Decreased Lactate Dehydrogenase Research Articles

Zonation of Ca2+ transport and enzyme activity in the caeca of rainbow trout - a simple structure with complex functions.

Trout caeca are vermiform structures projecting from the anterior intestine of the gastrointestinal tract. Despite their simple gross morphology, these appendages are physically distinct along the anterior-posterior axis, and ultrastructural evidence suggests zonation of function within the structures. Individual caeca from three sections (anterior, middle and posterior) were removed from the intestine of freshwater rainbow trout and investigated for ion transport and enzyme activity. Ca2+ absorption appeared as a combination of active and passive movement, with Michaelis-Menten kinetics observable under symmetrical conditions, and was inhibited by several pharmacological agents (ouabain, La3+ and a calmodulin antagonist). There was a decrease in ion transport function from adjacent to the intestine (proximal) to the distal tip of each caecum, along with decreasing transport from anterior to posterior for the proximal portion alone. Feeding increased the JMax and KM for Ca2+ absorption within all sections, whereas ion-poor water (IPW) exposure further increased the JMax and KM for Ca2+ transport in the anterior and middle sections. Increased Na+/K+-ATPase (NKA) and citrate synthase (CS) activity rates paralleled trends seen in Ca2+ transport. Feeding in freshwater and IPW exposure increased the glycolytic capacity of the caeca via increased pyruvate kinase (PK) and decreased lactate dehydrogenase (LDH) activity, while amino acid metabolism increased with IPW exposure through increased glutamate dehydrogenase (GDH) activity. Overall, feeding and IPW exposure each altered ionoregulation within the caeca of freshwater rainbow trout in a zone-specific pattern, with the anterior and proximal portions of the caeca being most affected. Increased carbohydrate and protein metabolism fueled the increased ATP demand of NKA through CS.

Ferulic acid regulates muscle fiber type formation through the Sirt1/AMPK signaling pathway.

Ferulic acid (FA) is a polyphenolic compound of plant cell walls. Several recent studies demonstrated that polyphenolic compounds could regulate muscle fiber type formation. In this study, we investigated the effect of FA on muscle fiber type formation and also explored its molecular mechanism in mouse C2C12 myotubes. Real-time quantitative PCR showed that FA significantly increased the mRNA abundances of myosin heavy chain (MyHC) I, MyHC IIa, sirtuin1 (Sirt1), peroxisome proliferator-activated receptor gamma coactivator-1-α (PGC-1α) and myocyte enhancer factor 2C (MEF2C), but decreased the mRNA abundance of MyHC IIb. FA increased succinate dehydrogenase (SDH) activity and decreased lactate dehydrogenase (LDH) activity. Western blot analysis showed that FA significantly increased the protein level of slow-MyHC, but significantly decreased the protein level of fast-MyHC, which were attenuated by AMP-activated protein kinase (AMPK) inhibitor Compound C, AMPKα2 siRNA or Sirt1 inhibitor EX527. We also showed that EX527 attenuated FA-induced increase in the phosphorylation levels of AMPK and liver kinase B1 (LKB1), indicating that AMPK serves as a downstream target of Sirt1. Our present study provides the first in vitro evidence that FA regulates muscle fiber type formation via the Sirt1/AMPK signal pathway.

Amnion-derived mesenchymal stem cells improve viability of endothelial cells exposed to shear stress in ePTFE grafts.

