scholarly journals Chronic oral administration of P. gingivalis induces microglial activation and degeneration of dopaminergic neurons possibly through increase in gut permeability and peripheral IL-17A in LRRK2 R1441G mice

2020 ◽  
Author(s):  
Yu-kun Feng ◽  
Yan-Wen Peng ◽  
Qiong-Li Wu ◽  
Feng-Yin Liang ◽  
Hua-Jing You ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Chronic Periodontitis ◽  
Dopaminergic Neurons ◽  
Microglial Activation ◽  
Mononuclear Cells ◽  
Late Onset ◽  
Interleukin 1 ◽  
Peripheral Inflammation ◽  
Peripheral Blood Mononuclear

Abstract Background The R1441G mutation in the leucine-rich repeat kinase 2 (LRRK2) gene results in late-onset Parkinson’s disease (PD). Peripheral inflammation and gut microbiota are closely associated with the pathogenesis of PD. Chronic periodontitis is a common type of peripheral inflammation, which is associated with PD. Porphyromonas gingivalis (Pg), the most common bacterium causing chronic periodontitis, can cause alteration of gut microbiota. It is not known whether Pg-induced dysbiosis plays a role in the pathophysiology of PD. Methods In this study, live Pg were orally administrated to animals, three times a week for one month. Pg-derived lipopolysaccharide (LPS) was used to stimulate peripheral blood mononuclear cells in vitro. The effects of oral Pg administration on the gut and brain were evaluated through behaviors, morphology, and cytokine expression. Results Dopaminergic neurons in the substantia nigra were reduced and activated microglial cells were increased in R1441G mice given oral Pg. In addition, an increase in mRNA expression of tumor necrosis factor (TNF-α) and interleukin-1 β (IL-1β) as well as protein level of α-synuclein together with a decrease in zonula occludens-1 (Zo-1) were detected in the colon in Pg-treated R1441G mice. Furthermore, serum interleukin-17A (IL-17A) and brain IL-17 receptor A (IL-17RA) were increased in Pg-treated R1441G mice. Conclusions These findings suggest that LRRK2 causes gut leakage and further mediates peripheral IL-17A response in Pg-treated animals. We, thus, put forward the hypothesis that IL-17A in the serum may result in activation of the IL-17A-IL-17RA axis that aggravates dysfunction of dopaminergic neurons and provokes microglial activation in LRRK2 R1441G mice.

scholarly journals Oral P. gingivalis impairs gut permeability and mediates immune responses associated with neurodegeneration in LRRK2 R1441G mice

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Yu-Kun Feng ◽  
Qiong-Li Wu ◽  
Yan-Wen Peng ◽  
Feng-Yin Liang ◽  
Hua-Jing You ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Chronic Periodontitis ◽  
Mononuclear Cells ◽  
Late Onset ◽  
Peripheral Inflammation ◽  
Interleukin 17A ◽  
Tnf Α ◽  
Lrrk2 Gene ◽  
Necrosis Factor

Abstract Background The R1441G mutation in the leucine-rich repeat kinase 2 (LRRK2) gene results in late-onset Parkinson’s disease (PD). Peripheral inflammation and gut microbiota are closely associated with the pathogenesis of PD. Chronic periodontitis is a common type of peripheral inflammation, which is associated with PD. Porphyromonas gingivalis (Pg), the most common bacterium causing chronic periodontitis, can cause alteration of gut microbiota. It is not known whether Pg-induced dysbiosis plays a role in the pathophysiology of PD. Methods In this study, live Pg were orally administrated to animals, three times a week for 1 month. Pg-derived lipopolysaccharide (LPS) was used to stimulate mononuclear cells in vitro. The effects of oral Pg administration on the gut and brain were evaluated through behaviors, morphology, and cytokine expression. Results Dopaminergic neurons in the substantia nigra were reduced, and activated microglial cells were increased in R1441G mice given oral Pg. In addition, an increase in mRNA expression of tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β) as well as protein level of α-synuclein together with a decrease in zonula occludens-1 (Zo-1) was detected in the colon in Pg-treated R1441G mice. Furthermore, serum interleukin-17A (IL-17A) and brain IL-17 receptor A (IL-17RA) were increased in Pg-treated R1441G mice. Conclusions These findings suggest that oral Pg-induced inflammation may play an important role in the pathophysiology of LRRK2-associated PD.

