Bradley E. Aouizerat

Faculty

Bradley E. Aouizerat headshot

Bradley E. Aouizerat

PhD

Professor, College of Dentistry

Bradley E. Aouizerat's additional information

BS, Microbiology/ Molecular Genetics - University of California at Los Angeles
PhD, Microbiology/ Molecular Genetics/lmmunology - University of California at Los Angeles
MAS, Master of Advance Science Research in Clinical - University of California at San Francisco

Oral-systemic health

American Heart Association
American Liver Foundation
American Pain Society
American Society for Human Genetics
International Association for the Study of Pain

Faculty Honors Awards

Excellence in Research Mentoring Faculty Teaching Award (2013)
Excellence in Research Mentoring Faculty Teaching Award (Nominee) (2012)
Excellence in Research Mentoring Faculty Teaching Award (Nominee) (2011)
Most Dedicated Mentor Award, PMCTR Fellowship Program (2009)
Early Career Investigator Award, Bayer Healthcare International (2006)
Multidisciplinary Clinical Research Scholar, Roadmap K12 (2006)
Early Career Faculty Award, Hellman Family (2005)
Faculty Mentorship Award Nominee (2005)
Young Investigator Award, National Hemophilia Foundation (2005)
National Liver Scholar Award, American Liver Foundation (2004)
Irvine H. Page Young Investigator Award (Finalist), American Heart Association (2004)
Faculty Mentorship Award Nominee (2004)
Sam and Rose Gilbert Fellowship, UCLA (1998)
Warsaw Fellowship (1998)

Publications

Brush swab as a noninvasive surrogate for tissue biopsies in epigenomic profiling of oral cancer

Viet, C. T., Zhang, X., Xu, K., Yu, G., Asam, K., Thomas, C. M., Callahan, N. F., Doan, C., Walker, P. C., Nguyen, K., Kidd, S. C., Lee, S. C., Grandhi, A., Allen, C. T., Young, S., Melville, J. C., Shum, J. W., Viet, D. T., Herford, A. S., … Aouizerat, B. E. (2021). Biomarker Research, 9(1). 10.1186/s40364-021-00349-x
Abstract
Abstract
Background: Oral squamous cell carcinoma (OSCC) has poor survival rates. There is a pressing need to develop more precise risk assessment methods to tailor clinical treatment. Epigenome-wide association studies in OSCC have not produced a viable biomarker. These studies have relied on methylation array platforms, which are limited in their ability to profile the methylome. In this study, we use MethylCap-Seq (MC-Seq), a comprehensive methylation quantification technique, and brush swab samples, to develop a noninvasive, readily translatable approach to profile the methylome in OSCC patients. Methods: Three OSCC patients underwent collection of cancer and contralateral normal tissue and brush swab biopsies, totaling 4 samples for each patient. Epigenome-wide DNA methylation quantification was performed using the SureSelectXT Methyl-Seq platform. DNA quality and methylation site resolution were compared between brush swab and tissue samples. Correlation and methylation value difference were determined for brush swabs vs. tissues for each respective patient and site (i.e., cancer or normal). Correlations were calculated between cancer and normal tissues and brush swab samples for each patient to determine the robustness of DNA methylation marks using brush swabs in clinical biomarker studies. Results: There were no significant differences in DNA yield between tissue and brush swab samples. Mapping efficiency exceeded 90% across all samples, with no differences between tissue and brush swabs. The average number of CpG sites with at least 10x depth of coverage was 2,716,674 for brush swabs and 2,903,261 for tissues. Matched tissue and brush swabs had excellent correlation (r = 0.913 for cancer samples and r = 0.951 for normal samples). The methylation profile of the top 1000 CpGs was significantly different between cancer and normal samples (mean p-value = 0.00021) but not different between tissues and brush swabs (mean p-value = 0.11). Conclusions: Our results demonstrate that MC-Seq is an efficient platform for epigenome profiling in cancer biomarker studies, with broader methylome coverage than array-based platforms. Brush swab biopsy provides adequate DNA yield for MC-Seq, and taken together, our findings set the stage for development of a non-invasive methylome quantification technique for oral cancer with high translational potential.

