scholarly journals Crocin inhibited amyloid-beta (Aβ) generation via promoting non-amyloidogenic APP processing and suppressed ER stress UPR signaling in N2a/APP cells

2021 ◽  
Author(s):  
Cuijun Lin ◽  
Qian Yue ◽  
Zirong Liang ◽  
Simon Ming Yuen Lee ◽  
Zaijun Zhang ◽  
...  
Keyword(s):  
Er Stress ◽  
Amyloid Beta ◽  
Cell Model ◽  
Crocus Sativus ◽  
Signaling Proteins ◽  
App Processing ◽  
Beneficial Effects ◽  
Protein Expressions ◽  
Aβ Generation ◽  
First Time

Background: Crocin is a major active component of saffron (Crocus sativus) with many beneficial effects. More recently, crocin has been proposed for management of neurodegenerative diseases such as Alzheimer's disease (AD). Here, we demonstrated for the first time that crocin reduced amyloid-beta generation through promoting alpha cleavage of APP processing and inhibited ER stress by attenuating UPR signaling in N2a/APP cells. Methodology: Mouse neuroblastoma N2a cells stably transfected with the Swedish mutant APP (N2a/APP) was used as a cellular model for AD pathogenesis. Vector transfected cells (N2a/vector) were employed to serve as control. The toxicity of crocin was first evaluated and non-toxic treatment of crocin (>30 micromolar for 24 h) was used for further investigations. Amyloid beta levels were determined by ELISA. Expression levels of UPR signaling proteins were determined by using Western blot. Results: Crocin significantly inhibited the protein expression of total APP in N2a/APP cells and promoted alpha cleavage of APP processing to increase sAPPalpha generation, but only modestly reduced BACE-1 and PS1, suggesting amyloid beta reduction by crocin was mainly associated with the non-amyloidogenic APP processing. Further investigation on ER stress related protein expressions showed that GRP78, CHOP, p-PERK, p-eIF2alpha, p-IREalpha, XBP1, ATF6alpha, and PDI were all significantly elevated in N2a/APP cells compared to N2a/vector. Crocin effectively reduced the levels of GRP78 and CHOP, and significantly inhibited p-PERK/p-eIF2, and AT6, while slightly reduced p-IRE1alpha. Conclusion: The present study showed that crocin was effective at blocking amyloid beta generation and inhibiting ER stress associated overactivation of UPR signaling in AD cell model N2a/APP. The results provided evidence for crocin as useful natural product for the treatment of AD.

scholarly journals The Isoquinoline Alkaloid Dauricine Targets Multiple Molecular Pathways to Ameliorate Alzheimer-Like Pathological Changes In Vitro

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Pan Liu ◽  
Xiao Chen ◽  
Haizhe Zhou ◽  
Liqun Wang ◽  
Zaijun Zhang ◽  
...  
Keyword(s):  
Cell Model ◽  
Isoquinoline Alkaloid ◽  
Signaling Proteins ◽  
Tau Hyperphosphorylation ◽  
Neuroprotective Effects ◽  
App Processing ◽  
N2a Cells ◽  
Associated Proteins ◽  
Related Proteins

Alzheimer’s disease (AD), the most common neurodegenerative disease, has no effective treatment. Dauricine (DAU), a benzyl tetrahydroisoquinoline alkaloid isolated from the root of Menispermum dauricum DC, reportedly has neuroprotective effects in cerebral ischemia. Here, we investigated the effects of DAU on N2a cells stably transfected with Swedish mutant amyloid precursor protein (N2a/APP), an AD-like cell model. ELISA and Western blot analysis revealed that DAU inhibited APP processing and reduced Aβ accumulation. In addition, DAU ameliorated tau hyperphosphorylation via PP2A, p35/25, and CDK5 pathways in N2a/APP cells. The amelioration of tau hyperphosphorylation by DAU was also validated in HEK293/Tau cells, another cell line with tau hyperphosphorylation. Proteomic analysis revealed 85 differentially expressed proteins in the lysates between the wild-type N2a cells (N2a/WT) and the N2a/APP cells in the presence or absence of DAU; these were classified into 6 main categories according to their functions: endoplasmic reticulum (ER) stress-associated proteins, oxidative stress-associated proteins, cytoskeleton proteins, molecular chaperones, mitochondrial respiration and metabolism-related proteins, and signaling proteins. Taken together, we demonstrated that DAU treatment reduces AD-like pathology, thereby suggesting that DAU has potential therapeutic utility in AD.