Transduction of inflammation from peripheral immune cells to the hippocampus induces neuronal hyperexcitability mediated by Caspase-1 activation

2020 ◽  
Author(s):  
Tarek Shaker ◽  
Bidisha Chattopadhyaya ◽  
Bénédicte Amilhon ◽  
Graziella Di Cristo ◽  
Alexander G. Weil
Keyword(s):  
Mononuclear Cells ◽  
Culture Media ◽  
Ectopic Expression ◽  
Peripheral Inflammation ◽  
Potential Contribution ◽  
Inflammation Markers ◽  
Peripheral Blood Mononuclear ◽  
Caspase 1 ◽  
Therapeutic Benefits

Abstract Background Recent studies report infiltration of peripheral blood mononuclear cells (PBMCs) into the central nervous system (CNS) in epileptic disorders, suggestive of a potential contribution of PBMC extravasation to the generation of seizures. Nevertheless, the underlying mechanisms involved in PBMC infiltrates promoting neuronal predisposition to ictogenesis remain unclear. Therefore, we developed an in vitro model mimicking PBMC infiltration into the brain in order to investigate potential transduction of inflammatory signals from PBMCs to the CNS.MethodsTo establish our model, we first extracted PBMCs from rat spleen, then, we immunologically primed PBMCs with lipopolysaccharide (LPS), followed by immunological activation with Nigericin. Thereafter, we cultured PBMCs on top of organotypic cortico-hippocampal brain slice cultures (OCHSCs) derived from the same rat, and compared PBMC-OCHSC co-cultures to OCHSCs exposed to PBMCs in the culture media. Also, we targeted a potential molecular pathway underlying transduction of peripheral inflammation to OCHSCs by incubating OCHSCs with the Caspase-1 inhibitor VX-765 prior to co-culturing PBMCs with OCHSCs. After 24 hours, we immunohistochemically analyzed inflammation markers in the cortex and the hippocampus. In addition, we performed whole-cell patch-clamp recordings in cortical layer II/III and hippocampal CA1 pyramidal neurons.ResultsIn the cortex, co-culturing immunoreactive PBMCs treated with LPS + Nigericin on top of OCHSCs induced ectopic expression of inflammation markers and enhanced neuronal excitation. In contrast, no excitability changes were detected after adding primed PBMCs, i.e. treated with LPS only, to OCHSCs. Strikingly, in the hippocampus, both immunoreactive and primed PBMCs elicited similar pro-inflammatory and pro-excitatory effects. However, when immunoreactive and primed PBMCs were cultured in the media separately from OCHSCs, only immunoreactive PBMCs gave rise to neuroinflammation and hyperexcitability in the hippocampus, whereas primed PBMCs failed to produce any significant changes. Finally, VX-765 application to OCHSCs, co-cultured with either immunoreactive or primed PBMCs, protected them from neuroinflammation and hippocampal hyperexcitability.ConclusionsOur study shows a higher susceptibility of the hippocampus to peripheral inflammation as compared to the cortex, mediated via Caspase-1-dependent signaling pathways. Thus, our findings suggest that Caspase-1 inhibition may potentially provide therapeutic benefits during hippocampal neuroinflammation and hyperexcitability secondary to peripheral innate immunity.

scholarly journals Transduction of inflammation from peripheral immune cells to the hippocampus induces neuronal hyperexcitability mediated by Caspase-1 activation

2020 ◽  
Author(s):  
Tarek Shaker ◽  
Bidisha Chattopadhyaya ◽  
Bénédicte Amilhon ◽  
Graziella Di Cristo ◽  
Alexander G. Weil
Keyword(s):  
Pyramidal Neurons ◽  
Mononuclear Cells ◽  
Culture Media ◽  
Cortical Layer ◽  
Peripheral Inflammation ◽  
Potential Contribution ◽  
Peripheral Blood Mononuclear ◽  
Caspase 1 ◽  
Therapeutic Benefits