Blood vessel reconstruction is an increasing need of patients suffering from cardiovascular diseases. For the development of microvascular prostheses, efficient endothelialization is mandatory to prevent graft occlusion. Here, we assessed the impact of amnion-derived mesenchymal stem/stromal cells (hAMSC), known for their important angiogenic potential, on the integrity and stability of endothelial cells exposed to shear stress in vascular grafts. Human placental endothelial cells (hPEC) were cultured at the inner surface of an expanded polytetrafluoroethylene (ePTFE) graft positioned within a bioreactor and exposed to a minimal shear stress of 0.015 dyne/cm2 or a physiological shear stress of 0.92 dyne/cm2. hAMSC attached to the outer graft surface were able to interact with human placental endothelial cells by paracrine factors. Microscopical analysis and evaluation of glucose/lactate metabolism evidenced successful cell seeding of the graft: hPEC formed a stable monolayer, hAMSC showed a continuous growth during 72 h incubation. hAMSC improved the viability of hPEC exposed to 0.015 dyne/cm2 as shown by a decreased lactate dehydrogenase release of 13% after 72 h compared to hPEC single culture. The viability-enhancing effect of hAMSC on hPEC was further improved by 13% under physiological shear stress. Angiogenesis array analysis revealed that hPEC exposed to physiological shear stress and hAMSC co-culture reduced the secretion of angiogenin, GRO, MCP-1, and TIMP-2. hAMSC exerted best survival-enhancing effects on hPEC under exposure to physiological shear stress and modulated endothelial function by paracrine factors. Our data support further studies on the development of grafts functionalized with hAMSC-derived secretomes to enable fast clinical application.

Human leukemia cells (HL-60) proteomic and biological signatures underpinning cryo-damage are differentially modulated by novel cryo-additives.

BackgroundCryopreservation is a routinely used methodology for prolonged storage of viable cells. The use of cryo-protective agents (CPAs) such as dimethylsulfoxide (DMSO), glycerol, or trehalose is paramount to reducing cellular cryo-injury, but their effectiveness is still limited. The current study focuses on establishing and modulating the proteomic and the corresponding biological profiles associated with the cryo-injury of human leukemia (HL-60) cells cryopreserved in DMSO alone or DMSO +/- novel CPAs (e.g., nigerose [Nig] or salidroside [Sal]).FindingsTo reduce cryo-damage, HL-60 cells were cultured prior and post cryopreservation in malondialdehyde Roswell Park Memorial Institute medium-1640 media +/- Nig or Sal. Shotgun proteomic analysis showed significant alterations in the levels of proteins in cells cryopreserved in Nig or Sal compared to DMSO. Nig mostly affected cellular metabolism and energy pathways, whereas Sal increased the levels of proteins associated with DNA repair/duplication, RNA transcription, and cell proliferation. Validation testing showed that the proteome profile associated with Sal was correlated with a 2.8-fold increase in cell proliferative rate. At the functional level, both Nig and Sal increased glutathione reductase (0.0012±6.19E-05 and 0.0016±3.04E-05 mU/mL, respectively) compared to DMSO controls (0.0003±3.7E-05 mU/mL) and reduced cytotoxicity by decreasing lactate dehydrogenase activities (from -2.5 to -4.75 fold) and lipid oxidation (-1.6 fold). In contrast, only Nig attenuated protein carbonylation or oxidation.ConclusionsWe have identified key molecules and corresponding functional pathways underpinning the effect of cryopreservation (+/- CPAs) of HL-60 cells. We also validated the proteomic findings by identifying the corresponding biological profiles associated with promoting an anti-oxidative environment post cryopreservation. Nig or Sal in comparison to DMSO showed differential or additive effects in regard to reducing cryo-injury and enhancing cell survival/proliferation post thaw. These results can provide useful insight to cryo-damage and the design of enhanced cryomedia formulation.

Matrine Protects Cardiomyocytes From Ischemia/Reperfusion Injury by Regulating HSP70 Expression Via Activation of the JAK2/STAT3 Pathway.

