Gender differences in autoantibodies to oxidative DNA base damage in cigarette smokers.

Oxidative DNA damage and antibodies to that damage have been implicated in lung, breast, and colorectal cancer. In this observational validation study, the relationship between anti-5-hydroxymethyl-2'-deoxyuridine (HMdU) autoantibody (aAb) and plasma micronutrients was assessed in 140 heavy smokers by ELISA. Anti-HMdU aAbs were 50% higher in women after adjustment for cigarettes/day (CPD; P = 0.002), although men smoked more and had higher plasma cotinine levels. The women reported taking more vitamin C (P < 0.005) and had higher plasma levels of alpha-carotene and beta-carotene (P < 0.001) and cryptoxanthin (P < 0.01) than men. Neither CPD nor cotinine was associated with aAb titers. Anti-HMdU aAbs were associated inversely with alpha-tocopherol (P = 0.10), retinol (P = 0.06), and age (P = 0.04) in women but not in men. In contrast to the men, women 50 years of age (P = 0.05). Given the same duration of exposure, women had higher anti-HMdU aAbs and also reached peak levels at a lower cumulative smoking exposure (30 years) compared with male smokers (40 years). Subjects smoked an average of 28.9 +/- 0.81 CPD and initiated smoking at 17.2 +/- 0.33 (SE) years of age. Therefore, smokers who reported smoking for 30 years were typically <50 years old. Women

Smoking cessation and the course of major depression: a follow-up study.

BACKGROUND: Smokers with a history of major depression who attempt to stop smoking have a higher risk of failure than non-depressed smokers. Anecdotal and post-hoc data suggest that those who successfully abstain are at increased risk of depression compared with individuals who continue to smoke. However, these studies confound effects of abstinence and history of depression. We aimed to assess whether there is an increased risk of depression and for how long that increase lasts. METHODS: We enrolled 100 smokers (>1 pack per day) with a history of major depression, but who were currently free from major depression and had not been on antidepressant medicine for at least 6 months, in a 2-month smoking-cessation trial. The primary outcome was recurrence of major depression, which we assessed by structured clinical interviews 3 and 6 months after the end of treatment. We verified smoking status by serum-sample cotinine concentrations. FINDINGS: 76 participants (42 successful abstainers, 34 smokers) were followed up. 13 abstainers and two smokers had an episode of major depression (odds ratio 7.17 [95% CI 1.5-34.5]; Kaplan-Meier survival curve, log-rank statistic 9.11 [p=003]). Risk of major depression was similar between the first and second 3 months of follow-up. INTERPRETATIONS: Smokers with a history of depression who abstain from smoking are at significantly increased risk of developing a new episode of major depression. This risk remains high for at least 6 months.

CREB/ATF proteins enhance the basal and CD154- and IL-4-induced transcriptional activity of the human Igamma1 proximal promoter.

To understand the underlying basis for the strong IL-4- and CD154-mediated Igamma1 promoter activity in Ramos 2G6 B cells, we carried out transient transfection assays with luciferase-based constructs containing approximately 2.2 kb and 500 bp of the human Igamma1 proximal promoter region. As a comparison, the corresponding regions of the human Igamma3 promoter were tested under identical conditions. We found that both Igamma1 and Igamma3 promoter constructs were activated upon transfection into Ramos B cells and that activity was significantly up-regulated by CD154 and IL-4 signals. However, the Igamma1 promoter was measurably stronger than the Igamma3 promoter with respect to both basal and induced responses. Sequence comparison revealed a divergent 36-bp region containing multiple putative transcription factor binding sites in the Igamma1 but not the Igamma3 promoter. A mutational "swap" of this sequence resulted in a marked decrease and increase in Igamma1 and Igamma3 basal and induced promoter activity, respectively. Gel retardation assays with Igamma1-specific probes revealed CREB-containing complexes that were not observed with the corresponding Igamma3 probes. Mutation of a single nucleotide in overlapping CREB sites in the Igamma1 sequence resulted in a significant decrease in basal activity with a corresponding reduction in the level of IL-4- and CD154-mediated transcription.