Abstract 1.1. Background Recent studies report infiltration of peripheral blood mononuclear cells (PBMCs) into the central nervous system (CNS) in epileptic disorders, suggestive of a potential contribution of PBMC extravasation to the generation of seizures. Nevertheless, the underlying mechanisms involved in PBMC infiltrates promoting neuronal predisposition to ictogenesis remain unclear. Therefore, we developed an in vitro model mimicking infiltration of activated PBMCs into the brain in order to investigate potential transduction of inflammatory signals from PBMCs to the CNS.1.2. Methods To establish our model, we first extracted PBMCs from rat spleen, then, immunologically primed PBMCs with lipopolysaccharide (LPS), followed by further activation with nigericin. Thereafter, we co-cultured these activated PBMCs with organotypic cortico-hippocampal brain slice cultures (OCHSCs) derived from the same rat, and compared PBMC-OCHSC co-cultures to OCHSCs exposed to PBMCs in the culture media. We further targeted a potential molecular pathway underlying transduction of peripheral inflammation to OCHSCs by incubating OCHSCs with the Caspase-1 inhibitor VX-765 prior to co-culturing PBMCs with OCHSCs. After 24 hours, we analyzed inflammation markers in the cortex and the hippocampus using semiquantitative immunofluorescence. In addition, we analyzed neuronal activity by whole-cell patch-clamp recordings in cortical layer II/III and hippocampal CA1 pyramidal neurons.1.3. Results In the cortex, co-culturing immunoreactive PBMCs treated with LPS + nigericin on top of OCHSCs upregulated inflammatory markers and enhanced neuronal excitation. In contrast, no excitability changes were detected after adding primed PBMCs (i.e. treated with LPS only), to OCHSCs. Strikingly, in the hippocampus, both immunoreactive and primed PBMCs elicited similar pro-inflammatory and pro-excitatory effects. However, when immunoreactive and primed PBMCs were cultured in the media separately from OCHSCs, only immunoreactive PBMCs gave rise to neuroinflammation and hyperexcitability in the hippocampus, whereas primed PBMCs failed to produce any significant changes. Finally, VX-765 application to OCHSCs, co-cultured with either immunoreactive or primed PBMCs, protected them from neuroinflammation and hippocampal hyperexcitability.1.4. Conclusions Our study shows a higher susceptibility of the hippocampus to peripheral inflammation as compared to the cortex, mediated via Caspase-1-dependent signaling pathways. Thus, our findings suggest that Caspase-1 inhibition may potentially provide therapeutic benefits during hippocampal neuroinflammation and hyperexcitability secondary to peripheral innate immunity.

scholarly journals Origin of the Induced Pluripotent Stem Cells Affects Their Differentiation into Dopaminergic Neurons

2020 ◽  
Vol 21 (16) ◽  
pp. 5705 ◽  
Author(s):  
Paula Chlebanowska ◽  
Maciej Sułkowski ◽  
Klaudia Skrzypek ◽  
Anna Tejchman ◽  
Agata Muszyńska ◽  
...  
Keyword(s):  
Dopaminergic Neurons ◽  
Mononuclear Cells ◽  
Viral Vector ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Ips Cells ◽  
Peripheral Blood Mononuclear ◽  
Induced Pluripotent

Neuronal differentiation of human induced pluripotent stem (iPS) cells, both in 2D models and 3D systems in vitro, allows for the study of disease pathomechanisms and the development of novel therapies. To verify if the origin of donor cells used for reprogramming to iPS cells can influence the differentiation abilities of iPS cells, peripheral blood mononuclear cells (PBMC) and keratinocytes were reprogrammed to iPS cells using the Sendai viral vector and were subsequently checked for pluripotency markers and the ability to form teratomas in vivo. Then, iPS cells were differentiated into dopaminergic neurons in 2D and 3D cultures. Both PBMC and keratinocyte-derived iPS cells were similarly reprogrammed to iPS cells, but they displayed differences in gene expression profiles and in teratoma compositions in vivo. During 3D organoid formation, the origin of iPS cells affected the levels of FOXA2 and LMX1A only in the first stages of neural differentiation, whereas in the 2D model, differences were detected at the levels of both early and late neural markers FOXA2, LMX1A, NURR1, TUBB and TH. To conclude, the origin of iPS cells may significantly affect iPS differentiation abilities in teratomas, as well as exerting effects on 2D differentiation into dopaminergic neurons and the early stages of 3D midbrain organoid formation.

