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1.
J Wound Care ; 33(Sup1): i-ix, 2024 Jan 01.
Article En | MEDLINE | ID: mdl-38197308

OBJECTIVE: Wound healing is an important aspect of health but needs further research to identify the effects and interactions of different treatment approaches on healing. The aims of this study were to investigate the effectiveness of one-hour negative pressure wound therapy (NPWT) and compare histological differences between one-hour NPWT and magnetic field energy (MFE) in rats on early-stage wound healing, wound size and angiogenesis. METHOD: Standardised wounds were created on Wistar rats that were allocated and divided into NPWT, MFE and control groups. Both treatments were applied for 1 hour/day for 10 days. Wound size, histological changes and wound area blood flow were assessed. RESULTS: The wound size of all groups was similar on days 0, 2 and 10. The MFE group's wound size was smaller than the NPWT group on days 4, 6 and 8 (p<0.05). Development of the granulation tissue in both the one-hour NPWT and MFE groups was greater than in the control group. Additionally, the inflammatory phase was shorter, and wounds entered the proliferative stage faster in the MFE group than both of the other groups. CONCLUSION: Treatment with MFE may be more effective in terms of early stage wound closure and angiogenesis. On the other hand, the NPWT group's wound area blood flow was significantly greater than the other two groups. MFE is superior to one-hour NPWT in terms of wound area and angiogenesis. Furthermore, it is worthwhile to note that one-hour NPWT increases bloodflow in the wound area, which stimulates healing.


Negative-Pressure Wound Therapy , Animals , Rats , Rats, Wistar , Wound Healing , Granulation Tissue , Magnetic Fields
2.
Shock ; 61(4): 527-540, 2024 Apr 01.
Article En | MEDLINE | ID: mdl-37752081

ABSTRACT: Objective: Extracellular purines such as adenosine triphosphate (ATP), uridine triphosphate (UTP), and uridine diphosphate (UDP) and the ATP degradation product adenosine are biologically active signaling molecules, which accumulate at sites of metabolic stress in sepsis. They have potent immunomodulatory effects by binding to and activating P1 or adenosine and P2 receptors on the surface of leukocytes. Here we assessed the levels of extracellular purines, their receptors, metabolic enzymes, and cellular transporters in leukocytes of septic patients. Methods: Peripheral blood mononuclear cells (PBMCs), neutrophils, and plasma were isolated from blood obtained from septic patients and healthy control subjects. Ribonucleic acid was isolated from cells, and mRNA levels for purinergic receptors, enzymes, and transporters were measured. Adenosine triphosphate, UTP, UDP, and adenosine levels were evaluated in plasma. Results: Adenosine triphosphate levels were lower in septic patients than in healthy individuals, and levels of the other purines were comparable between the two groups. Levels of P1 and P2 receptors did not differ between the two patient groups. mRNA levels of ectonucleoside triphosphate diphosphohydrolase (NTPDase) 1 or CD39 increased, whereas those of NTPDase2, 3, and 8 decreased in PBMCs of septic patients when compared with healthy controls. CD73 mRNA was lower in PBMCs of septic than in healthy individuals. Equilibrative nucleoside transporter (ENT) 1 mRNA concentrations were higher and ENT2, 3, and 4 mRNA concentrations were lower in PBMCs of septic subjects when compared with healthy subjects. Concentrative nucleoside transporter (CNT) 1 mRNA levels were higher in PBMCs of septic versus healthy subjects, whereas the mRNA levels of CNT2, 3, and 4 did not differ. We failed to detect differences in mRNA levels of purinergic receptors, enzymes, and transporters in neutrophils of septic versus healthy subjects. Conclusion: Because CD39 degrades ATP to adenosine monophosphate (AMP), the lower ATP levels in septic individuals may be the result of increased CD39 expression. This increased degradation of ATP did not lead to increased adenosine levels, which may be explained by the decreased expression of CD73, which converts AMP to adenosine. Altogether, our results demonstrate differential regulation of components of the purinergic system in PBMCs during human sepsis.


