scholarly journals Prostaglandin A1 inhibits the phosphorylation of tau via activating protein phosphotase 2A in a michael addition mechanism at the site of cysteine 377

2020 ◽  
Author(s):  
Guo-Biao Xu ◽  
Pei-Pei Guan ◽  
Pu Wang
Keyword(s):  
Cognitive Decline ◽  
Michael Addition ◽  
Dependent Manner ◽  
Western Blots ◽  
Michael Adduct ◽  
Term Administration ◽  
Prostaglandin A1

Abstract Background: Prostaglandin (PG) A1 is a metabolic product of cyclooxygenase 2 (COX-2), which potentially involved in regulating the development and progression of Alzheimer’s disease (AD). As a cyclopentenone (cy) PG, PGA1 is characterized by the presence of a chemically reactive α, β-unsaturated carbonyl. Although PGA1 is potentially involved in regulating multiple biological processes via michael addition, its specific roles in AD remained unclear.Methods: The tauP301S transgenic (Tg) mice were employed as in vivo AD models and neuroblastoma (N) 2a cells as in vitro neuronal models. By intracerebroventricular injected (i.c.v) with PGA1, the binding proteins to PGA1 are analyzed by HPLC-MS-MS. In addition, western blots are used to determine the phosphorylation of tau in PGA1 treated Tg mice in the absence or presence of okadaic acid (OA), an inhibitor of protein phosphotase (PP) 2A. Combining a synthesis of pull down assay, immunoprecipitation, western blots and HPLC-MS-MS, PP2A scaffold subunit A alpha (PPP2R1A) was identified to be activated by directly binding on PGA1 in cysteine 377-dependent manner. Via inhibiting the hyperphosphorylation of tau, morris maze test was employed to determine the inhibitory effects of PGA1 on cognitive decline of tauP301S Tg mice.Results: By incubation with neuroblastoma (n)2a cells and pull down assay, mass spectra (MS) analysis revealed that PGA1 binds with more than 1000 proteins, among which contains the proteins of AD, especially tau protein. Moreover, short-term administration of PGA1 to tauP301S Tg mice significantly decreased the phosphorylation of tau at the sites of Thr181, Ser202 and Ser404 in a dose-dependent manner. To the reason, it’s caused by activating PPP2R1A in tauP301S Tg mice. More importantly, PGA1 has the ability to form michael adduct with PPP2R1A via its cysteine 377 motif, which is critical for the enzymatic activity of PP2A. By activating PP2A, long-term application of PGA1 to tauP301S Tg mice significantly reduced the phosphorylation of tau, which results in improving the cognitive decline of tauP301S Tg mice.Conclusion: Our data provided the first insights needed to decipher the mechanisms underlying the ameliorating effects of PGA1 on cognitive decline of tauP301S Tg mice via activating PP2A in a PPP2R1AC377-dependent Michael adducting mechanisms.

scholarly journals The Molecular Mechanism of Chronic High-Dose Corticosterone-Induced Aggravation of Cognitive Impairment in APP/PS1 Transgenic Mice

2021 ◽  
Vol 13 ◽  
Author(s):  
Shen-Qing Zhang ◽  
Long-Long Cao ◽  
Yun-Yue Liang ◽  
Pu Wang
Keyword(s):  
Preclinical Model ◽  
High Dose ◽  
Term Administration ◽  
Amyloid Aβ ◽  
Β Amyloid ◽  
Stimulation Of ◽  
Bace 1

Clinical studies have found that some Alzheimer’s disease (AD) patients suffer from Cushing’s syndrome (CS). CS is caused by the long-term release of excess glucocorticoids (GCs) from the adrenal gland, which in turn, impair brain function and induce dementia. Thus, we investigated the mechanism of the effect of corticosterone (CORT) on the development and progression of AD in a preclinical model. Specifically, the plasma CORT levels of 9-month-old APP/PS1 Tg mice were abnormally increased, suggesting an association between GCs and AD. Long-term administration of CORT accelerated cognitive dysfunction by increasing the production and deposition of β-amyloid (Aβ). The mechanism of action of CORT treatment involved stimulation of the expression of BACE-1 and presenilin (PS) 1 in in vitro and in vivo. This observation was confirmed in mice with adrenalectomy (ADX), which had lower levels of GCs. Moreover, the glucocorticoid receptor (GR) mediated the effects of CORT on the stimulation of the expression of BACE-1 and PS1 via the PKA and CREB pathways in neuroblastoma N2a cells. In addition to these mechanisms, CORT can induce a cognitive decline in APP/PS1 Tg mice by inducing apoptosis and decreasing the differentiation of neurons.

scholarly journals Lansoprazole-Induced Osteoporosis via IP3R and SOCE Mediated Calcium Signaling Pathway