scholarly journals Amyloid beta oligomers modulate neuronal autophagy through the primary cilium

2021 ◽  
Author(s):  
Olatz Pampliega ◽  
Federico N. Soria ◽  
Narayana Pineda-Ramirez ◽  
Erwan Bezard
Keyword(s):  
Neurodegenerative Diseases ◽  
Amyloid Beta ◽  
Primary Cilium ◽  
Adult Brain ◽  
Dependent Manner ◽  
Aβ Oligomers ◽  
App Processing ◽  
Age Dependent ◽  
Aβ Generation

The major neurodegenerative diseases, like Alzheimer disease (AD), accumulate neuropathogenic proteins that compromise autophagic function. In AD, autophagy contributes to intracellular APP processing and amyloid beta (Aβ) generation by mutant presenilin-1 (PS1). However, how extracellular soluble Aβ oligomers (Aβo) impact intracellular autophagy is not well understood. The primary cilium (PC), a signaling organelle on the surface of mature neurons and glia, is able to bind Aβ. Since PC signaling pathways knowingly modify autophagy in non-brain cells, we here investigated the role of neuronal PC in the modulation of autophagy during acute extracellular Aβo overload. Our results show that, in vivo, recombinant Aβo require the presence of neuronal PC to modulate early autophagy and to induce the accumulation of autophagic vacuoles in an age-dependent manner. We show that activated Akt mediates these effects in an age-dependent manner, and that ciliary p75NTR receptor is required to block autophagy by Aβo. These findings demonstrate that neuronal PC in the adult brain participates in the deleterious effects mediated by soluble Aβo. The PC should therefore be considered as a target organelle to modulate autophagy for the treatment of neurodegenerative diseases.

scholarly journals Dextromethorphan Dampens Neonatal Astrocyte Activation and Endoplasmic Reticulum Stress Induced by Prenatal Exposure to Buprenorphine

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Chun-Hua Lin ◽  
Pao-Luh Tao ◽  
Huey-Jen Tsay ◽  
Yao-Chang Chiang ◽  
Wei-Tang Chang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Prenatal Exposure ◽  
Astrocyte Activation ◽  
Beneficial Effects ◽  
Er Stress Response ◽  
Primary Astrocyte ◽  
Cox 2 ◽  
First Time

Prenatal exposure to buprenorphine renders offspring vulnerable to cerebral impairments. In this study, our data demonstrate, for the first time, that prenatal exposure to buprenorphine escalates astrocyte activation concurrent with indications of endoplasmic reticulum (ER) stress in the hippocampi of neonates, and this can be prevented by the coadministration of dextromethorphan with buprenorphine. Furthermore, dextromethorphan can inhibit the accumulation of GPR37 in the hippocampus of newborns caused by buprenorphine and is accompanied by the proapoptotic ER stress response that involves the procaspase-3/CHOP pathway. Primary astrocyte cultures derived from the neonates of the buprenorphine group also displayed aberrant ER calcium mobilization and elevated basal levels of cyclooxygenase-2 (COX-2) at 14 days in vitro while showing sensitivity to lipopolysaccharide-activated expression of COX-2. Similarly, these long-lasting defects in the hippocampus and astrocytes were abolished by dextromethorphan. Our findings suggest that prenatal exposure to buprenorphine might instigate long-lasting effects on hippocampal and astrocytic functions. The beneficial effects of prenatal coadministration of dextromethorphan might be, at least in part, attributed to its properties in attenuating astrocyte activation and hippocampal ER stress in neonates.

