Semi-quantitative RT-PCR analysis of LIM mineralization protein 1 and its associated molecules in cultured human dental pulp cells

OBJECTIVE

LIM mineralization protein 1 (LMP-1), an intracellular signaling molecule, regulates osteoblast differentiation and maturation, as well as bone formation. However, the role of LMP-1 in the differentiation of human dental pulp cells and formation of dentin has not been determined. The study was to investigate the expression of LMP-1, the related proteins, such as bone morphogenetic proteins 2, 6 and 7 (BMP-2, BMP-6 and BMP-7), and core binding factor alpha 1 (Cbfa1) during the differentiation of cultured human dental pulp cells and the formation of mineralized nodules.

DESIGN

Differentiation of human dental pulp cells was induced by dexamethasone, asorbic acid and beta-glycerophosphate. The formation of mineralized nodules, was determined by Von Kossa staining and immunocytochemistry detection of dentin sialoprotein. Expression of LMP-1, the related proteins and the differentiation marker alkaline phosphatase (ALP) was analysed by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

The expression of LMP-1, BMP-2, BMP-6, BMP-7 and Cbfa1 was significantly increased in the process of dental pulp cells differentiation and the formation of mineralized nodules, while the pattern of the expression was distinct.

CONCLUSIONS

The elevated level of LMP-1, BMPs and Cbfa1 expression indicated they might play a role in the differentiation of human dental pulp cells and the formation of mineralized nodules.

Expression of angiotensin II receptor type 1 is reduced in advanced rat liver fibrosis

In this study, we assessed the hypothesis that the expression of angiotensin II receptor type 1 (AGTR1) in liver tissue changes with increasing fibrosis, which would influence the antifibrotic efficacy of AGTR1 blockers. Rats were treated with candesartancilexetil (CAN) initiated 8 or 15 days after bile duct occlusion (BDO). Four weeks after BDO, AGTR1 mRNA and protein were decreased compared to those in sham-operated animals depending on the amount of fibrosis. Starting CAN early, but not late, reduced mRNA of profibrotic TGF-beta, MMP2, and Smad2. However, CAN had no significant effect on collagen I, fibrosis, or intrahepatic resistance. In conclusion, progression of liver fibrosis reduces AGTR1 expression. Therefore, in our model, antifibrotic effects of CAN are insufficient to improve fibrosis or intrahepatic resistance. However, if AGTR1 blockade is started early, a decrease in essential profibrotic molecules is achieved. Hence, early initiation of therapy with AGTR1 blockers may be crucial for the prevention of cirrhosis.

Quantification of various growth factors in different demineralized bone matrix preparations

Besides autografts, allografts, and synthetic materials, demineralized bone matrix (DBM) is used for bone defect filling and treatment of non-unions. Different DBM formulations are introduced in clinic since years. However, little is known about the presents and quantities of growth factors in DBM. Aim of the present study was the quantification of eight growth factors important for bone healing in three different "off the shelf" DBM formulations, which are already in human use: DBX putty, Grafton DBM putty, and AlloMatrix putty. All three DBM formulations are produced from human donor tissue but they differ in the substitutes added. From each of the three products 10 different lots were analyzed. Protein was extracted from the samples with Guanidine HCL/EDTA method and human ELISA kits were used for growth factor quantification. Differences between the three different products were seen in total protein contend and the absolute growth factor values but also a large variability between the different lots was found. The order of the growth factors, however, is almost comparable between the materials. In the three investigated materials FGF basic and BMP-4 were not detectable in any analyzed sample. BMP-2 revealed the highest concentration extractable from the samples with approximately 3.6 microg/g tissue without a significant difference between the three DBM formulations. In DBX putty significantly more TGF-beta1 and FGFa were measurable compared to the two other DBMs. IGF-I revealed the significantly highest value in the AlloMatrix and PDGF in Grafton. No differences were accessed for VEGF. Due to the differences in the growth factor concentration between the individual samples, independently from the product formulation, further analyzes are required to optimize the clinical outcome of the used demineralized bone matrix.

Cell viability and protein composition in cryopreserved cartilage

Chondrocyte survival in frozen-stored osteochondral allografts is low. We analyzed different storage conditions to determine the best for maintenance or storage for preserving cartilage. We hypothesized cell viability and extracellular protein content could be improved with better cryopreservation. Articular cartilage from nine sheep femoral condyles were stored at 4 degrees C, -80 degrees C, and -196 degrees C with and without cryopreservative agents for 1 month. We determined cell viability and performed Western blot analysis for TGF-beta, IGF-1, and MMP-2, 9, and 13. We observed decreases in viability in cartilage stored at 4 degrees C: 36.2% viability when stored without solution, 40.4% in phosphate-buffered saline, and 48.1% in culture medium. TGF-beta and IGF-1 decreased in the first week in all groups. The groups stored at -80 degrees C and -196 degrees C contained less protease in the last 2 weeks. In the groups stored at 4 degrees C in phosphate-buffered saline, we detected no increase in the levels of MMPs. Our data discourage the use of frozen cartilage because of the decrease of cell viability and elevation in MMPs. However, modifying the freezing conditions might moderate these changes and improve the state of preserved cartilage.

