Browsing by Author "Wang, Youjin"

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    Bile acid synthesis, modulation, and dementia: A metabolomic, transcriptomic, and pharmacoepidemiologic study
    (PLOS, 2021-05-27) Varma, Vijay R.; Wang, Youjin; An, Yang; Varma, Sudhir; Bilgel, Murat; Doshi, Jimit; Legido-Quigley, Cristina; Delgado, João C.; Oommen, Anup M.; Roberts, Jackson A.; Wong, Dean F.; Davatzikos, Christos; Resnick, Susan M.; Troncoso, Juan C.; Pletnikova, Olga; O’Brien, Richard; Hak, Eelko; Baak, Brenda N.; Pfeiffer, Ruth; Baloni, Priyanka; Mohmoudiandehkordi, Siamak; Nho, Kwangsik; Kaddurah-Daouk, Rima; Bennett, David A.; Gadalla, Shahinaz M.; Thambisetty, Madhav; Radiology and Imaging Sciences, School of Medicine
    Background: While Alzheimer disease (AD) and vascular dementia (VaD) may be accelerated by hypercholesterolemia, the mechanisms underlying this association are unclear. We tested whether dysregulation of cholesterol catabolism, through its conversion to primary bile acids (BAs), was associated with dementia pathogenesis. Methods and findings: We used a 3-step study design to examine the role of the primary BAs, cholic acid (CA), and chenodeoxycholic acid (CDCA) as well as their principal biosynthetic precursor, 7α-hydroxycholesterol (7α-OHC), in dementia. In Step 1, we tested whether serum markers of cholesterol catabolism were associated with brain amyloid accumulation, white matter lesions (WMLs), and brain atrophy. In Step 2, we tested whether exposure to bile acid sequestrants (BAS) was associated with risk of dementia. In Step 3, we examined plausible mechanisms underlying these findings by testing whether brain levels of primary BAs and gene expression of their principal receptors are altered in AD. Step 1: We assayed serum concentrations CA, CDCA, and 7α-OHC and used linear regression and mixed effects models to test their associations with brain amyloid accumulation (N = 141), WMLs, and brain atrophy (N = 134) in the Baltimore Longitudinal Study of Aging (BLSA). The BLSA is an ongoing, community-based cohort study that began in 1958. Participants in the BLSA neuroimaging sample were approximately 46% male with a mean age of 76 years; longitudinal analyses included an average of 2.5 follow-up magnetic resonance imaging (MRI) visits. We used the Alzheimer's Disease Neuroimaging Initiative (ADNI) (N = 1,666) to validate longitudinal neuroimaging results in BLSA. ADNI is an ongoing, community-based cohort study that began in 2003. Participants were approximately 55% male with a mean age of 74 years; longitudinal analyses included an average of 5.2 follow-up MRI visits. Lower serum concentrations of 7α-OHC, CA, and CDCA were associated with higher brain amyloid deposition (p = 0.041), faster WML accumulation (p = 0.050), and faster brain atrophy mainly (false discovery rate [FDR] p = <0.001-0.013) in males in BLSA. In ADNI, we found a modest sex-specific effect indicating that lower serum concentrations of CA and CDCA were associated with faster brain atrophy (FDR p = 0.049) in males.Step 2: In the Clinical Practice Research Datalink (CPRD) dataset, covering >4 million registrants from general practice clinics in the United Kingdom, we tested whether patients using BAS (BAS users; 3,208 with ≥2 prescriptions), which reduce circulating BAs and increase cholesterol catabolism, had altered dementia risk compared to those on non-statin lipid-modifying therapies (LMT users; 23,483 with ≥2 prescriptions). Patients in the study (BAS/LMT) were approximately 34%/38% male and with a mean age of 65/68 years; follow-up time was 4.7/5.7 years. We found that BAS use was not significantly associated with risk of all-cause dementia (hazard ratio (HR) = 1.03, 95% confidence interval (CI) = 0.72-1.46, p = 0.88) or its subtypes. We found a significant difference between the risk of VaD in males compared to females (p = 0.040) and a significant dose-response relationship between BAS use and risk of VaD (p-trend = 0.045) in males.Step 3: We assayed brain tissue concentrations of CA and CDCA comparing AD and control (CON) samples in the BLSA autopsy cohort (N = 29). Participants in the BLSA autopsy cohort (AD/CON) were approximately 50%/77% male with a mean age of 87/82 years. We analyzed single-cell RNA sequencing (scRNA-Seq) data to compare brain BA receptor gene expression between AD and CON samples from the Religious Orders Study and Memory and Aging Project (ROSMAP) cohort (N = 46). ROSMAP is an ongoing, community-based cohort study that began in 1994. Participants (AD/CON) were approximately 56%/36% male with a mean age of 85/85 years. In BLSA, we found that CA and CDCA were detectable in postmortem brain tissue samples and were marginally higher in AD samples compared to CON. In ROSMAP, we found sex-specific differences in altered neuronal gene expression of BA receptors in AD. Study limitations include the small sample sizes in the BLSA cohort and likely inaccuracies in the clinical diagnosis of dementia subtypes in primary care settings. Conclusions: We combined targeted metabolomics in serum and amyloid positron emission tomography (PET) and MRI of the brain with pharmacoepidemiologic analysis to implicate dysregulation of cholesterol catabolism in dementia pathogenesis. We observed that lower serum BA concentration mainly in males is associated with neuroimaging markers of dementia, and pharmacological lowering of BA levels may be associated with higher risk of VaD in males. We hypothesize that dysregulation of BA signaling pathways in the brain may represent a plausible biologic mechanism underlying these results. Together, our observations suggest a novel mechanism relating abnormalities in cholesterol catabolism to risk of dementia.