Studies have shown that matrine showed cardiovascular protective effects; however, its role and mechanism in myocardial ischemia/reperfusion (I/R) injury remain unknown. The Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway activation and elevated heat shock protein (HSP) 70 are closely related to the prevention of myocardial I/R injury. The cardioprotective effects of matrine were determined in hypoxia/reoxygenation (H/R)-treated primary rat cardiomyocytes and left anterior descending coronary artery ligation and reperfusion animal models. The molecular mechanisms of matrine in myocardial I/R injury were focused on JAK2/STAT3 pathway activation and HSP70 expression. We found that matrine significantly increased H/R-induced the suppression of cell viability, decreased lactate dehydrogenase release, creatine kinase activity, and cardiomyocytes apoptosis in vitro. Moreover, matrine notably reduced the serum levels of creatine kinase-myocardial band (CK-MB) and cardiac troponin I, lessened the infarcted area of the heart, and decreased the apoptotic index of cardiomyocytes induced by I/R in vivo. Matrine activated the JAK2/STAT3 signaling, upregulated HSP70 expression both in vitro and in vivo. The cardioprotective effects of matrine were abrogated by AG490, a JAK2 inhibitor, and HSP70 siRNA. In addition, AG490 reduced HSP70 expression increased by matrine. In conclusion, matrine attenuates myocardial I/R injury by upregulating HSP70 expression via the activation of the JAK2/STAT3 pathway.

Oxymatrine attenuates amyloid beta 42 (Aβ1-42)-induced neurotoxicity in primary neuronal cells and memory impairment in rats.

Amyloid beta 42 (Aβ1-42)-induced oxidative stress causes the death of neuronal cells and is involved in the development of Alzheimer's disease. Oxymatrine (OMT) inhibits oxidative stress. In this study, we investigated the effect of OMT on Aβ1-42-induced neurotoxicity in vivo and in vitro. In the Morris water maze test, OMT significantly decreased escape latency and increased the number of platform crossings. In vitro, OMT markedly increased cell viability and superoxide dismutase activity. Moreover, OMT decreased lactate dehydrogenase leakage, malondialdehyde content, and reactive oxygen species in a dose-dependent manner. OMT upregulated the ratio of Bcl-2/Bax and downregulated the level of caspase-3. Furthermore, OMT inhibited the activation of MAP kinase (ERK 1/2, JNK) and nuclear factor κB. In summary, OMT may potentially be used in the treatment of Alzheimer's disease.

Humanin Attenuates NMDA-Induced Excitotoxicity by Inhibiting ROS-dependent JNK/p38 MAPK Pathway.

Humanin (HN) is a novel 24-amino acid peptide that protects neurons against N-methyl-d-aspartate (NMDA)-induced toxicity. However, the contribution of the different mitogen-activated protein kinases (MAPKs) signals to HN neuroprotection against NMDA neurotoxicity remains unclear. The present study was therefore aimed to investigate neuroprotective mechanisms of HN. We analyzed intracellular Ca2+ levels, reactive oxygen species (ROS) production, and the MAPKs signal transduction cascade using an in vitro NMDA-mediated excitotoxicity of cortical neurons model. Results showed that: (1) HN attenuated NMDA-induced neuronal insults by increasing cell viability, decreasing lactate dehydrogenase (LDH) release, and increasing cell survival; (2) HN reversed NMDA-induced increase in intracellular calcium; (3) pretreatment by HN or 1,2-bis(2-aminophenoxy)ethane-N,N,N’,N’-tetraacetic acid (BAPTA-AM), an intracellular calcium chelator, decreased ROS generation after NMDA exposure; (4) administration of HN or N-Acetyl-l-cysteine (NAC), a ROS scavenger, inhibited NMDA-induced JNK and p38 MAPK activation. These results indicated that HN reduced intracellular elevation of Ca2+ levels, which, in turn, inhibited ROS generation and subsequent JNK and p38 MAPK activation that are involved in promoting cell survival in NMDA-induced excitotoxicity. Therefore, the present study suggests that inhibition of ROS-dependent JNK/p38 MAPK signaling pathway serves an effective strategy for HN neuroprotection against certain neurological diseases.