Leukocytes, Mononuclear , Sepsis , Humans , Uridine Triphosphate/metabolism , Leukocytes, Mononuclear/metabolism , Adenosine , Adenosine Triphosphate/metabolism , Uridine Diphosphate , Adenosine Monophosphate , Receptors, Purinergic/metabolism , RNA, Messenger , Nucleoside Transport Proteins
3.
Respir Res ; 24(1): 186, 2023 Jul 13.
Article En | MEDLINE | ID: mdl-37438813

BACKGROUND: Trauma and a subsequent hemorrhagic shock (T/HS) result in insufficient oxygen delivery to tissues and multiple organ failure. Extracellular adenosine, which is a product of the extracellular degradation of adenosine 5' triphosphate (ATP) by the membrane-embedded enzymes CD39 and CD73, is organ protective, as it participates in signaling pathways, which promote cell survival and suppress inflammation through adenosine receptors including the A2BR. The aim of this study was to evaluate the role of CD39 and CD73 delivering adenosine to A2BRs in regulating the host's response to T/HS. METHODS: T/HS shock was induced by blood withdrawal from the femoral artery in wild-type, global knockout (CD39, CD73, A2BR) and conditional knockout (intestinal epithelial cell-specific deficient VillinCre-A2BRfl/fl) mice. At 3 three hours after resuscitation, blood and tissue samples were collected to analyze organ injury. RESULTS: T/HS upregulated the expression of CD39, CD73, and the A2BR in organs. ATP and adenosine levels increased after T/HS in bronchoalveolar lavage fluid. CD39, CD73, and A2BR mimics/agonists alleviated lung and liver injury. Antagonists or the CD39, CD73, and A2BR knockout (KO) exacerbated lung injury, inflammatory cytokines, and chemokines as well as macrophage and neutrophil infiltration and accumulation in the lung. Agonists reduced the levels of the liver enzymes aspartate transferase and alanine transaminase in the blood, whereas antagonist administration or CD39, CD73, and A2BR KO enhanced enzyme levels. In addition, intestinal epithelial cell-specific deficient VillinCre-A2BRfl/fl mice showed increased intestinal injury compared to their wild-type VillinCre controls. CONCLUSION: In conclusion, the CD39-CD73-A2BR axis protects against T/HS-induced multiple organ failure.


Adenosine , Multiple Organ Failure , Animals , Mice , Adenosine Triphosphate , Signal Transduction , Bronchoalveolar Lavage Fluid
4.
Shock ; 58(4): 321-331, 2022 10 01.
Article En | MEDLINE | ID: mdl-36018304

ABSTRACT: Trauma hemorrhagic shock (T/HS) is a clinical condition that causes multiple organ failure that needs rapid intervention. Restricted oxygen at the cellular level causes inflammation and subsequent cell death. Adenosine triphosphate is the universal intracellular energy currency and an important extracellular inflammatory signaling molecule. Adenosine, an endogenous nucleotide formed as a result of the breakdown of adenosine triphosphate, is also released during T/HS. Adenosine binds to four G protein-coupled receptors (A 1R , A 2a , A 2b , A 3R ) called adenosine receptors or P1 receptors. In the present study, we evaluated the effect of activation, inactivation, and genetic absence of A2aR (A2aR -/- mice) on T/HS-induced multiple organ failure. Wild-type mice were pretreated (30 min before shock induction) with an agonist or antagonist and then subjected to T/HS by withdrawing arterial blood and maintaining the blood pressure between 28 and 32 mm Hg. A2aR -/- mice were subjected to T/HS in the absence of pharmacologic treatment. Neutrophil sequestration was assessed by detecting myeloperoxidase, and Evans blue dye (EBD) method was used to analyze lung permeability. Blood and lung inflammatory cytokine levels were determined by sandwich enzyme-linked immunosorbent assay. The liver enzymes aspartate aminotransferase and alanine aminotransferase were determined spectrophotometrically from plasma. Activation of the apoptotic cascade was evaluated using a mouse apoptosis array. Our results demonstrate that the selective A2aR agonist CGS21680 decreases lung neutrophil sequestration, lung proinflammatory cytokines IL-6 and TNF-α, and bronchoalveolar lavage EBD. Pretreatment with the selective antagonist ZM241385 and genetic blockade in A2aR -/- mice increased neutrophil sequestration, proinflammatory cytokine levels, and bronchoalveolar lavage fluid EBD. The myeloperoxidase level in the lung was also increased in A2aR -/- mice. We observed that antiapoptotic markers decreased significantly with the absence of A2aR in the lung and spleen after T/HS. In conclusion, our data demonstrate that activation of A2aR regulates organ injury and apoptosis in the setting of T/HS.