scholarly journals The Dose of Somatostatin Analogues during Pre-Surgical Treatment Is a Key Factor to Achieve Surgical Remission in Acromegaly

Endocrines ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 241-250
Author(s):  
Marta Araujo-Castro ◽  
Eider Pascual-Corrales ◽  
Héctor Pian ◽  
Ignacio Ruz-Caracuel ◽  
Alberto Acitores Cancela ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Surgical Treatment ◽  
Surgical Outcomes ◽  
Pituitary Adenomas ◽  
Somatostatin Analogues ◽  
Beneficial Effects ◽  
Key Factor ◽  
Long Acting ◽  
First Time ◽  
Endocrine Complications

Purpose: to determine whether pre-surgical treatment using long-acting somatostatin analogues (SSAs) may improve surgical outcomes in acromegaly. Methods: retrospective study of 48 patients with acromegaly operated by endoscopic transsphenoidal approach and for first time. Surgical remission was evaluated based on the 2010 criteria. Results: most patients, 83.3% (n = 40), harbored macroadenomas and 31.3% (n = 15) invasive pituitary adenomas. In this case, 14 patients were treated with lanreotide LAR and 6 with octreotide LAR, median monthly doses of 97.5 [range 60–120] and 20 [range 20–30] mg, respectively, for at least 3 months preoperatively. Presurgical variables were comparable between pre-treated and untreated patients (p > 0.05). Surgical remission was more frequent in those pre-treated with monthly doses ≥90 mg of lanreotide or ≥30 mg of octreotide than in untreated or pre-treated with lower doses (OR = 4.64, p = 0.025). However, no differences were found between pre-treated and untreated patients when lower doses were included or between those treated for longer than 6 months compared to those untreated or pre-treated for shorter than 6 months. Similarly, no differences were found either in terms of surgical or endocrine complications (OR = 0.65, p = 0.570), independently of the doses and the duration of SSA treatment (p > 0.05). Conclusions: the dose of SSAs is a key factor during pre-surgical treatment, since the beneficial effects in surgical remission were observed with monthly doses equal or higher than 90 mg of lanreotide and 30 mg of octreotide, but not with lower doses.

scholarly journals AZP2006, a new promising treatment for Alzheimer’s and related diseases

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
N. Callizot ◽  
C. Estrella ◽  
S. Burlet ◽  
A. Henriques ◽  
C. Brantis ◽  
...  
Keyword(s):  
Therapeutic Application ◽  
Neuroprotective Effects ◽  
Beneficial Effects ◽  
Potential Therapeutic Application ◽  
Promising Treatment ◽  
Central Synapses ◽  
First Time ◽  
Pgrn Level

AbstractProgranulin (PGRN) is a protein with multiple functions including the regulation of neuroinflammation, neuronal survival, neurite and synapsis growth. Although the mechanisms of action of PGRN are currently unknown, its potential therapeutic application in treating neurodegenerative diseases is huge. Thus, strategies to increase PGRN levels in patients could provide an effective treatment. In the present study, we investigated the effects of AZP2006, a lysotropic molecule now in phase 2a clinical trial in Progressive Supranuclear Palsy patients, for its ability to increase PGRN level and promote neuroprotection. We showed for the first time the in vitro and in vivo neuroprotective effects of AZP2006 in neurons injured with Aβ1–42 and in two different pathological animal models of Alzheimer’s disease (AD) and aging. Thus, the chronic treatment with AZP2006 was shown to reduce the loss of central synapses and neurons but also to dramatically decrease the massive neuroinflammation associated with the animal pathology. A deeper investigation showed that the beneficial effects of AZP2006 were associated with PGRN production. Also, AZP2006 binds to PSAP (the cofactor of PGRN) and inhibits TLR9 receptors normally responsible for proinflammation when activated. Altogether, these results showed the high potential of AZP2006 as a new putative treatment for AD and related diseases.

