Expression Of Precursor Protein Research Articles

Fine-Tuning Amyloid Precursor Protein Expression through Nonsense-Mediated mRNA Decay.

Studies on genetic robustness recently revealed transcriptional adaptation (TA) as a mechanism by which an organism can compensate for genetic mutations through activation of homologous genes. Here, we discovered that genetic mutations, introducing a premature termination codon (PTC) in the amyloid precursor protein-b (appb) gene, activated TA of two other app family members, appa and amyloid precursor-like protein-2 (aplp2), in zebrafish. The observed transcriptional response of appa and aplp2 required degradation of mutant mRNA and did not depend on Appb protein level. Furthermore, TA between amyloid precursor protein (APP) family members was observed in human neuronal progenitor cells; however, compensation was only present during early neuronal differentiation and could not be detected in a more differentiated neuronal stage or adult zebrafish brain. Using knockdown and chemical inhibition, we showed that nonsense-mediated mRNA decay (NMD) is involved in degradation of mutant mRNA and that Upf1 and Upf2, key proteins in the NMD pathway, regulate the endogenous transcript levels of appa, appb, aplp1, and aplp2 In conclusion, our results suggest that the expression level of App family members is regulated by the NMD pathway and that mutations destabilizing app/APP mRNA can induce genetic compensation by other family members through TA in both zebrafish and human neuronal progenitors.

Retinoic acid related orphan receptor α is a genetic modifier that rescues retinal degeneration in a mouse model of Stargardt disease and Dry AMD.

Degeneration of the macula is associated with several overlapping diseases including age-related macular degeneration (AMD) and Stargardt Disease (STGD). Mutations in ATP Binding Cassette Subfamily A Member 4 (ABCA4) are associated with late-onset dry AMD and early-onset STGD. Additionally, both forms of macular degeneration exhibit deposition of subretinal material and photoreceptor degeneration. Retinoic acid related orphan receptor α (RORA) regulates the AMD inflammation pathway that includes ABCA4, CD59, C3 and C5. In this translational study, we examined the efficacy of RORA at attenuating retinal degeneration and improving the inflammatory response in Abca4 knockout (Abca4-/-) mice. AAV5-hRORA-treated mice showed reduced deposits, restored CD59 expression and attenuated amyloid precursor protein (APP) expression compared with untreated eyes. This molecular rescue correlated with statistically significant improvement in photoreceptor function. This is the first study evaluating the impact of RORA modifier gene therapy on rescuing retinal degeneration. Our studies demonstrate efficacy of RORA in improving STGD and dry AMD-like disease.

Histone deacetylase-3 regulates the expression of the amyloid precursor protein and its inhibition promotes neuroregenerative pathways in Alzheimer's disease models.

HDAC3 inhibition has been shown to improve memory and reduce amyloid-β (Aβ) in Alzheimer's disease (AD) models, but the underlying mechanisms are unclear. We investigated the molecular effects of HDAC3 inhibition on AD pathology, using invitro and exvivo models of AD, based on our finding that HDAC3 expression is increased in AD brains. For this purpose, N2a mouse neuroblastoma cells as well as organotypic brain cultures (OBCSs) of 5XFAD and wild-type mice were incubated with various concentrations of the HDAC3 selective inhibitor RGFP966 (0.1-10 μM) for 24 h. Treatment with RGFP966 or HDAC3 knockdown in N2a cells was associated with an increase on amyloid precursor protein (APP) and mRNA expressions, without alterations in Aβ42 secretion. Invitro chromatin immunoprecipitation analysis revealed enriched HDAC3 binding at APP promoter regions. The increase in APP expression was also detected in OBCSs from 5XFAD mice incubated with 1 μM RGFP966, without changes in Aβ. In addition, HDAC3 inhibition resulted in a reduction of activated Iba-1-positive microglia and astrocytes in 5XFAD slices, which was not observed in OBCSs from wild-type mice. mRNA sequencing analysis revealed that HDAC3 inhibition modulated neuronal regenerative pathways related to neurogenesis, differentiation, axonogenesis, and dendritic spine density in OBCSs. Our findings highlight the complexity and diversity of the effects of HDAC3 inhibition on AD models and suggest that HDAC3 may have multiple roles in the regulation of APP expression and processing, as well as in the modulation of neuroinflammatory and neuroprotective genes.