Shock, Hemorrhagic , Mice , Animals , Shock, Hemorrhagic/therapy , Multiple Organ Failure/etiology , Peroxidase/metabolism , Tumor Necrosis Factor-alpha/metabolism , Evans Blue , Alanine Transaminase , Interleukin-6 , Cytokines/metabolism , Receptors, Purinergic P1 , Aspartate Aminotransferases , Adenosine , Adenosine Triphosphate , Nucleotides , Oxygen
5.
Mol Neurobiol ; 59(1): 574-589, 2022 Jan.
Article En | MEDLINE | ID: mdl-34735672

Phosphodiesterase 10A (PDE10A) hydrolyzes adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP). It is highly expressed in the striatum. Recent evidence implied that PDE10A may be involved in the inflammatory processes following injury, such as ischemic stroke. Its role in ischemic injury was unknown. Herein, we exposed mice to 90 or 30-min middle cerebral artery occlusion, followed by the delivery of the highly selective PDE10A inhibitor TAK-063 (0.3 mg/kg or 3 mg/kg) immediately after reperfusion. Animals were sacrificed after 24 or 72 h, respectively. Both TAK-063 doses enhanced neurological function, reduced infarct volume, increased neuronal survival, reduced brain edema, and increased blood-brain barrier integrity, alongside cerebral microcirculation improvements. Post-ischemic neuroprotection was associated with increased phosphorylation (i.e., activation) of pro-survival Akt, Erk-1/2, GSK-3α/ß and anti-apoptotic Bcl-xL abundance, decreased phosphorylation of pro-survival mTOR, and HIF-1α, MMP-9 and pro-apoptotic Bax abundance. Interestingly, PDE10A inhibition reduced inflammatory cytokines/chemokines, including IFN-γ and TNF-α, analyzed by planar surface immunoassay. In addition, liquid chromatography-tandem mass spectrometry revealed 40 proteins were significantly altered by TAK-063. Our study established PDE10A as a target for ischemic stroke therapy.


Brain Edema/drug therapy , Cell Survival/drug effects , Ischemic Stroke/drug therapy , Neuroprotective Agents/therapeutic use , Phosphodiesterase Inhibitors/therapeutic use , Phosphoric Diester Hydrolases/metabolism , Animals , Brain Edema/metabolism , Disease Models, Animal , Ischemic Stroke/metabolism , Mice , Microcirculation/drug effects , Neuroprotection/drug effects , Neuroprotective Agents/pharmacology , Phosphodiesterase Inhibitors/pharmacology , Phosphorylation/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Pyrazoles/pharmacology , Pyrazoles/therapeutic use , Pyridazines/pharmacology , Pyridazines/therapeutic use , Signal Transduction/drug effects
6.
Turk J Med Sci ; 50(8): 1825-1837, 2020 12 17.
Article En | MEDLINE | ID: mdl-32222128

Background/aim: The management of dura-related complications, such as the repairment of dural tears and reconstruction of large dural defects, remain the most challenging subjects of neurosurgery. Numerous surgical techniques and synthetic or autologous adjuvant materials have emerged as an adjunct to primary dural closure, which may result in further complications or side effects. Therefore, the subcutaneous autologous free adipose tissue graft has been recommended for the protection of the central nervous system and repairment of the meninges. In addition, human adipose tissue is also a source of multipotent stem cells. However, epidural adipose tissue seems more promising than subcutaneous because of the close location and intercellular communication with the spinal cord. Herein, it was aimed to define differentiation capability of both subcutaneous and epidural adipose tissue-derived stem cells (ASCs). Materials and methods: Human subcutaneous and epidural adipose tissue specimens were harvested from the primary incisional site and the lumbar epidural space during lumbar spinal surgery, and ASCs were isolated. Results: The results indicated that both types of ASCs expressed the cell surface markers, which are commonly expressed stem cells; however, epidural ASCs showed lower expression of CD90 than the subcutaneous ASCs. Moreover, it was demonstrated that the osteogenic and neurogenic differentiation capability of epidural adipose tissue-derived ASCs was more pronounced than that of the subcutaneous ASCs. Conclusion: Consequently, the impact of characterization of epidural ASCs will allow for a new understanding for dural as well as central nervous system healing and recovery after an injury.