scholarly journals A Bibenzyl Component Moscatilin Mitigates Glycation-Mediated Damages in an SH-SY5Y Cell Model of Neurodegenerative Diseases through AMPK Activation and RAGE/NF-κB Pathway Suppression

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4574
Author(s):  
Mei Chou Lai ◽  
Wayne Young Liu ◽  
Shorong-Shii Liou ◽  
I-Min Liu
Keyword(s):  
Neurodegenerative Diseases ◽  
Cell Model ◽  
P53 Expression ◽  
Pheochromocytoma Cells ◽  
Beneficial Effects ◽  
Compound C ◽  
Species Production ◽  
Amp Activated Protein Kinase ◽  
Exposure Ages

Moscatilin can protect rat pheochromocytoma cells against methylglyoxal-induced damage. Elimination of the effect of advanced glycation end-products (AGEs) but activation of AMP-activated protein kinase (AMPK) are the potential therapeutic targets for the neurodegenerative diseases. Our study aimed to clarify AMPK signaling’s role in the beneficial effects of moscatilin on the diabetic/hyperglycemia-associated neurodegenerative disorders. AGEs-induced injury in SH-SY5Y cells was used as an in vitro neurodegenerative model. AGEs stimulation resulted in cellular viability loss and reactive oxygen species production, and mitochondrial membrane potential collapse. It was observed that the cleaved forms of caspase-9, caspase-3, and poly (ADP-ribose) polymerase increased in SH-SY5Y cells following AGEs exposure. AGEs decreased Bcl-2 but increased Bax and p53 expression and nuclear factor kappa-B activation in SH-SY5Y cells. AGEs also attenuated the phosphorylation level of AMPK. These AGEs-induced detrimental effects were ameliorated by moscatilin, which was similar to the actions of metformin. Compound C, an inhibitor of AMPK, abolished the beneficial effects of moscatilin on the regulation of SH-SY5Y cells’ function, indicating the involvement of AMPK. In conclusion, moscatilin offers a promising therapeutic strategy to reduce the neurotoxicity or AMPK dysfunction of AGEs. It provides a potential beneficial effect with AGEs-related neurodegenerative diseases.

scholarly journals Endoplasmic reticulum stress induces a novel Ca2+ signalling system initiated by Ca2+ microdomains

2020 ◽  
Author(s):  
Constanza Feliziani ◽  
Gonzalo Quasollo ◽  
Deborah Holstein ◽  
Macarena Fernandez ◽  
James C Paton ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Cell Model ◽  
Signal Transduction Pathway ◽  
Unfolded Proteins ◽  
Potent Inducer ◽  
Human Astrocytes ◽  
Receptor Isoforms ◽  
A Cell ◽  
Er Homeostasis

AbstractThe accumulation of unfolded proteins within the Endoplasmic Reticulum (ER) activates a signal transduction pathway termed the unfolded protein response (UPR), which attempts to restore ER homeostasis. If homeostasis cannot be restored, UPR signalling ultimately induces apoptosis. Ca2+ depletion in the ER is a potent inducer of ER stress. Despite the ubiquity of Ca2+ as intracellular messenger, the precise mechanism (s) by which Ca2+ release affects the UPR remains unknown. Use of a genetically encoded Ca2+ indicator (GCamP6) that is tethered to the ER membrane, uncovered novel Ca2+ signalling events initiated by Ca2+ microdomains in human astrocytes under ER stress, as well as in a cell model deficient in all three IP3 Receptor isoforms. Pharmacological and molecular studies indicate that these local events are mediated by translocons. Together, these data reveal the existence of a previously unrecognized mechanism by which stressor-mediated Ca2+ release regulates ER stress.

scholarly journals Inhibition of PKCδ reduces amyloid-β levels and reverses Alzheimer disease phenotypes