CD40:CD40L interactions in X-linked and non-X-linked hyper-IgM syndromes.

Hyper-IgM (HIM) syndrome is a rare immunodeficiency characterized by low or absent IgG, IgA, and IgE with normal or elevated levels of IgM. This disorder can be acquired or familial with either X-linked or autosomal patterns of inheritance. The X-linked form of the disease is a consequence of mutations in the CD40 ligand (CD40L) gene that encodes a protein expressed primarily on activated CD4+ T cells. The cognate interaction between CD40L on T cells and CD40 on antigen-stimulated B cells, macrophage, and dendritic cells is critical for the development of a comprehensive immune response. The non-X-linked form of HIM syndrome is heterogeneous and appears in some cases to be a consequence of mutations in the AlD gene which encodes a B cell specific protein required for class switch recombination, somatic mutation, and germinal center formation. However, mutations in other unidentified genes are clearly the basis of the disease in a subset of patients. In this article, we review the essential features of the X-linked and non-X-linked forms of HIM syndrome and discuss the critical role the CD40:CD40L receptor-ligand pair plays in the pathogenesis of these immune deficiencies.

Identification of a complex that binds to the CD154 3' untranslated region: implications for a role in message stability during T cell activation.

CD154 expression is regulated throughout a time course of CD3-dependent T cell activation by differential mRNA decay. To understand the molecular basis of the "stability" phase of this pathway, experiments were conducted to identify sequences and specific complexes important in this regulation. Gel retardation assays using extracts from both Jurkat T cells and CD3-activated CD4(+) T cells revealed a major complex (complex I) that bound a 65-bp highly CU-rich region of the CD154 3' untranslated region. The specificity of the CU-rich element for complex-I formation was confirmed by disruption of this complex by oligo(dCT) competition. Formation of complex I strongly correlated with CD154 mRNA stability across a time course of T cell activation. UV cross-linking identified a major oligo(dCT)-sensitive species at approximately 90 kDa that showed induced and increased expression in extracts from 24- and 48-hr anti-CD3-activated T cells, respectively. This protein was absent in equivalent extracts from resting or 2-h-activated T cells. Using an in vitro decay assay, we found that a CD154-specific transcript was more rapidly degraded in 2-h-activated extract and stabilized in the 24- and 48-h extracts compared to extracts from resting T cells. Disruption of complex I resulted in the rapid decay of a CD154-specific transcript demonstrating a functional role for complex I in mRNA stabilization in vitro. These studies support a model of posttranscriptional regulation of CD154 expression being controlled in part by the interaction of a poly(CU)-binding complex with a specific sequence in the 3' untranslated region.

A transcriptional defect underlies B lymphocyte dysfunction in a patient diagnosed with non-X-linked hyper-IgM syndrome.

To establish the underlying cause of hyper-IgM syndrome in one female patient, B cell function was examined in response to CD40- and IL-4-mediated pathways. When CD40-induced functional responses were measured in unfractionated B cells, CD80 up-regulation, de novo Cmu-Cgamma recombination, and Igamma transcription were all found to be relatively unaffected. However, CD40- and IL-4-mediated CD23 up-regulation and VDJ-Cgamma transcription were clearly diminished compared to control cells. IL-4-induced CD23 expression was measurably reduced in the CD20- population as well. These results suggested that the patient's defect is positioned downstream of CD40 contact and affects both CD40- and IL-4 signal transduction pathways. Further analysis of B cell function in CD19+ B cells revealed a clear B cell defect with respect to Igamma and mature VDJ-Cgamma transcription and IgG expression. However, under the same conditions Iepsilon transcription was relatively normal. Partial restoration of B cell function occurred if PBMC or CD19+ B cells were cultured in vitro in the presence of CD154 plus IL-4. Because addition of IL-4 to cocultures containing activated T cells failed to induce B cells to undergo differentiation, the ability of the patient's B cells to acquire a responsive phenotype correlated with receiving a sustained signal through CD40. These findings support a model in which the patient expresses an intrinsic defect that is manifested in the failure of specific genes to become transcriptionally active in response to either CD154 or IL-4 and results in a functionally unresponsive B cell phenotype.

