1
|
Melendez J, Sung YJ, Orr M, Yoo A, Schindler S, Cruchaga C, Bateman R. An interpretable machine learning-based cerebrospinal fluid proteomics clock for predicting age reveals novel insights into brain aging. Aging Cell 2024:e14230. [PMID: 38923730 DOI: 10.1111/acel.14230] [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] [Received: 01/12/2024] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 06/28/2024] Open
Abstract
Machine learning can be used to create "biologic clocks" that predict age. However, organs, tissues, and biofluids may age at different rates from the organism as a whole. We sought to understand how cerebrospinal fluid (CSF) changes with age to inform the development of brain aging-related disease mechanisms and identify potential anti-aging therapeutic targets. Several epigenetic clocks exist based on plasma and neuronal tissues; however, plasma may not reflect brain aging specifically and tissue-based clocks require samples that are difficult to obtain from living participants. To address these problems, we developed a machine learning clock that uses CSF proteomics to predict the chronological age of individuals with a 0.79 Pearson correlation and mean estimated error (MAE) of 4.30 years in our validation cohort. Additionally, we analyzed proteins highly weighted by the algorithm to gain insights into changes in CSF and uncover novel insights into brain aging. We also demonstrate a novel method to create a minimal protein clock that uses just 109 protein features from the original clock to achieve a similar accuracy (0.75 correlation, MAE 5.41). Finally, we demonstrate that our clock identifies novel proteins that are highly predictive of age in interactions with other proteins, but do not directly correlate with chronological age themselves. In conclusion, we propose that our CSF protein aging clock can identify novel proteins that influence the rate of aging of the central nervous system (CNS), in a manner that would not be identifiable by examining their individual relationships with age.
Collapse
Affiliation(s)
- Justin Melendez
- Tracy Family SILQ Center, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Neurology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Yun Ju Sung
- Department of Psychiatry, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Biostatistics, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Miranda Orr
- Department of Internal Medicine, Wake Forest School of Medicine Section of Gerontology and Geriatric Medicine Medical Center Boulevard, Winston-Salem, North Carolina, USA
| | - Andrew Yoo
- Department of Developmental Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Suzanne Schindler
- Department of Neurology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Carlos Cruchaga
- Department of Neurology, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Psychiatry, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Randall Bateman
- Tracy Family SILQ Center, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Neurology, Washington University in St. Louis, St. Louis, Missouri, USA
| |
Collapse
|
2
|
Crocker CE, Sharmeen R, Tran TT, Khan AM, Li W, Alcorn JL. Surfactant protein a attenuates generalized and localized neuroinflammation in neonatal mice. Brain Res 2023; 1807:148308. [PMID: 36871846 PMCID: PMC10065943 DOI: 10.1016/j.brainres.2023.148308] [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: 12/14/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023]
Abstract
Surfactant protein A (SP-A) has important roles in innate immunity and modulation of pulmonary and extrapulmonary inflammation. Given SP-A has been detected in rat and human brain, we sought to determine if SP-A has a role in modulating inflammation in the neonatal mouse brain. Neonatal wildtype (WT) and SP-A-deficient (SP-A-/-) mice were subjected to three models of brain inflammation: systemic sepsis, intraventricular hemorrhage (IVH) and hypoxic-ischemic encephalopathy (HIE). Following each intervention, RNA was isolated from brain tissue and expression of cytokine and SP-A mRNA was determined by real-time quantitative RT-PCR analysis. In the sepsis model, expression of most cytokine mRNAs was significantly increased in brains of WT and SP-A-/- mice with significantly greater expression of all cytokine mRNA levels in SP-A-/- mice compared to WT. In the IVH model, expression of all cytokine mRNAs was significantly increased in WT and SP-A-/- mice and levels of most cytokine mRNAs were significantly increased in SP-A-/- mice compared to WT. In the HIE model, only TNF-α mRNA levels were significantly increased in WT brain tissue while all pro-inflammtory cytokine mRNAs were significantly increased in SP-A-/- mice, and all pro-inflammatory cytokine mRNA levels were significantly higher in SP-A-/- mice compared to WT. SP-A mRNA was not detectable in brain tissue of adult WT mice nor in WT neonates subjected to these models. These results suggest that SP-A-/- neonatal mice subjected to models of neuroinflammation are more susceptible to both generalized and localized neuroinflammation compared to WT mice, thus supporting the hypothesis that SP-A attenuates inflammation in neonatal mouse brain.
