List of publications beginning July 7, 2021
Evaluation of artificial signal peptides for secretion of two lysosomal enzymes in CHO cells
(2021) Biochemical Journal, 478 (12), pp. 2309-2319.
Cheng, K.-W.a , Wang, F.a , Lopez, G.A.a , Singamsetty, S.b , Wood, J.b , Dickson, P.I.c , Chou, T.-F.a
a Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, United States
b Phoenix Nest Inc., Brooklyn, NY 11232, United States
c Department of Pediatrics, Washington University in St. Louis, St. Louis, MO 63110, United States
Abstract
Enzyme replacement therapy (ERT) is a scientifically rational and clinically proven treatment for lysosomal storage diseases. Most enzymes used for ERT are purified from the culture supernatant of mammalian cells. However, it is challenging to purify lysosomal enzymes with sufficient quality and quantity for clinical use due to their low secretion levels in mammalian cell systems. To improve the secretion efficiency of recombinant lysosomal enzymes, we evaluated the impact of artificial signal peptides on the production of recombinant lysosomal enzymes in Chinese hamster ovary (CHO) cell lines. We engineered two recombinant human lysosomal enzymes, N-acetyl-α-glucosaminidase (rhNAGLU) and glucosamine (N-acetyl)-6-sulfatase (rhGNS), by replacing their native signal peptides with nine different signal peptides derived from highly secretory proteins and expressed them in CHO K1 cells. When comparing the native signal peptides, we found that rhGNS was secreted into media at higher levels than rhNAGLU. The secretion of rhNAGLU and rhGNS can, however, be carefully controlled by altering signal peptides. The secretion of rhNAGLU was relatively higher with murine Igκ light chain and human chymotrypsinogen B1 signal peptides, whereas Igκ light chain signal peptide 1 and human chymotrypsinogen B1 signal peptides were more effective for rhGNS secretion, suggesting that human chymotrypsinogen B1 signal peptide is the most appropriate for increasing lysosomal enzyme secretion. Collectively, our results indicate that altering signal peptide can modulate the secretion of recombinant lysosome enzymes and will enable lysosomal enzyme production for clinical use. © 2021 The Author(s).
Funding details
National Institute of Neurological Disorders and StrokeNINDSU44NS089061
Document Type: Article
Publication Stage: Final
Source: Scopus
Detection of optic neuritis on routine brain MRI without and with the assistance of an image postprocessing algorithm
(2021) American Journal of Neuroradiology, 42 (6), pp. 1130-1135.
Schroeder, A.a , Van Stavern, G.b c , Orlowski, H.L.P.d , Stunkel, L.b c , Parsons, M.S.d , Rhea, L.e , Sharma, A.d
a Washington University in Saint Louis School of Medicine, St. LouisMO, United States
b Department of Ophthalmology and Visual Sciences, Washington University in Saint Louis School of Medicine, St. Louis, MO, United States
c Department of Neurology, Washington University in Saint Louis School of Medicine, St. Louis, MO, United States
d Mallinckrodt Institute of Radiology, Washington University in Saint Louis School of Medicine, St. Louis, MO, United States
e Department of Biostatistics, Washington University in Saint Louis School of Medicine, St. Louis, MO, United States
Abstract
Background and Purpose: At times, there is a clinical need for using routine brain MR imaging performed close to the time of onset of patients’ visual symptoms to firmly establish the diagnosis of optic neuritis. Our aim was to assess the diagnostic performance of radiologists in detecting optic neuritis on routine brain MR images and whether this performance could be enhanced using a postprocessing algorithm. Materials and Methods: In this retrospective case-control study of 60 patients (37 women, 23 men; mean age, 47.2 [SD, 17.9] years), 2 blinded neuroradiologists evaluated T2-weighted FLAIR and contrast-enhanced T1WI from brain MR imaging for the presence of imaging evidence of optic neuritis. Images were processed using an image-processing algorithm that aimed to selectively accentuate the signal intensity of diseased optic nerves. We assessed the effect of image processing on the contrast-to-noise ratio between the optic nerves and normal-appearing white matter and on the diagnostic performance of the neuroradiologists, including the interobserver reliability. Results: The average sensitivity of readers was 55%, 56.5%, and 30.0% on FLAIR, coronal contrast-enhanced T1WI, and axial contrast- enhanced T1WI, respectively. Sensitivities were lower in the absence of fat saturation on FLAIR (P = .001) and coronal contrast- enhanced T1WI (P = .04). Processing increased the contrast-to-noise ratio of diseased (P value range = .03 to <.001) but not of control optic nerves. Processing did not improve the sensitivity but improved the specificity and positive predictive value. Interobserver agreement improved from slight to good. Conclusions: Detection of optic neuritis on routine brain MR imaging is challenging. Specificity, positive predictive value, and interobserver agreement can be improved by postprocessing of MR images. © 2021 American Society of Neuroradiology. All rights reserved.