Alpha-, Beta-, and Gamma-Secretase, Amyloid Precursor Protein, and Tau Protein Genes in the Hippocampal CA3 Subfield in an Ischemic Model of Alzheimer's Disease with Survival up to 2 Years.

Understanding the phenomena underlying the non-selective susceptibility to ischemia of pyramidal neurons in the CA3 is important from the point of view of elucidating the mechanisms of memory loss and the development of dementia. The aim of the study was to investigate changes in genes expression of amyloid precursor protein, its cleaving enzymes and tau protein in CA3 post-ischemia with survival of 12-24 months. We used an ischemic model of Alzheimer's disease to study the above genes using an RT-PCR protocol. The expression of the amyloid precursor protein gene was above the control values at all times post-ischemia. The expression of the α-secretase gene also exceeded the control values post-ischemia. The expression of the β-secretase gene increased 12 and 24 months post-ischemia, and 18 months was below control values. Presenilin 1 and 2 genes expression was significantly elevated at all times post-ischemia. Also, tau protein gene expression was significantly elevated throughout the observation period, and peak gene expression was present 12 months post-ischemia. The study suggests that the genes studied are involved in the non-amyloidogenic processing of amyloid precursor protein. Additionally data indicate that brain ischemia with long-term survival causes damage and death of pyramidal neurons in the CA3 area of the hippocampus in a modified tau protein-dependent manner. Thus defining a new and important mechanism of pyramidal neuronal death in the CA3 area post-ischemia. In addition expression of tau protein gene modification after brain ischemia is useful in identifying ischemic mechanisms occurring in Alzheimer's disease.

The Tao Hong Si Wu Decoction ameliorates diabetes-associated cognitive dysfunction by inhibiting the formation of amyloid plaques.

The herbs in Tao Hong Si Wu Decoction (THSWD) are beneficial in the treatment of cognitive impairment. However, the underlying mechanisms of THSWD in treating diabetes-associated cognitive dysfunction (DACD) are not entirely explored. This study is aimed to investigate the therapeutic effects of THSWD in DACD model rats and the underlying mechanism. Ultra-high-phase liquid chromatography was employed to identify the main compounds contained in the THSWD extract. DACD rat model was induced by feeding with a high-sugar and high-fat diet and injecting streptozotocin (35mg/kg). DACD rats were gavaged with THSWD for 1week. The learning and memory abilities of the rats were measured by using the Morris water maze. Western blotting was used to detect the changes in DACD rat targets. Statistical methods were used to evaluate the correlation between proteins. The results show that THSWD effectively reduced the escape latency, hippocampal neuron damage, glycosylated hemoglobin, type A1C, and blood lipid levels in DACD rats. Furthermore, DACD rats showed significantly increased amyloid precursor protein, β-secretase, Aβ1-40 , Aβ1-42 , Tau phosphorylation, and advanced glycation end products (AGEs) expression. However, THSWD treatment can reverse this phenomenon. THSWD can improve the learning and memory abilities of DACD rats by inhibiting the expression of AEGs-AGE receptors pathway, which provides an experimental basis for the clinical application of THSWD. In addition, the experiment combines pharmacological and statistical methods, which offers a new perspective for the study of Chinese herbal medicine.

