Neuroprotective effects of VEGF administration after focal cerebral ischemia/reperfusion: Dose response and time window

Dl-3-N-Butylphthalide Attenuates Hypoxic Injury of Neural Stem Cells by Increasing Hypoxia-Inducible Factor-1alpha

OBJECTIVE

To assess the potential effect of dl-3-N-butylphthalide (dl-NBP) for the proliferation and differentiation of neural stem cells (NSCs) against hypoxia and the underlying mechanism.

MATERIALS AND METHODS

Hippocampal NSCs were obtained from fetal rats. NSCs combined with dl-NBP and single NSCs were cultured. The impact of siRNA-mediated hypoxia-inducible factor-1alpha (HIF-1α) knockdown on NSCs was detected with western blotting (WB) and quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR). Cell-counting kit-8 assay was used for evaluating the viability of NSCs. Levels of HIF-1α protein were measured using WB, and vascular endothelial growth factor (VEGF) expression was quantified using RT-qPCR and enzyme-linked immunosorbent assay.

RESULTS

Compared with 7 different concentrations of dl-NBP, 0.25 g/L was determined as the optimal concentration to significantly increase the viability of NSCs (p < 0.001). Dl-NBP can significantly increase the viability of hypoxic NSCs (p < 0.001) and improve the differentiation of hypoxic NSCs into astrocytes (p = 0.001) and oligodendrocytes (p < 0.001). Meanwhile, Dl-NBP can significantly elevate levels of HIF-1α protein (p < 0.001) and VEGF mRNA (p = 0.001) / protein (p < 0.001) in NSCs in the hypoxic environment. However, after transfection with HIF-1α siRNA in NSCs, the viability and differentiation of NSCs was not recovered using dl-NBP under the hypoxic condition, as well as levels of HIF-1α and VEGF.

CONCLUSION

Dl-NBP can reverse the weaker proliferation and differentiation power of NSCs in the hypoxic environment. The HIF-1α - VEGF pathway may be implicated in this protective effect of dl-NBP.

Up-regulation of ANXA1 suppresses polymorphonuclear neutrophil infiltration and myeloperoxidase activity by activating STAT3 signaling pathway in rat models of myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) is recognized as a major cause of morbidity and mortality which is commonly associated with coronary artery disease. In recent studies, annexin A1 gene (ANXA1) has been discovered to be involved in the treatment for MIRI. In this study, the primary focus was on the molecular mechanism of ANXA1 in polymorphonuclear neutrophil (PMN) infiltration and myeloperoxidase (MPO) activity in rats with MIRI. Initially, microarray analysis was carried out in order to identify differentially expressed genes. Moreover, a rat model of MIRI was established for evaluating the expression of ANXA1, signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in myocardial tissues. Following this, the ANXA1 vector, siRNA-ANXA1, and Stattic (inhibitor of STAT3 signaling pathway) were utilized for analyzing the regulatory role of ANXA1 in physiological indexes, hemodynamic parameters, inflammatory factors, myocardial infarct size, MPO activity, PMN infiltration, and apoptosis of PMNs. Furthermore, the relationship between ANXA1 and STAT3 signaling pathway was analyzed. Initially, a reduction in the expression of ANXA1, STAT3 and VEGF in myocardial tissues of MIRI rats was found. To elaborate, overexpressed ANXA1 inhibited levels of inflammatory factors, the activation of PMN infiltration, reduced the degree of PMN infiltration, and decreased the apoptosis of PMNs. More importantly, down-regulated ANXA1 inhibited the activation of STAT3 signaling pathway, which thereby suppressed VEGF expression. With this all taken into account, the present study presents that up-regulated ANXA1 inhibits PMN infiltration and MPO activity by activation of STAT3 signaling pathway in rats with MIRI.

