scholarly journals Optimization of Degradation Conditions with PRG, a Polysaccharide from Phellinus ribis, by RSM and the Neuroprotective Activity in PC12 Cells Damaged by Aβ25–35

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 3010 ◽  
Author(s):  
Pei Yang ◽  
Juan Jin ◽  
Qian Liu ◽  
Dongmei Ma ◽  
Jia Li ◽  
...  

In the previous work, we found PRG, a polysaccharide from Phellinus ribis, exhibited neurotrophic activity. To obtain an active structural unit with lower molecular weight, PRG was degraded to prepare the degraded PRG (DPRG) using ascorbic acid and H2O2. The aim of the paper was to obtain DPRG by optimizing the degradation conditions using response surface methodology (RSM) and to study its protective effects of PC12 cells induced by Aβ25–35. The optimum conditions were as follows; the concentration of H2O2-Vc was 17 mM and degradation temperature was 50 °C; when degradation time was 1.6 h, the experimental response value of PC12 cell viability was 83.4 ± 0.15%, which was in accordance with the predicted value (83.5%). We also studied the protective effects of DPRG against the Aβ25–35-induced neurotoxicity and explored the underlying mechanism. The results showed that treatment with DPRG could attenuate PC12 cells death. The mechanism was relative to the inhibition of cell apoptosis by increasing the MMP level and decreasing the protein expression of cytochrome C (Cytc) in PC12 cells. In conclusion, DPRG with lower molecular weight was obtained successfully. It possessed neuroprotective properties and might be a candidate for neurodegenerative disease treatment.

2011 ◽  
Vol 150 (5) ◽  
pp. 473-475 ◽  
Author(s):  
H. Maruoka ◽  
H. Sasaya ◽  
K. Sugihara ◽  
K. Shimoke ◽  
T. Ikeuchi

2020 ◽  
Author(s):  
Liangyuan Suo ◽  
Mingyu Wang

Abstract Background Dexmedetomidine (DEX) is a selective agonist of α2-adrenergic receptors with anesthetic activity and neuroprotective benefits. However, its mechanism of action at the molecular level remains poorly defined. In this study, we investigated the protective effects of Dex on OGD/R-induced neuronal apoptosis in PC12 cells, and evaluated its underlying mechanism(s) of neuroprotection and anti-inflammation.Methods An OGD/R model of PC12 cells was established. PC12 cells were cultured in vitro and divided into control, OGD/R, and OGD/R + Dex (1, 10, 50 µM) groups. Cell apoptosis was analyzed by flow cytometry and gene expression profiles were determined by qRT-PCR, western blot analysis, and enzyme linked immunosorbent assays (ELISA). The interaction between miRNA and its downstream targets were evaluated through luciferase reporter assays.Results Dex significantly decreased the rates of apoptosis rates and inhibited IL-1β, IL-6 and TNF-α release (p < 0.05). The expression of the pro-apoptotic proteins Bax and Caspase-3 were down-regulated, whilst Bcl-2 was upregulated in a dose-dependent manner (p < 0.05). MiR-17-5p was down-regulated in the OGD/R group compared to controls. Toll-like receptor 4 (TLR4), a key regulator of nuclear factor kappa-B (NF-κB) signaling, was identified as a novel target of miR-17-5p in PC12 cells. The expression of miR-17-5p was upregulated in the OGD/R + Dex group which suppressed TLR4 expression and reduced the secretion of proinflammatory cytokines.Conclusion DEX inhibits OGD/R-induced inflammation and apoptosis in PC12 cells by increasing miR-17-5p expression, downregulating TLR4, and inhibiting NF-κB signaling.


1980 ◽  
Vol 44 (03) ◽  
pp. 130-134 ◽  
Author(s):  
E B Tsianos ◽  
N E Stathakis

SummaryThe presence of soluble fibrin complexes (SFC) measured by gel filtration of plasma on 4% agarose columns, fibrinogen heterogeneity on 3.5% SDS-polyacrylamide gels and the concentrations of several plasma proteins were evaluated in 39 patients with diabetes mellitus (DM) and 19 matched control subjects. A small but significant increase of SFC was found in DM (p<0.01). On individual basis 51.2% of the patients had increased SFC (>M + 2 SD of the controls). Polyacrylamide gel electrophoresis of the SFC showed no evidence of cross-linking or proteolysis. Plasma clots formed in the presence of EDTA and trasylol were analysed in SDS-polyacrylamide gels in a normal and two lower molecular weight fibrin bands (band I, II, III). The percentage of band I fibrinogen was in diabetics (65.3 ± 4.7%) lower than that of the controls (71.8 ± 4.5%) (p < 0.01). Fibrinogen levels, antithrombin III, α1-antitrypsin, α2-macroglobulin and plasminogen were significantly increased in DM. We suggest that in DM there is an enhancement of intravascular fibrin formation and accelerated fibrinogen degradation to lower molecular weight forms.