Inhibition of autophagosome-lysosome fusion contributes to TDCIPP-induced Aβ1-42 production in N2a-APPswe cells

Alzheimer's disease is the most common form of dementia and is characterized by cognitive impairment. The disruption of autophagosome-lysosome function has been linked to the pathogenesis of Alzheimer's disease. Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphorus flame retardant that has the potential to cause neuronal damage. We found that TDCIPP significantly increased the expression of β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), presenilin-1 (PS1) and Aβ42. Proteomic studies with TMT labeling revealed changes in the profiles of N2a-APPswe cells after exposure to TDCIPP. Proteomic and bioinformatics analyses revealed that lysosomal proteins were dysregulated in N2a-APPswe cells after treatment with TDCIPP. The LC3, P62, CTSD, and LAMP1 levels were increased after TDCIPP exposure, and dysregulated protein expression was validated by Western blotting. The exposure to TDCIPP led to the accumulation of autophagosomes, and this phenomenon was enhanced in the presence of chloroquine (CQ). Our results revealed for the first time that TDCIPP could be a potential environmental risk factor for AD development. The inhibition of autophagosome-lysosome fusion may have a significant impact on the generation of Aβ1-42 in response to TDCIPP.

VGLUT2 and APP family: unraveling the neurobiochemical mechanisms of neurostimulation therapy to STZ-induced diabetes and neuropathy.

Diabetic Peripheral Neuropathy (DPN) poses an escalating threat to public health, profoundly impacting well-being and quality of life. Despite its rising prevalence, the pathogenesis of DPN remains enigmatic, and existing clinical interventions fall short of achieving meaningful reversals of the condition. Notably, neurostimulation techniques have shown promising efficacy in alleviating DPN symptoms, underscoring the imperative to elucidate the neurobiochemical mechanisms underlying DPN. This study employs an integrated multi-omics approach to explore DPN and its response to neurostimulation therapy. Our investigation unveiled a distinctive pattern of vesicular glutamate transporter 2 (VGLUT2) expression in DPN, rigorously confirmed through qPCR and Western blot analyses in DPN C57 mouse model induced by intraperitoneal Streptozotocin (STZ) injection. Additionally, combining microarray and qPCR methodologies, we revealed and substantiated variations in the expression of the Amyloid Precursor Protein (APP) family in STZ-induced DPN mice. Analyzing the transcriptomic dataset generated from neurostimulation therapy for DPN, we intricately explored the differential expression patterns of VGLUT2 and APPs. Through correlation analysis, protein-protein interaction predictions, and functional enrichment analyses, we predicted the key biological processes involving VGLUT2 and the APP family in the pathogenesis of DPN and during neurostimulation therapy. This comprehensive study not only advances our understanding of the pathogenesis of DPN but also provides a theoretical foundation for innovative strategies in neurostimulation therapy for DPN. The integration of multi-omics data facilitates a holistic view of the molecular intricacies of DPN, paving the way for more targeted and effective therapeutic interventions.

Asthma aggravates alzheimer's disease by up-regulating NF- κB signaling pathway through LTD4

Clinical studies have shown that asthma is a risk factor for dementia or Alzheimer’s disease (AD). To investigate whether asthma aggravates AD in APP/PS1 mice and explore the potential mechanisms, an asthma model was established using six-month-old APP/PS1 mice, and montelukast was used as a therapeutic agent in APP/PS1 mice with asthma. The Morris water maze test showed that asthma aggravates spatial learning and memory abilities. Asthma also upregulates the NF-κB inflammatory pathway in APP/PS1 mice and promotes the expression of beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), amyloid-β (Aβ) deposition, neuronal damage, synaptic plasticity deficiency, activation of microglia and astrocytes. The level of LTD4 and its receptor CysLT1R in the hippocampus of APP/PS1 mice after the asthma modeling was established was higher than that in APP/PS1 mice, suggesting that asthma may affect the pathology of AD through LTD4 and its receptor Cys-LT1R. Montelukast ameliorates these pathological changes and cognitive impairment. These results suggest that asthma aggravates AD pathology and cognitive impairment of APP/PS1 mice via upregulation of the NF-κB inflammatory pathway, and montelukast ameliorates these pathological changes.