Functional, structural and molecular aspects of diastolic heart failure in the diabetic (mRen-2)27 rat

OBJECTIVE

Diabetic cardiomyopathy is an increasingly recognized cause of cardiac failure despite preserved left ventricular systolic function. Given the over-expression of angiotensin II in human diabetic cardiomyopathy, we hypothesized that combining hyperglycaemia with an enhanced tissue renin-angiotensin system would lead to the development of diastolic dysfunction with adverse remodeling in a rodent model.

METHODS

Homozygous (mRen-2)27 rats and non-transgenic Sprague Dawley (SD) rats were randomized to receive streptozotocin (diabetic) or vehicle (non-diabetic) and followed for 6 weeks. Prior to tissue collection, animals underwent pressure-volume loop acquisition.

RESULTS

Diabetic Ren-2 rats developed impairment of both active and passive phases of diastole, accompanied by reductions in SERCA-2a ATPase and phospholamban along with activation of the fetal gene program. Structural features of diabetic cardiomyopathy in the Ren-2 rat included interstitial fibrosis, cardiac myocyte hypertrophy and apoptosis in conjunction with increased activity of transforming growth factor-beta (p<0.01 compared with non-diabetic Ren-2 rats for all parameters). No significant functional or structural derangements were observed in non-transgenic, SD diabetic rats.

CONCLUSION

These findings indicate that the combination of enhanced tissue renin-angiotensin system and hyperglycaemia lead to the development of diabetic cardiomyopathy. Fibrosis, and myocyte hypertrophy, a prominent feature of this model, may be a consequence of activation of the pro-sclerotic cytokine, transforming growth factor-beta, by the diabetic state.

Tetramethylpyrazine inhibits agiontensin II-induced nuclear factor-kappaB activation and bone morphogenetic protein-2 downregulation in rat vascular smooth muscle cells

Tetramethylpyrazine (TMP), an effective component of traditional Chinese medicine Chuanxiong, is commonly used to resolve embolism. Its possible therapeutic effect against atherosclerosis has received considerable attention recently. Angiotensin II (Ang II) is highly implicated in the proliferation of vascular smooth muscle cells (VSMCs), resulting in atherosclerosis. The mechanisms of TMP in the proliferation of VSMCs induced by Ang II remain to be defined. The present study was aimed to study the effect of TMP on Ang II-induced VSMC proliferation through detection of nuclear factor-kappaB (NF-kappaB) activity and bone morphogenetic protein-2 (BMP-2) expression. Primary cultured rat aortic smooth muscle cells were divided into the control group, Ang II group, Ang II + TMP group and TMP group. Cells in each group were harvested at different time points (15, 30 and 60 min for detection of NF-kappaB activity; 6, 12 and 24 h for measurement of BMP-2 expression). NF-kappaB activation was identified as nuclear staining by immunohistochemistry. BMP-2 expression was observed through Western blot, immunohistochemistry and in situ hybridization. The results showed that: (1) Ang II stimulated the activation of NF-kappaB. Translocation of NF-kappaB p65 subunit from cytoplasm to nucleus appeared as early as 15 min, peaked at 30 min (P<0.01) and declined after 1 h. (2) TMP inhibited Ang II-induced NF-kappaB activation (P<0.01). (3) Ang II increased BMP-2 expression at 6 h but declined it significantly at 12 and 24 h (P<0.01). (4) BMP-2 expression was also kept at high level at 6 h in Ang II + TMP group but maintained at the normal level at 12 and 24 h. (5) There was no significant difference in NF-kappaB activation and BMP-2 expression between the control group and TMP group. These results indicate that TMP inhibits Ang II-induced VSMC proliferation through repression of NF-kappaB activation and BMP-2 reduction, and BMP-2 expression is independent of the NF-kappaB pathway. In conclusion, TMP has therapeutic potential for the treatment of atherosclerosis.

