👤 Daniel J Beckman

Aging is the strongest risk factor for dementia; however, few studies have examined the association of biological aging with incident dementia. We analyzed 6069 cognitively unimpaired women (mean age = 70.0 ± 3.8 years) in the Women's Health Initiative Memory Study to examine the association of accelerated biological aging, measured with second and third-generation epigenetic clocks (AgeAccelPheno and AgeAccelGrim2, and DunedinPACE, respectively) with incident mild cognitive impairment (MCI) and probable dementia. Multivariable Cox proportional hazards models adjusted for age, education, race, ethnicity, smoking, hormone therapy regimen, physical activity, body mass index, and estimated white blood cell counts. For comparison, we also examined first-generation epigenetic clocks (AgeAccelHorvath; AgeAccelHannum). We evaluated effect modification by age, race/ethnicity, hormone therapy regimen, menopause type (natural vs. surgical), and APOE ε4 carriage. There were 1307 incident MCI or probable dementia events over a median follow-up of 9.3 (25th percentile = 6.1, 75th percentile = 16.1) years. The adjusted HRs (95% CI; p-value) for incident MCI/probable dementia per one-standard deviation increment were 1.07 (1.01-1.15; p = 0.03) for DunedinPACE, 1.11 (1.02-1.20; p = 0.01) for AgeAccelGrim2, and 1.01 (0.95-1.07; p = 0.74) for AgeAccelPheno. Only AgeAccelGrim2 remained significant under the Bonferroni-corrected threshold for significance (p < 0.02). Other epigenetic clocks were not associated with incident MCI/probable dementia. There was no effect modification in most subgroup analyses (p-interaction ≥ 0.05). In this cohort study of older women, accelerated biological aging measured by AgeAccelGrim2 was associated with higher risk of incident MCI/probable dementia. These findings provide evidence linking epigenetic biomarkers of biological aging with MCI and dementia development, independent of chronological age. Show less

The epigenetic mechanisms of asthma remain largely understudied in African Americans and Hispanics/Latinos, two populations disproportionately affected by asthma. We aimed to identify markers, regions and processes with differential patterns of DNA methylation (DNAm) in whole blood by asthma status in ethnically diverse children and youth, and to assess their functional consequences. DNAm levels were profiled with the Infinium MethylationEPIC or HumanMethylation450 BeadChip arrays among 1226 African Americans or Hispanics/Latinos and assessed for differential methylation per asthma status at the CpG and region (differentially methylated region (DMR)) level. Novel associations were validated in blood and/or nasal epithelium from ethnically diverse children and youth. The functional and biological implications of the markers identified were investigated by combining epigenomics with transcriptomics from study participants. 128 CpGs and 196 DMRs were differentially methylated after multiple testing corrections, including 92.3% and 92.8% novel associations, respectively. 41 CpGs were replicated in other Hispanics/Latinos, prioritising cg17647904 ( We report novel whole-blood DNAm markers for asthma underlying key processes of the disease pathophysiology and confirm the transferability of previous asthma DNAm associations to ethnically diverse populations. Show less

Many biomedical engineering degree programs lack substantial immersive clinical experiences for undergraduate students, creating a need for clinical immersion programs that contribute to training objectives that emphasize current clinical needs (Becker in Eur J Eng Educ 31:261-272, 2006; Davis et al. in J Eng Educ 91:211-221, 2002; Dym et al. in J Eng Educ 94:103-120, 2005). Immersive clinical experiences have the potential to bridge the gap between clinical and non-clinical learning objectives in biomedical engineering curriculum. In collaboration with Indiana University Health Methodist Hospital, we have created, executed, and evaluated a two-week cardiovascular clinical immersion program for biomedical engineering undergraduate students at Purdue University. As of August 2022, this program has run 11 times since 2014 with 60 participants to date, exposing students to intensive and non-intensive care environments, facilitating interactions with medical professionals, and encouraging exploration of innovative technologies shaping the training of clinicians with direct patient interaction. The variety of cardiovascular topics discussed and clinical settings observed has provided students with a unique, highly beneficial learning opportunity. Keys to the continued success and growth of similar programs include: recruiting a diverse team, support from administrative staff/clinicians, a funded student intern position, and careful consideration of liability/risk management. Areas of future consideration include, streamlining the order of scheduled events, determining if offering course credit would be beneficial to students, and tracking career trajectories after participations. Show less

Mitogen-activated protein kinases (MAPKs) regulate diverse cellular processes including proliferation, cell survival, differentiation, and apoptosis. While conventional MAPK constituents have well-defined roles in oncogenesis, the MEK5 pathway has only recently emerged in cancer research. In this review, we consider the MEK5 signaling cascade, focusing specifically on its involvement in drug resistance and regulation of aggressive cancer phenotypes. Moreover, we explore the role of MEK5/ERK5 in tumorigenesis and metastatic progression, discussing the discrepancies in preclinical studies and assessing its viability as a therapeutic target for anti-cancer agents. Show less