Betulinic acid alleviates myocardial hypoxia/reoxygenation injury via inducing Nrf2/HO-1 and inhibiting p38 and JNK pathways

Myocardial ischemia reperfusion injury (I/RI) can lead to acute myocardial infarction (MI), which is a common cardiovascular disease (CVD) leading to morbidity and mortality worldwide. Betulinic acid exerts protective effect on myocardial I/RI in rats; however, the mechanism remains unknown. The aim of the current study was to evaluate the effect of betulinic acid on myocardial I/RI in vitro and further investigate the underlying mechanism. Our results showed that betulinic acid increased cell viability and decreased lactate dehydrogenase (LDH) release in H9c2 cells exposed to H/R. Betulinic acid was found to suppress the production of oxidative stress markers in H/R-induced H9c2 cells. The H/R-mediated changes in caspase-3 activity and expressions of Bax and Bcl-2 were restored by betulinic acid treatment. Besides, betulinic acid enhanced the activation of Nrf2/HO-1 pathway, and inhibited the activation of p38 and JNK pathways in H/R-induced H9c2 cells. Moreover, treatment with Nrf2 specific siRNA or the specific inhibitors of p38 and JNK attenuated the protective effects of betulinic acid on H9c2 cells. The results denoted that betulinic acid protects the H9c2 cells from I/RI by inhibiting oxidative stress and cell apoptosis. The cardio-protective effects were mediated by the Nrf2/HO-1, p38 and JNK pathways.

Neuroprotective Effects of DTIO, A Novel Analog of Nec-1, in Acute and Chronic Stages After Ischemic Stroke

Receptor-interacting protein 1 kinase (RIP1K) plays a key role in necroptosis. Necrostatin-1 (Nec-1), a specific inhibitor of RIP1K, provides neuroprotection against ischemic brain injury, associating with inhibition of inflammation. Recently, our group synthesized a novel analog of Nec-1, 5-(3′,5′-dimethoxybenzal)-2-thio-imidazole-4-ketone (DTIO). The present study investigated the effect of DTIO on ischemic stroke-induced brain injury in both acute and chronic phase and its underlying mechanism. In vivo, DTIO treatment reduced infarct volume and improved neurological deficits in the acute phase after permanent middle cerebral artery occlusion (pMCAO) and it also attenuated brain atrophy and promoted brain functional recovery in the chronic phase post-cerebral ischemia/reperfusion (I/R). In vitro, DTIO treatment decreased lactate dehydrogenase (LDH) leakage and necrotic cell death in the oxygen and glucose deprivation (OGD) or oxygen and glucose deprivation and reoxygenation (OGD/R)-induced neuronal or astrocytic cell injury. Simultaneously, DTIO suppressed the production and release of inflammatory cytokines, and reduced the formation of glial scar. Homology modeling analysis illustrated that DTIO had an ability of binding to RIP1K. Furthermore, immunoprecipitation analysis showed that DTIO inhibited the phosphorylation of RIP1K and decreased the interaction between the RIP1K and RIP3K. In addition, knockdown of RIP1K had neuroprotective effects and inhibited the release of proinflammatory cytokines, but didn’t have a significant effect on DTIO-mediated neuroprotection. In conclusion, DTIO has protective effects on acute ischemic stroke and promotes functional recovery during chronic phase, associating with protecting ischemic neurons and astrocytes, inhibiting inflammation, and lessening the glial scar formation via inhibiting of the RIP1K.

Nicotinamide reverses behavioral impairments and provides neuroprotection in 3-nitropropionic acid induced animal model ofHuntington's disease: implication of oxidative stress- poly(ADP- ribose) polymerase pathway.

