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Cancer remains a major public health concern, mainly because of the incompletely understood dynamics of molecular mechanisms for progression and resistance to treatments. The link between melanoma and thyroid cancer (TC) has been noted in numerous patients. Nucleocytoplasmic transport of oncogenes and tumor suppressor proteins is a common mechanism in melanoma and TC that promotes tumorigenesis and tumor aggressiveness. However, this mechanism remains poorly understood. Papillary TC (PTC) patients have a 1.8-fold higher risk for developing cutaneous malignant melanoma than healthy patients. Our group and others showed that patients with melanoma have a 2.15 to 2.3-fold increased risk of being diagnosed with PTC. The BRAF V600E mutation has been reported as a biological marker for aggressiveness and a potential genetic link between malignant melanoma and TC. The main mechanistic factor in the connection between these two cancer types is the alteration of the RAS-RAF-MEK-ERK signaling pathway activation and translocation. The mechanisms of nucleocytoplasmic trafficking associated with RAS, RAF, and Wnt signaling pathways in melanoma and TC are reviewed. In addition, we discuss the roles of tumor suppressor proteins such as p53, p27, forkhead O transcription factors (FOXO), and NF-KB within the nuclear and cytoplasmic cellular compartments and their association with tumor aggressiveness. A meticulous English-language literature analysis was performed using the PubMed Central database. Search parameters included articles published up to 2021 with keyword search terms melanoma and thyroid cancer, BRAF mutation, and nucleocytoplasmic transport in cancer.

To determine if the insulin-like growth factor-1 (IGF-1) pathway is involved in the improvement in erectile function recovery in rats after nerve crush injury treated with pioglitazone (Pio). Sprague-Dawley rats were divided into four groups. The first group received sham operation (n = 5). The second group underwent bilateral cavernous nerve injury (BCNI, n = 7). The third group received BCNI and Pio treatment (BCNI + Pio, n = 7), whereas the fourth group underwent BCNI with Pio treatment and IGF-1 inhibition (BCNI + Pio + JB-1, n = 7). The IGF-1 receptor (IGF-1R) was inhibited by JB-1, a small molecular antagonist of the receptor. After 14 days of treatment, erectile function was measured via intracorporal pressure normalized to mean arterial pressure (ICP/MAP) and the major pelvic ganglion and cavernous nerve harvested for western blot and immunohistochemistry (IHC) of phosphorylated-IGF-1Rβ (p-IGF-1Rβ), phosphorylated-ERK1/2 (p-ERK1/2), and neuronal NOS (nNOS). BCNI + Pio animals exhibited improvements in ICP/MAP, similar to Sham animals, and BCNI + Pio + JB-1 rats demonstrated a reduced ICP/MAP similar to BCNI-only rats at all measured voltages. Western blot results showed upregulation of p-IGF-1Rβ was observed in the BCNI + Pio group. Low levels of p-ERK1/2 were seen in the JB-1-treated animals. The immunoblot results were supported by IHC findings. Intense IHC staining of nNOS was detected in the BCNI + Pio group. The group treated with JB-1 showed minimal protein expression of p-ERK1/2, nNOS, and p-IGF-1Rβ. Pio improves erectile function in rats undergoing BCNI via an IGF-1-mediated pathway.

The current study evaluated the immunomodulatory effects of Carica papaya pulp and seeds methanol (MeOH) extracts on mice infected with Listeria monocytogenes. Gas chromatography-mass spectrometry analysis identified 10 active constituents in C. papaya seed MeOH extract and 10 compounds in C. papaya pulp MeOH extract. The experimental animals were divided into negative control (G1) group, positive control (G2) group, pulp extract treated (G3) group, and seed extract treated (G4) group. After infection of animals (G2, G3, and G4), treatments were started for 3 weeks. Estimation of the immunological parameters showed a marked decrease in IgM levels and an increase in IgG levels in the treated groups (G3 and G4) compared with those in G2. The proinflammatory cytokines (IL-10, IL-12, IL-1β, IL-6, and TGF-β1) were decreased in the treated groups (G3 and G4) compared with those in G2. Nitric oxide levels were also decreased, and the percentages of phagocytosis increased compared with those of G2. The results demonstrated the immunomodulatory and anti-inflammatory effects of C. papaya pulp and seeds MeOH extracts. PRACTICAL APPLICATIONS: Based on the antioxidant and antibacterial activities exhibited by the pulp and seed MeOH extracts investigated in this study, Carica papaya might be considered as a natural source of phytochemicals that could be utilized in novel foods and pharmaceuticals. Further investigation are needed to identify and purify compounds that might be responsible for the observed effects.