Effect of Combination Therapy with Neuroprotective and Vasoprotective Agents on Cerebral Ischemia

Because most tested drugs are active against only one of the damaging processes associated with stroke, other mechanisms may cause cellular death. Thus, a combination of protective agents targeting different pathophysiological mechanisms may obtain better effects than a single agent. The major objective of this study was to investigate the effect of combination therapy with vascular endothelial growth factor (VEGF) and nerve growth factor (NGF) after controlled ischemic brain injury in rabbits.Methods:Animals were randomly assigned to one of the following groups: sham group, saline-treated control group or NGF+VEGF-treated group. Animals received an intracerebral microinjection of VEGF and NGF or saline at 5 or 8 hours after ischemia. The two specified time points of administration were greater than or equal to the existing therapeutic time window for monoterapy with VEGF or NGF alone (3 or 5 hours of ischemia). Infarct volume, water content, neurological deficits, neural cell apoptosis and the expression of caspase-3 and Bcl-2 were measured.Results:Compared with saline-treated controls, the combination therapy of VEGF and NGF significantly reduced infarct volume, water content, neural cell apoptosis and the expression of caspase-3, up-regulated the expression of Bcl-2 and improved functional recovery (bothp<0.01) when administered 5 or 8 hours after ischemia. The earlier the administration the better the neuroprotection.Conclusions:These results showed that the combination therapy with VEGF and NGF provided neuroprotective effects. In addition, the time window of combination treatment should be at least 8 hours after ischemia, which was wider than monotherapy.RÉSUMÉ:Les effets d’une polythérapie combinant agents neuro-protecteurs et agents vasoprotecteurs dans les cas d’ischémie cérébrale.Contexte:Étant donné que la plupart des médicaments préalablement testés tendent à n’agir contre seulement un des processus de dommage associés aux AVC, il est possible que d’autres processus entraînent une mort cellulaire. À cet effet, il se pourrait qu’une combinaison d’agents protecteurs ciblant divers mécanismes physiopathologiques permette d’obtenir de meilleurs résultats qu’un simple agent. Après avoir suscité de façon contrôlée des lésions cérébrales ischémiques chez des lapins, l’objectif principal de la présente étude a donc été de se pencher sur l’impact d’une polythérapie combinant la protéine dite « facteur de croissance de l’endothélium vasculaire » (ou « VEGF » en anglais) avec le « facteur de croissance des nerfs » (ou « NGF » en anglais).Méthodes:Les animaux ont été attribués au hasard à l’un des groupes suivants : ceux ayant reçu un traitement fictif ; ceux, du groupe témoin, ayant bénéficié d’un traitement à base de solution saline ; et finalement ceux ayant été traités au moyen des VEGF et NGF. À noter que les lapins ont reçu une micro-injection intracérébrale de VEGF et de NGF ou de solution saline 5 heures ou 8 heures à la suite de leur AVC. Ces deux délais d’administration des VEGF et NGF sont équivalents ou supérieurs aux délais actuels d’administration des VEGF ou NGF à titre de monothérapie (3 heures ou 5 heures à la suite d’un AVC). Tant le volume des infarctus, le contenu en eau, les déficits neurologiques ainsi causés, l’apoptose des neurones que l’expression des protéases caspase 3 et des protéines Bcl-2 ont été mesurés.Résultats:Si on la compare au traitement à base de solution saline administré au groupe témoin, la polythérapie à base de VEGF et de NGF, lorsqu’administrée 5 heures ou 8 heures à la suite de l’AVC, a su réduire de façon notable le volume des infarctus, le contenu en eau, l’apoptose des neurones et l’expression des protéases caspase 3. Elle a également permis de réguler à la hausse l’expression des protéines Bcl-2 en plus d’entraîner une amélioration de la récupération fonctionnelle (p< 0,01 pour ces deux aspects). Ainsi donc, plus tôt l’on opte pour cette polythérapie, meilleure sera la neuroprotection encourue.Conclusions:Ces résultats démontrent que la polythérapie à base de VEGF et de NGF procure des effets neuroprotecteurs. Quant au délai d’administration de ce traitement combinatoire, il devrait être d’au moins 8 heures à la suite d’un AVC, ce qui est plus élevé que la monothérapie.