1981 ◽  
Vol 45 (01) ◽  
pp. 090-094 ◽  
Author(s):  
Katsuo Sueishi ◽  
Shigeru Nanno ◽  
Kenzo Tanaka

SummaryFibrinogen degradation products were investigated for leukocyte chemotactic activity and for enhancement of vascular permeability. Both activities increased progressively with plasmin digestion of fibrinogen. Active fragments were partially purified from 24 hr-plasmin digests. Molecular weights of the permeability increasing and chemotactic activity fractions were 25,000-15,000 and 25,000 respectively. Both fractions had much higher activities than the fragment X, Y, D or E. Electron microscopic observation of the small blood vessels in rabbit skin correlated increased permeability with the formation of characteristic gaps between adjoining endothelial cells and their contraction.These findings suggest that lower molecular weight degradation products of fibrinogen may be influential in contributing to granulocytic infiltration and enhanced permeability in lesions characterized by deposits of fibrin and/or fibrinogen.


2019 ◽  
Vol 25 (39) ◽  
pp. 5327-5346 ◽  
Author(s):  
Konstantin P. Volcho ◽  
Sergey S. Laev ◽  
Ghulam Md Ashraf ◽  
Gjumrakch Aliev ◽  
Nariman F. Salakhutdinov

Neurodegenerative disorders (NDDs) like Alzheimer's disease, Parkinson’s disease and Huntington’s disease are a heterogeneous group of disorders with the progressive and severe loss of neurons. There are no full proof cures for these diseases, and only medicines are available that can alleviate some of the symptoms. Developing effective treatments for the NDDs is a difficult but necessary task. Hence, the investigation of monoterpenoids which modulate targets applicable to many NDDs is highly relevant. Many monoterpenoids have demonstrated promising neuroprotective activity mediated by various systems. It can form the basis for elaboration of agents which will be useful both for the alleviation of symptoms of NDDs and for the treatment of diseases progression and also for prevention of neurodegeneration. The further developments including detections of monoterpenoids and their derivatives with high neuroprotective or neurotrophic activity as well as the results of qualified clinical trials are needed to draw solid conclusions regarding the efficacy of these agents.


2018 ◽  
Vol 21 (8) ◽  
pp. 571-582 ◽  
Author(s):  
Juxiang Liu ◽  
Lianli Zhang ◽  
Dan Liu ◽  
Baocai Li ◽  
Mi Zhang

Aim & Objectives: Curcuminoids are characteristic constituents in Curcuma, displaying obviously neuroprotective activities against oxidative stress. As one of the Traditional Chinese Medicines from Curcuma, the radix of Curcuma aromatica is also rich in those chemicals, but its neuroprotective activity and mechanism remain unknown. The aim of the current study is to evaluate the neuroprotective effects of extracts from the radix of C. aromatica (ECAs) on H2O2-damaged PC12 cells. Material and Methods: The model of oxidative stress damage was established by treatment of 400 µM H2O2 on PC12 to induce cell damage. After the treatment of ECWs for 24 h, the cell viability, LDH, SOD, CAT and GSH were measured to evaluate the neuroprotection of ECAs on that model. The potential action mechanism was studied by measurement of level of ROS, cell apoptosis rate, mitochondrial membrane potential (MMP), morphologic change, the intracellular Ca2+ content (F340/F380) and the expressions of Bcl-2, Bax and Caspase-3. Additionally, the constituents from tested extracts were analyzed by HPLC-DAD-Q-TOF-MS method. Results: Compared with a positive control, Vitamin E, 10 µg/ml of 95% EtOH extract (HCECA) and 75% EtOH extract (MCECA) can markedly increase the rate of cell survival and enhance the antioxidant enzyme activities of SOD, CAT, increase the levels of GSH, decrease LDH release and the level of ROS, attenuate the intracellular Ca2+ overloading, reduce the cell apoptotic rate and stabilize MMP, down-regulate Bcl-2 expression, up-regulate Bax and caspase-3 expression, and improve the change of cell morphology. The chemical analysis showed that diarylheptanoids and sesquiterpenoids are the major chemicals in tested extracts and the former were richer in HCECA and MCECA than others. Conclusions: These findings indicated that the effects of HCECA and MCECA on inhibiting the cells damage induced by H2O2 in PC12 are better than other extracts from the radix of C. aromatica, and the active constituents with neuroprotective effects consisting in those two active extracts are diarylheptanoids.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Yunkyoung Lee ◽  
Hee-Sook Jun ◽  
Yoon Sin Oh