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    Impact of cytogenetic abnormalities on outcomes of adult Philadelphia-negative acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation: a study by the Acute Leukemia Working Committee of the Center for International Blood and Marrow Transplant Research
    (Ferrata Storti Foundation, 2019-09-26) Lazaryan, Aleksandr; Dolan, Michelle; Zhang, Mei-Jie; Wang, Hai-Lin; Kharfan-Dabaja, Mohamed A.; Marks, David I.; Bejanyan, Nelli; Copelan, Edward; Majhail, Navneet S.; Waller, Edmund K.; Chao, Nelson; Prestidge, Tim; Nishihori, Taiga; Kebriaei, Partow; Inamoto, Yoshihiro; Hamilton, Betty; Hashmi, Shahrukh K.; Kamble, Rammurti T.; Bacher, Ulrike; Hildebrandt, Gerhard C.; Stiff, Patrick J.; McGuirk, Joseph; Aldoss, Ibrahim; Beitinjaneh, Amer M.; Muffly, Lori; Vij, Ravi; Olsson, Richard F.; Byrne, Michael; Schultz, Kirk R.; Aljurf, Mahmoud; Seftel, Matthew; Savoie, Mary Lynn; Savani, Bipin N.; Verdonck, Leo F.; Cairo, Mitchell S.; Hossain, Nasheed; Bhatt, Vijaya Raj; Frangoul, Haydar A.; Abdel-Azim, Hisham; Al Malki, Monzr; Munker, Reinhold; Rizzieri, David; Khera, Nandita; Nakamura, Ryotaro; Ringdén, Olle; van der Poel, Marjolein; Murthy, Hemant S.; Liu, Hongtao; Mori, Shahram; De Oliveira, Satiro; Bolaños-Meade, Javier; Elsawy, Mahmoud; Barba, Pere; Nathan, Sunita; George, Biju; Pawarode, Attaphol; Grunwald, Michael; Agrawal, Vaibhav; Wang, Youjin; Assal, Amer; Castillo Caro, Paul; Kuwatsuka, Yachiyo; Seo, Sachiko; Ustun, Celalettin; Politikos, Ioannis; Lazarus, Hillard M.; Saber, Wael; Sandmaier, Brenda M.; De Lima, Marcos; Litzow, Mark; Bachanova, Veronika; Weisdorf, Daniel; Acute Leukemia Committee of the CIBMTR; Medicine, School of Medicine
    Cytogenetic risk stratification at diagnosis has long been one of the most useful tools to assess prognosis in acute lymphoblastic leukemia (ALL). To examine the prognostic impact of cytogenetic abnormalities on outcomes after allogeneic hematopoietic cell transplantation, we studied 1731 adults with Philadelphia-negative ALL in complete remission who underwent myeloablative or reduced intensity/non-myeloablative conditioning transplant from unrelated or matched sibling donors reported to the Center for International Blood and Marrow Transplant Research. A total of 632 patients had abnormal conventional metaphase cytogenetics. The leukemia-free survival and overall survival rates at 5 years after transplantation in patients with abnormal cytogenetics were 40% and 42%, respectively, which were similar to those in patients with a normal karyotype. Of the previously established cytogenetic risk classifications, modified Medical Research Council-Eastern Cooperative Oncology Group score was the only independent prognosticator of leukemia-free survival (P=0.03). In the multivariable analysis, monosomy 7 predicted post-transplant relapse [hazard ratio (HR)=2.11; 95% confidence interval (95% CI): 1.04-4.27] and treatment failure (HR=1.97; 95% CI: 1.20-3.24). Complex karyotype was prognostic for relapse (HR=1.69; 95% CI: 1.06-2.69), whereas t(8;14) predicted treatment failure (HR=2.85; 95% CI: 1.35-6.02) and overall mortality (HR=3.03; 95% CI: 1.44-6.41). This large study suggested a novel transplant-specific cytogenetic scheme with adverse [monosomy 7, complex karyotype, del(7q), t(8;14), t(11;19), del(11q), tetraploidy/near triploidy], intermediate (normal karyotype and all other abnormalities), and favorable (high hyperdiploidy) risks to prognosticate leukemia-free survival (P=0.02). Although some previously established high-risk Philadelphia-negative cytogenetic abnormalities in ALL can be overcome by transplantation, monosomy 7, complex karyotype, and t(8;14) continue to pose significant risks and yield inferior outcomes.