Huntington's disease (HD) is characterized by cognitive and psychiatric impairment caused by neuronal degeneration in the brain. Several studies have supported the hypothesis that oxidative stress is the main pathogenic factor in HD. The current study aims to determine the possible neuroprotective effects of nicotinamide on 3-nitropropionic acid (3-NP) induced HD. Male Wistar albino rats were divided into six groups. Group I was the vehicle-treated control, group II received 3-NP (20mg/kg, intraperitoneally (i.p.) for 4days, group III received nicotinamide (500mg/kg, i.p.). The remaining groups received a combination of 3-NP plus nicotinamide 100, 300 or 500mg/kg, i.p. respectively for 8days. Afterward, the motor function and hind paw activity in the limb withdrawal were tested; rats were then euthanized for biochemical and histopathological analyses. Treatment of rats with 3-NP altered the motor function, elevated oxidative stress and caused significant histopathological changes in the brain. The treatment of rats with nicotinamide (100, 300 and 500mg/kg) improved the motor function tested by locomotor activity test, movement analysis, and limb withdrawal test, which was associated with decreased oxidative stress markers (malondialdehyde, nitrites) and increased antioxidant enzyme (glutathione) levels. In addition, nicotinamide treatment decreased lactate dehydrogenase and prevented neuronal death in the striatal region. Our study, therefore, concludes that antioxidant drugs like nicotinamide might slow progression of clinical HD and may improve the motor functions in HD patients. To the best of our knowledge, this study is the first to explore the neuroprotective effects of nicotinamide on 3-NP-induced HD.

Glycine Protects the Liver from Reperfusion Injury following Pneumoperitoneum

Background: Experimental pneumoperitoneum induces ischemia/reperfusion injury (IRI) in the liver, most likely via Kupffer cell (KC)-dependent mechanisms. Glycine has been shown to ameliorate IRI in various animal models. Thus, this study was performed to assess the effects of glycine on the liver after pneumoperitoneum. Materials and Methods: Sprague-Dawley rats (220–250 g in weight) underwent CO₂ pneumoperitoneum (12 mm Hg) for 90 min. Some rats received i.v. glycine (1.5 mL, 300 mM) 10 min before pneumoperitoneum. Controls were given the same volume of Ringer’s solution. Transaminases, hepatic microcirculation, and phagocytosis of latex beads indexing both liver injury and KC activation were examined following pneumoperitoneum. Analysis of variance (ANOVA), plus a subsequent t test or χ² test (or Fisher’s exact test) were carried out as appropriate. Results are presented as mean ± SEM. Results: Glycine significantly decreased lactate dehydrogenase at 1 h and both aspartate aminotransferase and alanine aminotransferase at 2 h after pneumoperitoneum from 477 ± 43, 154 ± 17, and 60 ± 6 U/L in controls to 348 ± 25, 101 ± 11, and 34 ± 3 U/L, respectively (p < 0.05). In parallel, glycine significantly decreased both the rate of permanent adherence of leukocytes to the endothelium by up to 35% and the rate of phagocytosis by > 50% compared to the control group. Conclusion: Glycine decreased IRI after pneumoperitoneum, most likely via KC-dependent mechanisms.

Therapeutic effects of probiotics on neurotoxicity induced by clindamycin and propionic acid in juvenile hamsters.

The present study investigated the therapeutic effects of probiotics on brain intoxication induced by clindamycin and propionic acid (PPA) in hamsters. Fifty golden Syrian hamsters were randomly divided into five experimental groups of ten animals each: (A) control group receiving phosphate buffered saline; (B) oral buffered PPA-treated group being administered with a neurotoxic dose of 250mg/kg PPA during three days; (C) oral clindamycin-treated group receiving a single dose of 30mg clindamycin/kg; and (D, E) the two therapeutic groups being administered the same doses of clindamycin and PPA followed by probiotics for three weeks at a daily dose of 0.2g/kg. Biochemical parameters of energy metabolism and oxidative stress were examined in brain homogenates from all hamsters. The development of pathogenic bacteria was monitored on stool samples from all hamsters. Descriptive changes in fecal microbiota and overgrowth of Clostridium species in clindamycin and PPA treated hamsters were recorded. Interestingly, probiotics were shown effective to restore normal gut microbiota. Clindamycin and PPA treatments caused an elevation in lipid peroxidation and catalase activity, as oxidative stress markers, together with a reduction in GST activity and GSH level. Energy metabolism impairment was ascertained via the activation of creatine kinase and a decrease of lactate dehydrogenase. These findings suggest that bacteria overgrowth caused by PPA and clindamycin was efficient to illustrate signs of neuronal toxicity. The present study indicates that probiotic treatment can improve poor detoxification, oxidative stress, and altered gut microbiota as mechanisms implicated in the etiology of many neurological disorders.