Background Previous studies have documented improvement in erectile function after bilateral cavernous nerve injury (BCNI) in rats with the use of pioglitazone. Our group determined this improvement to be mediated by the insulin-like growth factor-1 (IGF-1) pathway. Aim To eliminate the systemic effects of pioglitazone and evaluate the local delivery of IGF-1 by polymeric microspheres after BCNI in the rat. Methods Male Sprague–Dawley rats aged 10–12 weeks were assigned at random to 3 groups: sham operation with phosphate buffered saline (PBS)-loaded microspheres (sham group), crush injury with PBS-loaded microspheres (crush group), and crush injury with IGF-1–loaded microspheres (IGF-1 group). Poly(lactic-co-glycolic) acid microspheres were injected underneath the major pelvic ganglion (MPG). IGF-1 was released at approximately 30 ng/mL/day per MPG per rat. Outcomes Functional results were demonstrated by maximal intracavernosal pressure (ICP) normalized to mean arterial pressure (MAP). Protein-level analysis data of IGF-1 receptor (IGF-1R), extracellular signal–regulated kinase (ERK)-1/2, and neuronal nitric oxide synthase (nNOS) were obtained using Western blot analysis and immunohistochemistry for both the cavernosal tissue and the MPG and cavernous nerve (CN). Results At 2 weeks after nerve injury, animals treated with IGF-1 demonstrated improved erectile functional recovery (ICP/MAP) at all voltages compared with BCNI (2.5V, P = .001; 5V, P < .001; 7.5V, P < .001). Western blot results revealed that up-regulation of the IGF-1R and ERK-1/2 in both the nervous and erectile tissue was associated with improved erectile function recovery. There were no significant between-group differences in nNOS protein levels in cavernosal tissue, but there was an up-regulation of nNOS in the MPG and CN. Immunohistochemistry confirmed these trends. Clinical Translation Local up-regulation of the IGF-1R in the neurovascular bed at the time of nerve injury may help men preserve erectile function after pelvic surgery, such as radical prostatectomy, eliminating the need for systemic therapy. Strengths & Limitations This study demonstrates that local drug delivery to the MPG and CN can affect the CN tissue downstream, but did not investigate the potential effects of up-regulation of the growth factor receptors on prostate cancer tissue. Conclusion Stimulating the IGF-1R at the level of the CN has the potential to mitigate erectile dysfunction in men after radical prostatectomy, but further research is needed to evaluate the safety of this growth factor in the setting of prostate cancer.

Electronic cigarettes (e-cigarettes) are devices designed to imitate conventional cigarettes and to deliver nicotine via inhalation without the toxicants of regular tobacco. The rationale of e-cigarettes invention is to reduce the toxicity associated with conventional cigarettes. However, few toxicity studies have been performed to evaluate the chemical nature of vapor generated from e-cigarettes and its impact on human health. Since their emergence in 2004, e-cigarettes have become widely available, and their use has increased exponentially worldwide. Calls to poison control centers about e-cigarette toxicity have been attributed to e-cigarettes. In May 2016, the Food and Drug Administration approved new regulations to prohibit minors from purchasing e-cigarettes in person or online. The benefits and risks of e-cigarette use are a subject of discussion among health organizations and researchers. This chapter explores the reproductive toxicity of formaldehyde, one of the major components of the vapor of e-cigarettes.

