An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease prog...An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in PD.Repetitive transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's disease.However,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain unknown.The purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated signaling.Animals with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod test.Immunoblot,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate putamen.Prolonged intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate putamen.Treatment with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor symptoms.After treatment with prolonged intermittent theta burst stimulation,complete motor recovery was observed.This improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst stimulation.Our results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)R.Intermittent theta burst stimulation reversed these effects by restoring the abundances of A_(1)R and A_(2A)R to control levels.The shift in ARs expression likely restored the balance between dopamine-adenosine signaling,ultimately leading to the recovery of motor control.展开更多
Objective To investigate the potential effects of angiogenic process by secretory phospholipase A2 (sPLA2)inhibitor-HyPE(linking N-derivatized phosphatidyl-ethanolamine to hyaluronic acid)on human bone marrow endothel...Objective To investigate the potential effects of angiogenic process by secretory phospholipase A2 (sPLA2)inhibitor-HyPE(linking N-derivatized phosphatidyl-ethanolamine to hyaluronic acid)on human bone marrow endothelial cell line(HBME-1). Methods In order to examine the suppressing effects of HyPE on HBME-1 proliferation, migration, and capillary-like tube formation, HBME-1 were activated by angiogenic factor, specifically by basic fibroblast growth factor(b-FGF), vascular endothelial growth factor(VEGF),and oncostatin M(OSM)(at a final concentration of 25, 20, and 2.5 ng/mL, respectively), then HBME-1 proliferation, migration, and tube forma-tion were studied in the absence or presence of HyPE. HBME-1 tube formation was specially analyzed in fibrin gel. Results HyPE effectively inhibited HBME-1 proliferation and migration as a dose-dependent manner, whatever HBME-1 were grown in the control culture medium or stimulated with b-FGF, VEGF, or OSM. In fibrin, the formations of HBME-1 derived tube-like structures were enhanced by all angiogenic factors, but these were strongly suppressed by HyPE. Conclusions The results support the involvement of sPLA2 in angiogenesis. It is proposed that sPLA2 inhibitor introduces a novel approach in the control of cancer development.展开更多
The regulatory effects of phospholipase A2(PLA2) inhibitors, chloroquine and dexamethasone, on the activity of blood PLA2 and its related lipid mediators during endotoxic shock were observed in rabbits. The rabbits we...The regulatory effects of phospholipase A2(PLA2) inhibitors, chloroquine and dexamethasone, on the activity of blood PLA2 and its related lipid mediators during endotoxic shock were observed in rabbits. The rabbits were randomized into 4 groups as follows : The normal control (NC) group consisted of 12 rabbits with sham injection . the endotoxic shork (ES) group of 31 rabbits, the chloquine pretreated (CQ) group of 16 rabbits receiving 3 mg/kg of chlorqouine and the dexamethasone-pretreated (DM) group of 10 rabbits receiving 5 mg/kg of dexamethasone. Blood was sampled before and 5 and 30 min, 1 ,3, 5 and 8 h after the administration of endotoxin for the determination of PLA2, platelet activating factor (PAF) , TXB2 and 6-keto-PGF1α. In addrtion, changes of mean arterial pressure (MAP) and respiratory rate (RR) were also carefully recorded. It was found that the activities of PLA2 and PAF and the levels of TXB2 and 6-keto-PGF1α. were significantly increased after the infusion of endotoxin. CQ and DM markedly suppressed the activities of PLA2 and PAF. The inhibition of CQ on TXB2 and 6-keto-PGF1α was greater than that of DM. Besides, CQ and DM could increase the survival rate of the animals from 48% to 75% (CQ group) and 70% (DM group). These findings suggest that PLA2 inhibitors such as CQ and DM can significantly attenuate the formation of shock mediators such as PLA2, PAF, TXB2 and 6-keto-PGF1α, and so improve the prognosis of the victims of endotoxic shock.展开更多
As of August 16,2021,there have been 207,173,086 confirmed cases and 4,361,996 deaths due to the coronavirus disease(COVID-19),and the pandemic remains a global challenge.To date,no effective and approved drugs are av...As of August 16,2021,there have been 207,173,086 confirmed cases and 4,361,996 deaths due to the coronavirus disease(COVID-19),and the pandemic remains a global challenge.To date,no effective and approved drugs are available for the treatment of COVID-19.Angiotensin-converting enzyme 2(ACE2)plays a crucial role in the invasion into host cells by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the etiological agent of COVID-19.Notably,ACE2 density is influenced by medical conditions,such as hypertension,or by drugs,including angiotensin-converting enzyme inhibitors(ACEIs)and angiotensin receptor blockers(ARBs),which can change the fate of SARS-CoV-2 infectivity.ACE2 is a target for these drugs and can be manipulated to limit the viral entry and replication within the cells.Different strategies aimed at blocking ACE2 with small molecules,peptides,and antibodies,or by neutralizing the virus through its competitive binding with human recombinant soluble ACE2(hrsACE2)are currently under investigation.In this article,we review the current state of knowledge that emphasizes the need to find effective therapeutic agents against COVID-19 by exploiting ACE2 as a potential target.The increased soluble ACE2 levels and the application of hrsACE2 in patients with COVID-19 can be implemented to control the disease.It has not yet been established whether hypertension and other comorbidities,independent of age,have a direct role in COVID-19.Therefore,the use of renin-angiotensin system inhibitors,ACEIs and ARBs,should not be discontinued during COVID-19 treatment.展开更多
基金supported by a grant from Ministry of Science,Technological Development and Innovation,Serbia,No.451-03-68/2022-14/200178(to NN)University of Defence,No.MFVMA/02/22-24(to MN)。
文摘An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in PD.Repetitive transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's disease.However,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain unknown.The purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated signaling.Animals with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod test.Immunoblot,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate putamen.Prolonged intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate putamen.Treatment with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor symptoms.After treatment with prolonged intermittent theta burst stimulation,complete motor recovery was observed.This improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst stimulation.Our results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)R.Intermittent theta burst stimulation reversed these effects by restoring the abundances of A_(1)R and A_(2A)R to control levels.The shift in ARs expression likely restored the balance between dopamine-adenosine signaling,ultimately leading to the recovery of motor control.