Reversal of behavioral decline and neuropathology by a complex vitamin supplement involves modulation of key neurochemical stressors

Metal ions are crucial for normal neurochemical signaling and perturbations in their homeostasis have been associated with neurodegenerative processes. Hypothesizing that in vivo modulation of key neurochemical processes including metal ion regulation (by transferrin receptor-1: TfR-1) in cells can improve disease outcome, we investigated the efficacy of a complex vitamin supplement (CVS) containing B-vitamins and ascorbic acid in preventing/reversing behavioral decline and neuropathology in rats. Wistar rats (eight weeks-old) were assigned into five groups (n = 8), including controls and those administered CVS (400 mg/kg/day) for two weeks before or after AlCl3 (100 mg/kg)-induced neurotoxicity. Following behavioral assessments, prefrontal cortex (PFC) and hippocampus were prepared for biochemical analyses, histology and histochemistry. CVS significantly reversed reduction of exploratory/working memory, frontal-dependent motor deficits, cognitive decline, memory dysfunction and anxiety. These correlated with CVS-dependent modulation of TfP-1 expression that were accompanied by significant reversal of neural oxidative stress in expressed superoxide dismutase, nitric oxide, catalase, glutathione peroxidase and malondialdehyde. Furthermore, CVS inhibited neural bioenergetics dysfunction, with increased labelling of glucokinase within PFC and hippocampus correlating with increased glucose-6-phosphate dehydrogenase and decreased lactate dehydrogenase expressions. These relates to inhibition of over-expressed acetylcholinesterase and increased total protein synthesis. Histological and Nissl staining of thin sections corroborated roles of CVS in reversing AlCl3-induced neuropathology. Summarily, we showed the role of CVS in normalizing important neurochemical molecules linking concurrent progression of oxidative stress, bioenergetics deficits, synaptic dysfunction and cellular hypertrophy during neurodegeneration.

Adiponectin Attenuates Oxygen–Glucose Deprivation-Induced Mitochondrial Oxidative Injury and Apoptosis in Hippocampal HT22 Cells via the JAK2/STAT3 Pathway

Ischemic stroke is among the leading causes of morbidity and mortality worldwide. Improving the tolerance of neurons to ischemia and reperfusion injury could be a feasible strategy against ischemia. Adiponectin (APN) is a major adipokine that regulates glucose and lipid metabolism and plays an important role in the protection of the cerebral nervous system. We aimed to investigate the effects of APN on oxygen and glucose deprivation (OGD)-induced neuronal injury in hippocampal neuronal HT22 cells. APN displayed neuroprotective effects against OGD, evidenced by increased cell viability and decreased lactate dehydrogenase release and apoptotic rate. Additionally, APN also maintained mitochondrial ultrastructure and transmembrane potential, attenuated reactive oxygen species and malondialdehyde, and increased superoxide dismutase and glutathione peroxidase activity. Moreover, APN promoted Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) phosphorylation, enhanced STAT3 nuclear translocation, increased the Bcl-2/Bax ratio, and decreased cleaved caspase-3. The aforementioned APN-induced effects were almost reversed by a JAK2 inhibitor, AG490. APN may attenuate OGD-induced hippocampal HT22 neuronal impairment by protecting cells against mitochondrial oxidative stress and apoptosis, mediated by JAK2/STAT3 signaling.