Document Type: Conference Paper
Publication Stage: Final
Source: Scopus
Polygenic risk scores for alcohol involvement relate to brain structure in substance-naïve children: Results from the ABCD study
(2021) Genes, Brain and Behavior, .
Hatoum, A.S.a , Johnson, E.C.a , Baranger, D.A.A.c , Paul, S.E.b , Agrawal, A.a , Bogdan, R.b
a Department of Psychiatry, Washington University St. Louis Medical School, St. Louis, MO, United States
b Department of Psychology & Brain Sciences, Washington University St. Louis, St. Louis, MO, United States
c Department of Psychiatry, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
Abstract
Brain imaging-derived structural correlates of alcohol involvement have largely been speculated to arise as a consequence of alcohol exposure. However, they may also reflect predispositional risk. In substance naïve children of European ancestry who completed the baseline session of the Adolescent Brain Cognitive Development (ABCD) Study (n = 3013), mixed-effects models estimated whether polygenic risk scores (PRS) for problematic alcohol use (PAU-PRS) and drinks per week (DPW-PRS) are associated with magnetic resonance imaging-derived brain structure phenotypes (i.e., total and regional: cortical thickness, surface area and volume; subcortical volume; white matter volume, fractional anisotropy, mean diffusivity). Follow-up analyses evaluated whether any identified regions were also associated with polygenic risk among substance naïve children of African ancestry (n = 898). After adjustment for multiple testing correction, polygenic risk for PAU was associated with lower volume of the left frontal pole and greater cortical thickness of the right supramarginal gyrus (|βs| > 0.009; ps < 0.001; psfdr < 0.046; r2s < 0.004). PAU PRS and DPW PRS showed nominally significant associations with a host of other regional brain structure phenotypes (e.g., insula surface area and volume). None of these regions showed any, even nominal association among children of African ancestry. Genomic liability to alcohol involvement may manifest as variability in brain structure during middle childhood prior to alcohol use initiation. Broadly, alcohol-related variability in brain morphometry may partially reflect predisposing genomic influence. Larger discovery genome-wide association studies and target samples of diverse ancestries are needed to determine whether observed associations may generalize across ancestral origins. © 2021 International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.
Author Keywords
adolescence; alcohol use; alcohol use disorder; cortical gray matter; drug naive; DTI; imaging genetics; multi-site study; polygenic risk scores; subcortical gray matter
Funding details
National Institutes of HealthNIH
U.S. Department of Veterans AffairsVAU01DA041022, U01DA041025, U01DA041028, U01DA041048, U01DA041089, U01DA041093, U01DA041106, U01DA041117, U01DA041120, U01DA041134, U01DA041148, U01DA041156, U01DA041174, U24DA041123, U24DA041147
Office of Research and DevelopmentORD
Health Services Research and DevelopmentHSR&D
Document Type: Article
Publication Stage: Article in Press
Source: Scopus
Neurofibrillary tau depositions emerge with subthreshold cerebral beta-amyloidosis in down syndrome
(2021) NeuroImage: Clinical, 31, art. no. 102740, .
Zammit, M.D.a b , Tudorascu, D.L.c , Laymon, C.M.d e , Hartley, S.L.a , Ellison, P.A.b , Zaman, S.H.f , Ances, B.M.g , Johnson, S.C.h , Stone, C.K.i , Sabbagh, M.N.j , Mathis, C.A.c , Klunk, W.E.c , Cohen, A.D.c , Handen, B.L.c , Christian, B.T.a b
a University of Wisconsin-Madison Waisman Center, Madison, WI, United States
b University of Wisconsin-Madison Department of Medical Physics, Madison, WI, United States
c University of Pittsburgh Department of Psychiatry, Pittsburgh, PA, United States
d University of Pittsburgh Department of Radiology, Pittsburgh, PA, United States
e University of Pittsburgh, Department of Bioengineering, Pittsburgh, PA, United States
f Cambridge Intellectual Disability Research Group, University of Cambridge, Cambridge, United Kingdom
g Washington University in St. Louis Department of Neurology, St. LouisMO, United States
h University of Wisconsin-Madison Alzheimer’s Disease Research Center, Madison, WI, United States
i University of Wisconsin-Madison Department of Medicine, Madison, WI, United States
j Cleveland Clinic Nevada, Las Vegas, NV, United States
Abstract
Introduction: Adults with Down syndrome are genetically predisposed to develop Alzheimer’s disease and accumulate beta-amyloid plaques (Aβ) early in life. While Aβ has been heavily studied in Down syndrome, its relationship with neurofibrillary tau is less understood. The aim of this study was to evaluate neurofibrillary tau deposition in individuals with Down syndrome with varying levels of Aβ burden. Methods: A total of 161 adults with Down syndrome (mean age = 39.2 (8.50) years) and 40 healthy, non-Down syndrome sibling controls (43.2 (12.6) years) underwent T1w-MRI, [C-11]PiB and [F-18]AV-1451 PET scans. PET images were converted to units of standardized uptake value ratios (SUVrs). Aβ burden was calculated using the amyloid load metric (AβL); a measure of global Aβ burden that improves quantification from SUVrs by suppressing the nonspecific binding signal component and computing the specific Aβ signal from all Aβ-carrying voxels from the image. Regional tau was assessed using control-standardized AV-1451 SUVr. Control-standardized SUVrs were compared across Down syndrome