Neuroprotective effect of total flavonoids from Ilex pubescens against focal cerebral ischemia/reperfusion injury in rats

Ilex pubescens is commonly used in traditional Chinese medicine to treat cardiovascular and cerebrovascular diseases, such as coronary artery disease and stroke. However, the underlying mechanisms remain to be fully elucidated. The aim of the present study was to investigate the effects of Ilex pubescens total flavonoids (IPTF) on neuroprotection and the potential mechanisms in a rat model of focal cerebral ischemia/reperfusion (I/R) injury. Rats were pretreated with intragastric administration of IPTF at doses of 200 and 100 mg/kg for 5 days; middle cerebral artery occlusion surgery was then performed to induce cerebral I/R injury. Neurological deficits were determined using the 5‑point neurological function score evaluation system, brain infarct sizes were determined by 2,3,5‑triphenyltetrazolium chloride staining and alterations in brain histology were determined by hematoxylin and eosin staining. The neurological deficit score, the infarcted area and the brain tissue pathological injury were significantly reduced when the rats were pretreated with IPTF. In addition, inflammatory mediators and neurotrophic factors in the brain were investigated. IPTF pretreatment decreased the activities of total nitric oxide synthase (TNOS), induced NOS (iNOS) and constitutive NOS (cNOS), and the levels of nitric oxide (NO), interleukin‑1β (IL‑1β) and tumor necrosis factor‑α (TNF‑α), however, it increased the levels of IL‑10 in brain tissues. Furthermore, pretreatment with IPTF also increased the protein expressions of brain‑derived neurotrophic factor, glial cell‑derived neurotrophic factor and vascular endothelial growth factor, when compared with the model group. In conclusion, the results of the present study demonstrated that IPTF has a neuroprotective effect against focal cerebral I/R injury in rats. The mechanism may be associated with the decreased production of certain proinflammatory cytokines including NO, IL‑1β, TNF‑α, TNOS, iNOS and cNOS, the increased production of the anti‑inflammatory cytokine IL‑10 and the increased secretion of neurotrophic factors.

Therapeutic potential of dental stem cells

Stem cell biology has become an important field in regenerative medicine and tissue engineering therapy since the discovery and characterization of mesenchymal stem cells. Stem cell populations have also been isolated from human dental tissues, including dental pulp stem cells, stem cells from human exfoliated deciduous teeth, stem cells from apical papilla, dental follicle progenitor cells, and periodontal ligament stem cells. Dental stem cells are relatively easily obtainable and exhibit high plasticity and multipotential capabilities. The dental stem cells represent a gold standard for neural-crest-derived bone reconstruction in humans and can be used for the repair of body defects in low-risk autologous therapeutic strategies. The bioengineering technologies developed for tooth regeneration will make substantial contributions to understand the developmental process and will encourage future organ replacement by regenerative therapies in a wide variety of organs such as the liver, kidney, and heart. The concept of developing tooth banking and preservation of dental stem cells is promising. Further research in the area has the potential to herald a new dawn in effective treatment of notoriously difficult diseases which could prove highly beneficial to mankind in the long run.

Combination of Ligusticum chuanxiong and Radix Paeoniae ameliorate focal cerebral ischemic in MCAO rats via endoplasmic reticulum stress-dependent apoptotic signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Combination of Ligusticum chuanxiong and Radix Paeoniae (XS) is highly effective in the treatment for focal cerebral ischemic, but the underlying mechanism is not clear. This study was conducted to evaluate the combinative effects of XS on MCAO rats and explore the underlying mechanisms.

