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Pershad Y, Mack T, Poisner H, Jakubek YA, Stilp AM, Mitchell BD, Lewis JP, Boerwinkle E, Loos RJF, Chami N, Wang Z, Barnes K, Pankratz N, Fornage M, Redline S, Psaty BM, Bis JC, Shojaie A, Silverman EK, Cho MH, Yun JH, DeMeo D, Levy D, Johnson AD, Mathias RA, Taub MA, Arnett D, North KE, Raffield LM, Carson AP, Doyle MF, Rich SS, Rotter JI, Guo X, Cox NJ, Roden DM, Franceschini N, Desai P, Reiner AP, Auer PL, Scheet PA, Jaiswal S, Weinstock JS, Bick AG. Determinants of mosaic chromosomal alteration fitness. Nat Commun 2024; 15:3800. [PMID: 38714703 PMCID: PMC11076528 DOI: 10.1038/s41467-024-48190-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 04/23/2024] [Indexed: 05/10/2024] Open
Abstract
Clonal hematopoiesis (CH) is characterized by the acquisition of a somatic mutation in a hematopoietic stem cell that results in a clonal expansion. These driver mutations can be single nucleotide variants in cancer driver genes or larger structural rearrangements called mosaic chromosomal alterations (mCAs). The factors that influence the variations in mCA fitness and ultimately result in different clonal expansion rates are not well understood. We used the Passenger-Approximated Clonal Expansion Rate (PACER) method to estimate clonal expansion rate as PACER scores for 6,381 individuals in the NHLBI TOPMed cohort with gain, loss, and copy-neutral loss of heterozygosity mCAs. Our mCA fitness estimates, derived by aggregating per-individual PACER scores, were correlated (R2 = 0.49) with an alternative approach that estimated fitness of mCAs in the UK Biobank using population-level distributions of clonal fraction. Among individuals with JAK2 V617F clonal hematopoiesis of indeterminate potential or mCAs affecting the JAK2 gene on chromosome 9, PACER score was strongly correlated with erythrocyte count. In a cross-sectional analysis, genome-wide association study of estimates of mCA expansion rate identified a TCL1A locus variant associated with mCA clonal expansion rate, with suggestive variants in NRIP1 and TERT.
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Shojaie A, Al Khleifat A, Sarraf P, Al-Chalabi A. Analysis of non-motor symptoms in amyotrophic lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener 2024; 25:237-241. [PMID: 37981575 DOI: 10.1080/21678421.2023.2280618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/01/2023] [Indexed: 11/21/2023]
Abstract
OBJECTIVE We investigated non-motor symptoms in ALS using sequential questionnaires; here we report the findings of the second questionnaire. METHODS A social media platform (Twitter, now known as X) was used to publicize the questionnaires. Data were downloaded from SurveyMonkey and analyzed by descriptive statistics, comparison of means, and regression models. RESULTS There were 182 people with ALS and 57 controls. The most important non-motor symptoms were cold limbs (60.4% cases, 14% controls, p = 9.67 x 10-10) and appetite loss (29.7% cases, 5.3% controls, p = 1.6 x 10-4). The weaker limb was most likely to feel cold (p = 9.67 x 10-10), and symptoms were more apparent in the evening and night. Appetite loss was reported as due to feeling full and the time taken to eat. People with ALS experienced medium-intensity pain, more usually shock-like pain than burning or cold-like pain, although the most prevalent type of pain was non-differentiated. CONCLUSIONS Non-motor symptoms are an important feature of ALS. Further investigation is needed to understand their physiological basis and whether they represent phenotypic differences useful for subtyping ALS.
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Hudson A, Shojaie A. Statistical inference on qualitative differences in the magnitude of an effect. Stat Med 2024; 43:1419-1440. [PMID: 38305667 PMCID: PMC10947912 DOI: 10.1002/sim.10025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2023] [Indexed: 02/03/2024]
Abstract
Qualitative interactions occur when a treatment effect or measure of association varies in sign by sub-population. Of particular interest in many biomedical settings are absence/presence qualitative interactions, which occur when an effect is present in one sub-population but absent in another. Absence/presence interactions arise in emerging applications in precision medicine, where the objective is to identify a set of predictive biomarkers that have prognostic value for clinical outcomes in some sub-population but not others. They also arise naturally in gene regulatory network inference, where the goal is to identify differences in networks corresponding to diseased and healthy individuals, or to different subtypes of disease; such differences lead to identification of network-based biomarkers for diseases. In this paper, we argue that while the absence/presence hypothesis is important, developing a statistical test for this hypothesis is an intractable problem. To overcome this challenge, we approximate the problem in a novel inference framework. In particular, we propose to make inferences about absence/presence interactions by quantifying the relative difference in effect size, reasoning that when the relative difference is large, an absence/presence interaction occurs. The proposed methodology is illustrated through a simulation study as well as an analysis of breast cancer data from the Cancer Genome Atlas.
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Shojaie A, Al Khleifat A, Opie-Martin S, Sarraf P, Al-Chalabi A. Non-motor symptoms in amyotrophic lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener 2024; 25:61-66. [PMID: 37798838 PMCID: PMC11090076 DOI: 10.1080/21678421.2023.2263868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/19/2023] [Indexed: 10/07/2023]
Abstract
OBJECTIVE While motor symptoms are well-known in ALS, non-motor symptoms are often under-reported and may have a significant impact on quality of life. In this study, we aimed to examine the nature and extent of non-motor symptoms in ALS. METHODS A 20-item questionnaire was developed covering the domains of autonomic function, sleep, pain, gastrointestinal disturbance, and emotional lability, posted online and shared on social media platforms to target people with ALS and controls. RESULTS A total of 1018 responses were received, of which 927 were complete from 506 people with ALS and 421 unaffected individuals. Cold limbs (p 1.66 × 10-36), painful limbs (p 6.14 × 10-28), and urinary urgency (p 4.70 × 10-23) were associated with ALS. People with ALS were more likely to report autonomic symptoms, pain, and psychiatric symptoms than controls (autonomic symptoms B = 0.043, p 6.10 × 10-5, pain domain B = 0.18, p 3.72 × 10-11 and psychiatric domain B = 0.173, p 1.32 × 10-4). CONCLUSIONS Non-motor symptoms in ALS are common. The identification and management of non-motor symptoms should be integrated into routine clinical care for people with ALS. Further research is warranted to investigate the relationship between non-motor symptoms and disease progression, as well as to develop targeted interventions to improve the quality of life for people with ALS.