Cutting Edge: Immature human dendritic cells express latency-associated peptide and inhibit T cell activation in a TGF-beta-dependent manner

Dendritic cells (DCs) play a critical role in both initiating immune responses and in maintaining peripheral tolerance. However, the exact mechanism by which DCs instruct/influence the generation of effector vs regulatory T cells is not clear. In this study, we present evidence that TGF-beta, an important immunoregulatory molecule, is present on the surface of ex vivo immature human DCs bound by latency-associated peptide (LAP). Maturation of DCs upon stimulation with LPS results in loss of membrane-bound LAP and up-regulation of HLA class II and costimulatory molecules. The presence of LAP on immature DCs selectively inhibits Th1 cell but not Th17 cell differentiation and is required for differentiation and/or survival of Foxp3-positive regulatory T cells. Taken together, our results indicate that surface expression of TGF-beta on DCs in association with LAP is one of the mechanisms by which immature DCs limit T cell activation and thus prevent autoimmune responses.

Grass pollen immunotherapy induces an allergen-specific IgA2 antibody response associated with mucosal TGF-beta expression

Allergen immunotherapy (IT) has long-term efficacy in IgE-mediated allergic rhinitis and asthma. IT has been shown to modify lymphocyte responses to allergen, inducing IL-10 production and IgG Abs. In contrast, a putative role for IgA and local TGF-beta-producing cells remains to be determined. In 44 patients with seasonal rhinitis/asthma, serum IgA1, IgA2, and polymeric (J chain-containing) Abs to the major allergen Phl p 5 were determined by ELISA before and after a 2-year double-blind trial of grass pollen (Phleum pratense) injection IT. Nasal TGF-beta expression was assessed by in situ hybridization. Sera from five IT patients were fractionated for functional analysis of the effects of IgA and IgG Abs on IL-10 production by blood monocytes and allergen-IgE binding to B cells. Serum Phl p 5-specific IgA2 Abs increased after a 2-year treatment (approximately 8-fold increase, p = 0.002) in contrast to IgA1. Increases in polymeric Abs to Phl p 5 (approximately 2-fold increase, p = 0.02) and in nasal TGF-beta mRNA (p = 0.05) were also observed, and TGF-beta mRNA correlated with serum Phl p 5 IgA2 (r = 0.61, p = 0.009). Post-IT IgA fractions triggered IL-10 secretion by monocytes while not inhibiting allergen-IgE binding to B cells as observed with IgG fractions. This study shows for the first time that the IgA response to IT is selective for IgA2, correlates with increased local TGF-beta expression, and induces monocyte IL-10 expression, suggesting that IgA Abs could thereby contribute to the tolerance developed in IT-treated allergic patients.

Characterization of human lung tumor-associated fibroblasts and their ability to modulate the activation of tumor-associated T cells

The tumor microenvironment of human non-small cell lung cancer (NSCLC) is composed largely of stromal cells, including fibroblasts, yet these cells have been the focus of few studies. In this study, we established stromal cell cultures from primary NSCLC through isolation of adherent cells. Characterization of these cells by flow cytometry demonstrated a population which expressed a human fibroblast-specific 112-kDa surface molecule, Thy1, alpha-smooth muscle actin, and fibroblast activation protein, but failed to express CD45 and CD11b, a phenotype consistent with that of an activated myofibroblast. A subset of the tumor-associated fibroblasts (TAF) was found to express B7H1 (PD-L1) and B7DC (PD-L2) constitutively, and this expression was up-regulated by IFN-gamma. Production of cytokines and chemokines, including IFN-gamma, monokine induced by IFN-gamma, IFN-gamma-inducible protein-10, RANTES, and TGF-beta1 was also demonstrated in these cells. Together, these characteristics provide multiple opportunities for the TAF to influence cellular interactions within the tumor microenvironment. To evaluate the ability of TAF to modulate tumor-associated T cell (TAT) activation, we conducted coculture experiments between autologous TAF and TAT. In five of eight tumors, TAF elicited a contact-dependent enhancement of TAT activation, even in the presence of a TGF-beta1-mediated suppressive effect. In the three other tumors, TAF had a net suppressive effect upon TAT activation, and, in one of these cases, blockade of B7H1 or B7DC was able to completely abrogate the TAF-mediated suppression. We conclude that TAF in human NSCLC are functionally and phenotypically heterogeneous and provide multiple complex regulatory signals that have the potential to enhance or suppress TAT function in the tumor microenvironment.

Expression of transforming growth factor-beta isoforms and their receptors in utero-vaginal junction of hen oviduct in presence or absence of resident sperm with reference to sperm storage

Our goal was to determine whether transforming growth factor beta (TGFbeta) isoforms were involved in the process of sperm survivability in the sperm-storage tubules (SST) in the utero-vaginal junction (UVJ) of hen oviduct. The birds were artificially inseminated. The mRNA expressions of three types of TGFbeta isoforms (TGFbeta2, TGFbeta3, and TGFbeta4) and three types of receptors (TbetaR1, TbetaR2, and TbetaR3) were examined in the presence or in the absence of resident sperm in SST by semi-quantitative reverse transcriptase-PCR. The mRNA expression of TGFbetas and TbetaRs in sperm was also examined. Immunocytochemistry and western blot were performed for TbetaR2 to confirm its localization in UVJ. The sperm were observed at least 10 days after insemination by histology. The mRNA expressions of TGFbetas and TbetaRs were significantly increased in UVJ in the presence of resident sperm in SST. The mRNA expressions of TGFbetas and TbetaRs were also observed in sperm. Immunohistochemistry revealed that TbetaR2 were located in lymphocytes in UVJ and SST cells. The presence of TbetaR2 in UVJ was also confirmed by western blot. These results suggest that enhanced expressions of TGFbetas and TbetaRs in UVJ may protect sperm in SST, probably by suppressing anti-sperm immunoreactions.