MATERIALS AND METHODS

MCAO rats were used to evaluate the protective effect of Ligusticum chuanxiong (CX), Radix Paeoniae Rubra (CS) and their combination (XS) on ameliorating focal cerebral ischemic. Cerebral ischemia deficits and infarct size were performed by 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin (H-E) staining. Activities of SOD, CAT and GSH-Px, as well as levels of LPO and MDA were detected by commercial kits while ELISA kits for the content of plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator (PA). Immunohistochemistry (IHC) and western blot analysis (WB) were carried out to examine the protein expressions including PKR-like endoplasmic reticulum kinase (PERK), cytoplasmic of glucose regulated protein 78 (GRP78), X box-binding protein-1 (XBP-1), activating transcription factor-6 (ATF-6), C/EBP-homologous protein (CHOP), metalloprotease-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), Bcl-2 associated X protein (Bax), and porcineB-cellleukemia/lymphoma-2 (Bcl-2) in brain tissues. Reverse transcription polymerase chain reaction (RT-PCR) and Quantitative PCR (Q-PCR) were applied to examine vascular endothelial growth factor (VEGF) and N-methyl-d-aspartate receptors (NMDAR1) mRNA levels.

RESULTS

CX, CS and their combination (XS) could reduce cerebral ischemia deficits and infarct size of MCAO rats. They increased SOD, CAT and GSH-Px activities, and reduced MDA and LPO levels in serum, markedly. A significant decrease of endoplasmic reticulum stress-related factors PERK, XBP-1, ATF-6 and CHOP protein expression levels while an increase of GRP78 and MVD expression by the treatment of CX, CS and XS. It could also be observed that their treatment could reduce apoptotic damage of brain tissues by up-regulating Bax level and down-regulating Bcl-2 level. Furthermore, the levels of MMP-9 and PAI-1 in serum and tissues of rats were down-regulated remarkably while TIMP-1 and PA levels were up-regulated. VEGF mRNA level was up-regulated dramatically whereas NMDAR1 was reduced. Importantly, the combination of CX and CS, namely XS, has a more meaningful improvement on focal cerebral ischemic than CX or CS alone.

CONCLUSION

All these revealed that the combined XS exerted more remarkable protective effects than alone. XS could inhibit neuronal apoptosis by attenuating ER-stress-dependent apoptotic signaling and protected the blood-brain barrier. These findings might supply beneficial hints for the synergy of CX and CS, and provide the basis for rationality of XS preparation and deserve further clinical investigations.

Expression and significance of angiostatin, vascular endothelial growth factor and matrix metalloproteinase-9 in brain tissue of diabetic rats with ischemia reperfusion

OBJECTIVE

To discuss the expression and significance of angiostatin, vascular endothelial growth factor and matrix metalloproteinase-9 in the brain tissue of diabetic rats with ischemia reperfusion.

METHODS

A total of 60 male Wistar rats were randomly divided into the normal group, sham group, diabetic cerebral infarction group and single cerebral infarction group according to the random number table, with 15 rats in each group. The high sucrose diet and intraperitoneal injection of streptozotocin were performed for the modeling of diabetic rats, while the thread-occlusion method was employed to build the model of cerebral ischemia reperfusion. The immunohistochemical staining was performed to detect the expression of angiostatin, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in the brain tissue.

RESULTS

The expression of angiostatin after the reperfusion in the brain tissue of rats in the single cerebral infarction group and diabetic cerebral infarction group was increased 6 h after the reperfusion, reached to the peak on 1 d and then decreased gradually. The expression of angiostatin in the diabetic cerebral infarction group 6 h, 1 d, 3 d and 7 d after the reperfusion was significantly higher than that in the single cerebral infarction group (P < 0.05). VEGF began to be increased 1 h after the reperfusion in the single cerebral infarction group and diabetic cerebral infarction group, reached to the peak at 6 h and then decreased gradually. The expression of VEGF in the diabetic cerebral infarction group at each time point after the reperfusion was significantly lower than that in the single cerebral infarction group (P < 0.05). MMP-9 began to be increased 1 h after the reperfusion in the single cerebral infarction group and diabetic cerebral infarction group, reached to the peak on 1 d and then decreased gradually. The expression of MMP-9 in the diabetic cerebral infarction group at each time point after the reperfusion was significantly higher than that in the single cerebral infarction group (P < 0.05).

CONCLUSIONS

The high glucose environment in which the diabetic cerebral infarction is occurred is to induce the formation of MMP-9 at first and then activate and increase the expression of angiostatin. Afterwards, the expression of VEGF is inhibited, resulting in the poor angiogenesis after cerebral infarction, which thus makes the injury of brain tissue after cerebral infarction even worse than the non-diabetes mellitus.