Circulating microRNAs are associated with variability in fasting blood glucose over 12-months and target pathways related to type 2 diabetes: A pilot study

Flowers, E., Allen, I. E., Kanaya, A. M., & Aouizerat, B. E. (2021). Diabetes and Vascular Disease Research, 18(6). 10.1177/14791641211055837
Abstract
Abstract
Introduction: MicroRNAs (miRs) may be important regulators of risk for type 2 diabetes (T2D). Circulating miRs may provide information about which individuals are at risk for T2D. The purpose of this study was to assess longitudinal associations between circulating miR expression and variability in fasting blood glucose (FBG) and to identify miR-targeted genes and biological pathways. Methods: Variability in FBG was estimated using standard deviation from participants (n = 20) in a previously completed yoga trial. Expression of 402 miRs was measured using hydrogel particle lithography. MirTarBase was used to identify mRNAs, and miRPathDB was used to identify pathways targeted by differentially expressed miRs. Results: Six circulating miRs (miR-192, miR-197, miR-206, miR-424, miR-486, and miR-93) were associated with variability in FBG and targeted 143 genes and 23 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Six mRNAs (AKT1, CCND1, ESR1, FASN, SMAD7, and VEGFA) were targeted by at least two miRs and four of those were located in miR-targeted KEGG pathways. Conclusions: Circulating miRs are associated with variability in FBG in individuals at risk for T2D. Further studies are needed to determine whether miRs may be prodromal biomarkers that can identify which individuals are at greatest risk to progress to T2D and which biological pathways underlie this risk.

Circulating microRNAs associated with prediabetes and geographic location in Latinos

Flowers, E., Ramírez-Mares, J. D., Velazquez-Villafaña, M., Rangel-Salazar, R., Sucher, A., Kanaya, A. M., Aouizerat, B. E., & De La Vega Monroy, M. L. L. (2021). International Journal of Diabetes in Developing Countries, 41(4), 570-578. 10.1007/s13410-020-00917-1
Abstract
Abstract
Background: Globally, type 2 diabetes is highly prevalent in individuals of Latino ancestry. The reasons underlying this high prevalence are not well understood, but both genetic and lifestyle factors are contributors. Circulating microRNAs are readily detectable in blood and are promising biomarkers to characterize biological responses (i.e., changes in gene expression) to lifestyle factors. Prior studies identified relationships between circulating microRNAs and risk for type 2 diabetes, but Latinos have largely been under-represented in these study samples. Aims/hypothesis: The aim of this study was to assess for differences in expression levels of three candidate microRNAs (miR-126, miR-146, miR-15) between individuals who had prediabetes compared to normal glycemic status and between individuals who self-identified with Latino ancestry in the United States (US) and native Mexicans living in or near Leon, Mexico. Methods: This was a cross-sectional study that included 45 Mexicans and 21 Latino participants from the US. Prediabetes was defined as fasting glucose 100–125 mg/dL or 2-h post-glucose challenge between 140 and 199 mg/dL. Expression levels of microRNAs from plasma were measured by qPCR. Linear and logistic regression models were used to assess relationships between individual microRNAs and glycemic status or geographic site. Results: None of the three microRNAs was associated with risk for type 2 diabetes. MiR-146a and miR-15 were significantly lower in the study sample from Mexico compared to the US. There was a significant interaction between miR-146a and BMI associated with fasting blood glucose. Conclusions/interpretation: This study did not replicate in Latinos prior observations from other racial groups of associations between miR-126, miR-146a, and miR-15 and risk for type 2 diabetes. Future studies should consider other microRNAs related to different biological pathways as possible biomarkers for type 2 diabetes in Latinos.