2021 ◽  
Author(s):  
Zi-Ping Cheng ◽  
Jie-Yang Liu ◽  
Meng-Yuan Ma ◽  
Shi-Yu Sun ◽  
Zeng-qing Ma ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Vehicle Group ◽  
Dependent Manner ◽  
Micro Ct ◽  
Mineral Density ◽  
Calcium Release Channel ◽  
Blood Calcium ◽  
Term Administration

Abstract Background: Many clinical studies have shown a correlation between proton pump inhibitors (PPIs) and osteoporosis or fractures. The purposes of this study were to establish a murine model of chronic oral administration of PPIs to verify whether PPIs caused bone metabolic impairment, and to investigate the relevant molecular mechanism underlying the effects of PPIs on MC3T3-E1 mouse osteoblasts.Methods: Lansoprazole-induced bone loss model was employed to investigate the damage effects of PPIs. In vivo, immunohistochemistry and HE staining, micro-CT analysis, blood biochemical tests were used to evaluate the effect of lansoprazole on bone injury in mice. In vitro, the effects and related signaling pathway of lansoprazole on MC3T3-E1 cells were investigated by CCK8, EDU kit, flow cytometry, laser confocal, patch clamp, PCR and Western blotting, etc.Results: After 6 months of lansoprazole gavage in ICR mice, micro-CT results showed that compared with the vehicle group, the bone mineral density (BMD) of high-dose group was significantly decreased (P<0.05), and the bone microarchitecture gradually degraded. Biochemical assay of bone serum found that blood calcium and phosphorus were both decreased (P<0.01). We found that long-term administration of lansoprazole impairs skeletal function in mice. In vitro, we found that lansoprazole (LPZ) could cause calcium overload in MC3T3-E1 cells leading to apoptosis, and 2-APB, an inhibitor of IP3R calcium release channel and SOC pathway, efctively blocked calcium increase caused by LPZ, thus protecting cell viability.Conclusion: Long-term administration of LPZ induced osteoporotic symptoms in mice, and LPZ triggered calcium elevation in osteoblasts in a concentration dependent manner, intracellular calcium ([Ca2+] persisted at a high concentration thereby causing endoplasmic reticulum stress (ERS) and inducing osteoblasts apoptosis.

scholarly journals Riligustilide Attenuated Renal Injury by the Blockade of Renin

2018 ◽  
Vol 50 (2) ◽  
pp. 654-667 ◽  
Author(s):  
Juan Kong ◽  
Li Han ◽  
Han Su ◽  
Yihan Hu ◽  
Xueshi Huang ◽  
...  
Keyword(s):  
Renal Injury ◽  
Chinese Herb ◽  
Underlying Mechanism ◽  
Vehicle Group ◽  
Mice Model ◽  
Kidney Fibrosis ◽  
Term Administration

Background/Aims: Nephropathy related with renin can be alleviated with ACE-inhibitors or AT1R blockers, whereas they might be ineffective after long-term administration because of a feedback production of enhanced renin. Therefore, it is urgent to develop a new category of anti-nephropathy medicine directly targeting renin. Riligustilide (C20), originally isolated from the Chinese herb Ligusticumporteri, a rhizome, was confirmed effective against many diseases. Methods: The therapeutic effect of C20 on renal injury and its underlying mechanism were investigated in three different nephrotic models, which were spontaneously hypertension rats (SHR) model, diabetic nephropathy in BTBR ob/ob mice model and 5/6-nephrectomized (5/6NX) rats model. Results: The intensity of kidney fibrosis was extensively decreased in the C20-treated rats compared to the vehicle animals. C20 significantly alleviated renal injury much more in 5/6 NX rats than in vehicle group. The rats in 5/6 NX without administrated C20 developed albuminuria earlier with more severe symptoms. Additionally, our findings showed that C20 down-regulated the renin expression and relocation of CREB-CBP complex in vivo and in vitro. Conclusion: C20 plays importantly reno-protective roles most likely through the relocation of CREB-CBP complex.

scholarly journals Upregulation of NOXA by 10-Hydroxycamptothecin plays a key role in inducing fibroblasts apoptosis and reducing epidural fibrosis

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2858 ◽  
Author(s):  
Jihang Dai ◽  
Yu Sun ◽  
Lianqi Yan ◽  
Jingcheng Wang ◽  
Xiaolei Li ◽  
...  
Keyword(s):  
Tunel Assay ◽  
Dependent Manner ◽  
Epidural Fibrosis ◽  
Western Blots ◽  
Positive Effects ◽  
Intrinsic Mechanism ◽  
Series Of Experiments ◽  
Dose Dependent