Neuroprotective effects of Ilexonin A following transient focal cerebral ischemia in rats

Ilexonin A is a compound isolated from the root of a plant commonly used in traditional Chinese medicine. The aim of the present study was to investigate the possible protective mechanism of Ilexonin A in rats subjected to occlusion of the middle cerebral artery (MCAO). Transient focal cerebral ischemia was induced by 2 h of MCAO, followed by reperfusion. Ilexonin A at doses of 20, 40 and 80 mg/kg were administered via intraperitoneal injection immediately following ischemia/reperfusion. The expression levels of glial fibrillary acidic protein (GFAP), ionized calcium‑binding adapter molecule‑1 (Iba‑1), vascular endothelial growth factor (VEGF), fetal liver kinase‑1 (Flk‑1) and Nestin were examined using immunostaining and Western blot analysis of the peri‑infarct region following ischemia/reperfusion. Ilexonin A significantly decreased the infarct volume and improved neurological deficits in a dose‑dependent manner. The expression levels of VEGF, Flk‑1 and Nestin were significantly increased in the rats treated with Ilexonin A, compared with the rats administered with saline. Following treatment with Ilexonin A, a higher number of GFAP‑positive astrocytes were found in the Ilexonin A‑treated rats at 1, 3 and 7 days, compared with the rats exposed to ischemia only, however, there were fewer astrocytes at 14 days, compared with the ischemia group. Ilexonin A significantly decreased the protein expression of Iba‑1. The results of the present study suggested that the protective effects of Ilexonin A were associated with revascularization, neuronal regeneration, and the regulation of astrocyte and microglia cell activation.

Effect of Electroacupuncture on Cell Apoptosis and ERK Signal Pathway in the Hippocampus of Adult Rats with Cerebral Ischemia-Reperfusion

Background. EA therapy is a traditional therapeutic approach for alleviation of cerebral I/R-induced brain injury. We investigated the effect of EA on MCAO rat model to examine the mechanism of apoptosis in the rat hippocampus. Methods. 200 male Sprague-Dawley rats were randomly divided into sham, I/R, EA, ERK inhibitor (PD), and ERK inhibitor+EA (PD+EA) groups. Each group was subdivided into 5 groups according to different time points. Locomotor behaviors were evaluated using neurological scales and morphological examination was performed using HE staining. Apoptosis index of neural cells in local infarcted area was measured by TUNEL and p-ERK expression was detected using immunohistochemistry technique and western blot analysis. Results. Neurological deficit scores and neural apoptosis in the EA group were lower than I/R group at the same time points, respectively. At different time points, p-ERK level was increased in the ischemic hippocampal CA1 in the EA group as compared to I/R group; the increased level was increased most at 1 day, 3 days, and 1 week (p < 0.01). Conclusion. EA alleviates neurological deficit, reduces apoptosis index, and simultaneously upregulates the expression of p-ERK signal pathway in rats subjected to I/R injury.

A Novel Ligustrazine Derivative T-VA Prevents Neurotoxicity in Differentiated PC12 Cells and Protects the Brain against Ischemia Injury in MCAO Rats

Broad-spectrum drugs appear to be more promising for the treatment of acute ischemic stroke. In our previous work, a new ligustrazine derivative (3,5,6-trimethylpyrazin-2-yl) methyl 3-methoxy-4-[(3,5,6-trimethylpyrazin-2-yl)methoxy]benzoate (T-VA) showed neuroprotective effect on injured PC12 cells (EC₅₀ = 4.249 µM). In the current study, we show that this beneficial effect was due to the modulation of nuclear transcription factor-κB/p65 (NF-κB/p65) and cyclooxygenase-2 (COX-2) expressions. We also show that T-VA exhibited neuroprotective effect in a rat model of ischemic stroke with concomitant improvement of motor functions. We propose that the protective effect observed in vivo is owing to increased vascular endothelial growth factor (VEGF) expression, decreased oxidative stress, and up-regulation of Ca²⁺–Mg²⁺ ATP enzyme activity. Altogether, our results warrant further studies on the utility of T-VA for the potential treatment of ischemic brain injuries, such as stroke.