Cyanidin-3-O-glucoside protects the brain and improves cognitive function in APPswe/PS1ΔE9 transgenic mice model

Cyanidin-3-O-glucoside (C3G) is a natural anthocyanin with antioxidant, anti-inflammatory, and antitumor properties. However, as the effects of C3G on the amyloidogenic pathway, autophagy, tau phosphorylation, neuronal cell death, and synaptic plasticity in Alzheimer’s disease models have not been reported, we attempted to investigate the same in the brains of APPswe/PS1ΔE9 mice were analyzed. After oral administration of C3G (30 mg/kg/day) for 16 weeks, the cortical and hippocampal regions in the brains of APPswe/PS1ΔE9 mice were analyzed. C3G treatment reduced the levels of soluble and insoluble Aβ (Aβ40 and Aβ42) peptides and reduced the protein expression of the amyloid precursor protein, presenilin-1, and β-secretase in the cortical and hippocampal regions. And C3G treatment upregulated the expression of autophagy-related markers, LC3B-II, LAMP-1, TFEB, and PPAR-α and downregulated that of SQSTM1/p62, improving the autophagy of Aβ plaques and neurofibrillary tangles. In addition, C3G increased the protein expression of phosphorylated-AMPK/AMPK and Sirtuin 1 and decreased that of mitogen-activated protein kinases, such as phosphorylated-Akt/Akt and phosphorylated-ERK/ERK, thus demonstrating its neuroprotective effects. Furthermore, C3G regulated the PI3K/Akt/GSK3β signaling by upregulating phosphorylated-Akt/Akt and phosphorylated-GSK3β/GSK3β expression. C3G administration mitigated tau phosphorylation and improved synaptic function and plasticity by upregulating the expression of synapse-associated proteins synaptophysin and postsynaptic density protein-95. Although the potential of C3G in the APPswe/PS1ΔE9 mouse models has not yet been reported, oral administration of the C3G is shown to protect the brain and improve cognitive behavior.Graphical

Localized APP expression results in progressive network dysfunction by disorganizing spike timing

Progressive cognitive decline in Alzheimer's disease could either be caused by a spreading molecular pathology or by an initially focal pathology that causes aberrant neuronal activity in a larger network. To distinguish between these possibilities, we generated a mouse model with expression of mutant human amyloid precursor protein (APP) in only hippocampal CA3 cells. We found that performance in a hippocampus-dependent memory task was impaired in young adult and aged mutant mice. In both age groups, we then recorded from the CA1 region, which receives inputs from APP-expressing CA3 cells. We observed that theta oscillation frequency in CA1 was reduced along with disrupted relative timing of principal cells. Highly localized pathology limited to the presynaptic CA3 cells is thus sufficient to cause aberrant firing patterns in postsynaptic neuronal networks, which indicates that disease progression is not only from spreading pathology but also mediated by progressively advancing physiological dysfunction.

Ethyl maltol disrupt iron homeostasis in SH-SY5Y neuroblastoma cell line.

Ethyl Maltol (EM) is a commonly used flavoring compound and has been reported to bind iron and facilitate iron transport. Since EM is membrane permeable, the potential that it disrupts intracellular iron homeostasis was investigated. EM increased the labile iron pool in SH-SY5Y cells and increased iron-responsive protein activity using a reporter assay in the HEK293 cells. EM induced the expression of transferrin receptor 1 messenger RNA (mRNA) and decreased the expression of ferritin light chain protein in SH-SY5Y cells. Expression of the iron-responsive amyloid precursor protein attenuated the effects of EM on these iron-responsive genes. EM treatment decreased cell viability and increased DNA damage. EM also increased the level of phosphorylated p53 and the expression of the p53-regulated genes, p21, and 14-3-3σ. The expression of amyloid precursor protein (APP) attenuated the effects of EM on viability, DNA damage, and the p53 response. Overall, we suggest that EM decreases cell viability through a mechanism involving the p53 pathway. The attenuated responses observed in cells expressing APP suggest that the effects of EM are due to disrupting iron homeostasis.