Collapse
Affiliation(s)
- Caroline E Crocker
- Division of Neonatology, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Romana Sharmeen
- Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Thu T Tran
- Division of Neonatology, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Amir M Khan
- Division of Neonatology, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Wen Li
- Division of Clinical and Translational Sciences, Department of Internal Medicine, the University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA; Biostatistics/Epidemiology/Research Design Component, Center for Clinical and Translational Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Joseph L Alcorn
- Division of Neonatology, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Pediatric Research Center, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| |
Collapse
|
3
|
Reger RM, Meinicke A, Härtig W, Knüpfer M, Thome U, Schob S, Krause M. Changes in CSF Surface Tension in Relation to Surfactant Proteins in Children with Intraventricular Hemorrhage. Brain Sci 2022; 12:brainsci12111440. [PMID: 36358367 PMCID: PMC9688901 DOI: 10.3390/brainsci12111440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 10/20/2022] [Accepted: 10/22/2022] [Indexed: 11/16/2022] Open
Abstract
The regulation of surface tension (ST) by surfactants plays an important role in the human respiratory system but is largely unexplored in brain homeostasis. The aim of this study was to evaluate changes in ST in relation to surfactant proteins (SPs) in children with intraventricular hemorrhage (IVH). CSF samples from 93 patients were analyzed for ST with a force tensiometer and SP-A-D and -G with ELISA assays. Patients belonged to six groups: (i) IVH before primary intervention (PI), (ii) IVH 4−28 days after PI, (iii) IVH 44−357 days after PI, (iv) hydrocephalus, (v) sepsis and (vi) controls. We found indirect correlations and significant differences in ST and SPs (all p < 0.001; except for SP-C, p = 0.007). Post hoc analyses showed significantly decreased ST in IVH patients before PI compared with patients with hydrocephalus, sepsis or controls (p < 0.001), but it increased in IVH patients over time. All SPs were significantly elevated when comparing IVH patients before PI with controls (all p < 0.001; except for SP-C, p = 0.003). Children suffering from IVH displayed an increase in SPs and a decrease in ST as coping mechanisms to preserve CSF flow. The increase in ST over time could serve as prognostic marker for the healing process.
Collapse
Affiliation(s)
- Rieka M. Reger
- Department of Neurosurgery, University Hospital Leipzig, 04103 Leipzig, Germany
| | - Anton Meinicke
- Paul Flechsig Institute for Brain Research, Leipzig University, 04103 Leipzig, Germany
| | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, Leipzig University, 04103 Leipzig, Germany
| | - Matthias Knüpfer
- Department of Neonatology, University Hospital Leipzig, 04103 Leipzig, Germany
| | - Ulrich Thome
- Department of Neonatology, University Hospital Leipzig, 04103 Leipzig, Germany
| | - Stefan Schob
- Department of Neuroradiology, University Hospital Halle, 06120 Halle (Saale), Germany
| | - Matthias Krause
- Department of Neurosurgery, University Hospital Leipzig, 04103 Leipzig, Germany
- Correspondence: ; Tel.: +49-341-9717500
| |
Collapse
|
4
|
Krause M, Härtig W, Mahr CV, Richter C, Schob J, Puchta J, Hoffmann KT, Nestler U, Thome U, Knüpfer M, Gebauer C, Schob S. CSF Surfactant Protein Changes in Preterm Infants After Intraventricular Hemorrhage. Front Pediatr 2020; 8:572851. [PMID: 33102410 PMCID: PMC7546901 DOI: 10.3389/fped.2020.572851] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/12/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction: Surfactant proteins (SP) have been shown to be inherent proteins of the human CNS and are altered during acute and chronic disturbances of CSF circulation. Aim of the study was to examine the changes of surfactant protein concentrations in CSF of preterm babies suffering from intraventricular hemorrhage. Patients and Methods: Consecutive CSF samples of 21 preterm infants with intraventricular hemorrhages (IVH) and posthemorrhagic hydrocephalus (PHHC) were collected at primary intervention, after 5-10 days and at time of shunt insertion ~50 days after hemorrhage. Samples were analyzed for surfactant proteins A, B, C, and G by ELISA assays and the results were compared to 35 hydrocephalus patients (HC) without hemorrhage and 6 newborn control patients. Results and Discussion: Premature patients with IVH showed a significant elevation of surfactant proteins SP-A, C, and G compared to HC and control groups: mean values for the respective groups were SP-A 4.19 vs. 1.08 vs. 0.38 ng/ml. Mean SP-C 3.63 vs. 1.47 vs. 0.48 ng/ml. Mean SP-G 3.86 vs. 0.17 vs. 0.2 ng/ml. SP-A and G concentrations were slowly falling over time without reaching normal values. SP-C levels declined faster following neurosurgical interventions and reached levels comparable to those of hydrocephalus patients without hemorrhage. Conclusion: Intraventricular hemorrhages of premature infants cause posthemorrhagic CSF flow disturbance and are associated with highly significant elevations of surfactant proteins A, C, and G independent of total CSF protein concentrations.