Advances in non-nicotine pharmacotherapy for smoking cessation.

Progress in understanding the pharmacological nature of tobacco addiction, along with the modest success rates achieved by the nicotine replacement therapies, has provided the major impetus for the development of non-nicotine drugs as smoking cessation aids. This article reviews evidence from controlled trials of several non-nicotine medications for the treatment of nicotine dependence. Clonidine was the first non-nicotine medication to show efficacy for smoking cessation in multiple studies, but its effect was found to be limited at best. Positive results across several trials have been consistently demonstrated for amfebutamone (bupropion). Encouraging results have also been observed for nortriptyline and moclobemide. Studies of combined treatments using non-nicotine medications (amfebutamone, mecamylamine, oral dextrose) with nicotine replacement therapy suggest increased efficacy relative to treatments using one or the other treatment strategy alone. Thus, available evidence indicates that non-nicotine drug treatments offer a promising panoply of therapeutic strategies for the addicted smoker.

A polymorphic CD40 ligand (CD154) molecule mediates CD40-dependent signalling but interferes with the ability of soluble CD40 to functionally block CD154:CD40 interactions.

We report the characterization of a naturally occurring polymorphism in CD40 ligand (CD40L, CD154) expressed by activated T cells from a young female patient. This polymorphism encodes a nonconservative Gly --> Arg substitution in amino acid 219 in the extracellular, CD40 binding domain of the molecule. Studies carried out with 293 epithelial cells ectopically expressing the polymorphic protein (CD154/G219R) revealed reduced levels of binding to different anti-CD154 monoclonal antibodies (mAb) and CD40-immunoglobulin (CD40-Ig). However, recognition of the polymorphic and wild-type CD154 molecules by a polyclonal antiserum was comparable, suggesting that the polymorphism affects the ability of the protein to interact with CD40 but does not significantly alter its surface expression. To determine if reduced cross-linking of CD40 mediated decreased functional effects, three CD40-dependent properties were measured. We found that pathways leading to the induction of surface CD23, CD80, and Igamma transcription were activated in response to CD154/G219R signalling. However, the decrease in affinity for CD40 by the mutated CD154 affected the ability of CD40-Ig to efficiently interfere with the binding and effectively block induced CD80 expression. In contrast, we found that the 5c8 mAb, which recognized the polymorphic molecule to a similar extent as wild-type CD154, effectively blocked the interaction between CD154/G219R and CD40 as measured by CD80 expression. These findings suggest that naturally occurring polymorphisms in the CD154 molecule may affect the ability of CD40-mediated functions to be blocked by soluble CD40 or anti-CD154 mAb in the therapeutic treatment of disease and graft rejection.

Tobacco cessation among patients with depression.

This article summarizes the research evidence on the association between smoking and depression. Across multiple studies and clinical and population-based samples, it has been demonstrated that, compared with nondepressed individuals, persons with depression are more likely to be smokers, to be dependent smokers, to have difficulty stopping smoking, and to experience more severe withdrawal symptoms. Further, they may be at risk of experiencing severe depression once they have stopped smoking. Based on the author's experience with this population of smokers, recommendations for assessing smokers' vulnerability to depression, their level of nicotine dependence, and psychological and pharmacological aids for smokers are offered.

Naltrexone effects on short-term and long-term smoking cessation.

OBJECTIVES: This study examined the efficacy of naltrexone, a long-acting opiate antagonist, as a smoking cessation aid in a double-blind placebo-controlled randomized trial. It was hypothesized that naltrexone would result in higher quit rates at the end of treatment and six months later. METHODS: Subjects were 68 smokers aged 18 to 65 who smoked at least 20 cigarettes daily and wished to stop smoking. They took naltrexone or placebo daily for four weeks and were seen weekly for individual smoking cessation therapy. RESULTS: A statistical trend towards a higher overall cessation rate (cotinine < 15 ng/mL) at end-of-treatment was observed among subjects treated with naltrexone than placebo (46.7% vs. 26.3%, respectively, odds ratio = 2.5, p < .10); however, this difference was attenuated at six months (27% vs. 15%, respectively, odds ratio = 1.9, p = ns). Stratified analysis indicated the usefulness of naltrexone primarily for female smokers and those with a history of major depression. These effects remained six months later. CONCLUSION: These results provide, at best, mild promise for naltrexone as a smoking cessation drug and provide another instance of a differential response to nicotine dependence treatment according to gender and depression history.

