog Name:
    Anti-P-Cadherin Antibody, clone 6A9