Collapse
Affiliation(s)
- Matthias Krause
- Department of Neurosurgery, University Hospital Leipzig, Leipzig, Germany
| | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, Medical Faculty of University Leipzig, Leipzig, Germany.,Department of Neuroradiology, University Hospital Leipzig, Leipzig, Germany
| | | | - Cindy Richter
- Department of Neuroradiology, University Hospital Leipzig, Leipzig, Germany
| | - Julia Schob
- Department of Ophthalmology, University Hospital Leipzig, Leipzig, Germany
| | - Joana Puchta
- Paul Flechsig Institute for Brain Research, Medical Faculty of University Leipzig, Leipzig, Germany.,Department of Neuroradiology, University Hospital Leipzig, Leipzig, Germany
| | | | - Ulf Nestler
- Department of Neurosurgery, University Hospital Leipzig, Leipzig, Germany
| | - Ulrich Thome
- Department of Neonatology, University Hospital Leipzig, Leipzig, Germany
| | - Matthias Knüpfer
- Department of Neonatology, University Hospital Leipzig, Leipzig, Germany
| | - Corinna Gebauer
- Department of Neonatology, University Hospital Leipzig, Leipzig, Germany
| | - Stefan Schob
- Department of Neuroradiology, University Hospital Leipzig, Leipzig, Germany
| |
Collapse
|
5
|
He W, You J, Wan Q, Xiao K, Chen K, Lu Y, Li L, Tang Y, Deng Y, Yao Z, Yue J, Cao G. The anatomy and metabolome of the lymphatic system in the brain in health and disease. Brain Pathol 2019; 30:392-404. [PMID: 31747475 DOI: 10.1111/bpa.12805] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/10/2019] [Indexed: 12/18/2022] Open
Abstract
Recent studies have demonstrated that the brain is equipped with a lymphatic drainage system that is actively involved in parenchymal waste clearance, brain homeostasis and immune regulation. However, the exact anatomic drainage routes of brain lymph fluid (BLF) remain elusive, hampering the physiological study and clinical application of this system. In this study, we systematically dissected the anatomy of the BLF pathways in a rat model. Moreover, we developed a protocol to collect BLF from the afferent lymphatic vessels of deep cervical lymph nodes (dcLNs) and cerebrospinal fluid (CSF) from the fourth ventricle. Nuclear magnetic resonance spectroscopy showed that BLF contains more metabolites than CSF, suggesting that BLF might be a more sensitive indicator of brain dynamics under physiological and pathological conditions. Finally, we identified several metabolites as potential diagnostic biomarkers for glioma, Parkinson's disease and CNS infectious diseases. Together, these data may provide insight into the physiology of the lymphatic system in the brain and into the clinical diagnosis of CNS disorders.
Collapse
Affiliation(s)
- Wenbo He
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jing You
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,Department of Biomedical Engineering, University of North Texas, Denton, TX
| | - Qianfen Wan
- Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Ke Xiao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Kening Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuan Lu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA
| | - Yajie Tang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yunte Deng
- Department of Pathology, Hubei Cancer Hospital, Wuhan, 430079, China
| | - Zhaohui Yao
- Department of Geriatrics, Renmin Hospital of Wuhan University, Jiefang Road, Wuhan, China
| | - Junqiu Yue
- Department of Pathology, Hubei Cancer Hospital, Wuhan, 430079, China
| | - Gang Cao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.,College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Bio-Medical Center, Huazhong Agricultural University, Wuhan, 430070, China.,Cooperative Innovation Center for Sustainable Pig Production (CICSPP), Huazhong Agricultural University, Wuhan, 430070, China
| |
Collapse
|
6
|
Weiß A, Krause M, Stockert A, Richter C, Puchta J, Bhogal P, Hoffmann KT, Emmer A, Quäschling U, Scherlach C, Härtig W, Schob S. Rheologically Essential Surfactant Proteins of the CSF Interacting with Periventricular White Matter Changes in Hydrocephalus Patients - Implications for CSF Dynamics and the Glymphatic System. Mol Neurobiol 2019; 56:7863-7871. [PMID: 31127529 DOI: 10.1007/s12035-019-01648-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 05/13/2019] [Indexed: 10/26/2022]