Transforming Growth Factor β Is a Critical Regulator of Adult Human Islet Plasticity

Tissue plasticity is well documented in the context of pancreatic regeneration and carcinogenesis, with recent reports implicating dedifferentiated islet cells both as endocrine progenitors and as the cell(s) of origin in pancreatic adenocarcinoma. Accordingly, it is noteworthy that accumulating evidence suggests that TGFβ signaling is essential to pancreatic endocrine development and maintenance, whereas its loss is associated with the progression to pancreatic adenocarcinoma. The aim of this study was to examine the role of TGFβ in an in vitro model of islet morphogenetic plasticity. Human islets were embedded in a collagen gel and cultured under conditions that induced transformation into duct-like epithelial structures (DLS). Addition of TGFβ caused a dose-dependent decrease in DLS formation. Although it was demonstrated that collagen-embedded islets secrete low levels of TGFβ, antibody-mediated neutralization of this endogenously released TGFβ improved DLS formation rates, suggesting local TGFβ concentrations may in fact be higher. Time course studies indicated that TGFβ signaling was associated with an increase in ERK and p38 MAPK phosphorylation, although inhibitor-based studies were consistent with an islet endocrine-stabilizing effect mediated by p38 alone. Localization of TGFβ signaling molecules suggested that the action of TGFβ is directly on the β-cell to inhibit apoptosis and thus stabilize endocrine phenotype.

Effect of chronic CB1 cannabinoid receptor antagonism on livers of rats with biliary cirrhosis

Recent studies have shown that the activated endocannabinoid system participates in the increase in IHR (intrahepatic resistance) in cirrhosis. The increased hepatic production of vasoconstrictive eicosanoids is involved in the effect of endocannabinoids on the hepatic microcirculation in cirrhosis; however, the mechanisms of these effects are still unknown. The aim of the present study was to investigate the effects of chronic CB(1) (cannabinoid 1) receptor blockade in the hepatic microcirculation of CBL (common bile-duct-ligated) cirrhotic rats. After 1 week of treatment with AM251, a specific CB(1) receptor antagonist, IHR, SMA (superior mesenteric artery) blood flow and hepatic production of eicosanoids [TXB(2) (thromboxane B(2)), 6-keto PGF(1alpha) (prostaglandin F(1alpha)) and Cys-LTs (cysteinyl leukotrienes)] were measured. Additionally, the protein levels of hepatic COX (cyclo-oxygenase) isoforms, 5-LOX (5-lipoxygenase), CB(1) receptor, TGF-beta(1) (transforming growth factor beta(1)), cPLA(2) [cytosolic PLA(2) (phospholipase A(2))], sPLA(2) (secreted PLA(2)) and collagen deposition were also measured. In AM251-treated cirrhotic rats, a decrease in portal venous pressure was associated with the decrease in IHR and SMA blood flow. Additionally, the protein levels of hepatic CB(1) receptor, TGF-beta(1), cPLA(2) and hepatic collagen deposition, and the hepatic levels of 5-LOX and COX-2 and the corresponding production of TXB(2) and Cys-LTs in perfusates, were significantly decreased after 1 week of AM251 treatment in cirrhotic rats. Furthermore, acute infusion of AM251 resulted in a decrease in SMA blood flow and an increase in SMA resistance in CBL rats. In conclusion, the chronic effects of AM251 treatment on the intrahepatic microcirculation were, at least partly, mediated by the inhibition of hepatic TGF-beta(1) activity, which was associated with decreased hepatic collagen deposition and the activated PLA(2)/eicosanoid cascade in cirrhotic livers.