Objective To investigate the effects of pioglitazone on pelvic ganglion neurons in a rat model of bilateral cavernosal nerve crush injury (BCNI), thereby elucidating the actions of pioglitazone in preventing post-prostatectomy neurogenic erectile dysfunction. Methods Sprague-Dawley rats aged 12 weeks were divided into four groups: (a) sham procedure, (b) BCNI, (c) BCNI + postsurgical pioglitazone, and (d) BCNI + pre and postsurgical pioglitazone (preventive therapy). Preoperative injection of Fluoro-Gold (FG) fluorescent tracer into the cavernosal tissue was performed for retrograde labeling of pelvic ganglion cells. Pelvic ganglia were resected at 2 weeks in all rats and processed for real-time polymerase chain reaction, immunohistochemistry, and Western blot to examine the expression of FG, neuronal nitric oxide synthase, β-III tubulin, neurturin, and glial cell line–derived neurotrophic factor family receptor alpha-2 (GFRα2). Results Animals treated with pre- and postsurgical pioglitazone demonstrated increased staining for FG similar to sham levels. Gene expression of neuronal nitric oxide synthase, neurturin, GFRα2, and β-III tubulin was also upregulated in the group receiving preventive therapy. Conclusion Pioglitazone provides a protective effect on pelvic ganglion neurons after BCNI.

The ability of the sulfur-containing compounds glutathione (GSH), glutathione disulphide (GSSG), S-methylglutathione (GSMe), lipoic acid (LA), and dihydrolipoic acid (DHLA) to protect against hypochlorous acid (HOCl)-mediated damage and peroxynitrite (ONOOH)-induced damage has been compared. Protective activity was assessed in competition assays by monitoring several detectors, i.e. dihydrorhodamine-123 (DHR-123) oxidation, alpha(1)-antiproteinase (alpha(1)-AP) inactivation, and glutathione S-transferase P1-1 (GST-P1-1) inactivation. In addition, nitration of tyrosine was measured to assess protection of the sulfur-containing compounds against ONOOH. For protection against HOCl, the efficacy of the antioxidant was controlled by the ratio of the reaction rates of the antioxidant and the detector molecule with the oxidant. The rank order of the activity of the antioxidants (GSH > DHLA approximately LA approximately GSMe > GSSG) appeared to be independent of the detector used. However, the rank order of the antioxidants against ONOOH-induced damage is strongly dependent on the detector. LA was 40 times less active than GSH in the inhibition of ONOOH-induced DHR-123 oxidation, whereas LA was 20 times more active than GSH in preventing the inhibition of GST-P1-1 by ONOOH. This points to different molecular mechanisms of ONOOH damage to DHR-123 compared with ONOOH damage to GST-P1-1. LA is a poor antioxidant in protecting against the form of ONOOH damage involved in DHR-123 oxidation. In the form of ONOOH toxicity involved in GST-P1-1 inhibition, LA is the most potent sulfur-containing antioxidant in our series. It is proposed that an intermediate product in which both sulfur atoms of LA have reacted is involved in the reaction of ONOOH with LA. The high potency of LA to protect GST-P1-1 against ONOOH might be of therapeutic interest.

The antioxidant activities of RRR-vitamin E (VE), all-rac-vitamin E (all-rac-VE), trolox, RRR-vitamin E acetate (VEA), all-rac-vitamin E phosphate (VEP) and RRR-vitamin E succinate (VES) were compared. In this study, the rank order in the inhibition of lipid peroxidation (LPO) of VE and its derivatives was trolox>VE approximately all-rac-VE>VEA>VES. VE and trolox inhibited LPO in non-heated and heated rat liver microsomes. It has generally been accepted that this is due to scavenging of free radicals by these antioxidants, and during this protection the antioxidants are oxidized. VEA and VES have to be converted into VE by esterases to obtain antioxidant activity against LPO. VEP, however, had a potent antioxidant effect of its own without conversion to VE. In contrast to VE, VEP is not consumed during this protection. Of the compounds tested, VEP is the most potent in induction of hemolysis of erythrocytes. EPR experiments using the spin label 16-doxylstearic acid showed that VEP reduces membrane fluidity, in contrast to VE. This indicates that VEP acts as a detergent and forms a barrier that might inhibit the transfer of radicals from one polyunsaturated fatty acid to another. This new mechanism may form the basis for a new class of antioxidants.