Endocrine resistance and metastatic progression are primary causes of treatment failure in breast cancer. While mitogen activated protein kinases (MAPKs) are known to promote ligand-independent cell growth, the role of the MEK5-ERK5 pathway in the progression of clinical breast carcinoma remains poorly understood. Here, we demonstrated increased ERK5 activation in 30 of 39 (76.9%) clinical tumor samples, as well as across breast cancer cell systems. Overexpression of MEK5 in MCF-7 cells promoted both hormone-dependent and hormone-independent tumorigenesis in vitro and in vivo and conferred endocrine therapy resistance to previously sensitive breast cancer cells. Expression of MEK5 suppressed estrogen receptor (ER)α, but not ER-β protein levels, and abrogated downstream estrogen response element (ERE) transcriptional activity and ER-mediated gene transcription. Global gene expression changes associated with upregulation of MEK5 included increased activation of ER-α independent growth signaling pathways and promotion of epithelial-to-mesenchymal transition (EMT) markers. Taken together, our findings show that the MEK5-ERK5 pathway mediates progression to an ER(-), mesenchymal and endocrine therapy resistant phenotype. Given the need for new clinical therapeutic targets, our results demonstrate the therapeutic potential of targeting the MEK5-ERK5 pathway in breast cancer. Show less

Despite intensive study of the mechanisms of chemotherapeutic drug resistance in human breast cancer, few reports have systematically investigated the mechanisms that underlie resistance to the chemotherapy-sensitizing agent tumor necrosis factor (TNF)-alpha. Additionally, the relationship between TNF-alpha resistance mediated by MEK5/Erk5 signaling and epithelial-mesenchymal transition (EMT), a process associated with promotion of invasion, metastasis, and recurrence in breast cancer, has not previously been investigated. To compare differences in the proteome of the TNF-alpha resistant MCF-7 breast cancer cell line MCF-7-MEK5 (in which TNF-alpha resistance is mediated by MEK5/Erk5 signaling) and its parental TNF-a sensitive MCF-7 cell line MCF-7-VEC, two-dimensional gel electrophoresis and high performance capillary liquid chromatography coupled with tandem mass spectrometry approaches were used. Differential protein expression was verified at the transcriptional level using RT-PCR assays. An EMT phenotype was confirmed using immunofluorescence staining and gene expression analyses. A short hairpin RNA strategy targeting Erk5 was utilized to investigate the requirement for the MEK/Erk5 pathway in EMT. Proteomic analyses and PCR assays were used to identify and confirm differential expression of proteins. In MCF-7-MEK5 versus MCF-7-VEC cells, vimentin (VIM), glutathione-S-transferase P (GSTP1), and creatine kinase B-type (CKB) were upregulated, and keratin 8 (KRT8), keratin 19 (KRT19) and glutathione-S-transferase Mu 3 (GSTM3) were downregulated. Morphology and immunofluorescence staining for E-cadherin and vimentin revealed an EMT phenotype in the MCF-7-MEK5 cells. Furthermore, EMT regulatory genes SNAI2 (slug), ZEB1 (delta-EF1), and N-cadherin (CDH2) were upregulated, whereas E-cadherin (CDH1) was downregulated in MCF-7-MEK5 cells versus MCF-7-VEC cells. RNA interference targeting of Erk5 reversed MEK5-mediated EMT gene expression. This study demonstrates that MEK5 over-expression promotes a TNF-alpha resistance phenotype associated with distinct proteomic changes (upregulation of VIM/vim, GSTP1/gstp1, and CKB/ckb; and downregulation of KRT8/krt8, KRT19/krt19, and GSTM3/gstm3). We further demonstrate that MEK5-mediated progression to an EMT phenotype is dependent upon intact Erk5 and associated with upregulation of SNAI2 and ZEB1 expression. Show less

Components of the mitogen-activated protein kinase (MAPK) cascade have been implicated in apoptotic regulation. This study used gene expression profiling analysis to identify and implicate mitogen-activated protein kinase kinase (MEK5)-BMK1 (big mitogen-activated kinase-1)/extracellular signal related protein kinase (ERK5) pathway as a novel target involved in chemoresistance. Differential gene expression between apoptotically sensitive (APO+) and apoptotically resistant (APO-) MCF-7 cell variants was determined by using microarray and confirmed by reverse transcriptase- polymerase chain reaction (RT-PCR). An apoptotic/viability reporter gene assay was used to deter-mine the effects of the transfection of a dominant-negative mutant of BMK1 (BMK1/DN) in conjunction with apoptotic-inducing agents (etoposide, tumor necrosis factor-alpha [TNF], or TNF-related apoptosis-inducing ligand [TRAIL]), with or without phorbol ester (PMA). Of the 1186 genes detected through microarray analysis, MEK5 was increased 22-fold in APO- cells. Overexpression of MEK5 was confirmed by using RT-PCR analysis. Expression of BMK1/DN alone resulted in a dose-dependent increase in cell death versus control (P <.05). In addition, BMK1/DN enhanced the sensitivity of MCF-7 cells to treatment-induced cell death (P <.05). The ability of PMA to partially suppress TRAIL- and TNF-induced cell death was inhibited by BMK1/DN. However, only TRAIL-induced activity suppression reached statistical significance (P <.05). The overexpression of MEK5 in APO- MCF-7 breast carcinoma cells shows that this MAPK signaling protein represents a potent survival molecule. Molecular inhibition of MEK5 signaling may represent a mechanism for sensitizing cancer cells to chemotherapeutic regimens. Show less