The type and frequency of immunoregulatory CD4+ T-cells govern the efficacy of antigen-specific immunotherapy in nonobese diabetic mice

Antigen-specific immunotherapy, an approach to selectively block autoimmune diabetes, generally declines in nonobese diabetic (NOD) mice as disease progresses. To define the parameters influencing the efficacy of antigen-specific immunotherapy once diabetes is established, plasmid DNA (pDNA) vaccination was used to suppress autoimmune-mediated destruction of syngeneic islet grafts in diabetic NOD recipients. pDNAs encoding a glutamic acid decarboxylase 65 (GAD65)-Ig molecule (pGAD65), interleukin (IL)-4 (pIL4), and IL-10 (pIL10) significantly delayed the onset of recurrent diabetes compared with pGAD65+pIL10-vaccinated recipients. Despite differences in efficacy, a similar frequency of GAD65-specific CD4(+) T-cells secreting IL-4, IL-10, or interferon-gamma were detected in mice treated with pGAD65+pIL4+pIL10 and pGAD65+pIL10. However, the frequency of FoxP3-expressing CD4(+)CD25(+)CD62L(hi) T-cells was increased in the renal and pancreatic lymph nodes of diabetic recipients vaccinated with pGAD65+pIL4+pIL10. These immunoregulatory CD4(+)CD25(+) T-cells (CD4(+)CD25(+) Treg) exhibited enhanced in vivo and in vitro suppressor activity that partially was transforming growth factor-beta dependent. Furthermore, duration of islet graft protection in pGAD65+pIL4+pIL10-vaccinated diabetic recipients correlated with the persistence of CD4(+)CD25(+) Treg. These data demonstrate that the frequency and maintenance of FoxP3-expressing CD4(+)CD25(+) Treg influence antigen-induced suppression of ongoing beta-cell autoimmunity in diabetic recipients.

Bone morphogenetic protein-2 acts upstream of myocyte-specific enhancer factor 2a to control embryonic cardiac contractility☆

OBJECTIVE

Cardiac contractility is regulated tightly as an extrinsic and intrinsic homeostatic mechanism to the heart. The molecular basis of the intrinsic system is largely unknown. Here, we test the hypothesis that bone morphogenetic protein-2 (BMP-2) mediates embryonic cardiac contractility upstream of myocyte-specific enhancer factor 2A (MEF2A).

METHODS

The BMP-2 and MEF2A expression pattern was analyzed by RT-PCR, Western blotting, whole-mount in situ hybridization, and an in vivo transgenic approach. The cardiac phenotype of BMP-2 and MEF2A knock-down zebrafish embryos was analysed. Cardiac contractions were recorded with a video camera. Myofibrillar organization was observed with transmission electron microscopy. Gene expression profiles were performed by quantitative real-time PCR analysis.

RESULTS

We demonstrate that BMP-2 and MEF2A are co-expressed in embryonic and neonatal cardiac myocytes. Furthermore, we provide evidence that BMP-2 is required for cardiac contractility in vitro and in vivo and that MEF2A expression can be activated by BMP-2 signaling in neonatal cardiomyocytes. BMP-2 is involved in the assembly of the cardiac contractile apparatus. Finally, we find that exogenous MEF2A is sufficient to rescue ventricular contractility defects in the absence of BMP-2 function.

CONCLUSIONS

In all, these observations indicate that BMP-2 and MEF2A are key components of a pathway that controls the cardiac ventricular contractility and suggest that the BMP2-MEF2A pathway can offer new opportunities for the treatment of heart failure.

Leishmania major induces distinct neutrophil phenotypes in mice that are resistant or susceptible to infection

Polymorphonuclear neutrophils (PMN) are key components of the inflammatory response contributing to the development of pathogen-specific immune responses. Following infection with Leishmania major, neutrophils are recruited within hours to the site of parasite inoculation. C57BL/6 mice are resistant to infection, and BALB/c mice are susceptible to infection, developing unhealing, inflammatory lesions. In this report, we investigated the expression of cell surface integrins, TLRs, and the secretion of immunomodulatory cytokines by PMN of both strains of mice, in response to infection with L. major. The parasite was shown to induce CD49d expression in BALB/c-inflammatory PMN, and expression of CD49d remained at basal levels in C57BL/6 PMN. Equally high levels of CD11b were expressed on PMN from both strains. In response to L. major infection, the levels of TLR2, TLR7, and TLR9 mRNA were significantly higher in C57BL/6 than in BALB/c PMN. C57BL/6 PMN secreted biologically active IL-12p70 and IL-10. In contrast, L. major-infected BALB/c PMN transcribed and secreted high levels of IL-12p40 but did not secrete biologically active IL-12p70. Furthermore, IL-12p40 was shown not to associate with IL-23 p19 but formed IL-12p40 homodimers with inhibitory activity. No IL-10 was secreted by BALB/c PMN. Thus, following infection with L. major, in C57BL/6 mice, PMN could constitute one of the earliest sources of IL-12, and in BALB/c mice, secretion of IL-12p40 could contribute to impaired, early IL-12 signaling. These distinct PMN phenotypes may thus influence the development of L. major-specific immune response.

