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Latest Paper:
Meeshanthini Vijayendran,
Carolyn Cutrona,
Steven R H Beach,
Gene H Brody,
Daniel Russell,
Robert A Philibert
Department of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, Iowa; Department of Psychiatry, The University of Iowa, Iowa City, Iowa.
Front Genet. 2012 ;3 :54
22514556
Department of Psychiatry, The University of Iowa, Iowa City IA, USA.
Chronic alcohol intake is associated with a wide variety of adverse health outcomes including depression, diabetes, and heart disease. Unfortunately, the molecular mechanisms through which these effects are conveyed are not clearly understood. To examine the potential role of epigenetic factors in this process, we examined the relationship of recent alcohol intake to genome wide methylation patterns using the Illumina 450 Methylation Bead Chip and lymphoblast DNA derived from 165 female subjects participating in the Iowa Adoption Studies. We found that the pattern of alcohol use over the 6-months immediately prior to phlebotomy was associated with, severity-dependent changes in the degree of genome wide methylation that preferentially hypermethylate the central portion of CpG islands with methylation at cg05600126, a probe in ABR, and the 5' untranslated region of BLCAP attaining genome wide significance in two point and sliding window analyses of probe methylation data, respectively. We conclude that recent alcohol use is associated with widespread changes in DNA methylation in women and that further study to confirm these findings and determine their relationship to somatic function are in order.
J Fam Psychol. 2012 Apr 2;:
22468688
Gene H Brody,
Tianyi Yu,
Yi-Fu Chen,
Steven M Kogan,
Gary W Evans,
Michael Windle,
Meg Gerrard,
Frederick X Gibbons,
Ronald L Simons,
Robert A Philibert
The purpose of this study was to investigate interactions between exposure to supportive family environments and genetic characteristics, which were hypothesized to forecast variations in allostatic load (AL) in a representative sample of 315 rural African American youths. Data on family environments were gathered when youths were 11-13, and genetic data were collected when they were 16, years of age. Data on AL were obtained at the beginning of emerging adulthood, age 19 years. The data analyses revealed that, as predicted, emerging adults exposed to less supportive family environments across preadolescence manifested higher levels of AL when they carried the short (s) allele at the 5-HTTLPR and an allele of DRD4 with seven or more repeats. This is an E(family environment) × G(5-HTTLPR status) × G(DRD4 status) interaction. These data suggest that African American youths carrying genes that confer sensitivity who are exposed to less supportive family environments may be at greater risk for adverse physical health consequences that AL presages.(PsycINFO Database Record (c) 2012 APA, all rights reserved).
Am J Public Health. 2012 Mar 15;:
22420807
Gene H. Brody and Yi-fu Chen are with the Center for Family Research, Institute for Behavioral Research, and Steven M. Kogan is with the Department of Child and Family Development, University of Georgia, Athens.
Objectives. This study was designed to test hypotheses about the prospective association of adolescents' perceptions of discrimination with increases in substance use and the processes that mediate this association. Methods. African American youths residing in rural Georgia (n = 573; mean age = 16.0 years) provided longitudinal data on their experiences with discrimination, substance use, school engagement, and affiliations with substance-using peers. Results. For male youths, perceived discrimination was significantly related to increases in substance use, and, as hypothesized, this association was mediated by the contributions of perceived discrimination to decreases in school engagement and increases in affiliations with substance-using peers. Analyses also indicated that discrimination influences substance use rather than vice versa. Conclusions. Results are consistent with the hypothesis that high levels of discrimination are linked to increases in substance use for African American male adolescents.(Am J Public Health. Published online ahead of print March 15, 2012: e1-e6. doi:10.2105/AJPH.2011.300588).
Front Genet. 2012 ;3 :12
22363339
Department of Psychiatry, The University of Iowa Iowa City, IA, USA.