The extract of Psoralea corylifolia seeds (PCE) has been widely used as a herbal medicine because of its beneficial effect on human health. In this study, we investigated the protective effects and molecular mechanisms of PCE on palmitate- (PA-) induced toxicity in PC12 cells, a neuron-like cell line. PCE significantly increased cell viability in PA-treated PC12 cells and showed antiapoptotic effects, as evidenced by decreased expression of cleaved caspase-3, cleaved poly(ADP-ribose) polymerase, and bax protein as well as increased expression of bcl-2 protein. In addition, PCE treatment reduced PA-induced reactive oxygen species production and upregulated mRNA levels of antioxidant genes such as nuclear factor (erythroid-derived 2)-like 2 and heme oxygenase 1. Moreover, PCE treatment recovered the expression of autophagy marker genes such as beclin-1 and p62, which was decreased by PA treatment. Treatment with isopsoralen, one of the major components of PCE extract, also recovered the expression of autophagy marker genes and reduced PA-induced apoptosis. In conclusion, PCE exerts protective effects against lipotoxicity via its antioxidant function, and this effect is mediated by activation of autophagy. PCE might be a potential pharmacological agent to protect against neuronal cell injury caused by oxidative stress or lipotoxicity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eui Jeong Han ◽  
Seo-Young Kim ◽  
Hee-Jin Han ◽  
Hyun-Soo Kim ◽  
Kil-Nam Kim ◽  
...  

AbstractThe present study aimed to evaluate the protective effect of a methanol extract of Sargassum horneri (SHM), which contains 6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one (HTT) and apo-9′-fucoxanthinone, against ultraviolet B (UVB)-induced cellular damage in human keratinocytes and its underlying mechanism. SHM significantly improved cell viability of UVB-exposed human keratinocytes by reducing the generation of intracellular reactive oxygen species (ROS). Moreover, SHM inhibited UVB exposure-induced apoptosis by reducing the formation of apoptotic bodies and the populations of the sub-G1 hypodiploid cells and the early apoptotic cells by modulating the expression of the anti- and pro-apoptotic molecules, Bcl-2 and Bax, respectively. Furthermore, SHM inhibited NF-κB p65 activation by inducing the activation of Nrf2/HO-1 signaling. The cytoprotective and antiapoptotic activities of SHM are abolished by the inhibition of HO-1 signaling. In further study, SHM restored the skin dryness and skin barrier disruption in UVB-exposed human keratinocytes. Based to these results, our study suggests that SHM protects the cells against UVB-induced cellular damages through the Nrf2/HO-1/NF-κB p65 signaling pathway and may be potentially useful for the prevention of UVB-induced skin damage.


Blood ◽  
1996 ◽  
Vol 88 (4) ◽  
pp. 1206-1214 ◽  
Author(s):  
RL Rosen ◽  
KD Winestock ◽  
G Chen ◽  
X Liu ◽  
L Hennighausen ◽  
...  

Granulocyte-macrophage colony-stimulating factor (GM-CSF) induces immediate effects in monocytes by activation of the Janus kinase (JAK2) and STAT transcription factor (STAT5) pathway. Recent studies have identified homologues of STAT5, STAT5A, and STAT5B, as well as lower molecular weight variants of STAT5. To define the activation of the STAT5 homologues and lower molecular weight variant in human monocytes and monocytes differentiated into macrophages by culture in macrophage- CSF (M-CSF), we measured the GM-CSF induced tyrosine phosphorylation of STAT5A, STAT5B, and any lower molecular weight STAT5 isoforms. Freshly isolated monocytes expressed 94-kD STAT5A, 92-kD STAT5B, and an 80-kD STAT5A molecule. Whereas 94-kD STAT5A was clearly tyrosine phosphorylated and bound to the enhancer element, the gamma response region (GRR), of the Fc gamma RI gene, substantially less tyrosine phosphorylated STAT5B bound to the immobilized GRR element. Macrophages lost their ability to express the 80-kD STAT5A protein, but retained their ability to activate STAT5A. STAT5A-STAT5A homodimers and STAT5A- STAT5B heterodimers formed in response to GM-CSF. Therefore, activation of STAT5A predominates compared to STAT5B when assayed by direct immunoprecipitation and by evaluation of bound STATs to immobilized GRR. Selective activation of STAT5 homologues in addition to generation of lower molecular isoforms may provide specificity and control to genes expressed in response to cytokines such as GM-CSF.


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