Hippocampal delivery of neurotrophic factor-α1/carboxypeptidase E gene prevents neurodegeneration, amyloidosis, memory loss in Alzheimer’s Disease male mice

Alzheimer’s Disease (AD) is a prevalent neurodegenerative disease characterized by tau hyperphosphorylation, Aβ1-42 aggregation and cognitive dysfunction. Therapeutic agents directed at mitigating tau aggregation and clearing Aβ1-42, and delivery of growth factor genes (BDNF, FGF2), have ameliorated cognitive deficits, but these approaches did not prevent or stop AD progression. Here we report that viral-(AAV) delivery of Neurotrophic Factor-α1/Carboxypeptidase E (NF-α1/CPE) gene in hippocampus at an early age prevented later development of cognitive deficits as assessed by Morris water maze and novel object recognition assays, neurodegeneration, and tau hyperphosphorylation in male 3xTg-AD mice. Additionally, amyloid precursor protein (APP) expression was reduced to near non-AD levels, and insoluble Aβ1-42 was reduced significantly. Pro-survival proteins: mitochondrial Bcl2 and Serpina3g were increased; and mitophagy inhibitor Plin4 and pro-inflammatory protein Card14 were decreased in AAV-NF-α1/CPE treated versus untreated AD mice. Thus NF-α1/CPE gene therapy targets many regulatory components to prevent cognitive deficits in 3xTg-AD mice and has implications as a new therapy to prevent AD progression by promoting cell survival, inhibiting APP overexpression and tau hyperphosphorylation.

Alcohol-drinking during later life by C57BL/6J mice induces sex- and age-dependent changes in hippocampal and prefrontal cortex expression of glutamate receptors and neuropathology markers

Heavy drinking can induce early-onset dementia and increase the likelihood of the progression and severity of Alzheimer's Disease and related dementias (ADRD). Recently, we showed that alcohol-drinking by mature adult C57BL/6J mice induces more signs of cognitive impairment in females versus males without worsening age-related cognitive decline in aged mice. Here, we immunoblotted for glutamate receptors and protein markers of ADRD-related neuropathology within the hippocampus and prefrontal cortex (PFC) of these mice after three weeks of alcohol withdrawal to determine protein correlates of alcohol-induced cognitive decline. Irrespective of alcohol history, age-related changes in protein expression included a male-specific decline in hippocampal glutamate receptors and an increase in the expression of a beta-site amyloid precursor protein cleaving enzyme (BACE) isoform in the PFC as well as a sex-independent increase in hippocampal amyloid precursor protein. Alcohol-drinking was associated with altered expression of glutamate receptors in the hippocampus in a sex-dependent manner, while all glutamate receptor proteins exhibited significant alcohol-related increases in the PFC of both sexes. Expression of BACE isoforms and phosphorylated tau varied in the PFC and hippocampus based on age, sex, and drinking history. The results of this study indicate that withdrawal from a history of alcohol-drinking during later life induces sex- and age-selective effects on glutamate receptor expression and protein markers of ADRD-related neuropathology within the hippocampus and PFC of potential relevance to the etiology, treatment and prevention of alcohol-induced dementia and Alzheimer's Disease.

Porphyromonas gingivalis-induced periodontitis could contribute to cognitive impairment in Sprague-Dawley rats via the P38 MAPK signaling pathway.

