scholarly journals Erythrocytes of Little Ground Squirrels Undergo Reversible Oxidative Stress During Arousal From Hibernation

2021 ◽  
Vol 12 ◽  
Author(s):  
Nisred K. Klichkhanov ◽  
Elena R. Nikitina ◽  
Zainab M. Shihamirova ◽  
Maria D. Astaeva ◽  
Shamil I. Chalabov ◽  
...  

The hibernation of small mammals is characterized by long torpor bouts alternating with short periods of arousal. During arousal, due to a significant increase in oxygen consumption, tissue perfusion, and the launch of thermogenesis in cells, a large amount of reactive oxygen species (ROS) and nitrogen (RNS) can be formed, which can trigger oxidative stress in cells. To estimate this possibility, we studied the intensity of free-radical processes in the red blood cells (RBCs) of little ground squirrels (LGS; Spermophilus pygmaeus) in the dynamics of arousal from hibernation. We found that in the torpid state, the degree of generation of ROS and RNS (8.3%, p>0.09; 20.7%, p<0.001, respectively), the degree of oxidative modification of membrane lipids and RBC proteins is at a low level (47%, p<0.001; 82.7%, p<0.001, respectively) compared to the summer control. At the same time, the activity of superoxide dismutase (SOD) and catalase (CAT) in RBC is significantly reduced (32.8%, p<0.001; 22.2%, p<0.001, respectively), but not the level of glutathione (GSH). In the torpid state, SOD is activated by exogenous GSH in concentration-dependent manner, which indicates reversible enzyme inhibition. During the arousal of ground squirrels, when the body temperature reaches 25°C, RBCs are exposed oxidative stress. This is confirmed by the maximum increase in the level of uric acid (25.4%, p<0.001) in plasma, a marker of oxidative modification of lipids [thiobarbituric acid reactive substances (TBARS); 82%, p < 0.001] and proteins (carbonyl groups; 499%, p < 0.001) in RBC membranes, as well as the decrease in the level of GSH (19.7%, p < 0.001) in erythrocytes relative to the torpid state and activity of SOD and CAT in erythrocytes to values at the Tb 20°C. After full recovery of body temperature, the level of GSH increases, the ratio of SOD/CAT is restored, which significantly reduces the degree of oxidative damage of lipids and proteins of RBC membranes. Thus, the oxidative stress detected at Tb 25°C was transient and physiologically regulated.

2021 ◽  
Vol 12 ◽  
Author(s):  
Burong Feng ◽  
Xiuye Zhao ◽  
Wei Zhao ◽  
Huiwei Jiang ◽  
Zijing Ren ◽  
...  

Aloe-emodin widely possesses antibacterial, anti-inflammatory, antioxidant, antiviral, and anti-infectious properties. This study investigated the effect of ethyl 2-succinate-anthraquinone (Luhui derivative, LHD) on inflammation. In vitro, a THP-1 macrophage inflammation model, made by 100 ng/ml phorbol-12-myristate-13-acetate (PMA) and 1 μg/ml LPS for 24 h, was constructed. The LHD group (6.25 μmol/L, 12.5 μmol/L, 25 μmol/L, 50 μmol/L) had no effect on THP-1 cell activity, and the expression of IL-6 mRNA was down-regulated in a concentration-dependent manner, of which the 25 μmol/L group had the best inhibitory effect. The migration of THP-1 macrophages induced by LPS was decreased by the LHD. Moreover, the LHD suppressed ROS fluorescence expression by inhibiting MDA expression and increasing SOD activity. In vivo, we revealed that the LHD, in different doses (6.25 mg/kg, 12.5 mg/kg, 25 mg/kg, 50 mg/kg), has a protective effect on stress physiological responses by assessing the body temperature of mice. Interestingly, acute lung injury (e.g., the structure of the alveoli disappeared and capillaries in the alveolar wall were dilated and congested) and liver damage (e.g., hepatocyte swelling, neutrophil infiltration, and hepatocyte apoptosis) were obviously improved at the same condition. Furthermore, we initially confirmed that the LHD can down-regulate the expression of NLRP3, IL-1β, and caspase-1 proteins, thereby mediating the NLRP3 inflammasome signaling pathway to produce anti-inflammatory effects. In conclusion, our results indicate that the LHD exerts anti-inflammatory activity via regulating the NLRP3 signaling pathway, inhibition of oxidative stress, and THP-1 macrophage migration.