Dimethyloxalylglycine treatment of brain-dead donor rats improves both donor and graft left ventricular function after heart transplantation

OBJECTIVE

Hypoxia inducible factor (HIF)-1 pathway signalling has a protective effect against ischemia/reperfusion injury. The prolyl-hydroxylase inhibitor dimethyloxalylglycine (DMOG) activates the HIF-1 pathway by stabilizing HIF-1α. In a rat model of brain death (BD)-associated donor heart dysfunction we tested the hypothesis that pre-treatment of brain-dead donors with DMOG would result in a better graft heart condition.

METHODS

BD was induced in anesthetized Lewis rats by inflating a subdurally placed balloon catheter. Controls underwent sham operations. Then, rats were injected with an intravenous dose of DMOG (30 mg/kg) or an equal volume of physiologic saline. After 5 hours of BD or sham operation, hearts were perfused with a cold (4°C) preservation solution (Custodiol; Dr. Franz Köhler Chemie GmbH; Germany), explanted, stored at 4°C in Custodiol, and heterotopically transplanted. Graft function was evaluated 1.5 hours after transplantation.

RESULTS

Compared with control, BD was associated with decreased left ventricular systolic and diastolic function. DMOG treatment after BD improved contractility (end-systolic pressure volume relationship E'max: 3.7 ± 0.6 vs 3.1 ± 0.5 mm Hg/µ1; p < 0.05) and left ventricular stiffness (end-diastolic pressure volume relationship: 0.13 ± 0.03 vs 0.31 ± 0.06 mm Hg/µ1; p < 0.05) 5 hours later compared with the brain-dead group. After heart transplantation, DMOG treatment of brain-dead donors significantly improved the altered systolic function and decreased inflammatory infiltration, cardiomyocyte necrosis, and DNA strand breakage. In addition, compared with the brain-dead group, DMOG treatment moderated the pro-apoptotic changes in the gene and protein expression.

CONCLUSIONS

In a rat model of potential brain-dead heart donors, pre-treatment with DMOG resulted in improved early recovery of graft function after transplantation. These results support the hypothesis that activation of the HIF-1 pathway has a protective role against BD-associated cardiac dysfunction.

Expression analysis following argon treatment in an in vivo model of transient middle cerebral artery occlusion in rats

Background

Argon treatment following experimental neurotrauma has been found neuroprotective in an array of in vivo and in vitro models. The inherent cellular and molecular mechanisms are still unknown. We seeked to shed light on these processes by examinig the cellular distribution and the expression of inflammatory markers and growth factors in argon treated brain tissue.

Methods

Male adult Sprague-Dawley rats were randomly assigned to one of the study groups: sham surgery + placebo, sham surgery + argon, tMCAO + placebo, and tMCAO + argon. Animals underwent 2 h-transient middle cerebral artery occlusion (tMCAO) using the endoluminal thread model or sham surgery without tMCAO. After the first hour of tMCAO or sham surgery a 1 h inhalative argon (50% argon/50% O₂) or placebo (50% N₂/50% O₂) treatment was performed. Brains were removed and evaluated after 24 h. RealTime-PCR was performed from biopsies of the penumbra and contralateral corresponding regions. Paraffin sections were immunostained with antibodies against GFAP, NeuN, and Iba1. Cell counts of astrocytes, neurons and microglia in different cortical regions were performed in a double-blinded manner.

Results

Fifteen animals per tMCAO group and twelve sham + placebo respectively eleven sham + argon animals completed the interventional procedure. We identified several genes (IL-1β, IL-6, iNOS, TGF-β, and NGF) whose transcription was elevated 24 h after the study intervention, and whose expression levels significantly differed between argon treatment and placebo following tMCAO. Except for the core region of ischemia, cell numbers were comparable between different treatment groups.