Abstract
Surfactant proteins (SP) are multi-systemic proteins playing crucial roles in the regulation of rheological properties of physiological fluids, host defense, and the clearance of potentially harmful metabolites. Hydrocephalus patients suffer from disturbed central nervous system (CNS) fluid homeostasis and exhibit remarkably altered SP concentrations within the cerebrospinal fluid (CSF). A connection between CSF-SPs, CSF flow, and ventricular dilatation, a morphological hallmark of hydrocephalus, has been reported previously. However, currently there are no studies investigating the link between rheologically active SPs and periventricular white matter changes caused by impaired CSF microcirculation in hydrocephalic conditions. Thus, the aim of this study was to assess their possible relationships. The present study included 47 individuals (27 healthy subjects and 20 hydrocephalus patients). CSF specimens were analyzed for concentrations of SP-A, SP-C, and SP-D by using enzyme-linked immunosorbent assays (ELISAs). Axial T2w turbo inversion recovery magnitude (TIRM) magnetic resonance imaging was employed in all cases. Using a custom-made MATLAB-based tool for quantification of magnetic resonance signal intensities in the brain, parameters related to disturbed deep white matter CSF microcirculation were estimated (TIRM signal intensity (SI)-mean, minimum, maximum, median, mode, standard deviation, and percentiles, p10th, p25th, p75th, p90th, as well as kurtosis, skewness, and entropy of the SI distribution). Subsequently, statistical analysis was performed (IBM SPSS 24™) to identify differences between hydrocephalic patients and healthy individuals and to further investigate the connections between CSF-SP changes and deep white matter signal intensities. SP-A (0.38 ± 0.23 vs. 0.76 ± 0.49 ng/ml) and SP-C (0.54 ± 0.28 vs. 1.27 ± 1.09 ng/ml) differed between healthy controls and hydrocephalus patients in a statistically significant manner. Also, corresponding quantification of white matter signal intensities revealed statistically significant differences between hydrocephalus patients and healthy individuals: SImean (370.41 ± 188.15 vs. 222.27 ± 99.86, p = 0.001), SImax (1115.30 ± 700.12 vs. 617.00 ± 459.34, p = 0.005), SImedian (321.40 ± 153.17 vs. 209.52 ± 84.86, p = 0.001), SImode (276.55 ± 125.63 vs. 197.26 ± 78.51, p = 0.011), SIstd (157.09 ± 110.07 vs. 81.71 ± 64.94, p = 0.005), SIp10 (229.10 ± 104.22 vs. 140.00 ± 63.12, p = 0.001), SIp25 (266.95 ± 122.62 vs. 175.63 ± 71.42, p = 0.002), SIp75 (428.80 ± 226.88 vs. 252.19 ± 110.91, p = 0.001), SIp90 (596.47 ± 345.61 vs. 322.06 ± 176.00, p = 0.001), skewness (1.19 ± 0.68 vs. 0.43 ± 1.19, p = 0.014), and entropy (5.36 ± 0.37 vs. 4.92 ± 0.51, p = 0.002). There were no differences regarding SP-D levels in hydrocephalus patients vs. healthy controls. In the acute hydrocephalic subgroup, correlations were as follows: SP-A showed a statistically significant correlation with SImax (r = 0.670, p = 0.024), SIstd (r = 0.697, p = 0.017), SIp90 (r = 0.621, p = 0.041), and inverse correlation with entropy (r = - 0.700, p = 0.016). SP-C correlated inversely with entropy (r = - 0.686, p = 0.020). For the chronic hydrocephalus subgroup, the following correlations were identified: SP-A correlated with kurtosis of the TIRM histogram (r = - 0.746, p = 0.021). SP-C correlated with SImean (r = - 0.688, p = 0.041), SImax (r = - 0.741, p = 0.022), SImedian (r = - 0.716, p = 0.030), SImode (r = - 0.765, p = 0.016), SIstd (r = - 0.671, p = 0.048), SIp25 (r = - 0.740, p = 0.023), SIp75 (r = - 0.672, p = 0.048), and SIp90 (r = - 0.667, p = 0.050). SP-D apparently does not play a major role in CSF fluid physiology. SP-A and SP-C are involved in different aspects of CNS fluid physiology. SP-A appears to play an essential compensatory role in acute hydrocephalus and seems less involved in chronic hydrocephalus. In contrary, SP-C profile and white matter changes are remarkably connected in CSF of chronic hydrocephalus patients. Considering the association between CSF flow phenomena, white matter changes, and SP-C profiles, the latter may especially contribute to the regulation of paravascular glymphatic physiology.