文摘Objective To investigate the potential effects of angiogenic process by secretory phospholipase A2 (sPLA2)inhibitor-HyPE(linking N-derivatized phosphatidyl-ethanolamine to hyaluronic acid)on human bone marrow endothelial cell line(HBME-1). Methods In order to examine the suppressing effects of HyPE on HBME-1 proliferation, migration, and capillary-like tube formation, HBME-1 were activated by angiogenic factor, specifically by basic fibroblast growth factor(b-FGF), vascular endothelial growth factor(VEGF),and oncostatin M(OSM)(at a final concentration of 25, 20, and 2.5 ng/mL, respectively), then HBME-1 proliferation, migration, and tube forma-tion were studied in the absence or presence of HyPE. HBME-1 tube formation was specially analyzed in fibrin gel. Results HyPE effectively inhibited HBME-1 proliferation and migration as a dose-dependent manner, whatever HBME-1 were grown in the control culture medium or stimulated with b-FGF, VEGF, or OSM. In fibrin, the formations of HBME-1 derived tube-like structures were enhanced by all angiogenic factors, but these were strongly suppressed by HyPE. Conclusions The results support the involvement of sPLA2 in angiogenesis. It is proposed that sPLA2 inhibitor introduces a novel approach in the control of cancer development.
文摘The regulatory effects of phospholipase A2(PLA2) inhibitors, chloroquine and dexamethasone, on the activity of blood PLA2 and its related lipid mediators during endotoxic shock were observed in rabbits. The rabbits were randomized into 4 groups as follows : The normal control (NC) group consisted of 12 rabbits with sham injection . the endotoxic shork (ES) group of 31 rabbits, the chloquine pretreated (CQ) group of 16 rabbits receiving 3 mg/kg of chlorqouine and the dexamethasone-pretreated (DM) group of 10 rabbits receiving 5 mg/kg of dexamethasone. Blood was sampled before and 5 and 30 min, 1 ,3, 5 and 8 h after the administration of endotoxin for the determination of PLA2, platelet activating factor (PAF) , TXB2 and 6-keto-PGF1α. In addrtion, changes of mean arterial pressure (MAP) and respiratory rate (RR) were also carefully recorded. It was found that the activities of PLA2 and PAF and the levels of TXB2 and 6-keto-PGF1α. were significantly increased after the infusion of endotoxin. CQ and DM markedly suppressed the activities of PLA2 and PAF. The inhibition of CQ on TXB2 and 6-keto-PGF1α was greater than that of DM. Besides, CQ and DM could increase the survival rate of the animals from 48% to 75% (CQ group) and 70% (DM group). These findings suggest that PLA2 inhibitors such as CQ and DM can significantly attenuate the formation of shock mediators such as PLA2, PAF, TXB2 and 6-keto-PGF1α, and so improve the prognosis of the victims of endotoxic shock.
文摘As of August 16,2021,there have been 207,173,086 confirmed cases and 4,361,996 deaths due to the coronavirus disease(COVID-19),and the pandemic remains a global challenge.To date,no effective and approved drugs are available for the treatment of COVID-19.Angiotensin-converting enzyme 2(ACE2)plays a crucial role in the invasion into host cells by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the etiological agent of COVID-19.Notably,ACE2 density is influenced by medical conditions,such as hypertension,or by drugs,including angiotensin-converting enzyme inhibitors(ACEIs)and angiotensin receptor blockers(ARBs),which can change the fate of SARS-CoV-2 infectivity.ACE2 is a target for these drugs and can be manipulated to limit the viral entry and replication within the cells.Different strategies aimed at blocking ACE2 with small molecules,peptides,and antibodies,or by neutralizing the virus through its competitive binding with human recombinant soluble ACE2(hrsACE2)are currently under investigation.In this article,we review the current state of knowledge that emphasizes the need to find effective therapeutic agents against COVID-19 by exploiting ACE2 as a potential target.The increased soluble ACE2 levels and the application of hrsACE2 in patients with COVID-19 can be implemented to control the disease.It has not yet been established whether hypertension and other comorbidities,independent of age,have a direct role in COVID-19.Therefore,the use of renin-angiotensin system inhibitors,ACEIs and ARBs,should not be discontinued during COVID-19 treatment.