Esculetin inhibits oxidative stress and apoptosis in H9c2 cardiomyocytes following hypoxia/reoxygenation injury

Esculetin (6,7-dihydroxycoumarin), a natural coumarin compound extracted from natural plants, was reported to be involved in ischemia/reperfusion (I/R) injury. However, the role of esculetin in myocardial I/R injury remains unclear. This study was designed to investigate the protective effects of esculetin on cardiomyocytes induced by hypoxia/reoxygenation (H/R), and explore the underlying mechanisms. Our results showed that esculetin improved the cell viability and decreased lactate dehydrogenase (LDH) release in H/R-stimulated H9c2 cells. In addition, esculetin significantly suppressed oxidative stress and apoptosis in H9c2 cells exposed to H/R treatment. Exploration of the underlying mechanisms of its action indicated that esculetin enhanced the activation of JAK2/STAT3 pathway in H/R-stimulated H9c2 cells. Taken together, these findings indicated that esculetin inhibits oxidative stress and apoptosis in H9c2 cardiomyocytes following H/R injury through the activation of JAK2/STAT3 pathway.

Telmisartan attenuates hydrogen peroxide-induced apoptosis in differentiated PC12 cells.

The present study investigated the protective actions of telmisartan, an angiotensin II type 1 receptor blocker (ARBs), against the cell apoptosis induced by exposure to hydrogen peroxide (H2O2) in differentiated PC12 cells. Preincubation of PC12 cells with telmisartan prevented H2O2-induced cytotoxicity as indicated by increased MTT (3,(4,5-dimethylthiazole-2-yl)2,5-diphenyl-tetrazolium bromide) reduction, decreased lactate dehydrogenase (LDH) release, and improved morphological changes. Hoechst 33,258 staining showed that telmisartan markedly reduced shrunken nuclei of the cells, and Western blot analysis indicated that telmisartan significantly attenuated caspase-3 activity, as indicated by decreased ratio of cleaved Caspase-3 to its precursor and increased ratio of Bcl-2/Bax. The present findings showed that telmisartan protected against cellular oxidative damages by inhibiting apoptotic response.

The iron pro-chelator BHAPI attenuates glutamate-induced oxidative stress via Wnt-β/catenin pathway in HT22 cells

Disturbances in intracellular iron homeostasis are associated with brain damage under various neuropathological conditions. However, exposure of neuronal cells to classical iron chelators could interfere with physiological iron functions in the brain. Thus, iron pro-chelators represent a more advanced approach to exert strong free-iron binding capacity only under oxidative stress conditions. In the present study, we investigated the protective effects of an iron pro-chelator BHAPI [(E)-N’-(1-(2-((4- (4,4,5,5-tetramethyl-1,2,3-dioxoborolan-2-yl)benzyl)oxy)phenyl)ethylidene) isonicotino hydrazide] against glutamate-induced toxicity in neuronal HT22 cells. The results showed that BHAPI significantly increased cell viability, decreased lactate dehydrogenase (LDH) release, inhibited apoptotic cell death and reduced the activation of caspase-3 after glutamate treatment. This protection was accompanied by the preservation of mitochondrial function, as evidenced by reduced mitochondrial oxidative stress, attenuated lipid peroxidation and enhanced ATP generation. In addition, BHAPI promoted Wnt/β-catenin signaling, which was related to destabilization of β-catenin destruction complex. The Wnt/β-catenin signaling inhibitor JW74, but not IWP2, partially prevented the protective effects of BHAPI. In conclusion, our data suggested that BHAPI acted as a neuroprotective agent against glutamate-induced toxicity, and this protection might be mediated by preservation of mitochondrial function and regulation of Wnt/β-catenin pathway.