Circulating MicroRNAs predict glycemic improvement and response to a behavioral intervention

Flowers, E., Allen, I. E., Kanaya, A. M., & Aouizerat, B. E. (2021). Biomarker Research, 9(1). 10.1186/s40364-021-00317-5
Abstract
Abstract
Background: MicroRNAs may be important regulators of risk for type 2 diabetes. The purpose of this longitudinal observational study was to assess whether circulating microRNAs predicted improvements in fasting blood glucose, a major risk factor for type 2 diabetes, over 12 months. Methods: The study included participants (n = 82) from a previously completed trial that tested the effect of restorative yoga on individuals with prediabetes. Circulating microRNAs were measured using a flow cytometry miRNA assay. Linear models were used to determine the optimal sets of microRNA predictors overall and by intervention group. Results: Subsets of microRNAs were significant predictors of final fasting blood glucose after 12-months (R2 = 0.754, p < 0.001) and changes in fasting blood glucose over 12-months (R2 = 0.731, p < 0.001). Three microRNAs (let-7c, miR-363, miR-374b) were significant for the control group only, however there was no significant interaction by intervention group. Conclusions: Circulating microRNAs are significant predictors of fasting blood glucose in individuals with prediabetes. Among the identified microRNAs, several have previously been associated with risk for type 2 diabetes. This is one of the first studies to use a longitudinal design to assess whether microRNAs predict changes in fasting blood glucose over time. Further exploration of the function of the microRNAs included in these models may provide new insights about the complex etiology of type 2 diabetes and responses to behavioral risk reduction interventions. Trial registration: This study was a secondary analysis of a previously completed clinical trial that is registered at clinicaltrials.gov (NCT01024816) on December 3, 2009.

Co-Occurrence of Symptoms and Gut Microbiota Composition Before Neoadjuvant Chemotherapy and Radiation Therapy for Rectal Cancer: A Proof of Concept

González-Mercado, V. J., Lim, J., Yu, G., Penedo, F., Pedro, E., Bernabe, R., Tirado-Gómez, M., & Aouizerat, B. (2021). Biological Research for Nursing, 23(3), 513-523. 10.1177/1099800421991656
Abstract
Abstract
Purpose: To examine a) whether there are significant differences in gut microbial diversity and in the abundance of gut microbial taxa; and b) differences in predicted functional pathways of the gut microbiome between those participants with high co-occurring symptoms and those with low co-occurring symptoms, prior to neoadjuvant chemotherapy and radiation therapy (CRT) for rectal cancer. Methods: Rectal cancer patients (n = 41) provided stool samples for 16 S rRNA gene sequencing and symptom ratings for fatigue, sleep disturbance, and depressive symptoms prior to CRT. Descriptive statistics were computed for symptoms. Gut microbiome data were analyzed using QIIME2, LEfSe, and the R statistical package. Results: Participants with high co-occurring symptoms (n = 19) had significantly higher bacterial abundances of Ezakiella, Clostridium sensu stricto, Porphyromonas, Barnesiella, Coriobacteriales Incertae Sedis, Synergistiaceae, Echerichia-Shigella, and Turicibacter compared to those with low co-occurring symptoms before CRT (n = 22). Biosynthesis pathways for lipopolysaccharide, L-tryptophan, and colanic acid building blocks were enriched in participants with high co-occurring symptoms. Participants with low co-occurring symptoms showed enriched abundances of Enterococcus and Lachnospiraceae, as well as pathways for β-D-glucoronosides, hexuronide/hexuronate, and nicotinate degradation, methanogenesis, and L-lysine biosynthesis. Conclusion: A number of bacterial taxa and predicted functional pathways were differentially abundant in patients with high co-occurring symptoms compared to those with low co-occurring symptoms before CRT for rectal cancer. Detailed examination of bacterial taxa and pathways mediating co-occurring symptoms is warranted.

Exploring the effects of genomic testing on fear of cancer recurrence among breast cancer survivors