Altered interleukin-1 and tumor necrosis factor production and secretion during pyrogenic tolerance to LPS in rabbits

1994 ◽  
Vol 267 (1) ◽  
pp. R329-R336 ◽  
Author(s):  
G. Wakabayashi ◽  
J. G. Cannon ◽  
J. A. Gelfand ◽  
B. D. Clark ◽  
K. Aiura ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Mononuclear Cells ◽  
Interleukin 1 ◽  
Interleukin 1 Beta ◽  
Peripheral Blood Mononuclear ◽  
In Vitro Synthesis ◽  
Circulating Levels ◽  
Necrosis Factor

Rabbits were injected intravenously with 10 micrograms/kg of endotoxin [lipopolysaccharide (LPS)] on days 0, 1, and 7, and rectal temperatures were monitored. The febrile responses were compared with circulating levels of interleukin-1 beta (IL-1 beta) and tumor necrosis factor (TNF) and in vitro synthesis of these cytokines by peripheral blood mononuclear cells (PBMC) isolated just before the injection of LPS. Fever after the first LPS injection was biphasic on day 0, attenuated and monophasic after the second LPS injection on day 1, and augmented after third injection of LPS on day 7. On day 1, circulating TNF and IL-1 beta levels were significantly (P < 0.05) decreased compared with those on days 0 and 7. Similarly, TNF and IL-1 beta synthesis by LPS-stimulated PBMC were significantly reduced on day 1. On day 7, cellular synthesis and secretion of IL-1 beta were significantly increased compared with that on day 0. A significant positive correlation was observed between fever index and total in vitro IL-1 beta synthesis by LPS-stimulated PBMC (r = 0.866, P = 0.001). These data demonstrate that pyrogenic tolerance in the rabbit after a single LPS injection is associated with decreased circulating IL-1 beta and TNF levels as well as decreased production of these cytokines in vitro. In addition, the pyrogenic hyperresponsiveness to LPS after 7 days is associated with increased synthesis and secretion of IL-1 beta from PBMC in vitro.

scholarly journals Long, Noncoding RNA SRA Induces Apoptosis of β-Cells by Promoting the IRAK1/LDHA/Lactate Pathway

2021 ◽  
Vol 22 (4) ◽  
pp. 1720
Author(s):  
Yu-Nan Huang ◽  
Shang-Lun Chiang ◽  
Yu-Jung Lin ◽  
Su-Ching Liu ◽  
Yen-Hsien Li ◽  
...  
Keyword(s):  
Noncoding Rna ◽  
Mononuclear Cells ◽  
Interleukin 1 ◽  
Critical Role ◽  
Metabolic Reprogramming ◽  
Β Cells ◽  
Β Cell ◽  
Peripheral Blood Mononuclear ◽  
Atp Production

Long non-coding RNA steroid receptor RNA activators (LncRNA SRAs) are implicated in the β-cell destruction of Type 1 diabetes mellitus (T1D), but functional association remains poorly understood. Here, we aimed to verify the role of LncRNA SRA regulation in β-cells. LncRNA SRAs were highly expressed in plasma samples and peripheral blood mononuclear cells (PBMCs) from T1D patients. LncRNA SRA was strongly upregulated by high-glucose treatment. LncRNA SRA acts as a microRNA (miR)-146b sponge through direct sequence–structure interactions. Silencing of lncRNA SRA increased the functional genes of Tregs, resulting in metabolic reprogramming, such as decreased lactate levels, repressed lactate dehydrogenase A (LDHA)/phosphorylated LDHA (pLDHA at Tyr10) expression, decreased reactive oxygen species (ROS) production, increased ATP production, and finally, decreased β-cell apoptosis in vitro. There was a positive association between lactate level and hemoglobin A1c (HbA1c) level in the plasma from patients with T1D. Recombinant human interleukin (IL)-2 treatment repressed lncRNA SRA expression and activity in β-cells. Higher levels of lncRNA-SRA/lactate in the plasma are associated with poor regulation in T1D patients. LncRNA SRA contributed to T1D pathogenesis through the inhibition of miR-146b in β-cells, with activating signaling transduction of interleukin-1 receptor-associated kinase 1 (IRAK1)/LDHA/pLDHA. Taken together, LncRNA SRA plays a critical role in the function of β-cells.

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