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Xia L, Hantrakun V, Teparrukkul P, Wongsuvan G, Kaewarpai T, Dulsuk A, Day NPJ, Lemaitre RN, Chantratita N, Limmathurotsakul D, Shojaie A, Gharib SA, West TE. Plasma Metabolomics Reveals Distinct Biological and Diagnostic Signatures for Melioidosis. Am J Respir Crit Care Med 2024; 209:288-298. [PMID: 37812796 PMCID: PMC10840774 DOI: 10.1164/rccm.202207-1349oc] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/09/2023] [Indexed: 10/11/2023] Open
Abstract
Rationale: The global burden of sepsis is greatest in low-resource settings. Melioidosis, infection with the gram-negative bacterium Burkholderia pseudomallei, is a frequent cause of fatal sepsis in endemic tropical regions such as Southeast Asia. Objectives: To investigate whether plasma metabolomics would identify biological pathways specific to melioidosis and yield clinically meaningful biomarkers. Methods: Using a comprehensive approach, differential enrichment of plasma metabolites and pathways was systematically evaluated in individuals selected from a prospective cohort of patients hospitalized in rural Thailand with infection. Statistical and bioinformatics methods were used to distinguish metabolomic features and processes specific to patients with melioidosis and between fatal and nonfatal cases. Measurements and Main Results: Metabolomic profiling and pathway enrichment analysis of plasma samples from patients with melioidosis (n = 175) and nonmelioidosis infections (n = 75) revealed a distinct immuno-metabolic state among patients with melioidosis, as suggested by excessive tryptophan catabolism in the kynurenine pathway and significantly increased levels of sphingomyelins and ceramide species. We derived a 12-metabolite classifier to distinguish melioidosis from other infections, yielding an area under the receiver operating characteristic curve of 0.87 in a second validation set of patients. Melioidosis nonsurvivors (n = 94) had a significantly disturbed metabolome compared with survivors (n = 81), with increased leucine, isoleucine, and valine metabolism, and elevated circulating free fatty acids and acylcarnitines. A limited eight-metabolite panel showed promise as an early prognosticator of mortality in melioidosis. Conclusions: Melioidosis induces a distinct metabolomic state that can be examined to distinguish underlying pathophysiological mechanisms associated with death. A 12-metabolite signature accurately differentiates melioidosis from other infections and may have diagnostic applications.
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Hampe CS, Shojaie A, Brooks-Worrell B, Dibay S, Utzschneider K, Kahn SE, Larkin ME, Johnson ML, Younes N, Rasouli N, Desouza C, Cohen RM, Park JY, Florez HJ, Valencia WM, Palmer JP, Balasubramanyam A. GAD65Abs Are Not Associated With Beta-Cell Dysfunction in Patients With T2D in the GRADE Study. J Endocr Soc 2024; 8:bvad179. [PMID: 38333889 PMCID: PMC10853002 DOI: 10.1210/jendso/bvad179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Indexed: 02/10/2024] Open
Abstract
Context Autoantibodies directed against the 65-kilodalton isoform of glutamic acid decarboxylase (GAD65Abs) are markers of autoimmune type 1 diabetes (T1D) but are also present in patients with Latent Autoimmune Diabetes of Adults and autoimmune neuromuscular diseases, and also in healthy individuals. Phenotypic differences between these conditions are reflected in epitope-specific GAD65Abs and anti-idiotypic antibodies (anti-Id) against GAD65Abs. We previously reported that 7.8% of T2D patients in the GRADE study have GAD65Abs but found that GAD65Ab positivity was not correlated with beta-cell function, glycated hemoglobin (HbA1c), or fasting glucose levels. Context In this study, we aimed to better characterize islet autoantibodies in this T2D cohort. This is an ancillary study to NCT01794143. Methods We stringently defined GAD65Ab positivity with a competition assay, analyzed GAD65Ab-specific epitopes, and measured GAD65Ab-specific anti-Id in serum. Results Competition assays confirmed that 5.9% of the patients were GAD65Ab positive, but beta-cell function was not associated with GAD65Ab positivity, GAD65Ab epitope specificity or GAD65Ab-specific anti-Id. GAD65-related autoantibody responses in GRADE T2D patients resemble profiles in healthy individuals (low GAD65Ab titers, presence of a single autoantibody, lack of a distinct epitope pattern, and presence of anti-Id to diabetes-associated GAD65Ab). In this T2D cohort, GAD65Ab positivity is likely unrelated to the pathogenesis of beta-cell dysfunction. Conclusion Evidence for islet autoimmunity in the pathophysiology of T2D beta-cell dysfunction is growing, but T1D-associated autoantibodies may not accurately reflect the nature of their autoimmune process.
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Wang Y, Shojaie A, Randolph T, Knight P, Ma J. GENERALIZED MATRIX DECOMPOSITION REGRESSION: ESTIMATION AND INFERENCE FOR TWO-WAY STRUCTURED DATA. Ann Appl Stat 2023; 17:2944-2969. [PMID: 38149262 PMCID: PMC10751029 DOI: 10.1214/23-aoas1746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Motivated by emerging applications in ecology, microbiology, and neuroscience, this paper studies high-dimensional regression with two-way structured data. To estimate the high-dimensional coefficient vector, we propose the generalized matrix decomposition regression (GMDR) to efficiently leverage auxiliary information on row and column structures. GMDR extends the principal component regression (PCR) to two-way structured data, but unlike PCR, GMDR selects the components that are most predictive of the outcome, leading to more accurate prediction. For inference on regression coefficients of individual variables, we propose the generalized matrix decomposition inference (GMDI), a general high-dimensional inferential framework for a large family of estimators that include the proposed GMDR estimator. GMDI provides more flexibility for incorporating relevant auxiliary row and column structures. As a result, GMDI does not require the true regression coefficients to be sparse, but constrains the coordinate system representing the regression coefficients according to the column structure. GMDI also allows dependent and heteroscedastic observations. We study the theoretical properties of GMDI in terms of both the type-I error rate and power and demonstrate the effectiveness of GMDR and GMDI in simulation studies and an application to human microbiome data.