Gormley, M., Knobf, M. T., Vorderstrasse, A., Aouizerat, B., Hammer, M., Fletcher, J., & D’Eramo Melkus, G. (2021). Psycho-Oncology, 30(8), 1322-1331. 10.1002/pon.5679
Abstract
Abstract
Objective: Fear of cancer recurrence (FCR) is the greatest unmet psychosocial need among breast cancer survivors (BCS). The Oncotype Dx® test predicts the 10-year risk of distant recurrence and benefit of adjuvant chemotherapy among women with early stage hormone receptor-positive breast cancer. Despite the test's clinical utility, psychosocial responses are poorly understood. Methods: A descriptive cross-sectional study was conducted to explore associations between Oncotype Dx® test results (Recurrence Score [RS]) and FCR, health-related quality of life (HRQOL), distress, anxiety, depression, illness representation and perceived risk. Bivariate analyses were used to examine the associations between variables followed by multiple linear regression to examine predictors of FCR. Results: Greater FCR was associated with higher distress, anxiety, depression, illness representation and poorer HRQOL. BCS's with a high Oncotype Dx® RS reported higher overall fear (p = 0.013) and greater perceived consequences of their cancer (p = 0.034) compared to BCS's with a low RS. Using multiple linear regression, anxiety ((Formula presented.) = 0.21, p = 0.016), greater emotional response (Formula presented.) = 0.45, p < 0.001) and perceived consequences ((Formula presented.) = 0.18, p = 0.039) of illness explained 58% of the variance (p < 0.001) in FCR. Conclusion: BCS's with higher risk of recurrence may experience higher FCR. However, for FCR, modifiable factors such as anxiety and illness representation (greater emotional response and perceived consequences of illness) may be more important than non-modifiable factors such as Oncotype Dx® test results and age. Further research is needed to develop personalized interventions to improve BCS's outcomes.

A genomic variant of ALPK2 is associated with increased liver fibrosis risk in HIV/HCV coinfected women

McIntosh, A. T., Wei, R., Ahn, J., Aouizerat, B. E., Kassaye, S. G., Augenbraun, M. H., Price, J. C., French, A. L., Gange, S. J., Anastos, K. M., & Goldman, R. (2021). PloS One, 16(3). 10.1371/journal.pone.0247277
Abstract
Abstract
HIV coinfection is associated with more rapid liver fibrosis progression in hepatitis C (HCV) infection. Recently, much work has been done to improve outcomes of liver disease and to identify targets for pharmacological intervention in coinfected patients. In this study, we analyzed clinical data of 1,858 participants from the Women’s Interagency HIV Study (WIHS) to characterize risk factors associated with changes in the APRI and FIB-4 surrogate measurements for advanced fibrosis. We assessed 887 non-synonymous single nucleotide variants (nsSNV) in a subset of 661 coinfected participants for genetic associations with changes in liver fibrosis risk. The variants utilized produced amino acid substitutions that either altered an N-linked glycosylation (NxS/T) sequon or mapped to a gene related to glycosylation processes. Seven variants were associated with an increased likelihood of liver fibrosis. The most common variant, ALPK2 rs3809973, was associated with liver fibrosis in HIV/HCV coinfected patients; individuals homozygous for the rare C allele displayed elevated APRI (0.61, 95% CI, 0.334 to 0.875) and FIB-4 (0.74, 95% CI, 0.336 to 1.144) relative to those coinfected women without the variant. Although warranting replication, ALPK2 rs3809973 may show utility to detect individuals at increased risk for liver disease progression.

Gut Microbiota and Depressive Symptoms at the End of CRT for Rectal Cancer: A Cross-Sectional Pilot Study

Gonzalez-Mercado, V. J., Lim, J., Saligan, L. N., Perez, N., Rodriguez, C., Bernabe, R., Ozorio, S., Pedro, E., Sepehri, F., & Aouizerat, B. (2021). Depression Research and Treatment, 2021. 10.1155/2021/7967552
Abstract
Abstract
Background. The role of alterations in gut microbiota composition (termed dysbiosis) has been implicated in the pathobiology of depressive symptoms; however, evidence remains limited. This cross-sectional pilot study is aimed at exploring whether depressive symptom scores changed during neoadjuvant chemotherapy and radiation therapy to treat rectal cancer, and if gut microbial taxa abundances and predicted functional pathways correlate with depressive symptoms at the end of chemotherapy and radiation therapy. Methods. 40 newly diagnosed rectal cancer patients (ages 28-81; 23 males) were assessed for depressive symptoms using the Hamilton Rating Scale for Depression (HAM-D) and provided stool samples for 16S rRNA sequencing. Gut microbiome data were analyzed using QIIME2, and correlations and regression analyses were performed in R. Results. Participants had significantly higher depressive symptoms at the end as compared to before CRT. The relative abundances of Gemella, Bacillales Family XI, Actinomyces, Streptococcus, Lactococcus, Weissella, and Leuconostocaceae were positively correlated (Spearman’s rho=0.42 to 0.32), while Coprobacter, Intestinibacter, Intestimonas, Lachnospiraceae, Phascolarctobacterium, Ruminiclostridium, Ruminococcaceae (UCG-005 and uncultured), Tyzzerella, and Parasutterella (Spearman’s rho=−0.43 to−0.31) were negatively correlated with HAM-D scores. Of the 14 predicted MetaCyc pathways that correlated with depressive symptom scores at the end of CRT, 11 (79%) were associated with biosynthetic pathways. Conclusions. Significant bacterial taxa and predicted functional pathways correlated with depressive symptoms at the end of chemotherapy and radiation therapy for rectal cancer which warrants further examination and replication of our findings.