Periodontitis is one of the most common oral diseases and has been shown to be a risk factor for systemic diseases. Our aim was to investigate the relationship between periodontitis and cognitive impairment and to explore the role of the P38 MAPK signaling pathway in this process. We established a periodontitis model by ligating the first molars of SD rats with silk thread and injecting Porphyromonas gingivalis (P. gingivalis) or P. gingivalis plus the P38 MAPK inhibitor SB203580 at the same time for ten weeks. We assessed alveolar bone resorption and spatial learning and memory using microcomputed tomography and the Morris water maze test, respectively. We used transcriptome sequencing to explore the genetic differences between the groups. The gingival tissue, peripheral blood and hippocampal tissue were assessed for the cytokines TNF-α, IL-1β, IL-6, IL-8 and C reactive protein (CRP) with enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR). We observed the presence of P. gingivalis in the hippocampus of rats by paraffin-fluorescence in situ hybridization (FISH). We determined the activation of microglia by immunofluorescence. Finally, Western blot analysis was employed to determine the expression of amyloid precursor protein (APP), β-site APP-cleaving enzyme 1 (BACE1) and P38MAPK pathway activation. We demonstrated that silk ligature-induced periodontitis plus injection of P. gingivalis into subgingival tissue could lead to memory and cognitive impairment. Transcriptome sequencing results suggested that there were neurodegenerative diseases in the P. gingivalis group, and the MWM test showed that periodontitis reduced the spatial learning and memory ability of mild cognitive impairment (MCI) model rats. We found high levels of inflammatory factors (TNF-α, IL-1β, IL-6, and IL-8) and CRP in the gingiva, peripheral blood and hippocampus, and the expression of APP and BACE1 was upregulated, as was the P38 MAPK pathway activation. Activated microglia and the presence of P. gingivalis were also found in the hippocampus. P38 MAPK inhibitors mitigated all of these changes. Our findings strongly suggest that topical application of P. gingivalis increases the inflammatory burden in the peripheral and central nervous systems (CNS) and that neuroinflammation induced by activation of P38 MAPK leads to impaired learning and memory in SD rats. It can also modulate APP processing. Therefore, P38 MAPK may serve as a linking pathway between periodontitis and cognitive impairment.

A Diet Containing Rutin Ameliorates Brain Intracellular Redox Homeostasis in a Mouse Model of Alzheimer’s Disease

Quercetin has been studied extensively for its anti-Alzheimer's disease (AD) and anti-aging effects. Our previous studies have found that quercetin and in its glycoside form, rutin, can modulate the proteasome function in neuroblastoma cells. We aimed to explore the effects of quercetin and rutin on intracellular redox homeostasis of the brain (reduced glutathione/oxidized glutathione, GSH/GSSG), its correlation with β-site APP cleaving enzyme 1 (BACE1) activity, and amyloid precursor protein (APP) expression in transgenic TgAPP mice (bearing human Swedish mutation APP transgene, APPswe). On the basis that BACE1 protein and APP processing are regulated by the ubiquitin-proteasome pathway and that supplementation with GSH protects neurons from proteasome inhibition, we investigated whether a diet containing quercetin or rutin (30 mg/kg/day, 4 weeks) diminishes several early signs of AD. Genotyping analyses of animals were carried out by PCR. In order to determine intracellular redox homeostasis, spectrofluorometric methods were adopted to quantify GSH and GSSG levels using o-phthalaldehyde and the GSH/GSSG ratio was ascertained. Levels of TBARS were determined as a marker of lipid peroxidation. Enzyme activities of SOD, CAT, GR, and GPx were determined in the cortex and hippocampus. ΒACE1 activity was measured by a secretase-specific substrate conjugated to two reporter molecules (EDANS and DABCYL). Gene expression of the main antioxidant enzymes: APP, BACE1, a Disintegrin and metalloproteinase domain-containing protein 10 (ADAM10), caspase-3, caspase-6, and inflammatory cytokines were determined by RT-PCR. First, overexpression of APPswe in TgAPP mice decreased GSH/GSSG ratio, increased malonaldehyde (MDA) levels, and, overall, decreased the main antioxidant enzyme activities in comparison to wild-type (WT) mice. Treatment of TgAPP mice with quercetin or rutin increased GSH/GSSG, diminished MDA levels, and favored the enzyme antioxidant capacity, particularly with rutin. Secondly, both APP expression and BACE1 activity were diminished with quercetin or rutin in TgAPP mice. Regarding ADAM10, it tended to increase in TgAPP mice with rutin treatment. As for caspase-3 expression, TgAPP displayed an increase which was the opposite with rutin. Finally, the increase in expression of the inflammatory markers IL-1β and IFN-γ in TgAPP mice was lowered by both quercetin and rutin. Collectively, these findings suggest that, of the two flavonoids, rutin may be included in a day-to-day diet as a form of adjuvant therapy in AD.