Liraglutide attenuates NLRP3 inflammasome-dependent pyroptosis via regulating SIRT1/NOX4/ROS pathway in H9c2 cells

The glucagon-like peptide-1 analog liraglutide has been proved to exert cardioprotective role via activating prosurvival pathways and suppressing inflammation. The activation of NLRP3 inflammasome plays an important role in ischemic injury. The effect of liraglutide on NLRP3 inflammasome-dependent pyroptosis remains unclear. In this study, we established a double stimulation model with TNF-α and hypoxia to mimic ischemic environment and to induce NLRP3 inflammasome activation in H9c2 cardiomyoblasts. Pretreatment with 100 nM liraglutide could efficiently inhibit TNF-α and hypoxia-induced inflammasome activation, as evidenced by the decreased expression of NLRP3, caspase-1 p20 and Gasdermin D N-terminal fragment. Meanwhile, the pyroptosis was also demonstrated to be suppressed, indicated by the increased cell viability and decreased lactate dehydrogenase release in the cells. Mechanistically, liraglutide reversed the level of SIRT1 and the selective SIRT1 inhibitor EX 527 significantly abolished the anti-pyroptosis role of liraglutide. Furthermore, liraglutide diminished the levels of ROS generation and NOX4 expression, which could also be blocked by EX 527. Our results uncovered the anti-pyroptosis role of liraglutide in TNF-α and hypoxia-stimulated H9c2 cells, which was associated with SIRT1/NOX4/ROS pathway.

Ameliorative effects of Spirulina platensis against lead-induced nephrotoxicity in newborn rats: Modulation of oxidative stress and histopathological changes.

Our experimental work was aimed at evaluating the safety and protective effects of dietary spirulina supplementation on the kidney of newborn rats, the offspring of lead contaminated lactating mothers. Female rats were randomly divided into four groups: group I (control) was given a normal diet, group II (positive control, S) received a diet enriched with spirulina, group III received only lead through drinking water (Pb), and group IV received both a diet enriched with spirulina and lead contaminated water (S Pb). The treatment of pregnant rats with lead administrated in drinking water, from the 5th day of pregnancy until day 14 after delivery, induced an increased level of renal lipid peroxidation, protein carbonyl, hydrogen peroxide and advanced oxidation protein product, a decreased renal content of glutathione and antioxidant enzyme activities such as superoxide dismutase, catalase and glutathione peroxidase in newborns. A statistically significant increase of renal DNA, mRNA, hematological parameters as well as in plasma urea and creatinine serum levels and lactate dehydrogenase was seen in pups, while those of uric acid declined. Interestingly, these biochemical modifications were accompanied by a significant decrease of lactate dehydrogenase in kidney, plasma alkaline phosphatase and gamma glutamyl-transpeptidase levels, urinary levels of creatinine and urea. Conversely, supplementation of lead-treated mother's with spirulina alleviated hematotoxicity induced by lead as evidenced, by restoring the biochemical markers cited above to near normal levels. Nevertheless, the distorted histoarchitecture in rat kidney attenuated following spirulina supplementation. It can be then concluded that spirulina is an important protective source against kidney impairments.

The effect of different substitute groups and molecular weights of fucoidan on neuroprotective and anticomplement activity

Ten fucoidan (FPS) derivatives were successfully synthesized, and their potential neuroprotective and anticomplement activities were investigated employing various established in vitro systems. The aim of the present study was to investigate the effects of different substitute groups and molecular weights of fucoidan on neuroprotective and anticomplement activities. All FPS derivatives possessed considerable neuroprotective and anticomplement activities and had stronger activities than FPS in certain tests. The in vitro results found that sulfated and benzoylated derivatives could reverse the decreased mitochondrial activity and decreased lactate dehydrogenase (LDH) and reactive oxygen species (ROS) release induced by 6-hydroxydopamine (6-OHDA, P<0.01 or P<0.001), which provides further evidence that sulfate and benzoylate groups could enhance the neuroprotective activity of fucoidan. In anticomplement experiments, all samples showed anticomplement activity in both systems; however, the sulfated and benzoylated derivatives showed better activity than fucoidan, with higher molecular weights showing the strongest activity. Available data suggested that substituted groups of fucoidan played an important role on neuroprotective and anticomplement activities. The mechanism of the influence of the neuroprotective and anticomplement activities of samples of the substituted groups was indicated.