The Structural Basis of Functional Improvement in Response to Human Umbilical Cord Blood Stem Cell Transplantation in Hearts With Postinfarct LV Remodeling.

Cellular therapy for myocardial repair has been one of the most intensely investigated interventional strategies for acute myocardial infarction. Although the therapeutic potential of stem cells has been demonstrated in various studies, the underlying mechanisms for such improvements are poorly understood. In the present study, we investigated the long-term effects of stem cell therapy on both myocardial fiber organization and regional contractile function using a rat model of postinfarct remodeling. Human nonhematopoietic umbilical cord blood stem cells (nh-UCBSCs) were administered via tail vein to rats 2 days after infarct surgery. Animals were maintained without immunosuppressive therapy. In vivo and ex vivo MR imaging was performed on infarct hearts 10 months after cell transplantation. Compared to the age-matched rats exposed to the identical surgery, both global and regional cardiac functions of the nh-UCBSC-treated hearts, such as ejection fraction, ventricular strain, and torsion, were significantly improved. More importantly, the treated hearts exhibited preserved fiber orientation and water diffusivities that were similar to those in sham-operated control hearts. These data provide the first evidence that nh-UCBSC treatment may prevent/delay untoward structural remodeling in postinfarct hearts, which supports the improved LV function observed in vivo in the absence of immunosuppression, suggesting a beneficial paracrine effect occurred with the cellular therapy.

Chemopreventive agents modulate the protein expression profile of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone plus benzo[a]pyrene-induced lung tumors in A/J mice.

We used isobaric tag labeling coupled with mass spectrometry to compare the relative abundance of proteins in lung tumors from A/J mice treated with a mixture of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and benzo[a]pyrene versus normal mouse lung tissues. Levels of 59 proteins changed-30 increased and 29 decreased-in tumor tissues versus normal tissues. Among proteins that showed increased levels in tumor tissues versus normal tissues were glycolytic enzymes, ribosomal proteins, fatty acid synthase, cathepsins D and H and carbonic anhydrase 2. On the other hand, the levels of cytochrome P450 enzymes 2B10 and 2F2, glutathione S-transferases mu-1, procollagen VI, Clara cell 10 kDA (CC10) protein, histones, receptor advanced glycation end product, and lung carbonyl reductase were lower in tumor tissues versus normal lung tissues. Upon dietary administration of a combination of N-acetyl-S-(N-2-phenethylthiocarbamoyl)-L-cysteine plus myo-inositol or indole-3-carbinol to carcinogen-treated mice, the relative abundance of 60S ribosomal protein L4 and carbonic anhydrase in tumor tissues decreased whereas that of histones, glutathione S-transferases mu, receptor advanced glycation end product, transglutaminase, and procollagen VI increased. Western assays with lung tissue homogenates not only verified the proteomics results for selected proteins but also showed differential expression of hypoxia inducible factor-1alpha, a transcription factor for most of the proteins that showed changes in relative abundance. This is the first report on the application of quantitative proteomics to study the relative abundance of proteins in a mouse model of lung carcinogenesis. These proteins may have utility for development of candidate lung cancer biomarkers and as targets of chemopreventive/chemotherapeutic agents.

Combinations of N-Acetyl-S-(N-2-Phenethylthiocarbamoyl)-L-Cysteine and myo-inositol inhibit tobacco carcinogen-induced lung adenocarcinoma in mice.

We have previously generated convincing evidence that combinations of N-acetyl-S-(N-2-phenethylthiocarbamoyl)-L-cysteine (PEITC-NAC; 3 micromol/g diet) and myo-inositol (MI; 56 micromol/g diet) were significantly more effective than the individual compounds as inhibitors of tobacco smoke carcinogen-induced lung tumorigenesis in A/J mice. In this study, we further investigated the efficacy of combinations of PEITC-NAC (9 or 15 micromol/g diet) and MI (56 micromol/g diet). Female A/J mice were treated with a mixture of the tobacco smoke carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and benzo[a]pyrene by gavage once weekly for 8 weeks. PEITC-NAC plus MI was given in the diet beginning at 1 day after the 4th of eight carcinogen treatments (temporal sequence A) or 1 week after the last carcinogen treatment (temporal sequence B). Regardless of the dose of carcinogen or PEITC-NAC plus MI, or temporal sequence, administration of PEITC-NAC plus MI significantly reduced the multiplicity of gross tumors and, in most instances, adenocarcinoma. PEITC-NAC plus MI was particularly effective against bigger tumors. The observed inhibition of lung tumorigenesis by PEITC-NAC plus MI was attributed, at least partly, to inhibition of cell proliferation and induction of apoptosis. These results clearly show the efficacy of PEITC-NAC plus MI in the prevention of tobacco carcinogen-induced lung adenocarcinoma in A/J mice and provide a basis for future evaluation of PEITC-NAC plus MI in clinical trials as a chemopreventive agent for current and former smokers.

Chemopreventive effect of kava on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone plus benzo[a]pyrene-induced lung tumorigenesis in A/J mice.