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Tin A, Fohner AE, Yang Q, Brody JA, Davies G, Yao J, Liu D, Caro I, Lindbohm JV, Duggan MR, Meirelles O, Harris SE, Gudmundsdottir V, Taylor AM, Henry A, Beiser AS, Shojaie A, Coors A, Fitzpatrick AL, Langenberg C, Satizabal CL, Sitlani CM, Wheeler E, Tucker-Drob EM, Bressler J, Coresh J, Bis JC, Candia J, Jennings LL, Pietzner M, Lathrop M, Lopez OL, Redmond P, Gerszten RE, Rich SS, Heckbert SR, Austin TR, Hughes TM, Tanaka T, Emilsson V, Vasan RS, Guo X, Zhu Y, Tzourio C, Rotter JI, Walker KA, Ferrucci L, Kivimäki M, Breteler MMB, Cox SR, Debette S, Mosley TH, Gudnason VG, Launer LJ, Psaty BM, Seshadri S, Fornage M. Identification of circulating proteins associated with general cognitive function among middle-aged and older adults. Commun Biol 2023; 6:1117. [PMID: 37923804 PMCID: PMC10624811 DOI: 10.1038/s42003-023-05454-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/12/2023] [Indexed: 11/06/2023] Open
Abstract
Identifying circulating proteins associated with cognitive function may point to biomarkers and molecular process of cognitive impairment. Few studies have investigated the association between circulating proteins and cognitive function. We identify 246 protein measures quantified by the SomaScan assay as associated with cognitive function (p < 4.9E-5, n up to 7289). Of these, 45 were replicated using SomaScan data, and three were replicated using Olink data at Bonferroni-corrected significance. Enrichment analysis linked the proteins associated with general cognitive function to cell signaling pathways and synapse architecture. Mendelian randomization analysis implicated higher levels of NECTIN2, a protein mediating viral entry into neuronal cells, with higher Alzheimer's disease (AD) risk (p = 2.5E-26). Levels of 14 other protein measures were implicated as consequences of AD susceptibility (p < 2.0E-4). Proteins implicated as causes or consequences of AD susceptibility may provide new insight into the potential relationship between immunity and AD susceptibility as well as potential therapeutic targets.
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Grants
- N01 HC095163 NHLBI NIH HHS
- RC2 HL102419 NHLBI NIH HHS
- HHSN268201500003C NHLBI NIH HHS
- UH3 NS100605 NINDS NIH HHS
- R01 HL103612 NHLBI NIH HHS
- 75N92020D00002 NHLBI NIH HHS
- U01 HL096812 NHLBI NIH HHS
- MC_UU_00006/1 Medical Research Council
- UF1 NS125513 NINDS NIH HHS
- 75N92020D00005 NHLBI NIH HHS
- N01AG12100 NIA NIH HHS
- N01HC95160 NHLBI NIH HHS
- R01 AG054076 NIA NIH HHS
- R01 HL120393 NHLBI NIH HHS
- BB/F019394/1 Biotechnology and Biological Sciences Research Council
- RF1 AG059421 NIA NIH HHS
- R01 HL131136 NHLBI NIH HHS
- N01 HC095168 NHLBI NIH HHS
- UL1 RR025005 NCRR NIH HHS
- R01 AG015928 NIA NIH HHS
- HHSN268201800004I NHLBI NIH HHS
- U01 HL080295 NHLBI NIH HHS
- N01HC95163 NHLBI NIH HHS
- N01 AG012100 NIA NIH HHS
- HHSN268201500001C NHLBI NIH HHS
- UL1 TR001079 NCATS NIH HHS
- N01 HC085082 NHLBI NIH HHS
- U01 HL096917 NHLBI NIH HHS
- R01 HL059367 NHLBI NIH HHS
- U01 HL130114 NHLBI NIH HHS
- HHSN268200800007C NHLBI NIH HHS
- R01 HL085251 NHLBI NIH HHS
- N01HC95169 NHLBI NIH HHS
- R01 NS087541 NINDS NIH HHS
- 75N92020D00001 NHLBI NIH HHS
- R01 HL086694 NHLBI NIH HHS
- R01 AG054628 NIA NIH HHS
- U01 HL096902 NHLBI NIH HHS
- R01 HL087652 NHLBI NIH HHS
- N01 HC095162 NHLBI NIH HHS
- U01 HG004402 NHGRI NIH HHS
- N01HC95164 NHLBI NIH HHS
- N01 HC085086 NHLBI NIH HHS
- N01HC55222 NHLBI NIH HHS
- R01 AG049607 NIA NIH HHS
- R01 AG065596 NIA NIH HHS
- N01 HC095165 NHLBI NIH HHS
- N01HC95162 NHLBI NIH HHS
- MR/R024227/1 Medical Research Council
- N01HC85086 NHLBI NIH HHS
- 75N92020D00003 NHLBI NIH HHS
- R01 HL105756 NHLBI NIH HHS
- N01HC95168 NHLBI NIH HHS
- N01 HC095169 NHLBI NIH HHS
- HHSN268201800003I NHLBI NIH HHS
- P30 DK063491 NIDDK NIH HHS
- HHSN268201800007I NHLBI NIH HHS
- HHSN268201700002C NHLBI NIH HHS
- R01 AG066524 NIA NIH HHS
- RF1 AG063507 NIA NIH HHS
- HHSN268201200036C NHLBI NIH HHS
- R01 HL144483 NHLBI NIH HHS
- HHSN268201800001C NHLBI NIH HHS
- HHSN268201700001I NHLBI NIH HHS
- R01 AG056477 NIA NIH HHS
- HHSN268201700004I NHLBI NIH HHS
- N01HC95165 NHLBI NIH HHS
- N01 HC095159 NHLBI NIH HHS
- U01 AG058589 NIA NIH HHS
- N01HC95159 NHLBI NIH HHS
- N01 HC095161 NHLBI NIH HHS
- HHSN268201500001I NHLBI NIH HHS
- HHSN271201200022C NIDA NIH HHS
- N01 HC025195 NHLBI NIH HHS
- N01HC95161 NHLBI NIH HHS
- UL1 TR001420 NCATS NIH HHS
- 75N92020D00004 NHLBI NIH HHS
- U01 HL096814 NHLBI NIH HHS
- P30 AG066509 NIA NIH HHS
- R01 HL132320 NHLBI NIH HHS
- 75N92020D00007 NHLBI NIH HHS
- P30 AG066546 NIA NIH HHS
- R01 AG033040 NIA NIH HHS
- MR/S011676/1 Medical Research Council
- U01 AG052409 NIA NIH HHS
- HHSN268201500003I NHLBI NIH HHS
- K01 AG071689 NIA NIH HHS
- 75N92021D00006 NHLBI NIH HHS
- R01 AG026307 NIA NIH HHS
- R01 AG020098 NIA NIH HHS
- HHSN268201700005C NHLBI NIH HHS
- HHSN268201700001C NHLBI NIH HHS
- N01HC85082 NHLBI NIH HHS
- HHSN268201700003C NHLBI NIH HHS
- N01 HC095166 NHLBI NIH HHS
- N01HC95167 NHLBI NIH HHS
- N01HC85083 NHLBI NIH HHS
- UH2 NS100605 NINDS NIH HHS
- N01HC25195 NHLBI NIH HHS
- 75N92019D00031 NHLBI NIH HHS
- U01 HL096899 NHLBI NIH HHS
- HHSN268201700004C NHLBI NIH HHS
- UL1 TR000040 NCATS NIH HHS
- HHSN268201700002I NHLBI NIH HHS
- HHSN268201700005I NHLBI NIH HHS
- P30 AG072947 NIA NIH HHS
- R01 AG025941 NIA NIH HHS
- Chief Scientist Office
- 75N92020D00006 NHLBI NIH HHS
- N01HC95166 NHLBI NIH HHS
- R01 AG023629 NIA NIH HHS