Adipose Tissue/metabolism , Cell Differentiation/physiology , Neurogenesis/physiology , Osteogenesis/physiology , Stem Cells/metabolism , Cells, Cultured , Epidural Space , Humans , Subcutaneous Fat/metabolism
7.
Behav Brain Res ; 379: 112338, 2020 02 03.
Article En | MEDLINE | ID: mdl-31733311

BACKGROUND: Newborn hypoxia ischemia (HI) is one of the most prevalent cases in the emergency and can result from fetal hypoxia during delivery. In HI, restricted blood supply to the fetal brain may cause epilepsy or mental disorders. METHODS: In the present study, seven-day-old pups were subjected HI and treated with different normobaric oxygen (NBO) concentrations (21%, 70% or 100%). In the acute phase, we analyzed infarct area, disseminate neuronal injury and surviving neurons. In addition, we studied the regulation of PTEN and MMP-9 proteins which were suggested to be activated by HI in the ischemic tissue. Moreover, long-term effects of NBO treatments were evaluated with open field, rotarod and Barnes maze tests. We also examined axonal plasticity with EGFP-AAV injection. RESULTS: Here, we demonstrate that hyperoxic NBO concentration causes an increase in cellular survival and a decrease in the number of apoptotic cells, meanwhile inhibiting the proteins involved in cellular death mechanisms. Moreover, we found that hyperoxia decreases anxiety, promotes motor coordination and improve spatial learning and memory. Notably that axonal sprouting was promoted by hyperoxia. CONCLUSION: Our data suggest that NBO is a promising approach for the treatment of newborn HI, which encourage proof-of-concept studies in newborn.


Hypoxia-Ischemia, Brain/therapy , Infant, Newborn, Diseases/therapy , Motor Activity/physiology , Neuronal Plasticity/physiology , Oxygen Inhalation Therapy , Recovery of Function/physiology , Spatial Learning/physiology , Animals , Animals, Newborn , Behavior, Animal/physiology , Cell Survival/physiology , Disease Models, Animal , Humans , Hypoxia-Ischemia, Brain/metabolism , Infant, Newborn , Matrix Metalloproteinase 9/metabolism , Neurons/physiology , Oxygen Inhalation Therapy/methods , PTEN Phosphohydrolase/metabolism , Rats , Rats, Sprague-Dawley
8.
Sci Rep ; 9(1): 19082, 2019 12 13.
Article En | MEDLINE | ID: mdl-31836786

The circadian rhythm is driven by a master clock within the suprachiasmatic nucleus which regulates the rhythmic secretion of melatonin. Bmal1 coordinates the rhythmic expression of transcriptome and regulates biological activities, involved in cell metabolism and aging. However, the role of Bmal1 in cellular- survival, signaling, its interaction with intracellular proteins, and how melatonin regulates its expression is largely unclear. Here we observed that melatonin increases the expression of Bmal1 and both melatonin and Bmal1 increase cellular survival after oxygen glucose deprivation (OGD) while the inhibition of Bmal1 resulted in the decreased cellular survival without affecting neuroprotective effects of melatonin. By using a planar surface immunoassay for PI3K/AKT signaling pathway components, we revealed that both melatonin and Bmal1 increased phosphorylation of AKT, ERK-1/2, PDK1, mTOR, PTEN, GSK-3αß, and p70S6K. In contrast, inhibition of Bmal1 resulted in decreased phosphorylation of these proteins, which the effect of melatonin on these signaling molecules was not affected by the absence of Bmal1. Besides, the inhibition of PI3K/AKT decreased Bmal1 expression and the effect of melatonin on Bmal1 after both OGD in vitro and focal cerebral ischemia in vivo. Our data demonstrate that melatonin controls the expression of Bmal1 via PI3K/AKT signaling, and Bmal1 plays critical roles in cellular survival via activation of survival kinases.