Lung cancer is the leading cause of cancer death, and chemoprevention is a potential strategy to help control this disease. Epidemiologic survey indicates that kava may be chemopreventive for lung cancer, but there is a concern about its potential hepatotoxicity. In this study, we evaluated whether oral kava could prevent 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) plus benzo[a]pyrene (B[a]P)-induced lung tumorigenesis in A/J mice. We also studied the effect of kava to liver. At a dose of 10 mg/g diet, 30-week kava treatment (8 weeks concurrent with NNK and B[a]P treatment followed by 22 weeks post-carcinogen treatment) effectively reduced lung tumor multiplicity by 56%. Kava also reduced lung tumor multiplicity by 47% when administered concurrently with NNK and B[a]P for 8 weeks. Perhaps most importantly, kava reduced lung tumor multiplicity by 49% when administered after the final NNK and B[a]P treatment. These results show for the first time the chemopreventive potential of kava against lung tumorigenesis. Mechanistically, kava inhibited proliferation and enhanced apoptosis in lung tumors, as shown by a reduction in proliferating cell nuclear antigen (PCNA), an increase in caspase-3, and cleavage of poly(ADP-ribose) polymerase (PARP). Kava treatment also inhibited the activation of nuclear factor kappaBNF-kappaB, a potential upstream mechanism of kava chemoprevention. Although not rigorously evaluated in this study, our preliminary data were not suggestive of hepatotoxicity. Based on these results, further studies are warranted to explore the chemopreventive potential and safety of kava.

Dose-dependent inhibition of tobacco smoke carcinogen-induced lung tumorigenesis in A/J mice by indole-3-carbinol.

Recently, we reported inhibition of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) plus benzo(a)pyrene (BaP)-induced lung tumorigenesis in A/J mice by indole-3-carbinol (I3C; 112 micromol/g diet) administered beginning at 50% in the carcinogen treatment phase. In this study, we examined the dose-dependent and postcarcinogen tumor-inhibitory activities of I3C. A mixture of NNK plus BaP (2 micromol each) administered by gavage as eight biweekly doses caused 21.1 +/- 5.2 lung tumors per mouse. Carcinogen-treated mice given diets containing I3C at 1, 10, 30, 71, and 112 micromol/g, beginning at 50% in the carcinogen treatment phase, had 17.9 +/- 6.1, 10.4 +/- 3.7, 9.8 +/- 5.1, 5.2 +/- 4.0, and 2.5 +/- 2.4 lung tumors per mouse, corresponding to reductions by 15%, 51%, 53%, 75%, and 88%, respectively. All reductions, except at the lowest dose level (1 micromol I3C/g diet), were significant (P < 0.001). Similarly, administration of I3C (112 micromol/g diet) beginning 1 week after the last dose of the carcinogen significantly reduced NNK plus BaP-induced lung tumor multiplicity to 5.6 +/- 3.5, corresponding to a reduction by 74%. Analyses of cell proliferation and apoptosis markers revealed that I3C reduced the number of Ki-67-positive cells and expression of proliferating cell nuclear antigen, phospho-Akt, and phospho-BAD and increased cleavage of poly(ADP-ribose) polymerase, suggesting that the lung tumor inhibitory effects of I3C were mediated, at least partly, through inhibition of cell proliferation and induction of apoptosis. These results clearly show the efficacy of I3C in the prevention of tobacco carcinogen-induced lung tumorigenesis in A/J mice and provide a basis for future evaluation of this compound in clinical trials as a chemopreventive agent for current and former smokers.

Heparan sulfate mediates neuroprotection from degeneration in experimental glutaric aciduria.

Glutaric aciduria type 1 (GA1) is a childhood metabolic disorder associated with crises that lead to striatal necrosis. Although the disorder can be controlled with diet, there is no current treatment to ameliorate the neurodegeneration following a metabolic crisis. We hypothesized that heparan sulfate (HS) administration would stimulate neural stem cell proliferation by dimerizing with FGF-2 and binding to the FGF-2 receptor on neural stem cells, thus enhancing the number of newly generated neurons to repair damage following a metabolic crisis. In addition, FGF-2 is known to exert neuroprotective effects independent of neurogenesis, so HS may also have neuroprotective activities. To test these hypotheses, ibotenic acid was injected into the striatum of adult mice, mimicking the metabolic crisis and damage caused by glutaric aciduria. Daily doses of HS and bromodeoxyuridine (BrdU) or BrdU alone were administered starting 1 day after the ibotenic acid lesion. BrdU was used to label dividing cells. Fluorescent immunohistochemistry was used to quantify the lesion size and evaluate the phenotype of BrdU-positive cells. Intrastriatal administration of ibotenic acid resulted in a substantial striatal lesion that occupied 18.5% of the ipsilateral brain hemisphere. In contrast, animals treated with HS exhibited a lesion volume representing <1% of the ipsilateral brain hemisphere (ANOVA; p < 0.0001). Increased neurogenesis, however, was not observed in this group. These results suggest that HS administration 2 days after a "metabolic crisis" can ameliorate brain injury in an animal model of GA1. The neuroprotective mechanisms of HS, however, remain to be elucidated but may exert their actions indirectly through binding with FGF-2.