Network meta-analysis on alcohol-mediated modulation of Alzheimer’s disease in the diseases of inflammation including COVID-19

Abstract Objectives Cross sectional surveys have reported that alcohol consumption has skyrocketed during the COVID-19 pandemic. Chronic alcohol use triggers systemic inflammation which leads to neuroinflammation and neurodegeneration. In the present study, we hypothesize that alcohol consumption and cytokine elevation during inflammatory conditions synergistically increase amyloid-beta precursor protein (APP) expression and worsens Alzheimer’s disease (AD) pathology. Methods QIAGEN Ingenuity Pathway Analysis (IPA) was employed to conduct network meta-analysis on the molecular mechanisms underlying ethanol (EtOH) influence on APP expression and AD in inflammatory conditions including COVID-19, inflammation of respiratory system, organ, absolute anatomical region, body cavity, joint, respiratory system component, gastrointestinal tract, large intestine, liver, central nerve system, and lung. IPA tools were utilized to identify the molecules associated with EtOH, inflammatory conditions and the common molecules between them. Results Simulation activity of EtOH, mimicking exposure to alcohol, upregulated the APP expression and augmented AD pathology in all inflammatory conditions including COVID-19. Our studies identified six molecules including ADORA2A, Cytokine, IFN-gamma, IL1-beta, Immunoglobulin and TNF, which concurrently contribute to increased APP expression and AD progression upon EtOH simulation in all diseases studied. Conclusions The present study has revealed molecular mechanisms underlying alcohol augmentation of AD in COVID-19 and other diseases of inflammation.

Emodin induces osteosarcoma cell apoptosis by promoting ATM protein cleavage

Purpose: To investigate the effect of emodin on osteosarcoma cell proliferation and apoptosis.
 Methods: The osteosarcoma cell proliferation ability was determined by CCK-8, apoptosis level and cell cycle were determined via flow cytometry. Honechst staining was used to determine the ratio of nuclear pyknosis, Western blotting was used to determine the expression of AKT, p-AKT and caspase-3 precursor protein in each group of osteosarcoma cells.
 Results: Emodin significantly inhibited the MG-63 cell proliferation and promoted the apoptosis of osteosarcoma cells in a dose-dependent manner (p < 0.05). It further blocked osteosarcoma cells in G1/G0 phase and decreased the expression of AKT, p-AKT, and caspase-3 (p < 0.05).
 Conclusion: Emodin inhibits osteosarcoma cell growth by inhibiting ATM protein cleavage. There is a need to carry out further investigation of the effect of emodin on osteosarcoma cells using animal models in order to ascertain its potential in the management of osteosarcoma.

