| 1. |
- Iram, T., et al.
(författare)
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Young CSF restores oligodendrogenesis and memory in aged mice via Fgf17
- 2022
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 605, s. 509-515
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Tidskriftsartikel (refereegranskat)abstract
- Recent understanding of how the systemic environment shapes the brain throughout life has led to numerous intervention strategies to slow brain ageing(1-3). Cerebrospinal fluid (CSF) makes up the immediate environment of brain cells, providing them with nourishing compounds(4,5). We discovered that infusing young CSF directly into aged brains improves memory function. Unbiased transcriptome analysis of the hippocampus identified oligodendrocytes to be most responsive to this rejuvenated CSF environment. We further showed that young CSF boosts oligodendrocyte progenitor cell (OPC) proliferation and differentiation in the aged hippocampus and in primary OPC cultures. Using SLAMseq to metabolically label nascent mRNA, we identified serum response factor (SRF), a transcription factor that drives actin cytoskeleton rearrangement, as a mediator of OPC proliferation following exposure to young CSF. With age, SRF expression decreases in hippocampal OPCs, and the pathway is induced by acute injection with young CSF. We screened for potential SRF activators in CSF and found that fibroblast growth factor 17 (Fgf17) infusion is sufficient to induce OPC proliferation and long-term memory consolidation in aged mice while Fgf17 blockade impairs cognition in young mice. These findings demonstrate the rejuvenating power of young CSF and identify Fgf17 as a key target to restore oligodendrocyte function in the ageing brain.
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| 2. |
- Iram, N, et al.
(författare)
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Age-related changes in expression and function of Toll-like receptors in human skin
- 2012
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Ingår i: Development (Cambridge, England). - : The Company of Biologists. - 1477-9129 .- 0950-1991. ; 139:22, s. 4210-4219
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Tidskriftsartikel (refereegranskat)abstract
- Toll-like receptors (TLRs) initiate innate immune responses and direct subsequent adaptive immunity. They play a major role in cutaneous host defense against micro-organisms and in the pathophysiology of several inflammatory skin diseases. To understand the role of TLRs in the acquisition of immunological competence, we conducted a comprehensive study to evaluate TLR expression and function in the developing human skin before and after birth and compared it with adults. We found that prenatal skin already expresses the same spectrum of TLRs as adult skin. Strikingly, many TLRs were significantly higher expressed in prenatal (TLRs 1-5) and infant and child (TLRs 1 and 3) skin than in adult skin. Surprisingly, neither dendritic cell precursors in prenatal skin nor epidermal Langerhans cells and dermal dendritic cells in adult skin expressed TLRs 3 and 6, whereas the staining pattern and intensity of both TLRs in fetal basal keratinocytes was almost comparable to those of adults. Stimulation of primary human keratinocytes from fetal, neonatal and adult donors with selected TLR agonists revealed that the synthetic TLR3 ligand poly (I:C) specifically, mimicking viral double-stranded RNA, induced a significantly enhanced secretion of CXCL8/IL8, CXCL10/IP-10 and TNFα in fetal and neonatal keratinocytes compared with adult keratinocytes. This study demonstrates quantitative age-specific modifications in TLR expression and innate skin immune reactivity in response to TLR activation. Thus, antiviral innate immunity already in prenatal skin may contribute to protect the developing human body from viral infections in utero in a scenario where the adaptive immune system is not yet fully functional.
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| 4. |
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| 5. |
- Thapa, Anshu, et al.
(författare)
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Carbon Nanotube Matrix for Highly Sensitive Biosensors To Detect Pancreatic Cancer Biomarker CA19-9
- 2017
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 9:31, s. 25878-25886
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Tidskriftsartikel (refereegranskat)abstract
- Biosensors fabricated with nanomaterials promise faster, cheaper, and more efficient alternatives to traditional, often bulky devices for early cancer diagnosis. In this study, we fabricated a thin film sensing unit on interdigitated gold electrodes combining polyethyleneimine and carbon nanotubes in a layer by layer fashion, onto which antibodies anti-CA19-9 were adsorbed with a supporting layer of N-hydroxysuccini-mide and 1-ethyl-3 (3-dimethylaminopropyl) carbodiimide solution. By use of impedance spectroscopy, the pancreatic cancer biomarker CA19-9 was detected in a buffer with limit of detection of 0.35 U/mL. This high sensitivity allowed for distinction between samples of blood serum from patients with distinct probabilities to develop pancreatic cancer. The selectivity of the biosensor was confirmed in subsidiary experiments with HT-29 and SW-620 cell lines and possible interferents, e.g., p53 protein, ascorbic acid, and glucose, where significant changes in capacitance could only be measured with HT-29 that contained the CA19-9 biomarker. Chemisorption of CA19-9 molecules onto the layer of anti-CA19-9 antibodies was the mechanism responsible for sensing while electrostatic interactions drove the adsorption of carbon nanotubes, according to polarization modulated infrared reflection absorption spectroscopy (PM-IRRAS). The adsorption behavior was successfully described by the Langmuir-Freundlich isotherm.
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