groups of Aβ-negative (A-) (AβL < 13.3), subthreshold A+ (13.3 ≤ AβL < 20) and conventionally A+ (AβL ≥ 20) individuals. The subthreshold A + group was identified as having significantly higher Aβ burden compared to the A- group, but not high enough to satisfy a conventional A + classification. Results: A large-sized association that survived adjustment for chronological age, mental age (assessed using the Peabody Picture Vocabulary Test), and imaging site was observed between AβL and AV-1451 within each Braak region (p < .05). The A + group showed significantly higher AV-1451 retention across all Braak regions compared to the A- and subthreshold A + groups (p < .05). The subthreshold A + group showed significantly higher AV-1451 retention in Braak regions I-III compared to an age-matched sample from the A- group (p < .05). Discussion: These results show that even the earliest detectable Aβ accumulation in Down syndrome is accompanied by elevated tau in the early Braak stage regions. This early detection of tau can help characterize the tau accumulation phase during preclinical Alzheimer’s disease progression in Down syndrome and suggests that there may be a relatively narrow window after Aβ accumulation begins to prevent the downstream cascade of events that leads to Alzheimer’s disease. © 2021 The Authors
Author Keywords
Amyloid; Down syndrome; Early detection; Neurofibrillary tau
Funding details
National Institutes of HealthNIH
National Institute on AgingNIAR01AG031110, U01AG051406, U54HD090256
National Institute of Child Health and Human DevelopmentNICHD
Document Type: Article
Publication Stage: Final
Source: Scopus
Diffusion basis spectrum imaging measures anti-inflammatory and neuroprotective effects of fingolimod on murine optic neuritis
(2021) NeuroImage: Clinical, 31, art. no. 102732, .
Yang, R.a b , Lin, T.-H.b , Zhan, J.b , Lai, S.c , Song, C.b , Sun, P.b , Ye, Z.b , Wallendorf, M.d , George, A.b , Cross, A.H.e f , Song, S.-K.b e g
a Department of Radiology, Guangzhou First People’s Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong 510640, China
b Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, United States
c Department of Medical Equipment, Guangdong Food and Drug Vocational College, Guangzhou, Guangdong 510520, China
d Department of Biostatistics, Washington University School of Medicine, St. Louis, MO 63110, United States
e Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, United States
f Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, United States
g Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, United States
Abstract
Objective: To prospectively determine whether diffusion basis spectrum imaging (DBSI) detects, differentiates and quantitates coexisting inflammation, demyelination, axonal injury and axon loss in mice with optic neuritis (ON) due to experimental autoimmune encephalomyelitis (EAE), and to determine if DBSI accurately measures effects of fingolimod on underlying pathology. Methods: EAE was induced in 7-week-old C57BL/6 female mice. Visual acuity (VA) was assessed daily to detect onset of ON after which daily oral-treatment with either fingolimod (1 mg/kg) or saline was given for ten weeks. In vivo DBSI scans of optic nerves were performed at baseline, 2-, 6- and 10-weeks post treatment. DBSI-derived metrics including restricted isotropic diffusion tensor fraction (putatively reflecting cellularity), non-restricted isotropic diffusion tensor fraction (putatively reflecting vasogenic edema), DBSI-derived axonal volume, axial diffusivity, λ∥ (putatively reflecting axonal integrity), and increased radial diffusivity, λ⊥ (putatively reflecting demyelination). Mice were killed immediately after the last DBSI scan for immunohistochemical assessment. Results: Optic nerves of fingolimod-treated mice exhibited significantly better (p < 0.05) VA than saline-treated group at each time point. During ten-week of treatment, DBSI-derived non-restricted and restricted-isotropic-diffusion-tensor fractions, and axonal volumes were not significantly different (p > 0.05) from the baseline values in fingolimod-treated mice. Transient DBSI-λ∥ decrease and DBSI-λ⊥ increase were detected during Fingolimod treatment. DBSI-derived metrics assessed in vivo significantly correlated (p < 0.05) with the corresponding histological markers. Conclusion: DBSI was used to assess changes of the underlying optic nerve pathologies in EAE mice with ON, exhibiting great potential as a noninvasive outcome measure for monitoring disease progression and therapeutic efficacy for MS. © 2021 The Author(s)
Author Keywords
Axonal loss; Demyelination; Fingolimod; Multiple sclerosis, diffusion basis spectrum imaging; Optic neuritis
Funding details
National Institutes of HealthNIHP01-NS059560, R01-NS047592, U01- EY025500
U.S. Department of DefenseDODW81XWH-12-1-0457
National Multiple Sclerosis SocietyFG-1507-05315, RG 4549A4/1, RG1701-26617
Foundation for Barnes-Jewish Hospital
National Natural Science Foundation of ChinaNSFC81971574
Natural Science Foundation of Guangdong Province2018A030313282
Natural Science Foundation of Jiangxi Province20202BABL216038, 202110018
Education Department of Jiangxi ProvinceGJJ180133
Guangzhou Municipal Science and Technology Project202002030268
Document Type: Article
Publication Stage: Final
Source: Scopus
Characterization of multiple sclerosis neuroinflammation and neurodegeneration with relaxation and diffusion basis spectrum imaging
(2021) Multiple Sclerosis Journal, .