Collapse
Affiliation(s)
- Alexander Weiß
- Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Matthias Krause
- Department of Neurosurgery, University Hospital Leipzig, Leipzig, Germany
| | - Anika Stockert
- Department of Neurology, University Hospital Leipzig, Leipzig, Germany
| | - Cindy Richter
- Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Joana Puchta
- Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.,Paul Flechsig Institute for Brain Research, University Leipzig, Leipzig, Germany
| | - Pervinder Bhogal
- Department of Interventional Neuroradiology, Royal London Hospital, London, UK
| | - Karl-Titus Hoffmann
- Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Alexander Emmer
- Department for Neurology, University Hospital Halle-Wittenberg, Halle, Germany
| | - Ulf Quäschling
- Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Cordula Scherlach
- Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, University Leipzig, Leipzig, Germany
| | - Stefan Schob
- Department of Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
| |
Collapse
|
7
|
Krause M, Peukert N, Härtig W, Emmer A, Mahr CV, Richter C, Dieckow J, Puchta J, Pirlich M, Hoffmann KT, Nestler U, Schob S. Localization, Occurrence, and CSF Changes of SP-G, a New Surface Active Protein with Assumable Immunoregulatory Functions in the CNS. Mol Neurobiol 2018; 56:2433-2439. [PMID: 30032421 DOI: 10.1007/s12035-018-1247-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/15/2018] [Indexed: 10/28/2022]
Abstract
Conventional surfactant proteins (A, B, C, and D) are important players of the innate immunity in the central nervous system and serve as effective regulators of cerebrospinal fluid rheology, probably being involved in clearance of detrimental metabolites like beta-amyloid and phospho-tau. Recently, a novel surfactant protein, SP-G, was described in kidneys and peripheral endocrine and exocrine glands. So far, its presence and possible functions in the central nervous system are unknown. Therefore, our study aimed to elucidate the presence of SP-G in the brain and its concentration in normal and pathologic samples of cerebrospinal fluid in order to gain first insight into its regulation and possible functions. A total of 121 samples of human cerebrospinal fluid (30 controls, 60 hydrocephalus patients, 7 central nervous system infections, and 24 brain hemorrhage patients) and 21 rat brains were included in our study. CSF samples were quantified using a commercially available ELISA system. Results were analyzed statistically using SPSS 22, performing Spearman Rho correlation and ANOVA with Dunnett's post hoc analysis. Rat brains were investigated via immunofluorescence to determine SP-G presence and colocalization with common markers like aquaporin-4, glial fibrillary acidic protein, platelet endothelial adhesion molecule 1, and neuronal nuclear antigen. SP-G occurs associated with brain vessels, comparable to other conventional SPs, and is present in a set of cortical neurons. SP-G is furthermore actively produced by ependymal and choroid plexus epithelium and secreted into the cerebrospinal fluid. Its concentrations are low in control subjects and patients suffering from aqueductal stenosis, higher in normal pressure hydrocephalus (p < 0.01), and highest in infections of the central nervous system and brain hemorrhage (p < 0.001). Interestingly, SP-G did correlate with total CSF protein in patients with CNS infections and hemorrhage, but not with cell count. Based on the changes in CSF levels of SP-G in hydrocephalus, brain hemorrhage, and CNS infections as well as its abundance at CSF flow-related anatomical structures closely associated with immunological barrier systems, importance for CSF rheology, brain waste clearance, and host defense is assumable. Thus, SP-G is a potential new CSF biomarker, possibly not only reflecting aspects of CNS innate immune responses, but also rheo-dynamically relevant changes of CSF composition, associated with CSF malabsorbtion. However, further studies are warranted to validate our findings and increase insight into the physiological importance of SP-G in the CNS.
Collapse
Affiliation(s)
- Matthias Krause
- Department for Neurosurgery, University Hospital Leipzig, Leipzig, Germany
| | - Nicole Peukert
- Department for Pediatric Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, Medical Faculty / University Leipzig, Leipzig, Germany
| | - Alexander Emmer
- Department for Neurology, University Hospital Halle-Wittenberg / Martin Luther University, Halle/Saale, Germany
| | | | - Cindy Richter
- Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Julia Dieckow
- Department for Ophthalmology, University Hospital Leipzig, Leipzig, Germany
| | - Joana Puchta
- Paul Flechsig Institute for Brain Research, Medical Faculty / University Leipzig, Leipzig, Germany.,Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Mandy Pirlich
- Department for Neurology, University Hospital Leipzig, Leipzig, Germany
| | - Karl-Titus Hoffmann
- Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Ulf Nestler
- Department for Neurosurgery, University Hospital Leipzig, Leipzig, Germany
| | - Stefan Schob
- Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
| |
Collapse
|
8
|
|
9
|
Sorensen GL. Surfactant Protein D in Respiratory and Non-Respiratory Diseases. Front Med (Lausanne) 2018; 5:18. [PMID: 29473039 PMCID: PMC5809447 DOI: 10.3389/fmed.2018.00018] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/19/2018] [Indexed: 12/16/2022] Open
Abstract
Surfactant protein D (SP-D) is a multimeric collectin that is involved in innate immune defense and expressed in pulmonary, as well as non-pulmonary, epithelia. SP-D exerts antimicrobial effects and dampens inflammation through direct microbial interactions and modulation of host cell responses via a series of cellular receptors. However, low protein concentrations, genetic variation, biochemical modification, and proteolytic breakdown can induce decomposition of multimeric SP-D into low-molecular weight forms, which may induce pro-inflammatory SP-D signaling. Multimeric SP-D can decompose into trimeric SP-D, and this process, and total SP-D levels, are partly determined by variation within the SP-D gene, SFTPD. SP-D has been implicated in the development of respiratory diseases including respiratory distress syndrome, bronchopulmonary dysplasia, allergic asthma, and chronic obstructive pulmonary disease. Disease-induced breakdown or modifications of SP-D facilitate its systemic leakage from the lung, and circulatory SP-D is a promising biomarker for lung injury. Moreover, studies in preclinical animal models have demonstrated that local pulmonary treatment with recombinant SP-D is beneficial in these diseases. In recent years, SP-D has been shown to exert antimicrobial and anti-inflammatory effects in various non-pulmonary organs and to have effects on lipid metabolism and pro-inflammatory effects in vessel walls, which enhance the risk of atherosclerosis. A common SFTPD polymorphism is associated with atherosclerosis and diabetes, and SP-D has been associated with metabolic disorders because of its effects in the endothelium and adipocytes and its obesity-dampening properties. This review summarizes and discusses the reported genetic associations of SP-D with disease and the clinical utility of circulating SP-D for respiratory disease prognosis. Moreover, basic research on the mechanistic links between SP-D and respiratory, cardiovascular, and metabolic diseases is summarized. Perspectives on the development of SP-D therapy are addressed.