1Department of Natural Sciences, Southern University at New Orleans, New Orleans, LA 70126, USA 2Department of Toxicology, Maastricht University, P. O. Box 616, MD Maastricht 6200, The Netherlands *Corresponding author Bashir M. Rezk, PhD Assistant Professor of Biology Department of Natural Sciences Southern University at New Orleans 6400 Press Drive New Orleans, LA 70126, USA Tel. 504-284-5405; +1(504)957-8806 E-mail: batteia@suno.edu

Tetrahydrofolate and 5-methyltetrahydrofolate are folates with high antioxidant activity. Identification of the antioxidant pharmacophore.Rezk BM, Haenen GR, van der Vijgh WJ, Bast A.Department of Pharmacology and Toxicology, Faculty of Medicine, Universiteit Maastricht, P.O. Box 616, NL 6200 MD, Maastricht, The Netherlands.The presumed protective effect of folic acid on the pathogenesis of cardiovascular, hematological and neurological diseases and cancer has been associated with the antioxidant activity of folic acid. Peroxynitrite (PON) scavenging activity and inhibition of lipid peroxidation (LPO) of the physiological forms of folate and of structurally related compounds were tested. It was found that the fully reduced forms of folate, i.e. tetrahydrofolate (THF) and 5-methyltetrahydrofolate (5-MTHF), had the most prominent antioxidant activity. It appeared that their protection against LPO is less pronounced than their PON scavenging activity. The antioxidant activity of these forms of folic acid resides in the pterin core, the antioxidant pharmacophore is 4-hydroxy-2,5,6-triaminopyrimidine. It is suggested that an electron donating effect of the 5-amino group is of major importance for the antioxidant activity of 4-hydroxy-2,5,6-triaminopyrimidine. A similar electron donating effect is probably important for the antioxidant activity of THF and 5-MTHF.

The antioxidant activity of phloretin: the disclosure of a new antioxidant pharmacophore in flavonoids.Rezk BM, Haenen GR, van der Vijgh WJ, Bast A.Department of Pharmacology and Toxicology, Faculty of Medicine, Universiteit Maastricht P.O. Box 616, 6200 MD Maastricht, The Netherlands.Phloretin is a dihydrochalcone flavonoid that displays a potent antioxidant activity in peroxynitrite scavenging and the inhibition of lipid peroxidation. Comparison with structurally related compounds revealed that the antioxidant pharmacophore of phloretin is 2,6-dihydroxyacetophenone. The potent activity of 2,6-dihydroxyacetophenone is due to stabilisation of its radical via tautomerisation. The antioxidant pharmacophore in the dihydrochalcone phloretin, i.e., the 2,6-dihydroxyacetophenone group, is different from the antioxidant pharmacophores previously reported in flavonoids. (c) 2002 Elsevier Science (USA).

the peroxisome proliferator-activated receptor-γ (PPAR-γ) family of nuclear hormone receptors has been extensively studied due to its antidiabetic, anti-inflammatory, and antiatherosclerotic actions. PPAR-γ heterodimerizes with the retinoid X receptor to regulate transcription of target genes by

Cachexia is a serious complication of many chronic diseases, such as congestive heart failure (CHF) and chronic kidney disease (CKD). Although patients with advanced CHF or CKD often have increased angiotensin II (Ang II) levels and cachexia and Ang II causes skeletal muscle wasting in rodents, the potential effects of Ang II on muscle regeneration are unknown. Muscle regeneration is highly dependent on the ability of a pool of muscle stem cells (satellite cells) to proliferate and to repair damaged myofibers or form new myofibers. Here we show that Ang II reduced skeletal muscle regeneration via inhibition of satellite cell (SC) proliferation. Ang II reduced the number of regenerating myofibers and decreased expression of SC proliferation/differentiation markers (MyoD, myogenin, and active-Notch) after cardiotoxin-induced muscle injury in vivo and in SCs cultured in vitro. Ang II depleted the basal pool of SCs, as detected in Myf5(nLacZ/+) mice and by FACS sorting, and this effect was inhibited by Ang II AT1 receptor (AT1R) blockade and in AT1aR-null mice. AT1R was highly expressed in SCs, and Notch activation abrogated the AT1R-mediated antiproliferative effect of Ang II in cultured SCs. In mice that developed CHF postmyocardial infarction, there was skeletal muscle wasting and reduced SC numbers that were inhibited by AT1R blockade. Ang II inhibition of skeletal muscle regeneration via AT1 receptor-dependent suppression of SC Notch and MyoD signaling and proliferation is likely to play an important role in mechanisms leading to cachexia in chronic disease states such as CHF and CKD.