Vavasour, I.M.a j , Sun, P.b , Graf, C.c , Yik, J.T.c , Kolind, S.H.d k l m , Li, D.K.B.e p , Tam, R.f o , Sayao, A.-L.g , Schabas, A.g , Devonshire, V.g , Carruthers, R.g , Traboulsee, A.g , Moore, G.R.W.h n , Song, S.-K.b , Laule, C.i q r s
a Department of Radiology, The University of British Columbia, UBC Hospital, Vancouver, BC, Canada
b Department of Radiology, Washington University, St. Louis, MO, United States
c Department of Physics & Astronomy, The University of British Columbia, Vancouver, BC, Canada
d Department of Radiology, The University of British Columbia, Vancouver, BC, Canada
e Department of Radiology, The University of British Columbia, Vancouver, BC, Canada
f Department of Radiology, The University of British Columbia, Vancouver, BC, Canada
g Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
h Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
i Department of Radiology, The University of British Columbia, Vancouver, BC, Canada
j International Collaboration on Repair Discoveries (ICORD), The University of British Columbia, Vancouver, BC, Canada
k International Collaboration on Repair Discoveries (ICORD), The University of British Columbia, Vancouver, BC, Canada
l Department of Physics Astronomy, The University of British Columbia, Vancouver, BC, Canada
m Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
n Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, BC, Canada
o School of Biomedical Engineering, The University of British Columbia, Vancouver, BC, Canada
p Department of Medicine, The University of British Columbia, Vancouver, BC, Canada
q International Collaboration on Repair Discoveries (ICORD), The University of British Columbia, Vancouver, BC, Canada
r Department of Physics Astronomy, The University of British Columbia, Vancouver, BC, Canada
s Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, BC, Canada
Abstract
Background: Advanced magnetic resonance imaging (MRI) methods can provide more specific information about various microstructural tissue changes in multiple sclerosis (MS) brain. Quantitative measurement of T1 and T2 relaxation, and diffusion basis spectrum imaging (DBSI) yield metrics related to the pathology of neuroinflammation and neurodegeneration that occurs across the spectrum of MS. Objective: To use relaxation and DBSI MRI metrics to describe measures of neuroinflammation, myelin and axons in different MS subtypes. Methods: 103 participants (20 clinically isolated syndrome (CIS), 33 relapsing-remitting MS (RRMS), 30 secondary progressive MS and 20 primary progressive MS) underwent quantitative T1, T2, DBSI and conventional 3T MRI. Whole brain, normal-appearing white matter, lesion and corpus callosum MRI metrics were compared across MS subtypes. Results: A gradation of MRI metric values was seen from CIS to RRMS to progressive MS. RRMS demonstrated large oedema-related differences, while progressive MS had the most extensive abnormalities in myelin and axonal measures. Conclusion: Relaxation and DBSI-derived MRI measures show differences between MS subtypes related to the severity and composition of underlying tissue damage. RRMS showed oedema, demyelination and axonal loss compared with CIS. Progressive MS had even more evidence of increased oedema, demyelination and axonal loss compared with CIS and RRMS. © The Author(s), 2021.
Author Keywords
brain; diffusion basis spectrum imaging; multiple sclerosis; T1 relaxation; T2 relaxation
Funding details
Genzyme
Novartis
Roche
Natural Sciences and Engineering Research Council of CanadaNSERC
Michael Smith Foundation for Health ResearchMSFHR
Multiple Sclerosis Society of CanadaMSSOC2302
Mitacs
MedImmune
Vancouver Coastal Health Research InstituteVCHRI
Document Type: Article
Publication Stage: Article in Press
Source: Scopus