Cross-tolerance of recipient-derived transforming growth factor-beta dendritic cells

Administration of donor-derived immature dendritic cells (DC) treated with transforming growth factor-beta (TGF-beta) to prevent allograft rejection is not applicable for clinical use. We therefore attempted to explore the use of recipient-derived DC pulsed with donor antigens via the indirect pathway (cross-priming). DC were propagated from C3H (H2(k)) bone marrow (BM) using granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). TGF-beta (0.2 ng/mL) was added at the initiation of culture. The resultant TGF-beta DC were pulsed with B10 (H2(b)) splenocyte lysate. Expression of major histocompatibility complex (MHC) class I and II was not affected, while CD40, CD80, and CD86 costimulatory molecules on DC were significantly inhibited by treatment with TGF-beta. C3H DC pulsed with B10 antigens stimulated a proliferative response in C3H T cells which was inhibited when DC were treated with TGF-beta, and the cytotoxic T-lymphocyte (CTL) activity was also inhibited. This observation correlated with reduced interferon-gamma (IFN-gamma) and increased IL-10 production. A single injection of TGF-beta DC prolonged allograft survival (median survival time [MST] 18 days vs 10 days in no-DC treatment control; P < .05). These data indicated that an approach utilizing recipient DC as a "vaccine" strategy is possible.

Inflammatory markers and mediators in tracheal fluid of premature infants treated with inhaled nitric oxide

OBJECTIVE

We compared serial measurements of inflammatory mediators and markers in infants treated with inhaled nitric oxide or placebo to assess the effects of inhaled nitric oxide therapy on lung inflammation during bronchopulmonary dysplasia. We investigated relationships between respiratory severity scores and airway concentrations of inflammatory markers/mediators.

METHODS

As part of the Nitric Oxide (to Prevent) Chronic Lung Disease trial, a subset of 99 infants (52 placebo-treated infants and 47 inhaled nitric oxide-treated infants; well matched at baseline) had tracheal aspirate fluid collected at baseline, at 2 to 4 days, and then weekly while still intubated during study gas treatment (minimum of 24 days). Fluid was assessed for interleukin-1beta, interleukin-8, transforming growth factor-beta, N-acetylglucosaminidase, 8-epi-prostaglandin F2alpha, and hyaluronan. Results were normalized to total protein and secretory component of immunoglobulin A.

RESULTS

At baseline, there was substantial variability of each measured substance and no correlation between tracheal aspirate fluid levels of any substance and respiratory severity scores. Inhaled nitric oxide administration did not result in any time-matched significant change for any of the analytes, compared with the placebo-treated group. There was no correlation between any of the measured markers/mediators and respiratory severity scores throughout the 24 days of study gas administration. In the posthoc analysis of data for inhaled nitric oxide-treated infants, there was a difference at baseline in 8-epi-prostaglandin F2alpha levels for infants who did (n = 21) and did not (n = 26) develop bronchopulmonary dysplasia at postmenstrual age of 36 weeks.

CONCLUSIONS

Inhaled nitric oxide, as administered in this study, seemed to be safe. Its use was not associated with any increase in airway inflammatory substances.

Effect of Mineral Trioxide Aggregate Cements on Transforming Growth Factor β1 and Bone Morphogenetic Protein Production by Human Fibroblasts In Vitro

The aim of this study was to evaluate and compare the effects of two commercial mineral trioxide aggregate (MTA) cements (ProRoot MTA and MTA Angelus) on transforming growth factor (TGF)-beta1 and bone morphogenetic protein (BMP)-2 levels produced by cultured human gingival fibroblasts (HGFs). Human gingival tissues were obtained from individuals with healthy periodontium. HGFs were grown at 37 degrees C in humidified atmosphere of 5% CO(2) in Dulbecco's modified Eagle's medium, supplemented with 10% fetal calf serum, penicillin, and streptomycin. After 24 and 72 hours of exposure to the MTA products, HGF viability was determined by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide assay. TGF-beta1 and BMP-2 levels in cell-free culture media were determined by enzyme-linked immunosorbent assay. Cell viability of the test groups was significantly lower than that of control at 24 and 72 hours (p < 0.05) but showed an increase at 72 hours (p < 0.05). Both test groups showed increased TGF beta-1 levels at 72 hours (p < 0.05), whereas the MTA Angelus group displayed higher TGF beta-1 levels than control and ProRoot MTA groups at 24 and 72 hours (p < 0.05). At 24 hours, BMP-2 levels of the ProRoot group were significantly higher than that of MTA Angelus (p < 0.05). Both test materials increased the BMP-2 levels within time (p < 0.05) and displayed similar levels at 72 hours (p > 0.05). These results suggest that both MTA products are capable of stimulating HGF to produce BMP-2, whereas the stimulatory effect for TGF beta-1 is material dependent.