1998 ◽  
Vol 274 (1) ◽  
pp. C245-C252 ◽  
Author(s):  
Junsuke Igarashi ◽  
Masashi Nishida ◽  
Shiro Hoshida ◽  
Nobushige Yamashita ◽  
Hiroaki Kosaka ◽  
...  

The effects of nitric oxide (NO) produced by cardiac inducible NO synthase (iNOS) on myocardial injury after oxidative stress were examined. Interleukin-1β induced cultured rat neonatal cardiac myocytes to express iNOS. After induction of iNOS,l-arginine enhanced NO production in a concentration-dependent manner. Glutathione peroxidase (GPX) activity in myocytes was attenuated by elevated iNOS activity and by an NO donor, S-nitroso- N-acetyl-penicillamine (SNAP). Although NO production by iNOS did not induce myocardial injury, NO augmented release of lactate dehydrogenase from myocyte cultures after addition of H2O2(0.1 mM, 1 h). Inhibition of iNOS with Nω-nitro-l-arginine methyl ester ameliorated the effects of NO-enhancing treatments on myocardial injury and GPX activity. SNAP augmented the myocardial injury induced by H2O2. Inhibition of GPX activity with antisense oligodeoxyribonucleotide for GPX mRNA increased myocardial injury by H2O2. Results suggest that the induction of cardiac iNOS promotes myocardial injury due to oxidative stress via inactivation of the intrinsic antioxidant enzyme, GPX.


Endocrinology ◽  
2009 ◽  
Vol 150 (11) ◽  
pp. 5125-5134 ◽  
Author(s):  
Dan Gratschev ◽  
Christoffer Löf ◽  
Jari Heikkilä ◽  
Anders Björkbom ◽  
Pramod Sukumaran ◽  
...  

Calcium entry is one of the main regulators of intracellular signaling. Here, we have described the importance of sphingosine, sphingosine kinase 1 (SK1), and sphingosine 1-phosphate (S1P) in regulating calcium entry in thyroid FRTL-5 cells. In cells incubated with the phosphatase inhibitor calyculin A, which evokes calcium entry without mobilizing sequestered intracellular calcium, sphingosine inhibited calcium entry in a concentration-dependent manner. Furthermore, inhibiting SK1 or the ATP-binding cassette ABCC1 multidrug transporter attenuated calcium entry. The addition of exogenous S1P restored calcium entry. Neither sphingosine nor inhibition of SK1 attenuated thapsigargin-evoked calcium entry. Blocking S1P receptor 2 or phospholipase C attenuated calcium entry, whereas blocking S1P receptor 3 did not. Overexpression of wild-type SK1, but not SK2, enhanced calyculin-evoked calcium entry compared with mock-transfected cells, whereas calcium entry was decreased in cells transfected with the dominant-negative G82D SK1 mutant. Exogenous S1P restored calcium entry in G82D cells. Our results suggest that the calcium entry pathway is blocked by sphingosine and that activation of SK1 and the production of S1P, through an autocrine mechanism, facilitate calcium entry through activation of S1P receptor 2. This is a novel mechanism by which the sphingosine-S1P rheostat regulates cellular calcium homeostasis.


2019 ◽  
Vol 102 (4) ◽  
pp. 1228-1234 ◽  
Author(s):  
Raid Al Akeel ◽  
Ayesha Mateen ◽  
Rabbani Syed

Abstract Background: Alanine-rich proteins/peptides (ARP), with bioactivity of up to 20 amino acid residues, can be observed by the body easily during gastrointestinal digestion. Objective: Populus trichocarpa extract’s capability to attenuate quorum sensing-regulated virulence and biofilm formation in Staphylococcus aureus is described. Methods: PT13, an ARP obtained from P. trichocarpa, was tested for its activity against S. aureus using the broth microdilution test; a crystal-violet biofilm assay was performed under a scanning electron microscope. The production of various virulence factors was estimated with PT13 treatment. Microarray gene expression profiling of PT13-treated S. aureus was conducted and compared with an untreated control. Exopolysaccharides (EPS) was estimated to observe the PT13 inhibition activity. Results: PT13 was antimicrobial toward S. aureus at different concentrations and showed a similar growth rate in the presence and absence of PT13 at concentrations ≤8 μg/mL. Biofilm production was interrupted even at low concentrations, and biofilm-related genes were down-regulated when exposed to PT13. The genes encoding cell adhesion and bacterial attachment protein were the major genes suppressed by PT13. In addition, hemolysins, clumping activity, and EPS production of S. aureus decreased after treatment in a concentration-dependent manner. Conclusions: A long-chain PT13 with effective actions that, even at low concentration levels, not only regulated the gene expression in the producer organism but also blocked the virulence gene expression in this Gram-positive human pathogen is described. Highlights: We identified a PT13 as a potential antivirulence agent that regulated production of bacterial virulence determinants (e.g., toxins, enzymes and biofilm), downwards and it may be a promising anti-virulence agent to be further developed as an anti-infective agent.