- R01 HL087641 NHLBI NIH HHS
- N01HC85079 NHLBI NIH HHS
- N01 HC085080 NHLBI NIH HHS
- UL1 TR001881 NCATS NIH HHS
- N01 HC095167 NHLBI NIH HHS
- HHSN268201800005I NHLBI NIH HHS
- N01HC85080 NHLBI NIH HHS
- HHSN268201700003I NHLBI NIH HHS
- HHSN268201800006I NHLBI NIH HHS
- N01 HC095164 NHLBI NIH HHS
- N01HC85081 NHLBI NIH HHS
- N01 HC095160 NHLBI NIH HHS
- The ARIC study has been funded in whole or in part with Federal funds from the National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services (contract numbers HHSN268201700001I, HHSN268201700002I, HHSN268201700003I, HHSN268201700004I and HHSN268201700005I), R01HL087641, R01HL059367 and R01HL086694; National Human Genome Research Institute contract U01HG004402; and National Institutes of Health contract HHSN268200625226C. Funding was also supported by 5RC2HL102419, R01NS087541 and R01HL131136. Neurocognitive data were collected by U01 2U01HL096812, 2U01HL096814, 2U01HL096899, 2U01HL096902, 2U01HL096917 from the NIH (NHLBI, NINDS, NIA and NIDCD). Infrastructure was partly supported by Grant Number UL1RR025005, a component of the National Institutes of Health and NIH Roadmap for Medical Research. This Cardiovascular Heath Study (CHS) research was supported by NHLBI contracts HHSN268201200036C, HHSN268200800007C, HHSN268201800001C, N01HC55222, N01HC85079, N01HC85080, N01HC85081, N01HC85082, N01HC85083, N01HC85086, 75N92021D00006; and NHLBI grants U01HL080295, R01HL087652, R01HL105756, R01HL103612, R01HL120393, R01HL085251, R01HL144483, and U01HL130114 with additional contribution from the National Institute of Neurological Disorders and Stroke (NINDS). Additional support was provided through R01AG023629, R01AG15928, and R01AG20098 from the National Institute on Aging (NIA). AEF is supported by K01AG071689. The Framingham Heart Study is conducted and supported by the National Heart, Lung, and Blood Institute (NHLBI) in collaboration with Boston University (Contract No. N01-HC-25195, HHSN268201500001I and 75N92019D00031). This work was also supported by grant R01AG063507, R01AG054076, R01AG049607, R01AG059421, R01AG033040, R01AG066524, P30AG066546, U01 AG052409, U01 AG058589 from from the National Institute on Aging and R01 AG017950, UH2/3 NS100605, UF1 NS125513 from National Institute of Neurological Disorders and Stroke and R01HL132320. AGES has been funded by NIA contracts N01-AG012100 and HSSN271201200022C, NIH Grant No. 1R01AG065596-01A1, Hjartavernd (the Icelandic Heart Association), and the Althingi (the Icelandic Parliament). M. R. Duggan, T. Tanaka, J. Candia, K. A. Walker, L. Ferrucci, L.J. Launer, O. Meirelles are funded by the National Institute on Aging Intramural Research Program. This study was funded, in part, by the National Institute on Aging Intramural Research Program. The Coronary Artery Risk Development in Young Adults Study (CARDIA) is supported by contracts HHSN268201800003I, HHSN268201800004I, HHSN268201800005I, HHSN268201800006I, and HHSN268201800007I from the National Heart, Lung, and Blood Institute (NHLBI). The LBC1921 was supported by the UK’s Biotechnology and Biological Sciences Research Council (BBSRC), The Royal Society, and The Chief Scientist Office of the Scottish Government. Genotyping was funded by the BBSRC (BB/F019394/1). LBC1936 is supported by the Biotechnology and Biological Sciences Research Council, and the Economic and Social Research Council [BB/W008793/1], Age UK (Disconnected Mind project), and the University of Edinburgh. Genotyping was funded by the BBSRC (BB/F019394/1). The Olink® Neurology Proteomics assay was supported by a National Institutes of Health (NIH) research grant R01AG054628. Phenotype harmonization, data management, sample-identity QC, and general study coordination, were provided by the TOPMed Data Coordinating Center (3R01HL-120393-02S1), and TOPMed MESA Multi-Omics (HHSN2682015000031/HSN26800004). The MESA projects are conducted and supported by the National Heart, Lung, and Blood Institute (NHLBI) in collaboration with MESA investigators. Support for the Multi-Ethnic Study of Atherosclerosis (MESA) projects are conducted and supported by the National Heart, Lung, and Blood Institute (NHLBI) in collaboration with MESA investigators. Support for MESA is provided by contracts 75N92020D00001, HHSN268201500003I, N01-HC-95159, 75N92020D00005, N01-HC-95160, 75N92020D00002, N01-HC-95161, 75N92020D00003, N01-HC-95162, 75N92020D00006, N01-HC-95163, 75N92020D00004, N01-HC-95164, 75N92020D00007, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168, N01-HC-95169, UL1-TR-000040, UL1-TR-001079, UL1-TR-001420, UL1TR001881, DK063491, and R01HL105756. The Three City (3C) Study is conducted under a partnership agreement among the Institut National de la Santé et de la Recherche Médicale (INSERM), the University of Bordeaux, and Sanofi-Aventis. The Fondation pour la Recherche Médicale funded the preparation and initiation of the study. The 3C Study is also supported by the Caisse Nationale Maladie des Travailleurs Salariés, Direction Générale de la Santé, Mutuelle Générale de l’Education Nationale (MGEN), Institut de la Longévité, Conseils Régionaux of Aquitaine and Bourgogne, Fondation de France, and Ministry of Research–INSERM Programme “Cohortes et collections de données biologiques.” Ilana Caro received a grant from the EUR digital public health. This PhD program is supported within the framework of the PIA3 (Investment for the future). Project reference 17-EURE-0019.