ARNTL Transcription Factors/metabolism , Melatonin/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Animals , Brain Ischemia/metabolism , Brain Ischemia/pathology , Cell Line , Cell Survival/drug effects , Glucose/deficiency , Male , Mice, Inbred C57BL , Neurons/drug effects , Neurons/metabolism , Neurons/pathology , Oxygen , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism
9.
Toxicol Appl Pharmacol ; 379: 114686, 2019 09 15.
Article En | MEDLINE | ID: mdl-31325559

Indolamine melatonin structurally resembles non-covalent proteasome inhibitors; however, the role of ubiquitin proteasome system (UPS) in neuronal survival and how melatonin carries out UPS inhibition remain largely unknown. With the use of melatonin treated cells, we evaluated the expression of Nedd4-1, an E3 ligase, how melatonin regulates its activity and its relationship with neuronal survival. Nedd4-1 was upregulated in the hypoxic condition in both control and Nedd4-1 overexpressed cells and melatonin treatment reversed its expression in both normoxic and hypoxic conditions, which was associated with increased cellular survival. Melatonin had no effect on the expression of Nedd4-1 at mRNA level. However, when melatonin was administered along with protein synthesis inhibitor cycloheximide, protein level of Nedd4-1 was further reduced, indicating that melatonin possibly downregulates Nedd4-1 after its synthesis. Notably, co-immunoprecipitation analyses followed by Liquid chromatography-Mass Spectrometry (LC-MS/MS) revealed that melatonin may dissociate ribosomal proteins, such as RS19, RL23A, and nucleophosmin from Nedd4-1, while 40S ribosomal protein S7 and 60S ribosomal protein L35 came into contact with Nedd4-1 upon melatonin treatment. By using IPA analyses, we obtained further data indicated novel target molecules of melatonin in hypoxic conditions, including OTOF, SF3B2, IPO5, ST13, FGFR3, Mx1/Mx2, playing roles in RNA splicing and trafficking, growth factor and interferon signaling. Here, we described a new insight into the role of melatonin in UPS functioning by proposing a molecular mechanism through which melatonin regulates Nedd4-1.


Cell Survival , Melatonin/physiology , Nedd4 Ubiquitin Protein Ligases/metabolism , Animals , Blotting, Western , Cells, Cultured , Cerebral Cortex/cytology , Cerebral Cortex/metabolism , Down-Regulation , Gas Chromatography-Mass Spectrometry , Hypoxia/metabolism , Immunoprecipitation , Melatonin/metabolism , Mice , Mice, Inbred C57BL , Neurons/metabolism , Neurons/physiology , Real-Time Polymerase Chain Reaction
10.
Mol Neurobiol ; 55(3): 2565-2576, 2018 03.
Article En | MEDLINE | ID: mdl-28421530

Occurrence of stroke cases displays a time-of-day variation in human. However, the mechanism linking circadian rhythm to the internal response mechanisms against pathophysiological events after ischemic stroke remained largely unknown. To this end, temporal changes in the susceptibility to ischemia/reperfusion (I/R) injury were investigated in mice in which the ischemic stroke induced at four different Zeitgeber time points with 6-h intervals (ZT0, ZT6, ZT12, and ZT18). Besides infarct volume and brain swelling, neuronal survival, apoptosis, ischemia, and circadian rhythm related proteins were examined using immunohistochemistry, Western blot, planar surface immune assay, and liquid chromatography-mass spectrometry tools. Here, we present evidence that midnight (ZT18; 24:00) I/R injury in mice resulted in significantly improved infarct volume, brain swelling, neurological deficit score, neuronal survival, and decreased apoptotic cell death compared with ischemia induced at other time points, which were associated with increased expressions of circadian proteins Bmal1, PerI, and Clock proteins and survival kinases AKT and Erk-1/2. Moreover, ribosomal protein S6, mTOR, and Bad were also significantly increased, while the levels of PRAS40, negative regulator of AKT and mTOR, and phosphorylated p53 were decreased at this time point compared to ZT0 (06:00). Furthermore, detailed proteomic analysis revealed significantly decreased CSKP, HBB-1/2, and HBA levels, while increased GNAZ, NEGR1, IMPCT, and PDE1B at midnight as compared with early morning. Our results indicate that nighttime I/R injury results in less severe neuronal damage, with increased neuronal survival, increased levels of survival kinases and circadian clock proteins, and also alters the circadian-related proteins.