The fibrosis that develops following laminectomy or discectomy often causes serious complications, and the proliferation of fibroblasts is thought to be the major cause of epidural fibrosis. 10-Hydroxycamptothecin (HCPT) has been proven to be efficient in preventing epidural fibrosis, but the exact mechanism is still unclear. NOXA is a significant regulator of cell apoptosis, which has been reported to be beneficial in the treatment of fibrosis. We performed a series of experiments, both in vitro and in vivo, to explore the intrinsic mechanism of HCPT that underlies the induction of apoptosis in fibroblasts, and also to investigate whether HCPT has positive effects on epidural fibrosis following laminectomy in rats. Fibroblasts were cultured in vitro and stimulated by varying concentrations of HCPT (0, 1, 2, 4 µg/ml) for various durations (0, 24, 48, 72 h); the effect of HCPT in inducing the apoptosis of fibroblasts was investigated via Western blots and TUNEL assay. Our results showed that HCPT could induce apoptosis in fibroblasts and up-regulate the expression of NOXA. Following the knockdown of NOXA in fibroblasts, the results of Western blot analysis showed that the level of apoptotic markers, such as cleaved-PARP and Bax, was decreased. The results from the TUNEL assay also showed a decreased rate of apoptosis in NOXA-knocked down fibroblasts. For the in vivo studies, we performed a laminectomy at the L1-L2 levels in rats and applied HCPT of different concentrations (0.2, 0.1, 0.05 mg/ml and saline) locally; the macroscopic histological assessment, hydroxyproline content analysis and histological staining were performed to evaluate the effect of HCPT on reducing epidural fibrosis. The TUNEL assay in epidural tissues showed that HCPT could obviously induce apoptosis in fibroblasts in a dose-dependent manner. Also, immunohistochemical staining showed that the expression of NOXA increased as the concentrations of HCPT increased. Our findings are the first to demonstrate that upregulation of NOXA by HCPT plays a key role in inducing fibroblast apoptosis and in reducing epidural fibrosis. These findings might provide a potential therapeutic target for preventing epidural fibrosis following laminectomy.

Vitamin D as a Regulator of Adipocyte Differentiation Effects in vivo and in vitro

2018 ◽  
Vol 69 (3) ◽  
pp. 731-734
Author(s):  
Alin Constantin Pinzariu ◽  
Teodor Oboroceanu ◽  
Florin Zugun Eloae ◽  
Ioana Hristov ◽  
Victor Vlad Costan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Adipocyte Differentiation ◽  
Dependent Manner ◽  
Omental Adipose Tissue ◽  
In Vivo Experiments ◽  
Dose Dependent ◽  
Stromal Stem Cells

The age-associated adiposity and the effect of long-term vitamin D was studied in vitamin D deficient rats. In in vivo experiments, the influence of a 9 months of vitamin D treatment (weekly oral gavage with 0.125 mg vitamin D3 (5000 IU)/100g body weight) on the adipocyte precursors from the omental adipose tissue was examinated. In in vitro experiment, rat adipose-derived mesenchymal stromal/stem cells (ASCs) were induced to differentiate into adipocytes in the presence or absence of 25(OH)D3 (0.25, 25, and 2500 nmol/L). ASCs derived from vitamin D-treated animals showed an increase adipogenic potential as compared to vitamin D-deficient rats. The addition of 25(OH)D3 inhibits the adipocyte differentiation and lipid deposition in a dose dependent manner.

Comparison of In Vitro Cardiovascular Function with In Vivo Echocardiographic Assessment After Long-Term Administration of Cyclosporine to Rats

1998 ◽  
Vol 31 (6) ◽  
pp. 828-832 ◽  
Author(s):  
Ruediger C. Braun-Dullaeus ◽  
Markus Feussner ◽  
Gerhard Walker ◽  
Harald Tillmanns ◽  
Werner Haberbosch
Keyword(s):  
Cardiovascular Function ◽  
Term Administration ◽  
Echocardiographic Assessment

scholarly journals Library of Selenocyanate and Diselenide Derivatives as In Vivo Antichagasic Compounds Targeting Trypanosoma Cruzi Mitochondrion

2021 ◽  
Vol 14 (5) ◽  
pp. 419
Author(s):  
Rubén Martín-Escolano ◽  
Daniel Molina-Carreño ◽  
Daniel Plano ◽  
Socorro Espuelas ◽  
María J. Rosales ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Health Concern ◽  
Dependent Manner ◽  
Pharmacological Activities ◽  
Selenium Compounds ◽  
Fast Acting