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Pershad Y, Mack T, Poisner H, Jakubek YA, Stilp AM, Mitchell BD, Lewis JP, Boerwinkle E, Loos RJ, Chami N, Wang Z, Barnes K, Pankratz N, Fornage M, Redline S, Psaty BM, Bis JC, Shojaie A, Silverman EK, Cho MH, Yun J, DeMeo D, Levy D, Johnson A, Mathias R, Taub M, Arnett D, North K, Raffield LM, Carson A, Doyle MF, Rich SS, Rotter JI, Guo X, Cox N, Roden DM, Franceschini N, Desai P, Reiner A, Auer PL, Scheet P, Jaiswal S, Weinstock JS, Bick AG. Determinants of mosaic chromosomal alteration fitness. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.10.20.23297280. [PMID: 37905118 PMCID: PMC10615010 DOI: 10.1101/2023.10.20.23297280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Clonal hematopoiesis (CH) is characterized by the acquisition of a somatic mutation in a hematopoietic stem cell that results in a clonal expansion. These driver mutations can be single nucleotide variants in cancer driver genes or larger structural rearrangements called mosaic chromosomal alterations (mCAs). The factors that influence the variations in mCA fitness and ultimately result in different clonal expansion rates are not well-understood. We used the Passenger-Approximated Clonal Expansion Rate (PACER) method to estimate clonal expansion rate for 6,381 individuals in the NHLBI TOPMed cohort with gain, loss, and copy-neutral loss of heterozygosity mCAs. Our estimates of mCA fitness were correlated (R 2 = 0.49) with an alternative approach that estimated fitness of mCAs in the UK Biobank using a theoretical probability distribution. Individuals with lymphoid-associated mCAs had a significantly higher white blood cell count and faster clonal expansion rate. In a cross-sectional analysis, genome-wide association study of estimates of mCA expansion rate identified TCL1A , NRIP1 , and TERT locus variants as modulators of mCA clonal expansion rate.
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Li T, Ferraro N, Strober BJ, Aguet F, Kasela S, Arvanitis M, Ni B, Wiel L, Hershberg E, Ardlie K, Arking DE, Beer RL, Brody J, Blackwell TW, Clish C, Gabriel S, Gerszten R, Guo X, Gupta N, Johnson WC, Lappalainen T, Lin HJ, Liu Y, Nickerson DA, Papanicolaou G, Pritchard JK, Qasba P, Shojaie A, Smith J, Sotoodehnia N, Taylor KD, Tracy RP, Van Den Berg D, Wheeler MT, Rich SS, Rotter JI, Battle A, Montgomery SB. The functional impact of rare variation across the regulatory cascade. CELL GENOMICS 2023; 3:100401. [PMID: 37868038 PMCID: PMC10589633 DOI: 10.1016/j.xgen.2023.100401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 03/08/2023] [Accepted: 08/10/2023] [Indexed: 10/24/2023]
Abstract
Each human genome has tens of thousands of rare genetic variants; however, identifying impactful rare variants remains a major challenge. We demonstrate how use of personal multi-omics can enable identification of impactful rare variants by using the Multi-Ethnic Study of Atherosclerosis, which included several hundred individuals, with whole-genome sequencing, transcriptomes, methylomes, and proteomes collected across two time points, 10 years apart. We evaluated each multi-omics phenotype's ability to separately and jointly inform functional rare variation. By combining expression and protein data, we observed rare stop variants 62 times and rare frameshift variants 216 times as frequently as controls, compared to 13-27 times as frequently for expression or protein effects alone. We extended a Bayesian hierarchical model, "Watershed," to prioritize specific rare variants underlying multi-omics signals across the regulatory cascade. With this approach, we identified rare variants that exhibited large effect sizes on multiple complex traits including height, schizophrenia, and Alzheimer's disease.
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Prater KE, Green KJ, Mamde S, Sun W, Cochoit A, Smith CL, Chiou KL, Heath L, Rose SE, Wiley J, Keene CD, Kwon RY, Snyder-Mackler N, Blue EE, Logsdon B, Young JE, Shojaie A, Garden GA, Jayadev S. Human microglia show unique transcriptional changes in Alzheimer's disease. NATURE AGING 2023; 3:894-907. [PMID: 37248328 PMCID: PMC10353942 DOI: 10.1038/s43587-023-00424-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 04/25/2023] [Indexed: 05/31/2023]
Abstract
Microglia, the innate immune cells of the brain, influence Alzheimer's disease (AD) progression and are potential therapeutic targets. However, microglia exhibit diverse functions, the regulation of which is not fully understood, complicating therapeutics development. To better define the transcriptomic phenotypes and gene regulatory networks associated with AD, we enriched for microglia nuclei from 12 AD and 10 control human dorsolateral prefrontal cortices (7 males and 15 females, all aged >60 years) before single-nucleus RNA sequencing. Here we describe both established and previously unrecognized microglial molecular phenotypes, the inferred gene networks driving observed transcriptomic change, and apply trajectory analysis to reveal the putative relationships between microglial phenotypes. We identify microglial phenotypes more prevalent in AD cases compared with controls. Further, we describe the heterogeneity in microglia subclusters expressing homeostatic markers. Our study demonstrates that deep profiling of microglia in human AD brain can provide insight into microglial transcriptional changes associated with AD.
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12
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Shojaie A, Rota S, Al Khleifat A, Ray Chaudhuri K, Al-Chalabi A. Non-motor symptoms in amyotrophic lateral sclerosis: lessons from Parkinson's disease. Amyotroph Lateral Scler Frontotemporal Degener 2023:1-10. [PMID: 37349906 DOI: 10.1080/21678421.2023.2220748] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Amyotrophic lateral sclerosis and Parkinson's disease are neurodegenerative diseases of the motor system which are now recognized also to affect non-motor pathways. Non-motor symptoms have been acknowledged as important determinants of quality of life in Parkinson's disease, and there is increasing interest in understanding the extent and role of non-motor symptoms in amyotrophic lateral sclerosis. We therefore reviewed what is known about non-motor symptoms in amyotrophic lateral sclerosis, using lessons from Parkinson's disease.