Regulation of CD154 (CD40 ligand) mRNA stability during T cell activation.

The CD154 protein (CD40 ligand), which is critical to the regulation of both humoral and cellular immune responses, is expressed transiently on the surface of activated CD4+ T cells. To determine whether control of mRNA stability contributes to the highly regulated expression of CD154 during T cell activation, CD4+ T cells were isolated from human peripheral blood and stimulated for various lengths of time with plate-bound anti-CD3 mAb. At early times after anti-CD3 activation, the CD154 message was found to be very unstable, however, the stability measurably increased after 24-48 h of activation. Similar analyses of TNF-alpha and c-myc mRNA decay throughout a time course of T cell activation revealed patterns of regulation that were distinct from CD154. Similar to the effect on TNF-alpha mRNA, stimulation of T cells with PMA + ionomycin greatly increased the stability of CD154 message. However, CD154 message stability was only modestly increased in T cells coactivated with anti-CD3 and anti-CD28 at 5 h and not increased by costimulation at 24 h. Finally, an analysis of both mRNA and surface protein expression over a time course of T cell activation with anti-CD3 revealed a rapid induction of expression early after activation. This induction was followed by a more gradual decrease in expression over the next 48 h. Together, these data support a role for posttranscriptional regulation in the control and overall expression of CD154 in activated T cells.

Cigarette smoking and major depression.

The authors review recent literature that has demonstrated an association between cigarette smoking behavior and major depression. Persons with major depression are more likely to smoke and to have difficulty when they try to stop. When they manage to succeed in stopping, such persons are at increased risk of experiencing mild to severe states of depression, including full blown major depression. The period of vulnerability to a new depressive episode appears to vary from a few weeks to several months after cessation. This knowledge suggests a relationship between smoking and depression that is complex, pernicious, and potentially life-long. It is recommended that cessation treatments incorporate screening procedures that will identify those patients with a propensity to depression and monitor the emergence of postcessation depression, particularly in those with a history of depression.

CD40 ligand exerts differential effects on the expression of I gamma transcripts in subclones of an IgM+ human B cell lymphoma line.

The CD40:CD40 ligand (CD40L) interaction plays a critical role in T cell-dependent isotype switching. To elucidate the role of CD40 signaling in the activation of gamma germline transcription and as an extension, in targeting Cgamma regions for isotype switching, an IgM+ Burkitt lymphoma cell line (Ramos 2G6) was assayed for the up-regulation of germline gamma transcripts after CD40L stimulation. Independent Ramos 2G6 subclones that either expressed (Igamma+) or did not express (Igamma-) basal levels of Igamma transcripts were assessed for their transcriptional response to CD40L signaling by contact with either a Jurkat T cell line (D1.1) or a transfected CD40L-expressing epithelial cell line (293/CD40L) in the presence or absence of IL-4. Both Igamma- and Igamma+ Ramos 2G6 subclones cultured with IL-4 and CD40L markedly up-regulated germline transcription predominantly from the gamma1, gamma2, and gamma3 subclasses over levels obtained with IL-4 alone. In addition, these two signals were required to obtain de novo switch recombination. However, incubation with CD40L alone resulted in a substantial increase in germline transcription only in the Igamma+ and not the Igamma- subclones. Observed basal transcription at the gamma1 locus also correlated with the ability of not only the gamma1 locus, but also the gamma2 and gamma3 loci, to up-regulate germline transcripts in response to CD40 signaling. These data are consistent with CD40:CD40L contact up-regulating germline transcription only after the B cell has received a signal that alters the transcriptional state of the heavy chain locus.

Contribution of genetic and nutritional factors to DNA damage in heavy smokers.