Emerging evidence suggests that mesenchymal stem cells (MSCs) are often recruited to tumor sites but their functional significance in tumor growth and disease progression remains elusive. Herein we report that prostate cancer (PC) cell microenvironment subverts PC patient adipose-derived stem cells (pASCs) to undergo neoplastic transformation. Unlike normal ASCs, the pASCs primed with PC cell conditioned media (CM) formed prostate-like neoplastic lesions in vivo and reproduced aggressive tumors in secondary recipients. The pASC tumors acquired cytogenetic aberrations and mesenchymal-to-epithelial transition and expressed epithelial, neoplastic, and vasculogenic markers reminiscent of molecular features of PC tumor xenografts. Our mechanistic studies revealed that PC cell-derived exosomes are sufficient to recapitulate formation of prostate tumorigenic mimicry generated by CM-primed pASCs in vivo. In addition to downregulation of the large tumor suppressor homolog2 and the programmed cell death protein 4, a neoplastic transformation inhibitor, the tumorigenic reprogramming of pASCs was associated with trafficking by PC cell-derived exosomes of oncogenic factors, including H-ras and K-ras transcripts, oncomiRNAs miR-125b, miR-130b, and miR-155 as well as the Ras superfamily of GTPases Rab1a, Rab1b, and Rab11a. Our findings implicate a new role for PC cell-derived exosomes in clonal expansion of tumors through neoplastic reprogramming of tumor tropic ASCs in cancer patients. Stem Cells 2014;32:983–997

Objective To evaluate the effect of the tyrosine kinase inhibitor imatinib mesylate (Gleevec) on human corpus cavernosum (HCC) smooth muscle tone. Methods HCC were obtained from 18 erectile dysfunction (ED) patients undergoing penile prosthesis surgery. The effects of imatinib in HCC strips were investigated in the presence of various inhibitors. The human phosphoreceptor protein tyrosine kinase (PTK) array (Proteome Profiler Array) detected changes in receptor phosphorylation before and after imatinib. Immunohistochemistry was used to localize phosphorylated c-kit (CD117/stem cell factor) in HCC smooth muscle cells. Results Phenylephrine-induced contraction in HCC was significantly inhibited by imatinib (97.7% ± 2.3%). l -nitro-arginine methyl ester ( l -NAME) or guanylyl cyclase inhibitor [1H-1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (ODQ) alone did not reverse the effect of imatinib, but suppressed this response in combination (18.0% ± 0.6%). The K + channel blockers (apamin and tetraethyl ammonium) decreased the imatinib-induced relaxation by 64% and 51%, respectively. PTK microarray analysis of 42 different phospho-receptor tyrosine kinases showed 14 were clearly activated in HCC. Imatinib treatment significantly inhibited phosphorylation of PTKs. A high level of CD117/c-kit–positive immunostaining was detected in untreated HCC smooth muscle, but not in treated HCC. Conclusion Imatinib caused HCC smooth muscle relaxation in vitro mediated by nitric oxide/guanosine monophosphate signaling, involving the large-conductance Ca(2+)-activated K(+)-channels (BK(Ca)) or by inhibiting the upregulated PTK pathway. These results suggest that imatinib may also benefit erectile dysfunction patients who are not responsive to phosphodiesterase-5 inhibitors.

Summary Pomegranate (POM) juice may benefit the erectile process, but the scientific evidence is lacking. This study evaluates the molecular characterisation and confirmation of POM's action on human corpus cavernosum (HCC) obtained from patients (n = 16) undergoing penile prosthesis implantation. After phenylephrine contraction, the relaxant effects of POM with various inhibitors in the presence and absence of palmitic acid (PA)-induced acute oxidative stress were investigated. Electrical field stimulation (EFS)- and acetylcholine (ACh)-induced relaxation were performed using organ bath preparation. Expression of neuronal nitric oxide synthase (nNOS), endothelial (eNOS), phosphodiesterase (PDE)-5A and cGMP levels were assessed in cells from ex vivo organ cultures of HCC, using RT-PCR, ELISA and immunohistochemistry techniques. POM induced marked relaxation of HCC (maximum response: 97.0 ± 3.1%) and reversed the PA-induced decrease of EFS (20 Hz). nNOS transcription was increased by 7-fold in POM-treated cells without influencing eNOS and PDE5A expressions. We conclude that POM induced marked relaxation of HCC via: (i) nNOS stimulation, and (ii) downstream relaxation stimulated by nNOS and cGMP and bypassing the NO and PDE5. This action provides a rationale for the therapeutic or preventative use of POM in men with erectile dysfunction who do not respond well to PDE5 inhibitors.