2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Bhavna Vaid ◽  
Bhupinder Singh Chopra ◽  
Sachin Raut ◽  
Amin Sagar ◽  
Maulik D. Badmalia ◽  
...  

Delineation of factors which affect wound healing would be of immense value to enable on-time or early healing and reduce comorbidities associated with infections or biochemical stress like diabetes. Plasma gelsolin has been identified earlier to significantly enable injury recovery compared to placebo. This study evaluates the role of rhuGSN for its antioxidant and wound healing properties in murine fibroblasts (3T3-L1 cell line). Total antioxidant capacity of rhuGSN increased in a concentration-dependent manner (0.75-200 μg/mL). Cells pretreated with 0.375 and 0.75 μg/mL rhuGSN for 24 h exhibited a significant increase in viability in a MTT assay. Preincubation of cells with rhuGSN for 24 h followed by oxidative stress induced by exposure to H2O2 for 3 h showed cytoprotective effect. rhuGSN at 12.5 and 25 μg/mL concentration showed an enhanced cell migration after 20 h of injury in a scratch wound healing assay. The proinflammatory cytokine IL-6 levels were elevated in the culture supernatant. These results establish an effective role of rhuGSN against oxidative stress induced by H2O2 and in wound healing of 3T3-L1 fibroblast cells.


2020 ◽  
Vol 859 ◽  
pp. 132-138
Author(s):  
Nusara Piyapolrungroj ◽  
Panadda Phattanawasin ◽  
Uthai Sotanaphun ◽  
May Phyu Thein Maw

The oral delivery is the most practical route to deliver drugs into the body, however drug-metabolizing enzymes and drug transporters can play important roles in modulating drug absorption. This study intended to find a natural bioenhancer for improving drug bioavailability. Two limonoids, including limonin deepoxy and nomilin, isolated from pomelo pulp were studied and the inhibition effects on human CYP3A4 and P-gp were investigated. Testosterone 6β-hydroxylation was performed in recombinant human CYP3A4 to discover the effects on CYP activity. Daunorubicin transport in Caco-2 and calcein-AM uptake in LLC-PK1 and LLC-GA5-COL300 were conducted to evaluate the effects on P-gp function. The results show that both limonin deepoxy and nomilin could inhibit CYP3A4 and only nomilin exhibited mechanism-based inhibition. Nomilin was able to inhibit human P-gp in the concentration-dependent manner. Taken together, nomilin demonstrated strong activities on both CYP3A4 and P-gp, indicating that nomilin could possibly be used as a bioavailability enhancer.


Reproduction ◽  
2004 ◽  
Vol 127 (3) ◽  
pp. 397-406 ◽  
Author(s):  
B Safieh-Garabedian ◽  
G M Mouneimne ◽  
W El-Jouni ◽  
M Khattar ◽  
R Talhouk

The effect of endotoxin on mammary CID-9 cells, which differentiate in culture and express β-casein, was investigated. Cells in culture supplemented with lactogenic hormones and dripped with EMS-Matrix (EMS-drip), were treated daily with endotoxin (0.5–500 μg/ml). Endotoxin at concentrations of less or equal to 10 μg/ml did not affect cell growth and viability up to 5 days post endotoxin treatment. Endotoxin (0.01–10 μg/ml) was added to the culture medium, upon confluence, and functional parameters were examined within 48 h post endotoxin treatment. Nuclear factor-κB (NF-κB) (p52) increased in nuclear extracts from endotoxin-stimulated cells within 1 h of treatment, while β-casein mRNA and protein expression decreased in a concentration-dependent manner at 24 and 48 h post treatment. Zymography showed that the 72 and 92 kDa gelatinase activity increased in cells at 24 and 48 h post endotoxin treatment at 10 and 50 μg/ml. At the latter concentration, the active form of 72 kDa gelatinase was induced at 48 h. Interleukin-6 and tumor necrosis factor-α levels increased at 1–3 h post endotoxin treatment and peaked at 6 h in cells on plastic and EHS-drip. Nerve growth factor (NGF) levels increased in control and endotoxin-treated cells in a time-dependent manner, and endotoxin increased NGF levels in culture at 6 and 9 h post endotoxin treatment. This study shows that endotoxin activated NF-κB, suppressed β-casein expression and upregulated gelatinases, cytokines and NGF. This model could be used to investigate the role of mammary cells in initiating and propagating inflammation and to test candidate molecules for potential anti-inflammatory properties.