Prior epidemiological evidence suggests that genes controlling the metabolism of carcinogens and antioxidant/nutritional status are associated with lung cancer risk, possibly through their ability to modulate DNA damage by carcinogens. We performed a cross-sectional analysis of 159 heavy smokers from a cohort of subjects enrolled in a smoking cessation program. A total of 159 blood samples were analyzed to determine the relative contributions of genetic polymorphisms [CYP1A1 MspI and exon 7 and glutathione S-transferase M1 (GSTM1)] and plasma micronutrients to polycyclic aromatic hydrocarbon-DNA (PAH-DNA) adduct levels. DNA damage in smokers was affected by genetic polymorphisms and nutritional status. Smokers with the CYP1A1 exon 7 valine polymorphism had significantly higher (2-fold, P < or = 0.03) levels of DNA damage than those without. In parallel models, PAH-DNA adducts were inversely associated with plasma levels of retinol (beta = -0.93, P = 0.01), beta-carotene (beta = -0.18, P = 0.09), and alpha-tocopherol (beta = -0.28, P = 0.21) in 159 subjects. The association between smoking-adjusted plasma beta-carotene levels and DNA damage was only significant in those subjects lacking the GSTM1 detoxification gene (beta = -0.30, P = 0.05, n = 75). There was a statistical interaction between beta-carotene and alpha-tocopherol; when beta-carotene was low, alpha-tocopherol had a significant protective effect (beta = -0.78, P = 0.04) on adducts, but not when beta-carotene was high (beta = -0.16, P = 0.57). Plasma alpha-tocopherol was significantly correlated with beta-carotene (r = 0.36, P = 0.0005) and less strongly with retinol (r = 0.20, P = 0.0005). These results suggest that several micronutrients may act in concert to protect against DNA damage and highlight the importance of assessing overall antioxidant status. In conclusion, a subset of smokers may be at increased risk of DNA damage and possibly lung cancer due to the combined effect of low plasma micronutrients and genetic susceptibility factors. The use of biological markers to assess efficacy of interventions and to study mechanisms of micronutrients is timely given the current debate regarding the use of chemopreventive agents in high risk populations.

Major depression following smoking cessation.

OBJECTIVE: The authors examined the incidence and predictors of major depression following successful smoking cessation treatment, with special attention to the influence of past major depression. METHOD: Three-month follow-up data were obtained from 126 subjects who successfully completed a 10-week smoking cessation program. RESULTS: The 3-month incidence of new major depression following treatment for nicotine dependence was 2%, 17%, and 30% among subjects with histories of no major depression, single major depression, and recurrent major depression, respectively. A history of major depression and persistent withdrawal symptoms independently predicted posttreatment major depression. CONCLUSIONS: Continued patient care beyond the 2-4-week period associated with the nicotine withdrawal syndrome is indicated when abstinence is attempted by smokers with prior major depression.

Depression after smoking cessation: case reports.

BACKGROUND: Cigarette smokers with a history of major depression are at risk for developing depressive mood when they attempt cessation. Whether cessation can also provoke more severe depressions, however, has not been well documented. METHOD: Six case reports of severe depressive episodes after smoking cessation are described. RESULTS: Four cases occurred among smokers with a history of major depression but who were not depressed at the time of cessation. Two cases involved smokers with no previous history of major depression. Variability in both the timing and the outcome of the postcessation depressions was observed. CONCLUSION: The risk that depressive states may emerge or be exacerbated after smoking cessation, particularly in patients with a history of major depression, must be kept in mind in the treatment of nicotine dependence.

Decline of DNA damage and other biomarkers in peripheral blood following smoking cessation.