Conclusion

In our study, we found an elevated expression of several inflammatory markers and growth factors following tMCAO + argon compared to tMCAO + placebo. Although conflicting the previously described neuroprotective effects of argon following experimental ischemia, these findings might still be associated with each other. Further studies will have to evaluate their relevance and potential relationship.

Effect of hypoxia on generation of neurospheres from adipose tissue-derived canine mesenchymal stromal cells

Adipose tissue-derived mesenchymal stromal cells (AT-MSCs) are good candidates for cell therapy due to the accessibility of fat tissue and the abundance of AT-MSCs therein. Neurospheres are free-floating spherical condensations of cells with neural stem/progenitor cell (NSPC) characteristics that can be derived from AT-MSCs. The aims of this study were to examine the influence of oxygen (O2) tension on generation of neurospheres from canine AT-MSCs (AT-cMSCs) and to develop a hypoxic cell culture system to enhance the survival and therapeutic benefit of generated neurospheres. AT-cMSCs were cultured under varying oxygen tensions (1%, 5% and 21%) in a neurosphere culture system. Neurosphere number and area were evaluated and NSPC markers were quantified using real-time quantitative PCR (qPCR). Effects of oxygen on neurosphere expression of hypoxia inducible factor 1, α subunit (HIF1A) and its target genes, erythropoietin receptor (EPOR), chemokine (C-X-C motif) receptor 4 (CXCR4) and vascular endothelial growth factor (VEGF), were quantified by qPCR. Neural differentiation potential was evaluated in 21% O2 by cell morphology and qPCR. Neurospheres were successfully generated from AT-cMSCs at all O2 tensions. Expression of nestin mRNA (NES) was significantly increased after neurosphere culture and was significantly higher in 1% O2 compared to 5% and 21% O2. Neurospheres cultured in 1% O2 had significantly increased levels of VEGF and EPOR. There was a significant increase in CXCR4 expression in neurospheres generated at all O2 tensions. Neurosphere culture under hypoxia had no negative effect on subsequent neural differentiation. This study suggests that generation of neurospheres under hypoxia could be beneficial when considering these cells for neurological cell therapies.

Vascular endothelial growth factor and monocyte chemoattractant protein-1 levels unaltered in symptomatic atherosclerotic carotid plaque patients from north India

We aimed to identify the role of vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein (MCP-1) as a serum biomarker of symptomatic carotid atherosclerotic plaque in North Indian population. Individuals with symptomatic carotid atherosclerotic plaque have high risk of ischemic stroke. Previous studies from western countries have shown an association between VEGF and MCP-1 levels and the incidence of ischemic stroke. In this study, venous blood from 110 human subjects was collected, 57 blood samples of which were obtained from patients with carotid plaques, 38 neurological controls without carotid plaques, and another 15 healthy controls who had no history of serious illness. Serum VEGF and MCP-1 levels were measured using commercially available enzyme-linked immunosorbent assay. We also correlated the data clinically and carried out risk factor analysis based on the detailed questionnaire obtained from each patient. For risk factor analysis, a total of 70 symptomatic carotid plaque cases and equal number of age and sex matched healthy controls were analyzed. We found that serum VEGF levels in carotid plaque patients did not show any significant change when compared to either of the controls. Similarly, there was no significant upregulation of MCP-1 in the serum of these patients. The risk factor analysis revealed that hypertension, diabetes, and physical inactivity were the main correlates of carotid atherosclerosis (p < 0.05). Prevalence of patients was higher residing in urban areas as compared to rural region. We also found that patients coming from mountain region were relatively less vulnerable to cerebral atherosclerosis as compared to the ones residing at non mountain region. On the contrary, smoking, obesity, dyslipidemia, alcohol consumption, and tobacco chewing were not observed as the determinants of carotid atherosclerosis risk in North India (p > 0.05). We conclude that the pathogenesis of carotid plaques may progress independent of these inflammatory molecules. In parallel, risk factor analysis indicates hypertension, diabetes, and sedentary lifestyle as the most significant risk factors of ischemic stroke identified in North India. This could be helpful in early identification of subjects at risk for stroke and devising health care strategies.