Peripheral mononuclear cell preparations are commonly used as proxies for other tissues in studies of the role of gene expression and methylation in human disease. Whether changes in peripheral DNA methylation are associated with changes in peripheral blood or brain gene expression is not clear. In order to test the former hypothesis and determine which genome-wide methylation platform was most suitable for our studies of peripheral blood cells, we compared the results from two commercially available genome-wide methylation arrays with respect to genome-wide gene expression using lymphoblast DNA and RNA from eight individuals at the promoters of 5619 genes. We found that methylation signatures at these gene promoters were significantly correlated with one another across platforms and with genome-wide gene expression, but the extent of that relationship is dependent on choice of platform and degree of methylation. Taken in context with data from other studies, these data demonstrate that peripheral blood cell methylation is associated with gene expression and that further studies to clarify the extent of this relationship, and the relationship between central and peripheral DNA methylation are in order.
Martha M Monick,
Steven R H Beach,
Jeff Plume,
Rory Sears,
Meg Gerrard,
Gene H Brody,
Robert A Philibert
Department of Medicine, The University of Iowa, Iowa City, Iowa.
Smoking is associated with a wide variety of adverse health outcomes including cancer, chronic obstructive pulmonary disease, diabetes, depression, and heart disease. Unfortunately, the molecular mechanisms through which these effects are conveyed are not clearly understood. To examine the potential role of epigenetic factors in these processes, we examined the relationship of smoking to genome wide methylation and gene expression using biomaterial from two independent samples, lymphoblast DNA and RNA (n = 119) and lung alveolar macrophage DNA (n = 19). We found that in both samples current smoking status was associated with significant changes in DNA methylation, in particular at the aryl hydrocarbon receptor repressor (AHRR), a known tumor suppressor. Both baseline DNA methylation and smoker associated DNA methylation signatures at AHRR were highly correlated (r = 0.94 and 0.45, respectively). DNA methylation at the most differentially methylated AHRR CpG residue in both samples, cg0557592, was significantly associated with AHRR gene expression. Pathway analysis of lymphoblast data (genes with most significant methylation changes) demonstrated enrichment in protein kinase C pathways and in TGF beta signaling pathways. For alveolar macrophages, pathway analysis demonstrated alterations in inflammation-related processes. We conclude that smoking is associated with functionally significant genome wide changes in DNA methylation in both lymphoblasts and pulmonary macrophages and that further integrated investigations of these epigenetic effects of smoking on carcinogenesis and other related co-morbidities are indicated. © 2012 Wiley Periodicals, Inc.
Ronald L Simons,
Man Kit Lei,
Steven R H Beach,
Gene H Brody,
Robert A Philibert,
Frederick X Gibbons
University of Georgia.
Although G×E studies are typically based on the assumption that some individuals possess genetic variants that enhance their vulnerability to environmental adversity, the differential susceptibility perspective posits that these individuals are simply more susceptible to environmental influence than others. An important implication of this model is that those persons most vulnerable to adverse social environments are the same ones who reap the most benefit from environmental support. The present study tested several implications of this proposition. Using longitudinal data from a sample of several hundred African Americans, we found that relatively common variants of the dopamine receptor gene and the serotonin transporter gene interact with social environmental conditions to predict aggression in a manner consonant with differential susceptibility. When the social environment was adverse, individuals with these genetic variants manifested more aggression than other genotypes, whereas when the environment was supportive they demonstrated less aggression than other genotypes. Further, we found that these genetic variants interact with environmental conditions to foster various cognitive schemas and emotions in a manner consistent with differential susceptibility and that a latent construct formed by these schemas and emotions mediated the effect of gene by environment interaction on aggression.