Minocycline protects against asthma independently of its antibiotic function and was recently reported as a potent poly(ADP-ribose) polymerase (PARP) inhibitor. In an animal model of asthma, a single administration of minocycline conferred excellent protection against ovalbumin-induced airway eosinophilia, mucus hypersecretion, and Th2 cytokine production (IL-4/IL-5/IL-12(p70)/IL-13/GM-CSF) and a partial protection against airway hyperresponsiveness. These effects correlated with pronounced reduction in lung and sera allergen-specific IgE. A reduction in poly(ADP-ribose) immunoreactivity in the lungs of minocycline-treated/ovalbumin-challenged mice correlated with decreased oxidative DNA damage. The effect of minocycline on PARP may be indirect, as the drug failed to efficiently block direct PARP activation in lungs of N-methyl-N'-nitro-N-nitroso-guanidine-treated mice or H(2)O(2)-treated cells. Minocycline blocked allergen-specific IgE production in B cells potentially by modulating T cell receptor (TCR)-linked IL-4 production at the mRNA level but not through a modulation of the IL-4-JAK-STAT-6 axis, IL-2 production, or NFAT1 activation. Restoration of IL-4, ex vivo, rescued IgE production by minocycline-treated/ovalbumin-stimulated B cells. IL-4 blockade correlated with a preferential inhibition of the NF-κB activation arm of TCR but not GSK3, Src, p38 MAPK, or ERK1/2. Interestingly, the drug promoted a slightly higher Src and ERK1/2 phosphorylation. Inhibition of NF-κB was linked to a complete blockade of TCR-stimulated GATA-3 expression, a pivotal transcription factor for IL-4 expression. Minocycline also reduced TNF-α-mediated NF-κB activation and expression of dependent genes. These results show a potentially broad effect of minocycline but that it may block IgE production in part by modulating TCR function, particularly by inhibiting the signaling pathway, leading to NF-κB activation, GATA-3 expression, and subsequent IL-4 production.

Angiotensin II (Ang II) causes skeletal muscle wasting via an increase in muscle catabolism. To determine whether the wasting effects of Ang II were related to its ability to increase NADPH oxidase-derived reactive oxygen species (ROS) we infused wild-type C57BL/6J or p47 phox −/− mice with vehicle or Ang II for 7 days. Superoxide production was increased 2.4-fold in the skeletal muscle of Ang II infused mice, and this increase was prevented in p47 phox −/− mice. Apocynin treatment prevented Ang II-induced superoxide production in skeletal muscle, consistent with Ang II increasing NADPH oxidase derived ROS. Ang II induced loss of body and skeletal muscle weight in C57BL/6J mice, whereas the reduction was significantly attenuated in p47 phox −/− animals. The reduction of skeletal muscle weight caused by Ang II was associated with an increase of proteasome activity, and this increase was completely prevented in the skeletal muscle of p47 phox −/− mice. In conclusion, Ang II-induced skeletal muscle wasting is in part dependent on NADPH oxidase derived ROS.

Publisher Summary This chapter describes how a variety of extraneous and internal factors can induce developmental and testicular toxicity leading to teratogenesis, poor sperm quality and male factor infertility. Developmental and reproductive toxicologists and epidemiologists have identified and classified several environmental chemicals and pharmaceutical products including teratogens and endocrine disruptors that lead to developmental and reproductive disorders. Hence, it is extremely important to understand the role of such toxicants and environmental endocrine disruptors. Convincing evidence exists that chemical exposures may lead to increased estrogenic activity, reduced androgen levels, or otherwise interfere with the action of androgen during development, thus causing male reproductive system abnormalities. The severity of testicular damage is related to the category of chemotherapeutic agent used, the dose and duration of therapy, and the developmental stage of the testis. The recovery of spermatogenesis is variable and depends upon the total therapeutic dose and duration of treatment. In addition to endocrine-disruptor mechanisms, endocrine disruptors including pesticides, xenobiotics, heavy metals, radiations, smoking and alcohol generate free radicals that can induce developmental and reproductive abnormalities. Reactive oxygen species (ROS) can also induce oxidation of critical-SH groups in proteins and DNA, which will alter cellular integrity and function with an increased susceptibility to attack by toxicants. The hazard identification and dose–response data are developed from experimental animal studies that may be supplemented with data from in vitro studies. This information is then extrapolated and integrated to characterize and assess the risk to the human population.