[The utility of exhaled breath condensate analysis for asthma management]

Asthma is a chronic inflammatory disorder of the airways; therefore, establishing a simple monitoring system of airway inflammation would be useful for asthma management. Exhaled breath condensate (EBC), which is formed by breathing with a cooling system, is a non-invasive biomarker for airway inflammation. We have shown that nine kinds of molecules; namely, IL-4, IL-8, IL-17, TNF-alpha, RANTES, IP-10, TGF-beta, MIP-1alpha, and MIP-1beta, are over-expressed in asthmatic airways compared with those of healthy subjects using EBC analysis. In addition, the levels of some over-expressed molecules and lung physiologic indices are correlated. RANTES expression was significantly correlated with the degree of airflow limitation. Further, both TNF-alpha and TGF-beta values were significantly correlated with the degree of airway responsiveness and variability of peak expiratory flow. Additionally, the comparison of molecular properties between EBC and saliva indicated that saliva contamination is not a dominant contributor to the assessment of inflammatory molecules in EBC. Analysis of inflammatory molecules using EBC should be useful for monitoring the asthmatic airway condition, and might be a promising approach to assess the efficacy of pharmacologic interventions and to investigate the pathophysiology of asthma.

Using Biological Markers to Predict Risk of Radiation Injury

Recent advances in our understanding of the molecular events leading to the development of normal tissue complications after radiotherapy has led to an effort to identify biological markers that could identify patients at increased or decreased risk for treatment related injury. The goal of this effort is to improve the therapeutic ratio and enable physicians to optimize therapy for individual patients. In radiotherapy of the thoracic region, the lung is one of the most critical dose-limiting organs. This review briefly introduces the mechanisms of radiation-induced lung injury and gives a summary of clinical research focused on evaluating changes in biological markers before, during, and after radiation therapy of the thorax.

The role of bone morphogenetic protein-2 in vivo in regeneration of peripheral nerves

We investigated the effects of bone morphogenetic protein-2 (BMP-2) and some other BMPs on regeneration of peripheral motor nerves in vivo. The facial nerves of 24 New Zealand rabbits were crushed to examine a series of retrograde changes in the facial nuclei and axons, in what has been called the "axon reaction". The facial nerves of the experimental group were treated with epineurial coaptation and BMP-2 after the injury. Nerves not treated with BMP-2 were regarded as controls. The expression of BMP-2 was investigated by in situ hybridisation in the neurons of facial nuclei. The electrophysiology, image analysis and transmission electron microscopy were used to evaluate the level of the recovery of facial nerves. The results showed that the axons in the experimental group were thicker and denser than those in the control group four weeks later. The expression of BMP-2 in the neurons of facial nuclei increased after injury. The electron microscopic observations showed that the axons' degeneration in the experimental group was less than that in the control group. Despite the morphological difference between the two groups, there was no apparent difference between them in nerve conduction velocity. These findings suggest that BMP-2 might be involved in the regeneration of facial nerves, and might function as a potential neurotrophic factor.

Hypoxia/reoxygenation and TGF-β increase αB-crystallin expression in human optic nerve head astrocytes

Reactive astrocytes in glaucomatous optic nerve changes are characterized by an increased expression of alphaB-crystallin and transforming growth factor-beta (TGF-beta). In the pathogenesis of glaucomatous optic nerve damage, ischemia/reperfusion injury may play an important role. The goal of the present study was to determine the influence of hypoxia/reoxygenation and TGF-beta on the expression of alphaB-crystallin in cultured human astrocytes of the optic nerve head (ONH). Cultured human astrocytes were incubated under hypoxic conditions (1% O2 for 4-12 h) with subsequent reoxygenation (12-24 h). Additionally, cells were treated with 1.0 ng/ml TGF-beta1 and TGF-beta2 for 12-48 h. Expression of alphaB-crystallin was examined by Northern- and Western-blotting. Levels of TGF-beta1 and TGF-beta2 were analyzed by RT-PCR analysis and ELISA. The effect of TGF-beta blocking on the hypoxia/reoxygenation modulated expression of alphaB-crystallin was investigated by simultaneous incubation with neutralizing antibodies against TGF-beta during the reoxygenation phase. Hypoxia/reoxygenation increased the expression of alphaB-crystallin at the mRNA (2.8- to 3.1-fold) and protein level (1.8- to 2.1-fold). Treatment with 1.0 ng/ml TGF-beta1 and TGF-beta2 for 12-48 h markedly enhanced alphaB-crystallin mRNA expression approximately three- to fourfold. Using Western blot analysis, this increase ranged from 2 to 3 times. Both cytokines showed a twofold increase after 12 and 24 h of reoxygenation at the mRNA and a two- to threefold increase at the protein level. Simultaneous treatment with neutralizing antibodies against both TGF-beta isoforms prevented the hypoxia/reoxygenation-mediated elevation of alphaB-crystallin. The process of hypoxia/reoxygenation is capable of inducing the expression of alphaB-crystallin and TGF-ss in cultured ONH astrocytes. Therefore, optimization of conditions leading to hypoxia/reoxygenation in the ONH of glaucomatous patients may help to lower the incidence of characteristic changes in the optic nerve.