Blood ◽  
2003 ◽  
Vol 101 (2) ◽  
pp. 664-672 ◽  
Author(s):  
Markus Warmuth ◽  
Nicola Simon ◽  
Olga Mitina ◽  
Ruth Mathes ◽  
Doriano Fabbro ◽  
...  

The leukemogenic tyrosine kinase Bcr-Abl contains a highly conserved inhibitor-binding pocket (IBP), which serves as a binding site for imatinib mesylate. Mutations at the IBP may lead to resistance of the Abl kinase against imatinib mesylate. To examine the mechanisms of imatinib mesylate binding and resistance in more detail, we created several point mutations at amino acid positions 315 and 380 of Abl, blocking the access to the IBP and rendering Bcr-Abl imatinib mesylate–resistant. Moreover, introduction of a mutation destabilizing the inactive conformation of Abl (Asp276Ser/Glu279Ser) also led to imatinib mesylate resistance, suggesting that the inhibitor required inactivation of the kinase prior to binding. These Bcr-Abl mutants were then used to evaluate the binding mode and specificity of 2 compounds, PP1 and CGP76030, originally characterized as Src kinase inhibitors. Both compounds inhibited Bcr-Abl in a concentration-dependent manner by overlapping binding modes. However, in contrast to imatinib mesylate, PP1 and CGP76030 blocked cell growth and survival in cells expressing various inhibitor-resistant Abl mutants. Studies on the potential signaling mechanisms demonstrated that in cells expressing inhibitor-resistant Bcr-Abl mutants, PP1 and CGP76030 inhibited the activity of Src family tyrosine kinases and Akt but not signal transducer and activator of transcription–5 (STAT5) and JUN kinase (Jnk). The results suggest that the use of Src kinase inhibitors is a potential strategy to prevent or overcome clonal evolution of imatinib mesylate resistance in Bcr-Abl+ leukemia.


2013 ◽  
Vol 33 (5) ◽  
Author(s):  
Rajesh Bhardwaj ◽  
Hans-Michael Müller ◽  
Walter Nickel ◽  
Matthias Seedorf

Ca2+ (calcium) homoeostasis and signalling rely on physical contacts between Ca2+ sensors in the ER (endoplasmic reticulum) and Ca2+ channels in the PM (plasma membrane). STIM1 (stromal interaction molecule 1) and STIM2 Ca2+ sensors oligomerize upon Ca2+ depletion in the ER lumen, contact phosphoinositides at the PM via their cytosolic lysine (K)-rich domains, and activate Ca2+ channels. Differential sensitivities of STIM1 and STIM2 towards ER luminal Ca2+ have been studied but responses towards elevated cytosolic Ca2+ concentration and the mechanism of lipid binding remain unclear. We found that tetramerization of the STIM1 K-rich domain is necessary for efficient binding to PI(4,5)P2-containing PM-like liposomes consistent with an oligomerization-driven STIM1 activation. In contrast, dimerization of STIM2 K-rich domain was sufficient for lipid binding. Furthermore, the K-rich domain of STIM2, but not of STIM1, forms an amphipathic α-helix. These distinct features of the STIM2 K-rich domain cause an increased affinity for PI(4,5)P2, consistent with the lower activation threshold of STIM2 and a function as regulator of basal Ca2+ levels. Concomitant with higher affinity for PM lipids, binding of CaM (calmodulin) inhibited the interaction of the STIM2 K-rich domain with liposomes in a Ca2+ and PI(4,5)P2 concentration-dependent manner. Therefore we suggest that elevated cytosolic Ca2+ concentration down-regulates STIM2-mediated ER–PM contacts via CaM binding.


2021 ◽  
Vol 58 (2) ◽  
Author(s):  
Chinyere Aloke ◽  
Emmanuel Igwe ◽  
Nwogo Obasi ◽  
Pascal Amu ◽  
Egwu Ogbonnia