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Kalani R, Bartz TM, Psaty BM, Elkind MSV, Floyd JS, Gerszten RE, Shojaie A, Heckbert SR, Bis JC, Austin TR, Tirschwell DL, Delaney JAC, Longstreth WT. Plasma Proteomic Associations With Incident Ischemic Stroke in Older Adults: The Cardiovascular Health Study. Neurology 2023; 100:e2182-e2190. [PMID: 37015819 PMCID: PMC10238156 DOI: 10.1212/wnl.0000000000207242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 02/16/2023] [Indexed: 04/06/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Plasma proteomics may elucidate novel insights into the pathophysiology of ischemic stroke (IS), identify biomarkers of IS risk, and guide development of nascent prevention strategies. We evaluated the relationship between the plasma proteome and IS risk in the population-based Cardiovascular Health Study (CHS). METHODS Eligible CHS participants were free of prevalent stroke and underwent quantification of 1,298 plasma proteins using the aptamer-based SOMAScan assay platform from the 1992-1993 study visit. Multivariable Cox proportional hazards regression was used to evaluate associations between a 1-SD increase in the log2-transformed estimated plasma protein concentrations and incident IS, adjusting for demographics, IS risk factors, and estimated glomerular filtration rate. For proteins independently associated with incident IS, a secondary stratified analysis evaluated associations in subgroups defined by sex and race. Exploratory analyses evaluated plasma proteomic associations with cardioembolic and noncardioembolic IS and proteins associated with IS risk in participants with left atrial dysfunction but without atrial fibrillation. RESULTS Of 2,983 eligible participants, the mean age was 74.3 (±4.8) years, 61.2% were women, and 15.4% were Black. Over a median follow-up of 12.6 years, 450 participants experienced an incident IS. N-terminal probrain natriuretic peptide (NTproBNP, adjusted HR 1.37, 95% CI 1.23-1.53, p = 2.08 × 10-08) and macrophage metalloelastase (MMP12, adjusted HR 1.30, 95% CI 1.16-1.45, p = 4.55 × 10-06) were independently associated with IS risk. These 2 associations were similar in men and women and in Black and non-Black participants. In exploratory analyses, NTproBNP was independently associated with incident cardioembolic IS, E-selectin with incident noncardioembolic IS, and secreted frizzled-related protein 1 with IS risk in participants with left atrial dysfunction. DISCUSSION In a cohort of older adults, NTproBNP and MMP12 were independently associated with IS risk. We identified plasma proteomic determinants of incident cardioembolic and noncardioembolic IS and found a novel protein associated with IS risk in those with left atrial dysfunction.
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Stanaway IB, Wallace JC, Hong S, Wilder CS, Green FH, Tsai J, Knight M, Workman T, Vigoren EM, Smith MN, Griffith WC, Thompson B, Shojaie A, Faustman EM. Alteration of oral microbiome composition in children living with pesticide-exposed farm workers. Int J Hyg Environ Health 2023; 248:114090. [PMID: 36516690 PMCID: PMC9898171 DOI: 10.1016/j.ijheh.2022.114090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/30/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022]
Abstract
Our prior work shows that azinphos-methyl pesticide exposure is associated with altered oral microbiomes in exposed farmworkers. Here we extend this analysis to show the same association pattern is also evident in their children. Oral buccal swab samples were analyzed at two time points, the apple thinning season in spring-summer 2005 for 78 children and 101 adults and the non-spray season in winter 2006 for 62 children and 82 adults. The pesticide exposure for the children were defined by the farmworker occupation of the cohabitating household adult and the blood azinphos-methyl detection of the cohabitating adult. Oral buccal swab 16S rRNA sequencing determined taxonomic microbiota proportional composition from concurrent samples from both adults and children. Analysis of the identified bacteria showed significant proportional changes for 12 of 23 common oral microbiome genera in association with azinphos-methyl detection and farmworker occupation. The most common significantly altered genera had reductions in the abundance of Streptococcus, suggesting an anti-microbial effect of the pesticide. Principal component analysis of the microbiome identified two primary clusters, with association of principal component 1 to azinphos-methyl blood detection and farmworker occupational status of the household. The children's buccal microbiota composition clustered with their household adult in ∼95% of the households. Household adult farmworker occupation and household pesticide exposure is associated with significant alterations in their children's oral microbiome composition. This suggests that parental occupational exposure and pesticide take-home exposure pathways elicit alteration of their children's microbiomes.
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Pi H, Xia L, Ralph DD, Rayner SG, Shojaie A, Leary PJ, Gharib SA. Metabolomic Signatures Associated With Pulmonary Arterial Hypertension Outcomes. Circ Res 2023; 132:254-266. [PMID: 36597887 PMCID: PMC9904878 DOI: 10.1161/circresaha.122.321923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 12/20/2022] [Indexed: 01/05/2023]
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is a complex disease characterized by progressive right ventricular (RV) failure leading to significant morbidity and mortality. Investigating metabolic features and pathways associated with RV dilation, mortality, and measures of disease severity can provide insight into molecular mechanisms, identify subphenotypes, and suggest potential therapeutic targets. METHODS We collected data from a prospective cohort of PAH participants and performed untargeted metabolomic profiling on 1045 metabolites from circulating blood. Analyses were intended to identify metabolomic differences across a range of common metrics in PAH (eg, dilated versus nondilated RV). Partial least squares discriminant analysis was first applied to assess the distinguishability of relevant outcomes. Significantly altered metabolites were then identified using linear regression, and Cox regression models (as appropriate for the specific outcome) with adjustments for age, sex, body mass index, and PAH cause. Models exploring RV maladaptation were further adjusted for pulmonary vascular resistance. Pathway enrichment analysis was performed to identify significantly dysregulated processes. RESULTS A total of 117 participants with PAH were included. Partial least squares discriminant analysis showed cluster differentiation between participants with dilated versus nondilated RVs, survivors versus nonsurvivors, and across a range of NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels, REVEAL 2.0 composite scores, and 6-minute-walk distances. Polyamine and histidine pathways were associated with differences in RV dilation, mortality, NT-proBNP, REVEAL score, and 6-minute walk distance. Acylcarnitine pathways were associated with NT-proBNP, REVEAL score, and 6-minute walk distance. Sphingomyelin pathways were associated with RV dilation and NT-proBNP after adjustment for pulmonary vascular resistance. CONCLUSIONS Distinct plasma metabolomic profiles are associated with RV dilation, mortality, and measures of disease severity in PAH. Polyamine, histidine, and sphingomyelin metabolic pathways represent promising candidates for identifying patients at high risk for poor outcomes and investigation into their roles as markers or mediators of disease progression and RV adaptation.