2018 ◽  
Vol 215 (6) ◽  
pp. 1665-1677 ◽  
Author(s):  
Ying Du ◽  
Yingjun Zhao ◽  
Chuan Li ◽  
Qiuyang Zheng ◽  
Jing Tian ◽  
...  
Keyword(s):  
Alzheimer Disease ◽  
Amyloid Β ◽  
Neuritic Plaque ◽  
App Processing ◽  
Disease Phenotypes ◽  
Kinase C ◽  
Bace1 Expression ◽  
Pkc Isoforms ◽  
Exon 9 ◽  
Aβ Generation

β-amyloid protein (Aβ) plays a central role in the pathogenesis of Alzheimer disease (AD). Aβ is generated from sequential cleavage of amyloid precursor protein (APP) by β-site APP-cleaving enzyme 1 (BACE1) and the γ-secretase complex. Although activation of some protein kinase C (PKC) isoforms such as PKCα and ε has been shown to regulate nonamyloidogenic pathways and Aβ degradation, it is unclear whether other PKC isoforms are involved in APP processing/AD pathogenesis. In this study, we report that increased PKCδ levels correlate with BACE1 expression in the AD brain. PKCδ knockdown reduces BACE1 expression, BACE1-mediated APP processing, and Aβ production. Conversely, overexpression of PKCδ increases BACE1 expression and Aβ generation. Importantly, inhibition of PKCδ by rottlerin markedly reduces BACE1 expression, Aβ levels, and neuritic plaque formation and rescues cognitive deficits in an APP Swedish mutations K594N/M595L/presenilin-1 with an exon 9 deletion–transgenic AD mouse model. Our study indicates that PKCδ plays an important role in aggravating AD pathogenesis, and PKCδ may be a potential target in AD therapeutics.

scholarly journals Effect of Supplementation with Hydroethanolic Extract of Campomanesia xanthocarpa (Berg.) Leaves and Two Isolated Substances from the Extract on Metabolic Parameters of Mice Fed a High-Fat Diet

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2693 ◽  
Author(s):  
Carla Maiara Lopes Cardozo ◽  
Aline Carla Inada ◽  
Claudia Andrea Lima Cardoso ◽  
Wander Fernando de Oliveira Filiú ◽  
Bernardo Barcelar de Farias ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Metabolic Disorders ◽  
Brazilian Cerrado ◽  
American Institute ◽  
High Fat ◽  
Beneficial Effects ◽  
Diet Induced Obesity ◽  
Protein Expressions ◽  
Hydroethanolic Extract ◽  
Lipid Parameters

There are still controversies regarding the correlation between the beneficial effects for health and the administration of isolated compounds or crude extracts in therapeutic applications. Campomanesia xanthocarpa, found in the Brazilian Cerrado, demonstrated beneficial effects in metabolic disorders associated with obesity. We investigated the effects of Campomanesia xanthocarpa hydroethanolic extract and two isolated substances from the extract (S1 and S2) in a diet-induced obesity (DIO) model. Male Swiss mice were divided into five groups: (1) American Institute of Nutrition (AIN-93M) diet, (2) high-fat diet (HF), (3) HF supplemented with C. xanthocarpa hydroethanolic leaf extract at 100 mg/kg (HFE), (4) HF supplemented with S1 at 1 mg/kg (HFS1) and (5) HF supplemented with S2 at 1 mg/kg (HFS2). The HFS1, HFS2 and HFE groups did not present decreasing body weight or visceral adiposity gain. No differences in glycemic and lipid parameters, or in the expression of protein content in two cytokines, interleukin-6 (IL-6) and anti-inflammatory (IL-10), were observed. Only the HFS1 group displayed decreased food intake. Even though substantial effects such as an improvement in obesity features or the metabolic and histological parameters promoted by S1, S2 and the extract were not observed, further investigations are necessary to evaluate the principal genes and protein expressions involved in regulating food behavior promoted by S1.

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