ARNTL Transcription Factors/biosynthesis , Brain Ischemia/metabolism , Circadian Rhythm/physiology , Neurons/metabolism , Proto-Oncogene Proteins c-akt/biosynthesis , Stroke/metabolism , Animals , Brain Ischemia/pathology , Cell Survival/physiology , Circadian Clocks/physiology , DNA Fragmentation , Male , Mice , Mice, Inbred BALB C , Neurons/pathology , Stroke/pathology
11.
Exp Neurol ; 296: 23-31, 2017 10.
Article En | MEDLINE | ID: mdl-28669743

Conflicting data in the literature about the function of P2X7R in survival following ischemia necessitates the conductance of in-depth studies. To investigate the impacts of activation vs inhibition of the receptor on neuronal survival as well as the downstream signaling cascades, in addition to optic nerve transection (ONT), 30min and 90min of middle cerebral artery occlusion (MCAo) models were performed in mice. Intracellular calcium levels were assessed in primary cortical neuron cultures. Here, we show that P2X7R antagonist Brilliant Blue G (BBG) decreased DNA fragmentation, infarct volume, brain swelling, neurological deficit scores and activation of microglial cells after focal cerebral ischemia. BBG also significantly increased the number of surviving retinal ganglion cells (RGCs) after ONT and the number of surviving neurons following MCAo. Importantly, receptor agonist BzATP resulted in increased activation of microglial cells and induced phosphorylation of ERK, AKT and JNK. These results indicated that inhibition of P2X7R with BBG promoted neuronal survival, not through the activation of survival kinase pathways, but possibly by improved intracellular Ca2+ overload and decreased the levels of Caspase 1, IL-1ß and Bax proteins. On the other hand, BzATP-mediated increased number of activated microglia and increased survival kinase levels in addition to increased caspase-1 and IL-1ß levels indicate the complex nature of the P2X7 receptor-mediated signaling in neuronal injury.


Brain Ischemia/metabolism , Brain Ischemia/pathology , Neurons/pathology , Optic Nerve Injuries/metabolism , Optic Nerve Injuries/pathology , Receptors, Purinergic P2/metabolism , Adenosine Triphosphate/analogs & derivatives , Adenosine Triphosphate/pharmacology , Adenosine Triphosphate/therapeutic use , Animals , Animals, Newborn , Brain/blood supply , Brain/drug effects , Brain Edema/etiology , Brain Ischemia/drug therapy , Calcium-Binding Proteins/metabolism , Cells, Cultured , Cerebral Cortex/cytology , Cytokines/metabolism , DNA Fragmentation/drug effects , Disease Models, Animal , Infusions, Intraventricular , Male , Mice , Mice, Inbred C57BL , Microfilament Proteins/metabolism , Neurons/drug effects , Optic Nerve Injuries/drug therapy , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation Inhibitors/therapeutic use , Rosaniline Dyes/metabolism
12.
Redox Biol ; 12: 657-665, 2017 08.
Article En | MEDLINE | ID: mdl-28395173

Apart from its potent antioxidant property, recent studies have revealed that melatonin promotes PI3K/Akt phosphorylation following focal cerebral ischemia (FCI) in mice. However, it is not clear (i) whether increased PI3K/Akt phosphorylation is a concomitant event or it directly contributes to melatonin's neuroprotective effect, and (ii) how melatonin regulates PI3K/Akt signaling pathway after FCI. In this study, we showed that Akt was intensively phosphorylated at the Thr308 activation loop as compared with Ser473 by melatonin after FCI. Melatonin treatment reduced infarct volume, which was reversed by PI3K/Akt inhibition. However, PI3K/Akt inhibition did not inhibit melatonin's positive effect on brain swelling and IgG extravasation. Additionally, phosphorylation of mTOR, PTEN, AMPKα, PDK1 and RSK1 were increased, while phosphorylation of 4E-BP1, GSK-3α/ß, S6 ribosomal protein were decreased in melatonin treated animals. In addition, melatonin decreased apoptosis through reduced p53 phosphorylation by the PI3K/Akt pathway. In conclusion, we demonstrated the activation profiles of PI3K/Akt signaling pathway components in the pathophysiological aspect of ischemic stroke and melatonin's neuroprotective activity. Our data suggest that Akt phosphorylation, preferably at the Thr308 site of the activation loop via PDK1 and PTEN, mediates melatonin's neuroprotective activity and increased Akt phosphorylation leads to reduced apoptosis.