Differential influences mediated by PARP-1 on the balance of pro-neutrophilic or pro-macrophagic stimulatory factors may govern the nature of airway inflammation in response to different stimuli. We reported that PARP-1 exhibits differential roles in expression of inflammatory factors. Here, we show that PARP-1 deletion was associated with a significant reduction in inflammatory cell recruitment to mouse airways upon intratracheal administration of LPS. However, PARP-1 deletion exerted little effect in response to TNF exposure. LPS induced massive neutrophilia and moderate recruitment of macrophages, and TNF induced recruitment of primarily macrophages with smaller numbers of neutrophils in the lungs. Following either exposure, macrophage recruitment was blocked severely in PARP-1−/− mice, and this was associated with a marked reduction in MCP-1 and MIP-1α. This association was corroborated partly by macrophage recruitment in response to intratracheal administration of MCP-1 in PARP-1−/− mice. Surprisingly, although neutrophil recruitment was reduced significantly in LPS-treated PARP-1−/− mice, neutrophil numbers increased in TNF-treated mice, suggesting that PARP-1 deletion may promote a macrophagic-to-neutrophilic shift in the inflammatory response upon TNF exposure. Neutrophil-specific chemokines mKC and MIP-2 were reduced significantly in lungs of LPS-treated but only partially reduced in TNF-treated PARP-1−/− mice. Furthermore, the MIP-2 antagonist abrogated the shift to a neutrophilic response in TNF-exposed PARP-1−/− mice. Although CXCR2 expression increased in response to either stimulus in PARP-1+/+ mice, the DARC increased only in lungs of TNF-treated PARP-1+/+ mice; both receptors were reduced to basal levels in treated PARP-1−/− mice. Our results show that the balance of pro-neutrophilic or pro-macrophagic stimulatory factors and the differential influence of PARP-1 on these factors are critical determinants for the nature of the airway inflammatory response.

The aims of this study were to investigate the role of poly(ADP-ribose) polymerase (PARP)-1 in dyslipidemia-associated vascular dysfunction as well as autonomic nervous system dysregulation. Apolipoprotein (ApoE)(-/-) mice fed a high-fat diet were used as a model of atherosclerosis. Vascular and autonomic functions were measured in conscious mice using telemetry. The study revealed that PARP-1 plays an important role in dyslipidemia-associated vascular and autonomic dysfunction. Inhibition of this enzyme by gene knockout partially restored baroreflex sensitivity in ApoE(-/-) mice without affecting baseline heart-rate and arterial pressure, and also improved heart-rate responses following selective blockade of the autonomic nervous system. The protective effect of PARP-1 gene deletion against dyslipidemia-induced endothelial dysfunction was associated with preservation of eNOS activity. Dyslipidemia induced PARP-1 activation was accompanied by oxidative tissue damage, as evidenced by increased expression of iNOS and subsequent protein nitration. PARP-1 gene deletion reversed these effects, suggesting that PARP-1 may contribute to vascular and autonomic pathologies by promoting oxidative tissue injury. Further, inhibition of this oxidative damage may account for protective effects of PARP-1 gene deletion on vascular and autonomic functions. This study demonstrates that PARP-1 participates in dyslipidemia-mediated dysregulation of the autonomic nervous system and that PARP-1 gene deletion normalizes autonomic and vascular dysfunctions. Maintenance of eNOS activity may be associated with the protective effect of PARP-1 gene deletion against dyslipidemia-induced endothelial dysfunction.