Collagen loss and impaired wound healing is associated with c-Myb deficiency

Collagen type I serves as an abundant structural and signalling component of skin. It is also an established target gene of the transcription factor, c-Myb. When c-myb-/- embryos were examined it was observed that their skin was markedly thinner than normal. Importantly, immunohistochemical investigation showed complete absence of collagen type I. Although these homozygous knock-out embryos fail to develop beyond day 15, fibroblasts established from these embryos (mouse embryonic fibroblasts [MEFs]) show defective proliferative responses. Furthermore, in vitro scratch wound assays demonstrated that these c-myb-/- MEFs also exhibit slower closure than their wild-type counterparts. Embryonic lethality has meant that examination of the role of c-Myb in adult mouse skin has not been reported to date. However, in view of the abundance of collagen type I in normal skin, its role in skin integrity and the in vitro data showing proliferative and migration defects in c-myb-/- MEFs, we investigated the consequences of heterozygous c-myb loss in adult mice on the complex process of skin repair in response to injury. Our studies clearly demonstrate that heterozygous c-myb deficiency has a functional effect on wound repair, collagen type I levels and, in response to wounding, transforming growth factor-beta1 (an important collagen stimulating factor) induction expression is aberrantly high. Manipulation of c-Myb may therefore provide new therapeutic opportunities for improving wound repair while uncontrolled expression may underpin some fibrotic disorders.

Localized viral vector delivery to enhance in situ regenerative gene therapy

A lyophilization method was developed to locally release adenoviral vectors directly from biomaterials for in situ regenerative gene therapy. Adenovirus expressing a beta-galactosidase reporter gene (AdLacZ) was mixed with different excipient formulations and lyophilized on hydroxyapatite (HA) disks followed by fibroblasts culturing and 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-gal) staining, suggesting 1 M sucrose in phosphate-buffered saline had best viability. Adenovirus release studies showed that greater than 30% virus remained on the material surface up to 16 h. Lyophilized adenovirus could be precisely localized in defined patterns and the transduction efficiency was also improved. To determine if the lyophilization formulations could preserve viral bioactivity, the lyophilized AdLacZ was tested after being stored at varying temperatures. Bioactivity of adenovirus lyophilized on HA was maintained for greater than 6 months when stored at -80 degrees C. In vivo studies were performed using an adenovirus encoding BMP-2 (AdBMP-2). AdBMP-2 was lyophilized in gelatin sponges and placed into rat critical-size calvarial defects for 5 weeks. Micro-computed tomography (micro-CT) analysis demonstrated that free-form delivery of AdBMP-2 had only modest effects on bone formation. In contrast, AdBMP-2 lyophilized in gelatin sponges led to more than 80% regeneration of critical-size calvarial defects.

Stem cell-related cardiac gene expression early after murine myocardial infarction

OBJECTIVE

Clinical experimental stem cell therapy after myocardial infarction appears feasible, but its use has preceded the understanding of the working mechanism. The ischemic recipient cardiac environment is determinative for the attraction and subsequent fate of stem cells. Here, we studied expression levels of genes that are anticipated to be essential for adequate stem cell-based cardiac repair at various time-points during the 1 month period following myocardial infarction (MI).

METHODS

Gene expression in the hearts of mice that underwent MI by permanent or transient (30 min) ligation of the coronary artery was monitored using quantitative RT-PCR analysis of mRNA isolated from whole heart sections as well as from specific, laser micro-dissected, regions of sections. Protein expression was performed by immunohistochemical stainings and Western blot analysis.

RESULTS

Many inflammatory genes were highly expressed for at least 1 week after MI. The expression of pro-angiogenic genes such as bFGF, VEGF-A and VEGF-R2 changed only marginally post-MI. Markers used to test stem cell gene expression remained unchanged post-MI with the exception of G-CSF and GM-CSF, which are genes that are also known to enhance the inflammatory response. Analysis of micro-dissected regions revealed that SDF-1, SCF (both stem cell attractants) and VEGF-R2 (involved in angiogenesis) gene expression was slightly decreased especially in the infarcted region.

CONCLUSION

Genes that are generally considered to participate in stem cell-related processes and angiogenesis were not upregulated after MI, whereas the inflammatory gene expression dominated. Modulation of this imbalance might be of value for stem cell-mediated therapy.