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    Reduced intensity conditioning for acute myeloid leukemia using melphalan- vs busulfan-based regimens: a CIBMTR report
    (SAGE, 2020-07-14) Zhou, Zheng; Nath, Rajneesh; Cerny, Jan; Wang, Hai-Lin; Zhang, Mei-Jie; Abdel-Azim, Hisham; Agrawal, Vaibhav; Ahmed, Gulrayz; Al-Homsi, A. Samer; Aljurf, Mahmoud; Alkhateeb, Hassan B.; Assal, Amer; Bacher, Ulrike; Bajel, Ashish; Bashir, Qaiser; Battiwalla, Minocher; Bhatt, Vijaya Raj; Byrne, Michael; Cahn, Jean-Yves; Cairo, Mitchell; Choe, Hannah; Copelan, Edward; Cutler, Corey; Damlaj, Moussab B.; DeFilipp, Zachariah; De Lima, Marcos; Diaz, Miguel Angel; Farhadfar, Nosha; Foran, James; Freytes, César O.; Gerds, Aaron T.; Gergis, Usama; Grunwald, Michael R.; Gul, Zartash; Hamadani, Mehdi; Hashmi, Shahrukh; Hertzberg, Mark; Hildebrandt, Gerhard C.; Hossain, Nasheed; Inamoto, Yoshihiro; Isola, Luis; Jain, Tania; Kamble, Rammurti T.; Khan, Muhammad Waqas; Kharfan-Dabaja, Mohamed A.; Kebriaei, Partow; Kekre, Natasha; Khera, Nandita; Lazarus, Hillard M.; Liesveld, Jane L.; Litzow, Mark; Liu, Hongtao; Marks, David I.; Martino, Rodrigo; Mathews, Vikram; Mishra, Asmita; Murthy, Hemant S.; Nagler, Arnon; Nakamura, Ryotaro; Nathan, Sunita; Nishihori, Taiga; Olin, Rebecca; Olsson, Richard F.; Palmisiano, Neil; Patel, Sagar S.; Patnaik, Mrinal M.; Pawarode, Attaphol; Perales, Miguel-Angel; Politikos, Ioannis; Popat, Uday; Rizzieri, David; Sandmaier, Brenda M.; Savani, Bipin N.; Seo, Sachiko; Shah, Nirav N.; Uy, Geoffrey L.; Valcárcel, David; Verdonck, Leo F.; Waller, Edmund K.; Wang, Youjin; Weisdorf, Daniel; Wirk, Baldeep; Wong, Eric; Yared, Jean A.; Saber, Wael; Medicine, School of Medicine
    There is a lack of large comparative study on the outcomes of reduced intensity conditioning (RIC) in acute myeloid leukemia (AML) transplantation using fludarabine/busulfan (FB) and fludarabine/melphalan (FM) regimens. Adult AML patients from Center for International Blood and Marrow Transplant Research who received first RIC allo-transplant between 2001 and 2015 were studied. Patients were excluded if they received cord blood or identical twin transplant, total body irradiation in conditioning, or graft-versus-host disease (GVHD) prophylaxis with in vitro T-cell depletion. Primary outcome was overall survival (OS), secondary end points were leukemia-free survival (LFS), nonrelapse mortality (NRM), relapse, and GVHD. Multivariate survival model was used with adjustment for patient, leukemia, and transplant-related factors. A total of 622 patients received FM and 791 received FB RIC. Compared with FB, the FM group had fewer transplant in complete remission (CR), fewer matched sibling donors, and less usage of anti-thymocyte globulin or alemtuzumab. More patients in the FM group received marrow grafts and had transplantation before 2005. OS was significantly lower within the first 3 months posttransplant in the FM group (hazard ratio [HR] = 1.82, P < .001), but was marginally superior beyond 3 months (HR = 0.87, P = .05). LFS was better with FM compared with FB (HR = 0.89, P = .05). NRM was significantly increased in the FM group during the first 3 months of posttransplant (HR = 3.85, P < .001). Long-term relapse was lower with FM (HR = 0.65, P < .001). Analysis restricted to patients with CR showed comparable results. In conclusion, compared with FB, the FM RIC showed a marginally superior long-term OS and LFS and a lower relapse rate. A lower OS early posttransplant within 3 months was largely the result of a higher early NRM.