Serial samples from 40 heavy smokers ( > or = pack/day for > or = 1 year) enrolled in a smoking cessation program were assayed for cotinine, polycyclic aromatic hydrocarbon (PAH)-DNA, 4-aminobiphenyl-hemoglobin (4-ABP-Hb) adducts, and glycophorin A (GPA) mutations. Blood samples were taken while subjects were smoking, and 10 weeks and 8 and 14 months after quitting. Cotinine was used to assess compliance with the cessation protocol. A significant reduction in mean PAH-DNA and 4-ABP-Hb adducts was observed after cessation in all persons who were cotinine-verified quitters ( < or = 25 ng/ml) for > or = 8 months (P < 0.05). Neither the GPA N/phi nor the GPA N/N mutation Vf was significantly reduced after smoking cessation, but results are limited by the small number (n = 18) of heterozygous individuals studied. The substantial reduction (50-75%) in PAH-DNA and 4-ABP-Hb adduct levels after quitting indicates these carcinogen adducts are reflective of smoking. Passive exposure to smoke at home was significantly associated with PAH-DNA adducts in active smokers and in ex-smokers 10 weeks after quitting (P < 0.01). The estimated half-life of the PAH-DNA adducts in leukocytes is 9-13 weeks by inspection of the mean biomarker levels from baseline and 10 weeks sample and 23 (95% confidence interval, 10-36 weeks) using a linear regression model that adjusted for background.(ABSTRACT TRUNCATED AT 250 WORDS)

Mood, major depression, and fluoxetine response in cigarette smokers.

OBJECTIVE: Two smoking cessation studies provided venues to 1) look for differences in affective symptoms between cigarette smokers with and without a history of major depression or other psychiatric diagnoses who were not currently depressed and 2) evaluate the efficacy of fluoxetine in ameliorating affective symptoms in smokers with a history of major depression but not currently depressed. METHOD: Part I: Three hundred sixty-eight smokers who enrolled in a smoking cessation treatment study completed baseline self-rating scales. The relationship between the scale scores and a history of major depression and other psychiatric diagnoses was examined. Part II: Thirty-nine smokers with a history of major depression were enrolled in a randomized, double-blind study that examined the utility of fluoxetine as an aid to smoking cessation. Self-rated scales were compared at baseline and after 3 weeks of medication treatment before the attempt to quit. RESULTS: A history of major depression had significant main effects across all scale scores; subjects with such a history rated themselves as more symptomatic. The effects of other psychiatric diagnoses were neither as pervasive nor as robust. There were no differences in baseline scores between the fluoxetine- and placebo-treated groups and no change within the placebo group after 3 weeks. There was significant improvement from baseline in several subscale scores for the group treated with fluoxetine. However, comparison of the score changes for the placebo and fluoxetine groups did not show a statistically significant difference, which limited the ability to conclude that active treatment was better than placebo. CONCLUSIONS: Subjects with a history of major depression, but without current affective illness, reported themselves to be more symptomatic than those without such-a history. Furthermore, in a group of smokers with a history of major depression, affective symptoms, without concurrent syndromal illness, may be ameliorated by treatment with fluoxetine.

T lymphocyte T cell-B cell-activating molecule/CD40-L molecules induce normal B cells or chronic lymphocytic leukemia B cells to express CD80 (B7/BB-1) and enhance their costimulatory activity.

Activation-induced cell surface molecules are involved in mediating bidirectional T-B lymphocyte signaling that is important in the induction of T or B lymphocyte effector functions. In this regard, T-BAM/CD40-L is an activation-induced CD4+ T cell surface molecule known to be important in inducing B cell effector functions. This report demonstrates that T-BAM/CD40-L molecules on a Jurkat T cell leukemia subclone (D1.1) or nonlymphoid 293 kidney cell transfectants induce B cells or B-CLL cells to express CD80 (B7/BB-1) in a manner that is specifically inhibited by anti-T-BAM/CD40-L mAb 5C8. Because activation-induced B cell surface molecules, such as CD80, deliver costimulatory signals to T cells that augment T cell proliferation, the functional costimulatory capacity of T-BAM/CD40-L-primed B cells and B-CLL cells was studied. T-BAM/CD40-L-primed B cells or B-CLL cells augment the proliferative responses of allogenic T cells. Furthermore, T-BAM/CD40-L priming is specifically inhibited by mAb 5C8. Together, these studies demonstrate that T-BAM/CD40-L induces CD80 expression on resting B cells or B-CLL cells. Moreover, T-BAM/CD40-L signaling enhances B cell costimulatory capacity. These studies suggest that T-BAM/CD40-L molecules not only induce B cell differentiative processes that result in Ab secretion, but also enable B cells to prime Ag-specific T cells for subsequent clonal expansion.