Collapse
Affiliation(s)
- Grith L Sorensen
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
10
|
Schob S, Weiß A, Surov A, Dieckow J, Richter C, Pirlich M, Horvath-Rizea D, Härtig W, Hoffmann KT, Krause M, Quäschling U. Elevated Surfactant Protein Levels and Increased Flow of Cerebrospinal Fluid in Cranial Magnetic Resonance Imaging. Mol Neurobiol 2017; 55:6227-6236. [PMID: 29282698 DOI: 10.1007/s12035-017-0835-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 12/08/2017] [Indexed: 12/14/2022]
Abstract
Surfactant proteins (SPs) are a multifunctional group of proteins, responsible for the regulation of rheological properties of body fluids, host defense, and cellular waste clearance. Their concentrations are changed in cerebrospinal fluid (CSF) of patients suffering from communicating hydrocephalus. Hydrocephalic conditions are accompanied by altered CSF flow dynamics; however, the association of CSF-SP concentrations and CSF flow has not yet been investigated. Hence, the aim of this study was to evaluate the association between SP concentrations in the CSF and marked CSF flow phenomena at different anatomical landmarks of CSF spaces. Sixty-one individuals (15 healthy subjects and 46 hydrocephalus patients) were included in this study. CSF specimens were analyzed for SP-A, SP-B, SP-C, and SP-D concentrations by the use of enzyme-linked immunosorbent assays (ELISA). CSF flow was evaluated in axial T2_turbo inversion recovery magnitude (TIRM)-weighted and sagittal T2-weighted magnetic resonance imaging sections using a 4-grade scale (1-no flow, 2-subtle flow, 3-moderate flow, and 4-strong flow). CSF-SP concentrations (mean ± standard deviation) of the overall collective were as follows: SP-A = 0.73 ± 0.58 ng/ml, SP-B = 0.17 ± 0.93 ng/ml, SP-C = 0.95 ± 0.75 ng/ml, and SP-D = 7.43 ± 5.17 ng/ml. The difference between healthy controls and hydrocephalic patients regarding CSF concentrations of SP-A (0.34 ± 0.22 vs. 0.81 ± 0.59 ng/ml) and SP-C (0.48 ± 0.29 vs. 1.10 ± 0.79 ng/ml) revealed to be statistically significant as calculated by means of ANOVA (p values of 0.022 and 0.007, respectively). CSF flow voids were detectable at all investigated landmarks of the CSF spaces (foramina of Monro, third ventricle, mesencephalic aqueduct, prepontine cistern, fourth ventricle, cisterna magna, and craniocervical junction). CSF flow voids, reported as mean ± standard deviation, revealed to be significantly increased in hydrocephalic patients compared to controls as calculated by means of ANOVA (respective p values are given in brackets following values of descriptive statistics) at the following sites: foramina of Monro (1.60 ± 0.91 vs. 2.37 ± 0.99, p = 0.01), fourth ventricle (1.67 ± 0.98 vs. 2.52 ± 1.05, p = 0.007), and the cisterna magna (1.93 ± 1.10 vs. 2.72 ± 1.13, p = 0.022). Spearman's rank order calculation identified significant correlations for CSF flow voids at the foramina of Monro and the third ventricle with SP-A (r = 0.429, p = 0.001 and r = 0.464, p < 0.001) and CSF flow void at the mesencephalic duct with SP-D (r = - 0.371, p = 0.039). Furthermore, SP-C showed a moderate inverse correlation with age (r = - 0.302, p = 0.022). The present study confirmed statistically significant differences in SP-CSF concentrations between healthy controls and hydrocephalic patients. Additionally, significant correlations between SP concentrations in CSF with increased CSF flow were identified. These findings underline the role of SPs as regulators of CSF rheology.