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Prater KE, Green KJ, Sun W, Smith CL, Chiou KL, Mamde S, Heath LM, Rose S, Keene CD, Kwon RY, Snyder‐Mackler N, Blue EE, Young JE, Logsdon BA, Shojaie A, Garden GA, Jayadev S. Transcriptomic profiling of myeloid cells in Alzheimer’s Disease brain illustrates heterogeneity of microglia endolysosomal subtypes. Alzheimers Dement 2022. [DOI: 10.1002/alz.062391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Zhao S, Shojaie A. NETWORK DIFFERENTIAL CONNECTIVITY ANALYSIS. Ann Appl Stat 2022; 16:2166-2182. [PMID: 37842097 PMCID: PMC10569671 DOI: 10.1214/21-aoas1581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Identifying differences in networks has become a canonical problem in many biological applications. Existing methods try to accomplish this goal by either directly comparing the estimated structures of two networks, or testing the null hypothesis that the covariance or inverse covariance matrices in two populations are identical. However, estimation approaches do not provide measures of uncertainty, e.g., p-values, whereas existing testing approaches could lead to misleading results, as we illustrate in this paper. To address these shortcomings, we propose a qualitative hypothesis testing framework, which tests whether the connectivity structures in the two networks are the same. our framework is especially appropriate if the goal is to identify nodes or edges that are differentially connected. No existing approach could test such hypotheses and provide corresponding measures of uncertainty. Theoretically, we show that under appropriate conditions, our proposal correctly controls the type-I error rate in testing the qualitative hypothesis. Empirically, we demonstrate the performance of our proposal using simulation studies and applications in cancer genomics.
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Tank A, Covert I, Foti N, Shojaie A, Fox EB. Neural Granger Causality. IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 2022; 44:4267-4279. [PMID: 33705309 PMCID: PMC9739174 DOI: 10.1109/tpami.2021.3065601] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
While most classical approaches to Granger causality detection assume linear dynamics, many interactions in real-world applications, like neuroscience and genomics, are inherently nonlinear. In these cases, using linear models may lead to inconsistent estimation of Granger causal interactions. We propose a class of nonlinear methods by applying structured multilayer perceptrons (MLPs) or recurrent neural networks (RNNs) combined with sparsity-inducing penalties on the weights. By encouraging specific sets of weights to be zero-in particular, through the use of convex group-lasso penalties-we can extract the Granger causal structure. To further contrast with traditional approaches, our framework naturally enables us to efficiently capture long-range dependencies between series either via our RNNs or through an automatic lag selection in the MLP. We show that our neural Granger causality methods outperform state-of-the-art nonlinear Granger causality methods on the DREAM3 challenge data. This data consists of nonlinear gene expression and regulation time courses with only a limited number of time points. The successes we show in this challenging dataset provide a powerful example of how deep learning can be useful in cases that go beyond prediction on large datasets. We likewise illustrate our methods in detecting nonlinear interactions in a human motion capture dataset.
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Austin TR, McHugh CP, Brody JA, Bis JC, Sitlani CM, Bartz TM, Biggs ML, Bansal N, Buzkova P, Carr SA, deFilippi CR, Elkind MSV, Fink HA, Floyd JS, Fohner AE, Gerszten RE, Heckbert SR, Katz DH, Kizer JR, Lemaitre RN, Longstreth WT, McKnight B, Mei H, Mukamal KJ, Newman AB, Ngo D, Odden MC, Vasan RS, Shojaie A, Simon N, Smith GD, Davies NM, Siscovick DS, Sotoodehnia N, Tracy RP, Wiggins KL, Zheng J, Psaty BM. Proteomics and Population Biology in the Cardiovascular Health Study (CHS): design of a study with mentored access and active data sharing. Eur J Epidemiol 2022; 37:755-765. [PMID: 35790642 PMCID: PMC9255954 DOI: 10.1007/s10654-022-00888-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 06/03/2022] [Indexed: 11/08/2022]
Abstract
BACKGROUND In the last decade, genomic studies have identified and replicated thousands of genetic associations with measures of health and disease and contributed to the understanding of the etiology of a variety of health conditions. Proteins are key biomarkers in clinical medicine and often drug-therapy targets. Like genomics, proteomics can advance our understanding of biology. METHODS AND RESULTS In the setting of the Cardiovascular Health Study (CHS), a cohort study of older adults, an aptamer-based method that has high sensitivity for low-abundance proteins was used to assay 4979 proteins in frozen, stored plasma from 3188 participants (61% women, mean age 74 years). CHS provides active support, including central analysis, for seven phenotype-specific working groups (WGs). Each CHS WG is led by one or two senior investigators and includes 10 to 20 early or mid-career scientists. In this setting of mentored access, the proteomic data and analytic methods are widely shared with the WGs and investigators so that they may evaluate associations between baseline levels of circulating proteins and the incidence of a variety of health outcomes in prospective cohort analyses. We describe the design of CHS, the CHS Proteomics Study, characteristics of participants, quality control measures, and structural characteristics of the data provided to CHS WGs. We additionally highlight plans for validation and replication of novel proteomic associations. CONCLUSION The CHS Proteomics Study offers an opportunity for collaborative data sharing to improve our understanding of the etiology of a variety of health conditions in older adults.
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Yu S, Drton M, Shojaie A. Generalized score matching for general domains. INFORMATION AND INFERENCE : A JOURNAL OF THE IMA 2022; 11:739-780. [PMID: 35721800 PMCID: PMC9203079 DOI: 10.1093/imaiai/iaaa041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 11/28/2020] [Indexed: 06/15/2023]
Abstract
Estimation of density functions supported on general domains arises when the data are naturally restricted to a proper subset of the real space. This problem is complicated by typically intractable normalizing constants. Score matching provides a powerful tool for estimating densities with such intractable normalizing constants but as originally proposed is limited to densities on [Formula: see text] and [Formula: see text]. In this paper, we offer a natural generalization of score matching that accommodates densities supported on a very general class of domains. We apply the framework to truncated graphical and pairwise interaction models and provide theoretical guarantees for the resulting estimators. We also generalize a recently proposed method from bounded to unbounded domains and empirically demonstrate the advantages of our method.
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Bloch J, Greaves-Tunnell A, Shea-Brown E, Harchaoui Z, Shojaie A, Yazdan-Shahmorad A. Network structure mediates functional reorganization induced by optogenetic stimulation of non-human primate sensorimotor cortex. iScience 2022; 25:104285. [PMID: 35573193 PMCID: PMC9095749 DOI: 10.1016/j.isci.2022.104285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/22/2022] [Accepted: 04/19/2022] [Indexed: 11/04/2022] Open
Abstract
Because aberrant network-level functional connectivity underlies a variety of neural disorders, the ability to induce targeted functional reorganization would be a profound development toward therapies for neural disorders. Brain stimulation has been shown to induce large-scale network-wide functional connectivity changes (FCC), but the mapping from stimulation to the induced changes is unclear. Here, we develop a model which jointly considers the stimulation protocol and the cortical network structure to accurately predict network-wide FCC in response to optogenetic stimulation of non-human primate primary sensorimotor cortex. We observe that the network structure has a much stronger effect than the stimulation protocol on the resulting FCC. We also observe that the mappings from these input features to the FCC diverge over frequency bands and successive stimulations. Our framework represents a paradigm shift for targeted neural stimulation and can be used to interrogate, improve, and develop stimulation-based interventions for neural disorders.