Antioxidants/administration & dosage , Brain Ischemia/drug therapy , Melatonin/administration & dosage , PTEN Phosphohydrolase/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Animals , Antioxidants/pharmacology , Brain Ischemia/immunology , Brain Ischemia/metabolism , Disease Models, Animal , Gene Expression Regulation/drug effects , Immunoglobulin G/metabolism , Melatonin/pharmacology , Mice , Phosphorylation , Proto-Oncogene Proteins c-akt/chemistry , Pyruvate Dehydrogenase Acetyl-Transferring Kinase , Signal Transduction/drug effects , Threonine/metabolism
13.
Metab Brain Dis ; 31(4): 827-35, 2016 08.
Article En | MEDLINE | ID: mdl-26943480

Hypoxic-ischemia (HI) is a widely used animal model to mimic the preterm or perinatal sublethal hypoxia, including hypoxic-ischemic encephalopathy. It causes diffuse neurodegeneration in the brain and results in mental retardation, hyperactivity, cerebral palsy, epilepsy and neuroendocrine disturbances. Herein, we examined acute and subacute correlations between neuronal degeneration and serum growth factor changes, including growth hormone (GH), insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) after hypoxic-ischemia (HI) in neonatal rats. In the acute phase of hypoxia, brain volume was increased significantly as compared with control animals, which was associated with reduced GH and IGF-1 secretions. Reduced neuronal survival and increased DNA fragmentation were also noticed in these animals. However, in the subacute phase of hypoxia, neuronal survival and brain volume were significantly decreased, accompanied by increased apoptotic cell death in the hippocampus and cortex. Serum GH, IGF-1, and IGFBP-3 levels were significantly reduced in the subacute phase of HI. Significant retardation in the brain and body development were noted in the subacute phase of hypoxia. Here, we provide evidence that serum levels of growth-hormone and factors were decreased in the acute and subacute phase of hypoxia, which was associated with increased DNA fragmentation and decreased neuronal survival.


Growth Hormone/blood , Hypoxia-Ischemia, Brain/blood , Insulin-Like Growth Factor Binding Protein 3/blood , Insulin-Like Growth Factor I/metabolism , Neurons/pathology , Animals , Cell Survival , DNA Fragmentation , Disease Models, Animal , Female , Hypoxia-Ischemia, Brain/pathology , Male , Rats
14.
Neurosci Lett ; 612: 92-97, 2016 Jan 26.
Article En | MEDLINE | ID: mdl-26639427

The tissue damage that emerges during traumatic brain injury (TBI) is a consequence of a variety of pathophysiological events, including free radical generation and over-activation of N-methyl-d-aspartate-type glutamate receptors (NMDAR). Considering the complex pathophysiology of TBI, we hypothesized that combination of neuroprotective compounds, targeting different events which appear during injury, may be a more promising approach for patients. In this context, both NMDAR antagonist memantine and free radical scavenger melatonin are safe in humans and promising agents for the treatment of TBI. Herein, we examined the effects of melatonin administered alone or in combination with memantine on the activation of signaling pathways, injury development and DNA fragmentation. Both compounds reduced brain injury moderately and the density of DNA fragmentation significantly. Notably, melatonin/memantine combination decreased brain injury and DNA fragmentation significantly, which was associated with reduced p38 and ERK-1/2 phosphorylation. As compared with melatonin and memantine groups, SAPK/JNK-1/2 phosphorylation was also reduced in melatonin/memantine combined animals. In addition, melatonin, memantine and their combination decreased iNOS activity significantly. Here, we provide evidence that melatonin/memantine combination protects brain from traumatic injury, which was associated with decreased DNA fragmentation, p38 phosphorylation and iNOS activity.