Inducible nitric oxide synthase (iNOS) inhibition was recently shown to exert no effect on allergen challenge in human asthma, raising serious concerns about the role of the protein in the disease. The present study investigated the role of iNOS in ovalbumin-induced eosinophilia from the perspective of its relationship with poly(ADP-ribose) polymerase-1 (PARP-1) and oxidative DNA damage. A mouse model of ovalbumin-induced eosinophilia was used to conduct the studies. iNOS-associated protein nitration and tissue damage were partially responsible for allergen-induced eosinophilia. iNOS expression was required for oxidative DNA damage and PARP-1 activation upon allergen challenge. PARP-1 was required for iNOS expression and protein nitration, and this requirement was connected to nuclear factor-kappaB. PARP-1 was an important substrate for iNOS-associated by-products after ovalbumin-challenge. PARP-1 nitration blocked its poly(ADP-ribosyl)ation activity. Interleukin-5 re-establishment in ovalbumin-exposed PARP-1(-/-) mice reversed eosinophilia and partial mucus production without a reversal of iNOS expression, concomitant protein nitration or associated DNA damage. The present results demonstrate a reciprocal relationship between inducible nitric oxide synthase and poly(ADP-ribose) polymerase-1 and suggest that expression of inducible nitric oxide synthase may be dispensable for eosinophilia after interleukin-5 production. Inducible nitric oxide synthase may be required for oxidative DNA damage and full manifestation of mucus production. Such dispensability may explain, in part, the reported ineffectiveness of inducible nitric oxide synthase inhibition in preventing allergen-induced inflammation in humans.

Objective— Type 2 diabetes is associated with increased advanced glycation end product (AGE) formation and vasculopathy. We hypothesized that AGEs contribute to resistance artery dysfunction. Methods and Results— Type 2 diabetic db − /db − (diabetic) and nondiabetic db − /db + (control) mice were treated with the AGE inhibitor (aminoguanidine: 50 mg/Kg/d) for 3 months. Isolated mesenteric resistance arteries (MRAs) were mounted in an arteriograph. Pressure-induced myogenic tone (MT) was increased in diabetic mice but was unaffected by aminoguanidine treatment. Phenylephrine-induced contraction and nitric oxide donor-induced endothelium-independent relaxation were similar in all groups. In diabetic mice, endothelium-dependent relaxation in response to shear-stress or acetylcholine was altered and was associated with reduced eNOS protein and mRNA expression. Aminoguanidine treatment improved endothelial function and restored eNOS expression. AGE formation and hypoxia markers (plasminogen activator inhibitor 1 and Bnip3) were increased in MRA from diabetic mice and normalized with Aminoguanidine. Primary cultured endothelial cells (ECs) isolated from resistance arteries subjected to high glucose for 48 hours showed decreased eNOS expression and phosphorylation in response to calcium ionophore. High glucose decreased antioxidant protein (MnSOD) and increased prooxidant proteins (gp91phox) expression leading to increased oxidative stress generation, as assessed by DHE staining and endothelial NADH/NADPH oxidase activity. The preincubation of ECs with aminoguanidine restored eNOS-phosphorylation and expression as well as the balance between pro- and antioxidant factors induced by high glucose. Conclusions— We provide evidence of a link between AGEs, oxidative stress, and resistance artery EC dysfunction in type 2 diabetic mice. Thus, AGEs and oxidative stress may be a potential target for overcoming diabetic microvessels complications.

Alpha-tocopheryl succinate (TOS) is a well-known potent and selective apoptotic agent. This apoptotic activity has been ascribed to its detergent-like property which is also shared by the structurally related compound, alpha-tocopheryl phosphate (TOP). TOP meets the structural requirements that have been described for the apoptotic activity of TO esters, i.e. the combination of three structural, one functional, one signalling and one hydrophobic domain. In this study, we have investigated the effect of TOP on the osteosarcoma cell line MG-63 using TOS as a reference compound. As compared with TOS, TOP showed a higher proliferative and apoptosis inducing activity on the MG-63 cancer cell line. The cytotoxic effect of TOP and TOS seems to be due to the effect of the intact compounds, since only a minor conversion into alpha-tocopheryl (TO) could be detected. EPR experiments showed that TOS and TOP reduced membrane fluidity, whereas TO had no effect. In addition, induction of erythrocyte hemolysis by TOP depended on the pH. These results suggest that the detergent-like activity of these compounds might be involved in their biological effect. Due to the potent biological activities, TOP might be clinically useful.