Collapse
Affiliation(s)
- Stefan Schob
- Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
| | - Alexander Weiß
- Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Alexey Surov
- Department for Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany
| | - Julia Dieckow
- Department for Ophthalmology, University Hospital Leipzig, Leipzig, Germany
| | - Cindy Richter
- Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.,Institute for Anatomy, University Hospital Leipzig, Leipzig, Germany
| | - Mandy Pirlich
- Department for Neurology, University Hospital Leipzig, Leipzig, Germany
| | | | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, Medical Faculty / University Hospital Leipzig, Leipzig, Germany
| | - Karl-Titus Hoffmann
- Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - Matthias Krause
- Department for Neurosurgery, University Hospital Leipzig, Leipzig, Germany
| | - Ulf Quäschling
- Department for Neuroradiology, University Hospital Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| |
Collapse
|
11
|
Cerebrospinal fluid biomarkers of infantile congenital hydrocephalus. PLoS One 2017; 12:e0172353. [PMID: 28212403 PMCID: PMC5315300 DOI: 10.1371/journal.pone.0172353] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 02/04/2017] [Indexed: 11/19/2022] Open
Abstract
Introduction Hydrocephalus is a complex neurological disorder with a pervasive impact on the central nervous system. Previous work has demonstrated derangements in the biochemical profile of cerebrospinal fluid (CSF) in hydrocephalus, particularly in infants and children, in whom neurodevelopment is progressing in parallel with concomitant neurological injury. The objective of this study was to examine the CSF of children with congenital hydrocephalus (CHC) to gain insight into the pathophysiology of hydrocephalus and identify candidate biomarkers of CHC with potential diagnostic and therapeutic value. Methods CSF levels of amyloid precursor protein (APP) and derivative isoforms (sAPPα, sAPPβ, Aβ42), tau, phosphorylated tau (pTau), L1CAM, NCAM-1, aquaporin 4 (AQP4), and total protein (TP) were measured by ELISA in 20 children with CHC. Two comparative groups were included: age-matched controls and children with other neurological diseases. Demographic parameters, ventricular frontal-occipital horn ratio, associated brain malformations, genetic alterations, and surgical treatments were recorded. Logistic regression analysis and receiver operating characteristic curves were used to examine the association of each CSF protein with CHC. Results CSF levels of APP, sAPPα, sAPPβ, Aβ42, tau, pTau, L1CAM, and NCAM-1 but not AQP4 or TP were increased in untreated CHC. CSF TP and normalized L1CAM levels were associated with FOR in CHC subjects, while normalized CSF tau levels were associated with FOR in control subjects. Predictive ability for CHC was strongest for sAPPα, especially in subjects ≤12 months of age (p<0.0001 and AUC = 0.99), followed by normalized sAPPβ (p = 0.0001, AUC = 0.95), tau, APP, and L1CAM. Among subjects ≤12 months, a normalized CSF sAPPα cut-point of 0.41 provided the best prediction of CHC (odds ratio = 528, sensitivity = 0.94, specificity = 0.97); these infants were 32 times more likely to have CHC. Conclusions CSF proteins such as sAPPα and related proteins hold promise as biomarkers of CHC in infants and young children, and provide insight into the pathophysiology of CHC during this critical period in neurodevelopment.
Collapse
|
12
|
Schob S, Weiß A, Dieckow J, Richter C, Pirlich M, Voigt P, Surov A, Hoffmann KT, Quaeschling U, Preuß M. Correlations of Ventricular Enlargement with Rheologically Active Surfactant Proteins in Cerebrospinal Fluid. Front Aging Neurosci 2017; 8:324. [PMID: 28101052 PMCID: PMC5209370 DOI: 10.3389/fnagi.2016.00324] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 12/14/2016] [Indexed: 12/25/2022] Open
Abstract
Purpose: Surfactant proteins (SPs) are involved in the regulation of rheological properties of body fluids. Concentrations of SPs are altered in the cerebrospinal fluid (CSF) of hydrocephalus patients. The common hallmark of hydrocephalus is enlargement of the brain ventricles. The relationship of both phenomena has not yet been investigated. The aim of this study was to evaluate the association between SP concentrations in the CSF and enlargement of the brain ventricles. Procedures: Ninty-six individuals (41 healthy subjects and 55 hydrocephalus patients) were included in this retrospective analysis. CSF specimens were analyzed for SP-A, SP-B, SP-C and SP-D concentrations by use of enzyme linked immunosorbent assays (ELISA). Ventricular enlargement was quantified in T2 weighted (T2w) magnetic resonance imaging (MRI) sections using an uni-dimensional (Evans’ Index) and a two-dimensional approach (lateral ventricles area index, LVAI). Results: CSF-SP concentrations (mean ± standard deviation in ng/ml) were as follows: SP-A 0.71 ± 0.58, SP-B 0.18 ± 0.43, SP-C 0.89 ± 0.77 and SP-D 7.4 ± 5.4. Calculated values of Evans’ Index were 0.37 ± 0.11, a calculation of LVAI resulted in 0.18 ± 0.15 (each mean ± standard deviation). Significant correlations were identified for Evans’ Index with SP-A (r = 0.388, p < 0.001) and SP-C (r = 0.392, p < 0.001), LVAI with SP-A (r = 0.352, p = 0.001), SP-C (r = 0.471, p < 0.001) and SP-D (r = 0.233, p = 0.025). Furthermore, SP-C showed a clear inverse correlation with age (r = −0.357, p = 0.011). Conclusion: The present study confirmed significant correlations between SPs A, C and D in the CSF with enlargement of the inner CSF spaces. In conclusion, SPs clearly play an important role for CSF rheology. CSF rheology is profoundly altered in hydrocephalic diseases, however, diagnosis and therapy of hydrocephalic conditions are still almost exclusively based on ventricular enlargement. Until now it was unclear, whether the stage of the disease, as represented by the extent of ventricular dilatation, is somehow related to the changes of SP levels in the CSF. Our study is the first to provide evidence that increasing ventriculomegaly is accompanied by enhanced changes of rheologically active compounds in the CSF and therefore introduces completely new aspects for hydrocephalus testing and conservative therapeutic approaches.