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Shojaie A, Fox EB. Granger Causality: A Review and Recent Advances. ANNUAL REVIEW OF STATISTICS AND ITS APPLICATION 2022; 9:289-319. [PMID: 37840549 PMCID: PMC10571505 DOI: 10.1146/annurev-statistics-040120-010930] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Introduced more than a half-century ago, Granger causality has become a popular tool for analyzing time series data in many application domains, from economics and finance to genomics and neuroscience. Despite this popularity, the validity of this framework for inferring causal relationships among time series has remained the topic of continuous debate. Moreover, while the original definition was general, limitations in computational tools have constrained the applications of Granger causality to primarily simple bivariate vector autoregressive processes. Starting with a review of early developments and debates, this article discusses recent advances that address various shortcomings of the earlier approaches, from models for high-dimensional time series to more recent developments that account for nonlinear and non-Gaussian observations and allow for subsampled and mixed-frequency time series.
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Chakraborty S, Shojaie A. Nonparametric Causal Structure Learning in High Dimensions. ENTROPY 2022; 24:e24030351. [PMID: 35327862 PMCID: PMC8947566 DOI: 10.3390/e24030351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/21/2022] [Accepted: 02/25/2022] [Indexed: 12/10/2022]
Abstract
The PC and FCI algorithms are popular constraint-based methods for learning the structure of directed acyclic graphs (DAGs) in the absence and presence of latent and selection variables, respectively. These algorithms (and their order-independent variants, PC-stable and FCI-stable) have been shown to be consistent for learning sparse high-dimensional DAGs based on partial correlations. However, inferring conditional independences from partial correlations is valid if the data are jointly Gaussian or generated from a linear structural equation model—an assumption that may be violated in many applications. To broaden the scope of high-dimensional causal structure learning, we propose nonparametric variants of the PC-stable and FCI-stable algorithms that employ the conditional distance covariance (CdCov) to test for conditional independence relationships. As the key theoretical contribution, we prove that the high-dimensional consistency of the PC-stable and FCI-stable algorithms carry over to general distributions over DAGs when we implement CdCov-based nonparametric tests for conditional independence. Numerical studies demonstrate that our proposed algorithms perform nearly as good as the PC-stable and FCI-stable for Gaussian distributions, and offer advantages in non-Gaussian graphical models.
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Brooks-Worrell B, Hampe CS, Hattery EG, Palomino B, Zangeneh SZ, Utzschneider K, Kahn SE, Larkin ME, Johnson ML, Mather KJ, Younes N, Rasouli N, Desouza C, Cohen RM, Park JY, Florez HJ, Valencia WM, Shojaie A, Palmer JP, Balasubramanyam A. Islet Autoimmunity is Highly Prevalent and Associated With Diminished β-Cell Function in Patients With Type 2 Diabetes in the Grade Study. Diabetes 2022; 71:db210590. [PMID: 35061024 PMCID: PMC9375448 DOI: 10.2337/db21-0590] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/08/2021] [Indexed: 11/13/2022]
Abstract
Islet autoimmunity may contribute to β-cell dysfunction in type 2 diabetes (T2D). Its prevalence and clinical significance have not been rigorously determined. In this ancillary study to the Glycemia Reduction Approaches in Diabetes-A Comparative Effectiveness (GRADE) Study, we investigated the prevalence of cellular and humoral islet autoimmunity in patients with T2D duration 4·0±3·0 y, HbA1c 7·5±0·5% on metformin alone. We measured T cell autoreactivity against islet proteins, islet autoantibodies against GAD65, IA2, ZnT8, and β-cell function. Cellular islet autoimmunity was present in 41·3%, humoral islet autoimmunity in 13·5%, and both in 5·3%. β-cell function calculated as iAUC-CG and ΔC-peptide(0- 30)/Δglucose(0-30) from an oral glucose tolerance test was lower among T cell-positives (T+) than T cell-negatives (T-) using two different adjustments for insulin sensitivity (iAUC-CG: 13·2% [95% CI 0·3, 24·4%] or 11·4% [95% CI 0·4, 21·2%] lower; ΔC-peptide(0-30)/Δglucose(0-30)) 19% [95% CI 3·1, 32·3%] or 17·7% [95% CI 2·6, 30·5%] lower). T+ patients had 17% higher HbA1c (95% CI 0·07, 0·28) and 7·7 mg/dL higher fasting plasma glucose levels (95% CI 0·2,15·3) than T- patients. We conclude that islet autoimmunity is much more prevalent in T2D patients than previously reported. T cell-mediated autoimmunity is associated with diminished β-cell function and worse glycemic control.
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Zhang K, Safikhani A, Tank A, Shojaie A. Penalized estimation of threshold auto-regressive models with many components and thresholds. Electron J Stat 2022; 16:1891-1951. [PMID: 37051046 PMCID: PMC10088520 DOI: 10.1214/22-ejs1982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thanks to their simplicity and interpretable structure, autoregressive processes are widely used to model time series data. However, many real time series data sets exhibit non-linear patterns, requiring nonlinear modeling. The threshold Auto-Regressive (TAR) process provides a family of non-linear auto-regressive time series models in which the process dynamics are specific step functions of a thresholding variable. While estimation and inference for low-dimensional TAR models have been investigated, high-dimensional TAR models have received less attention. In this article, we develop a new framework for estimating high-dimensional TAR models, and propose two different sparsity-inducing penalties. The first penalty corresponds to a natural extension of classical TAR model to high-dimensional settings, where the same threshold is enforced for all model parameters. Our second penalty develops a more flexible TAR model, where different thresholds are allowed for different auto-regressive coefficients. We show that both penalized estimation strategies can be utilized in a three-step procedure that consistently learns both the thresholds and the corresponding auto-regressive coefficients. However, our theoretical and empirical investigations show that the direct extension of the TAR model is not appropriate for high-dimensional settings and is better suited for moderate dimensions. In contrast, the more flexible extension of the TAR model leads to consistent estimation and superior empirical performance in high dimensions.
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