Accumulating evidences have reinforced the use of medicinal plants in the treatment of various ailments as a result of negative side effects associated with conventional drugs. Plant components such as phenols and flavonoids with antioxidant potential have confirmed protective roles against oxidative stress-induced degenerative diseases like diabetes mellitus (DM). The current study was carried out to investigate the effect of seed pod ethanol extract from Copaifera salikounda (SPEECS) in alloxan-induced diabetic rats. SPEECS was obtained by maceration of seed pod powder in absolute ethanol for 72 h, filtered, concentrated and dried in-vacuo. Gas chromatography-mass spectrometry (GC–MS) technique was used to quantitatively elucidate the chemical constituents of SPEECS. Twenty-four male albino rats were randomly allocated into four groups (n=6): normal control, DM control, DM + 200 mg/kg SPEECS and DM + 400 mg/kg SPEECS groups. DM was induced in the Wistar albino rats through intraperitoneal injection of 200 mg/kg body weight of alloxan. After 14 days of treatment, the body weight changes and the fasting blood glucose level were determined in the different groups. Also, serum biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), albumin (ALB), total protein (TP), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were estimated. The GC-MS results confirm nine bioactive compounds with 9-octadecenoic acid (55.75%) being most abundant. SPEECS (200 and 400 mg/kg) administration significantly (P 0.05) caused gain in weight, decreased fasting blood glucose and reversed the elevated liver function enzymes (ALT, AST, ALP) while total TP and ALB were markedly elevated relative to DM control group. Furthermore, SPEECS attenuated the activities of SOD and CAT while the level of MDA was significantly (P 0.05) decreased in dose dependent manner in comparison to the DM control. This study indicated that SPEECS can alleviate hyperglyceamia of DM. Key words: Copaifera salikounda; oxidative stress; medicinal plants; diabetes mellitus; phytochemicals; orthodox ANTIDIABETIČNI UČINEK EKSTRAKTA ETANOLA Copaifera salikounda (HECKEL) NA SLADKORNO BOLEZEN, SPROŽENO Z ALLOXAN-om, PRI PODGANAHIzvleček: Obstaja vedno več dokazov, ki poudarjajo uporabnost zdravilnih rastlin pri zdravljenju različnih bolezni, tudi zaradi različnih negativnih stranskih učinkov, povezanih s konvencionalnimi zdravili. Rastlinske sestavine kot so fenoli in flavonoidi z antioksidativnim potencialom, imajo po nekaterih raziskavah zaščitno vlogo pred degenerativnimi boleznimi, ki jih povzroča oksidativni stres, kot je sladkorna bolezen diabetes mellitus (DM). Študija je bila izvedena z namenom raziskovanja učinka etanolnega semenskega ekstrakta iz rastline Copaifera salikounda (SPEECS) pri podganah s sladkorno boleznijo, ki jo je povzročil alloxan. SPEECS je bil pridobljen z maceracijo praška semen v prahu v absolutnem etanolu 72 ur ter nadaljnjo filtracijo, koncentracijo in sušenjem v vakuumu. Za kvantitativno ugotavljanje kemijskih sestavin SPEECS je bila uporabljena tehnika plinske kromatografije in masne spektrometrije (GC-MS). Štiriindvajset samcev podgan Wistar je bilo naključno razporejenih v štiri skupine (n=6): normalna kontrola, kontrola DM, DM + 200 mg/kg SPEECS in DM + 400 mg/kg SPEECS. DM je bil pri podganah sprožen z intraperitonealno injekcijo 200 mg/kg telesne mase alloxana. Po 14 dneh zdravljenja so bile pri različnih skupinah določene spremembe telesne teže in nivo glukoze v krvi (na tešče). Poleg tega so avtorji raziskave izmerili še nekatere serumske biokemične parametre kot so ravni alaninske aminotransferaze (ALT), aspartatne aminotransferaze (AST), alkalne fosfataze (ALP), albumina (ALB), skupnih proteinov (TP), malondialdehida (MDA), superoksiddismutaze (SOD) in katalaze (CAT). Rezultati GC-MS so v izvlečku SPEECS pokazali devet bioaktivnih spojin, v katerih je največ 9-oktadecenojske kisline (55,75%). SPEECS (200 in 400 mg/kg) je povzročil znatno (P 0,05) povečanje telesne mase, znižanje glukoze v krvi na tešče in znižal raven encimov pokazateljev jetrne funkcije (ALT, AST, ALP), medtem ko je bila raven TP in ALB pri podganah, ki so prejemale SPEECS izrazito povišana v primerjavi z DM kontrolno skupino. Zdravljenje s  SPEECS je tudi oslabilo aktivnosti SOD in CAT, medtem ko se je raven MDA znatno zmanjšala (P 0,05) v primerjavi s kontrolno skupino DM. Ta študija je pokazala, da lahko SPEECS ublaži hiperglikemijo pri sladkorni bolezni pri podganah.Ključne besede: Copaifera salikounda; oksidativni stres; zdravilne rastline; sladkorna bolezen; fitokemikalije; ortodoksni


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