scholarly journals The Effects of Fibrinogen’s Interactions with Its Neuronal Receptors, Intercellular Adhesion Molecule-1 and Cellular Prion Protein

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1381
Author(s):  
Nurul Sulimai ◽  
Jason Brown ◽  
David Lominadze

Neuroinflammatory diseases, such as Alzheimer’s disease (AD) and traumatic brain injury (TBI), are associated with the extravascular deposition of the fibrinogen (Fg) derivative fibrin and are accompanied with memory impairment. We found that during the hyperfibrinogenemia that typically occurs during AD and TBI, extravasated Fg was associated with amyloid beta and astrocytic cellular prion protein (PrPC). These effects coincided with short-term memory (STM) reduction and neurodegeneration. However, the mechanisms of a direct Fg–neuron interaction and its functional role in neurodegeneration are still unclear. Cultured mouse brain neurons were treated with Fg in the presence or absence of function-blockers of its receptors, PrPC or intercellular adhesion molecule-1 (ICAM-1). Associations of Fg with neuronal PrPC and ICAM-1 were characterized. The expression of proinflammatory marker interleukin 6 (IL-6) and the generation of reactive oxygen species (ROS), mitochondrial superoxide, and nitrite in neurons were assessed. Fg-induced neuronal death was also evaluated. A strong association of Fg with neuronal PrPC and ICAM-1, accompanied with overexpression of IL-6 and enhanced generation of ROS, mitochondrial superoxide, and nitrite as well as the resulting neuronal death, was found. These effects were reduced by blocking the function of neuronal PrPC and ICAM-1, suggesting that the direct interaction of Fg with its neuronal receptors can induce overexpression of IL-6 and increase the generation of ROS, nitrite, and mitochondrial superoxide, ultimately leading to neuronal death. These effects can be a mechanism of neurodegeneration and the resultant memory reduction seen during TBI and AD.

2021 ◽  
Vol 22 (5) ◽  
pp. 2391
Author(s):  
Nurul Sulimai ◽  
Jason Brown ◽  
David Lominadze

Many neuroinflammatory diseases, like traumatic brain injury (TBI), are associated with an elevated level of fibrinogen and short-term memory (STM) impairment. We found that during TBI, extravasated fibrinogen deposited in vasculo-astrocyte interfaces, which was associated with neurodegeneration and STM reduction. The mechanisms of this fibrinogen-astrocyte interaction and its functional role in neurodegeneration are still unclear. Cultured mouse brain astrocytes were treated with fibrinogen in the presence or absence of function-blocking antibody or peptide against its astrocyte receptors intercellular adhesion molecule-1 (ICAM-1) or cellular prion protein (PrPC), respectively. Fibrinogen interactions with astrocytic ICAM-1 and PrPC were characterized. The expression of pro-inflammatory markers, generations of reactive oxygen species (ROS) and nitric oxide (NO) in astrocytes, and neuronal death caused by astrocyte-conditioned medium were assessed. Data showed a strong association between fibrinogen and astrocytic ICAM-1 or PrPC, overexpression of pro-inflammatory cytokines and overproduction of ROS and NO, resulting in neuronal apoptosis and death. These effects were reduced by blocking the function of astrocytic ICAM-1 and PrPC, suggesting that fibrinogen association with its astrocytic receptors induce the release of pro-inflammatory cytokines, resulting in oxidative stress, and ultimately neuronal death. This can be a mechanism of neurodegeneration and the resultant STM reduction seen during TBI.


Diabetes ◽  
1996 ◽  
Vol 45 (10) ◽  
pp. 1336-1343 ◽  
Author(s):  
D. Chakrabarti ◽  
X. Huang ◽  
J. Beck ◽  
J. Henrich ◽  
N. McFarland ◽  
...  

Author(s):  
Nasser Gholijani ◽  
Esmaeil Hashemi ◽  
Zahra Amirghofran

Background: Macrophages are the main players involved in inflammation. Intercellular adhesion molecule-1 (ICAM-1) facilitates macrophage polarization prior to extravasation into inflamed tissue. Piperine a natural product derived from black pepper possess useful biological and pharmacological activities. In current study, the possible anti-inflammatory effect of piperine on the expression of ICAM-1 on J774.1 murine macrophage cell line was investigated. Methods: Lipopolysaccharide (LPS)-stimulated J774.1 cells were cultured in the presence of different concentrations of piperine to examine the changes in ICAM-1 expression by real-time PCR and flow cytometry. Results: We found that piperine decreased ICAM-1 gene expression level from 2.4 ± 0.25 RFC (relative fold change) in LPS-only treated cells to 0.85 ± 0.525 RFC at 1μg/ml (p<0.05), 0.43 ± 0.27 RFC at 10μg/ml (p<0.01), and 0.26 ± 0.25 RFC at 20μg/ml (p<0.01). In flow cytometry, piperine at all concentrations significantly decreased ICAM-1 surface expressions (P<0.05). The geometric mean fluorescence intensity (g-MFI) in LPS-only treated cells (792 ± 57.3) decreased to 482±70 gMFI at 20 µg/ml piperine. Conclusion: According to the results of this study, by decreasing the expression of ICAM-1, piperine is suggested as a candidate to reduce inflammation and has the potential for therapeutic benefits for immune-mediated diseases.


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