Objective: This report addresses the long-term efficacy of the Adults in the Making (AIM) prevention program on deterring the escalation of alcohol use and development of substance use problems, particularly among rural African American emerging adults confronting high levels of contextual risk. Method: African American youths (M age, pretest = 17.7 years) were assigned randomly to the AIM (n = 174) or control (n = 173) group. Past 3-month alcohol use, past 6-month substance use problems, risk taking, and susceptibility cognitions were assessed at pretest and at 6.4, 16.6, and 27.5 months after pretest. Pretest assessments of parent-child conflict, affiliations with substance-using companions, and perceived racial discrimination were used to construct a contextual risk factor index. Results: A protective stabilizing hypothesis was supported; the long-term efficacy of AIM in preventing escalation of alcohol use and substance use problems was greater for youths with higher pretest contextual risk scores. Consistent with a mediation-moderation hypothesis, AIM-induced reductions over time in risk taking and susceptibility cognitions were responsible for the AIM × contextual risk prevention effects on alcohol use and substance use problems. Conclusions: Training in developmentally appropriate protective parenting processes and self-regulatory skills during the transition from adolescence to emerging adulthood for rural African Americans may contribute to a self-sustaining decreased interest in alcohol use and a lower likelihood of developing substance use problems.(PsycINFO Database Record (c) 2011 APA, all rights reserved).
Pediatrics. 2011 Dec 12;:
22157131
Gene H Brody,
Yi-Fu Chen,
Steven M Kogan,
Tianyi Yu,
Virginia K Molgaard,
Ralph J Diclemente,
Gina M Wingood
aCenter for Family Research, University of Georgia, Athens, Georgia.
OBJECTIVES:The present research addressed the following important question in pediatric medicine: Can participation in a new family-centered preventive intervention, the Strong African American Families-Teen (SAAF-T) program, deter conduct problems, substance use, substance use problems, and depressive symptoms among rural black adolescents across 22 months?METHODS:Data were collected from 502 black families in rural Georgia, assigned randomly to SAAF-T or an attention control condition. The prevention condition consisted of 5 consecutive meetings at community facilities with separate, concurrent sessions for caregivers and adolescents followed by a caregiver-adolescent session in which families practiced skills they learned in the separate sessions. Adolescents self-reported conduct problem behaviors, substance use, substance use problems, and depressive symptoms at ages 16 years (pretest) and 17 years 10 months (long-term assessment).RESULTS:Adolescents who participated in SAAF-T evinced lower increases in conduct problem behavior, substance use, substance use problems, and depressive symptom frequencies than did adolescents in the attention control condition across the 22 months between pretest and long-term assessment.CONCLUSIONS:This is the first study to demonstrate efficacy in a prevention program designed to deter conduct problems, substance use, substance use problems, and depressive symptoms among rural black adolescents. Because SAAF-T is a manualized, structured program, it can be easily disseminated to public health agencies, schools, churches, boys' and girls' clubs, and other community organizations.
Prev Sci. 2011 Nov 29;:
22124939
Steven M Kogan,
Gene H Brody,
Virginia K Molgaard,
Christina M Grange,
Desirée A H Oliver,
Tracy N Anderson,
Ralph J Diclemente,
Gina M Wingood,
Yi-Fu Chen,
Megan C Sperr
University of Georgia, Athens, GA, USA, smkogan@uga.edu.
This study addresses two limitations in the literature on family-centered intervention programs for adolescents: ruling out nonspecific factors that may explain program effects and engaging parents into prevention programs. The Rural African American Families Health project is a randomized, attention-controlled trial evaluating the efficacy of the Strong African American Families-Teen (SAAF-T) program, a family-centered risk-reduction intervention for rural African American adolescents. Rural African American families (n = 502) with a 10th-grade student were assigned randomly to receive SAAF-T or a similarly structured, family-centered program that focused on health and nutrition. Families participated in audio computer-assisted self-interviews at baseline and 6-month follow-up. Program implementation procedures yielded a design with equivalent doses, five sessions of family-centered intervention programming for families in each condition. Of eligible families screened for participation, 76% attended four or five sessions of the program. Consistent with our primary hypotheses, SAAF-T youth, compared to attention-control youth, demonstrated higher levels of protective family management skills, a finding that cannot be attributed to nonspecific factors such as aggregating families in a structured, interactive setting.
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