Model-Based Patterns of Lymphedema Symptomatology: Phenotypic and Biomarker Characterization

Fu, M. R., Aouizerat, B. E., Yu, G., Conley, Y., Axelrod, D., Guth, A. A., Gagner, J. P., Qiu, J. M., & Zagzag, D. (2021). Current Breast Cancer Reports, 13(1). 10.1007/s12609-020-00397-6
Abstract
Abstract
Purpose of the Study: More than 50% of breast cancer survivors without a diagnosis of lymphedema suffer daily from numerous and co-occurring lymphedema symptoms. This study aimed to identify lymphedema symptom patterns and the association of such patterns with phenotypic characteristics and biomarkers using latent class analysis (LCA). A prospective, descriptive, and repeated-measure design was used to enroll 140 women and collect data. Recent Findings: LCA identified three distinct lymphedema symptom classes at 8 weeks and 12 months post-surgery: low, moderate, and severe symptom classes and associated phenotypic characteristics. Participants were more likely to be in the severe symptom classes at 12 months post-surgery if they had lower education level, cording, an axillary syndrome at 8 weeks post-surgery, neoadjuvant chemotherapy, and radiation. Summary: Pre-surgery level of IL1-a, IL-6, IL-8, and VEGF was associated with the severe symptom class at 8 weeks post-surgery, suggesting that such biomarkers may be used to predict risk for lymphedema symptoms.

Prevalence and correlates of restless legs syndrome in men living with HIV

Wallace, D. M., Alcaide, M. L., Wohlgemuth, W. K., Jones Weiss, D. L., Starita, C. U., Patel, S. R., Stosor, V., Levine, A., Skvarca, C., Long, D. M., Rubtsova, A., Adimora, A. A., Gange, S. J., Spence, A. B., Anastos, K., Aouizerat, B. E., Anziska, Y., & Punjabi, N. M. (2021). PloS One, 16(10). 10.1371/journal.pone.0258139
Abstract
Abstract
Background Data on the prevalence and correlates of restless legs syndrome (RLS) in people with HIV are limited. This study sought to determine the prevalence of RLS, associated clinical correlates, and characterize sleep-related differences in men with and without HIV. Methods Sleep-related data were collected in men who have sex with men participating in the Multicenter AIDS Cohort Study (MACS). Demographic, health behaviors, HIV status, comorbidities, and serological data were obtained from the MACS visit coinciding with sleep assessments. Participants completed questionnaires, home polysomnography, and wrist actigraphy. RLS status was determined with the Cambridge-Hopkins RLS questionnaire. RLS prevalence was compared in men with and without HIV. Multinomial logistic regression was used to examine correlates of RLS among all participants and men with HIV alone. Sleep-related differences were examined in men with and without HIV by RLS status. Results The sample consisted of 942 men (56% HIV+; mean age 57 years; 69% white). The prevalence of definite RLS was comparable in men with and without HIV (9.1% vs 8.7%). In multinomial regression, HIV status was not associated with RLS prevalence. However, white race, anemia, depression, and antidepressant use were each independently associated with RLS. HIV disease duration was also associated with RLS. Men with HIV and RLS reported poorer sleep quality, greater sleepiness, and had worse objective sleep efficiency/ fragmentation than men without HIV/RLS. Conclusions The prevalence of RLS in men with and without HIV was similar. Screening for RLS may be considered among people with HIV with insomnia and with long-standing disease.