PS-B10-7: A VASCULAR SMOOTH MUSCLE POTASSIUM CHANNEL DYSFUNCTION UNDERLIES SMALL VESSEL DISEASE OF THE BRAIN IN BOTH HYPERTENSION AND ALZHEIMER'S DISEASE

Alzheimer's disease (AD) and hypertension-related vascular dementia share many common clinical and radiological features. Indeed, at post-mortem the majority of patients diagnosed with either disorder show extensive small vessel disease (SVD) of the brain. One phenotypic character of SVD is a reduction in cerebral blood flow (CBF). The large-conductance calcium-activated potassium (BK) channel reduces arterial contractility through hyperpolarisation of the vascular smooth muscle cell membrane. The BK channel is activated via small, localised calcium release events from ryanodine receptors (RyR), known as calcium sparks. We wished to examine whether defects in calcium spark to BK channel coupling contributes to the SVD phenotype in these diseases, which could suggest new avenues for therapy based on improvement of brain vascular health. Male spontaneously hypertensive (BPH/2) mice and normotensive controls (BPN/3) were used at 8 months of age to study hypertension-induced cSVD. To study AD we used 18–20 month old male APP23 mice that have a 7-fold increased expression of amyloid precursor protein, which results in significant amyloid-beta accumulation as is seen in human AD. During this study we used a range of physiological techniques; mainly pressure myography, patch clamp electrophysiology and high-speed spinning disc confocal microscopy, to investigate in depth, vascular ion channel function within the cerebral microvasculature of these mice. Pressure-induced constriction from cerebral pial arteries was significantly greater in both the BPH/2 and APP23 animals compared to controls. Pressure myography studies revealed that in both models there was a reduction in BK channel activity. This was confirmed with electrophysiology data that showed a decrease in spontaneous transient outward currents, which represent BK channel openings in response to calcium sparks. In the APP23 model, this reduction in BK channel function was due to a decrease in calcium spark frequency. However in the BPH/2 mice, spark frequency was equal between hypertensive individuals and controls. In this model separation of the BK channel and RyR resulted in BK channel dysfunction. Overall our data indicates that vascular BK channel dysfunction is a common mechanism underpinning reduced CBF in SVD. Therefore, therapies aimed at improving vascular BK channel function could provide new therapeutic targets for the treatment of both AD and hypertension-induced vascular dementia.

Breviscapine Combined with BMSCs Reduces Aβ Deposition in Rat with Alzheimer's Disease by Regulating Circular RNA ciRS-7.

This study aimed to clarify that breviscapine combined with bone marrow mesenchymal stem cells (BMSCs) treatment can reduce Aβ deposition in Alzheimer's disease (AD) patients. AD is a common degenerative disease of the central nervous system. Aβ protein deposition in the cerebral cortex and hippocampus causes neuronal peroxidation damage, synaptic dysfunction, neuroinflammation, and nerve cell apoptosis, and ultimately leads to AD. To investigate whether breviscapine combined with BMSCs treatment can reduce Aβ deposition in AD. The AD rat model was successfully induced by Aβ1-42. The expression of protein and mRNA was detected by western blot and reverse transcription-quantitative PCR (RT-qPCR), respectively. In AD rat brain tissue, the expression of circular RNA ciRS-7 (ciRS-7), ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), and NF-kappaB p65 was significantly downregulated, and the expression of β-amyloid precursor protein (APP), β-site APPcleaving enzyme 1 (BAEC1), and Aβ was upregulated. The expression of ciRS-7, UCHL1, and p65 was significantly upregulated after breviscapine or BMSCs treatment, and there was increased APP and BAEC1 degradation. Notably, breviscapine combined with BMSCs treatment was more effective than either treatment alone. In SH-SY5Y cells, overexpression of ciRS-7 reduced Aβ deposition by upregulating UCHL1 to degrade APP and BAEC1, but these effects were reversed with inhibition of NF-kB signaling. Finally, knockdown of ciRS-7 elevated Aβ, APP, and BAEC1 expression in each group of rats compared with the control. Breviscapine combined with BMSCs treatment can reduce Aβ deposition in AD rats and promote the degradation of APP and BAEC1 by activating NF-kB to promote UCHL1 expression.

Multi-targeted anti-inflammatory drugs for the treatment of neurological disorders.

Multi-targeted anti-inflammatory drugs for the treatment of neurological disorders.