Brain Injuries/drug therapy , Free Radical Scavengers/pharmacology , Melatonin/pharmacology , Memantine/pharmacology , Neuroprotective Agents/pharmacology , Animals , Brain/drug effects , Brain/pathology , Brain Infarction/pathology , Brain Injuries/pathology , Brain Injuries/physiopathology , DNA Fragmentation/drug effects , Free Radical Scavengers/therapeutic use , Male , Melatonin/therapeutic use , Memantine/therapeutic use , Mice, Inbred BALB C , Neuroprotective Agents/therapeutic use
15.
Oncotarget ; 6(31): 30604-14, 2015 Oct 13.
Article En | MEDLINE | ID: mdl-26416428

In order to protect the brain before an irreversible injury occurs, penumbral oxygenation is the primary goal of current acute ischemic stroke treatment. However, hyperoxia treatment remains controversial due to the risk of free radical generation and vasoconstriction. Melatonin is a highly potent free radical scavenger that protects against ischemic stroke. Considering its anti-oxidant activity, we hypothesized that melatonin may augment the survival-promoting action of normobaric oxygen (NBO) and prevent brain infarction. Herein, we exposed mice to 30 or 90 min of intraluminal middle cerebral artery occlusion (MCAo) and evaluated the effects of NBO (70% or 100% over 90 min), administered either alone or in combination with melatonin (4 mg/kg, i.p.), on disseminate neuronal injury, neurological deficits, infarct volume, blood-brain barrier (BBB) permeability, cerebral blood flow (CBF) and cell signaling. Both NBO and particularly melatonin alone reduced neuronal injury, neurological deficits, infarct volume and BBB permeability, and increased post-ischemic CBF, evaluated by laser speckle imaging (LSI). They also improved CBF significantly in the ischemic- core and penumbra, which was associated with reduced IgG extravasation, DNA fragmentation, infarct volume, brain swelling and neurological scores. Levels of phosphorylated Akt, anti-apoptotic Bcl-xL, pro-apoptotic Bax and endothelial nitric oxide synthase (NOS) were re-regulated after combined oxygen and melatonin delivery, whereas neuronal and inducible NOS, which were increased by oxygen treatment, were not influenced by melatonin. Our present data suggest that melatonin and NBO are promising approaches for the treatment of acute-ischemic stroke, which encourage proof-of-concept studies in human stroke patients.


Antioxidants/therapeutic use , Brain Ischemia/therapy , Brain/blood supply , Free Radical Scavengers/therapeutic use , Melatonin/therapeutic use , Oxygen/therapeutic use , Stroke/therapy , Animals , Blood-Brain Barrier/drug effects , Blood-Brain Barrier/physiopathology , Brain/pathology , Brain Edema/pathology , DNA Fragmentation , Disease Models, Animal , Immunoglobulin G/blood , Infarction, Middle Cerebral Artery/physiopathology , Mice , Mice, Inbred BALB C , Microcirculation , Nitric Oxide Synthase Type III/metabolism , Proto-Oncogene Proteins c-akt/metabolism , bcl-2-Associated X Protein/metabolism , bcl-X Protein/metabolism
16.
Front Cell Neurosci ; 8: 422, 2014.
Article En | MEDLINE | ID: mdl-25565957

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are widely used for secondary stroke prevention. Besides their lipid-lowering activity, pleiotropic effects on neuronal survival, angiogenesis, and neurogenesis have been described. In view of these observations, we were interested whether HMG-CoA reductase inhibition in the post-acute stroke phase promotes neurological recovery, peri-lesional, and contralesional neuronal plasticity. We examined effects of the HMG-CoA reductase inhibitor rosuvastatin (0.2 or 2.0 mg/kg/day i.c.v.), administered starting 3 days after 30 min of middle cerebral artery occlusion for 30 days. Here, we show that rosuvastatin treatment significantly increased the grip strength and motor coordination of animals, promoted exploration behavior, and reduced anxiety. It was associated with structural remodeling of peri-lesional brain tissue, reflected by increased neuronal survival, enhanced capillary density, and reduced striatal and corpus callosum atrophy. Increased sprouting of contralesional pyramidal tract fibers crossing the midline in order to innervate the ipsilesional red nucleus was noticed in rosuvastatin compared with vehicle-treated mice, as shown by anterograde tract tracing experiments. Western blot analysis revealed that the abundance of HMG-CoA reductase was increased in the contralesional hemisphere at 14 and 28 days post-ischemia. Our data support the idea that HMG-CoA reductase inhibition promotes brain remodeling and plasticity far beyond the acute stroke phase, resulting in neurological recovery.

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