Collapse
Affiliation(s)
- Stefan Schob
- Department of Neuroradiology, Leipzig University Leipzig, Germany
| | - Alexander Weiß
- Department of Neuroradiology, Leipzig University Leipzig, Germany
| | - Julia Dieckow
- Department of Ophthalmology, Leipzig University Leipzig, Germany
| | - Cindy Richter
- Institute of Anatomy, Leipzig University Leipzig, Germany
| | - Mandy Pirlich
- Department of Neurology, Leipzig University Leipzig, Germany
| | - Peter Voigt
- Department of Neuroradiology, Leipzig University Leipzig, Germany
| | - Alexey Surov
- Department of Diagnostic and Interventional Radiology, Leipzig University Hospital Leipzig, Germany
| | | | - Ulf Quaeschling
- Department of Neuroradiology, Leipzig University Leipzig, Germany
| | - Matthias Preuß
- Department of Neurosurgery, Leipzig University Leipzig, Germany
| |
Collapse
|
13
|
Schob S, Dieckow J, Fehrenbach M, Peukert N, Weiss A, Kluth D, Thome U, Quäschling U, Lacher M, Preuß M. Occurrence and colocalization of surfactant proteins A, B, C and D in the developing and adult rat brain. Ann Anat 2016; 210:121-127. [PMID: 27838560 DOI: 10.1016/j.aanat.2016.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/12/2016] [Accepted: 10/10/2016] [Indexed: 12/18/2022]
Abstract
BACKGROUND Surfactant proteins (SP's) have been described as inherent proteins of the human central nervous system (CNS). Their distribution pattern in brain tissue and altered cerebrospinal fluid (CSF) - concentrations in different CNS pathologies are indicative of their immunological and rheological importance. The aim of this study has been to investigate when - compared to the lungs - SP's are expressed in the developing rat brain and which functional components in the CNS participate in their production. MATERIAL AND METHODS Brain and lung tissue from embryonal (days 10, 12, 14, 16, 17 and 20), newborn, and adult rats were harvested and investigated for expression of SP-A, SP-B, SP-C and SP-D using immunofluorescence microscopy in order to identify and compare the time points of their occurence in the respective tissue. To better identify the location of SP expression in the rat brain, SP's were colocalized with use of an astrocyte marker (GFAP), a neuronal marker (NeuN), an endothelial marker (CD31) and an axonal marker (NF). RESULTS AND CONCLUSION SP-A and SP-C are expressed in the CNS of rats during early embryonic age whereas SP-B and SP-D are first present in the adult rat brain. All SP's are expressed in cells adjacent to CSF spaces, probably influencing and maintaining physiological CSF flow. SP's A and C are abundant at the site of the blood brain barrier (BBB).
Collapse
Affiliation(s)
- Stefan Schob
- Department of Neuroradiology, University Leipzig, Germany.
| | - Julia Dieckow
- Department of Ophthalmology, University Leipzig, Germany
| | | | - Nicole Peukert
- Department of Pediatric Surgery, University Leipzig, Germany
| | | | - Dietrich Kluth
- Department of Pediatric Surgery, University Leipzig, Germany
| | - Ulrich Thome
- Department of Neonatology, University Leipzig, Germany
| | - Ulf Quäschling
- Department of Neuroradiology, University Leipzig, Germany
| | - Martin Lacher
- Department of Pediatric Surgery, University Leipzig, Germany
| | | |
Collapse
|