Chagas disease is usually caused by tropical infection with the insect-transmitted protozoan Trypanosoma cruzi. Currently, Chagas disease is a major public health concern worldwide due to globalization, and there are no treatments neither vaccines because of the long-term nature of the disease and its complex pathology. Current treatments are limited to two obsolete drugs, benznidazole and nifurtimox, which lead to serious drawbacks. Taking into account the urgent need for strict research efforts to find new therapies, here, we describe the in vitro and in vivo trypanocidal activity of a library of selected forty-eight selenocyanate and diselenide derivatives that exhibited leishmanicidal properties. The inclusion of selenium, an essential trace element, was due to the well-known extensive pharmacological activities for selenium compounds including parasitic diseases as T. cruzi. Here we present compound 8 as a potential compound that exhibits a better profile than benznidazole both in vitro and in vivo. It shows a fast-acting behaviour that could be attributed to its mode of action: it acts in a mitochondrion-dependent manner, causing cell death by bioenergetic collapse. This finding provides a step forward for the development of a new antichagasic agent.

Production of the plasma-cell survival factor a proliferation-inducing ligand (APRIL) peaks in myeloid precursor cells from human bone marrow

Blood ◽  
2011 ◽  
Vol 118 (7) ◽  
pp. 1838-1844 ◽  
Author(s):  
Thomas Matthes ◽  
Isabelle Dunand-Sauthier ◽  
Marie-Laure Santiago-Raber ◽  
Karl-Heinz Krause ◽  
Olivier Donze ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Plasma Cells ◽  
Myeloid Cells ◽  
Precursor Cells ◽  
Dependent Manner ◽  
Term Survival ◽  
Cell Survival Factor

AbstractThe bone marrow (BM) is an organ extremely efficient in mediating long-term survival of plasma cells (PCs), ensuring an immune humoral memory. This implies that the BM must provide continuously key PC survival factors. Our results show that the BM is an organ constitutively rich in a proliferation-inducing ligand (APRIL), a member of the tumor necrosis factor superfamily implicated in PC survival. APRIL production is induced during hematopoiesis in myeloid cells by non–lineage-committing factors such as stem cell factor, thrombopoietin, IL-3, and FMS-like tyrosine kinase 3 ligand. Notably, APRIL production, both in the human and mouse systems, peaks in myeloid precursor cells, before dropping in fully mature granulocytes. Myeloid cells secrete APRIL that circulates freely in BM plasma to act on PCs, usually at distance from APRIL production sites. Selective APRIL in vivo antagonism and in vitro coculture experiments further demonstrated that myeloid precursor cells mediates PC survival in an APRIL-dependent manner Thus, APRIL production by myeloid precursor cells shows that the 2 main BM functions, hematopoiesis and long-term PC survival, are linked. Such constitutive and high APRIL production may explain why BM mediates long-term PC survival.

scholarly journals Deciphering the Formulation Secret Underlying Chinese Huo-Clearing Herbal Drink

2021 ◽  
Vol 12 ◽  
Author(s):  
Jianan Wang ◽  
Bo Zhou ◽  
Xiangdong Hu ◽  
Shuang Dong ◽  
Ming Hong ◽  
...  
Keyword(s):  
Lower Percentage ◽  
Dependent Manner ◽  
Prunella Vulgaris ◽  
Cellular Inflammation ◽  
Optimal Health ◽  
Dose Dependent ◽  
Body Heat

Herbal teas or herbal drinks are traditional beverages that are prevalent in many cultures around the world. In Traditional Chinese Medicine, an herbal drink infused with different types of medicinal plants is believed to reduce the ‘Shang Huo’, or excessive body heat, a status of sub-optimal health. Although it is widely accepted and has a very large market, the underlying science for herbal drinks remains elusive. By studying a group of herbs for drinks, including ‘Gan’ (Glycyrrhiza uralensis Fisch. Ex DC.), ‘Ju’ (Dendranthema morifolium (Ramat.) Tzvelev), ‘Bu’ (Microcos paniculata L.), ‘Jin’ (Lonicera japonica Thunb.), ‘Xia’ (Prunella vulgaris L.), and ‘Ji’ (Plumeria rubra L.), the long-term jargon is connected with the inflammation of modern immunology through a few pro-inflammatory markers. In vitro studies have indicated that cellular inflammation is lowered by Ju and Jin either individually or synergistically with Gan. Among all herbs, only Gan detoxicated cellular toxicity of Bu in a dose dependent manner. The synergistic formulation of Ju and Gan, or Jin and Gan, in a reduction of Shang Huo, was tested in vivo. Both combinations exhibited a lower percentage of neutrophils, monocytes, and CD4+/CD8+ ratio in the blood, as well as inflammatory cytokines. Furthermore, body weight in the combinatory groups was more stable than treatments using single herbs. The combination of old traditional oriental methods with Western science logistics, has resulted in the formulation of different herbs into one concoction for the use of detoxification and synergism.

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