Social isolation initiated post-weaning augments ischemic brain injury by promoting pro-inflammatory responses

Social isolation is associated with poor stroke outcome, but the underlying molecular mechanisms were largely unknown. In male Balb/C mice exposed to transient middle cerebral artery occlusion (MCAo), we examined the effects of social isolation initiated post-weaning on ischemic injury, cytokine/chemokine responses and cell signaling using a broad panel of techniques that involved immunocytochemistry, cytokine/chemokine array and Western blots. Social isolation initiated post-weaning elevated infarct size, brain edema and neuronal injury in the ischemic brain tissue 3 days after MCAo, and increased microglia/ macrophage and leukocyte accumulation. In line with the increased immune cell recruitment, levels of several proinflammatory cytokines (e.g., IL-1α, IL-1β, IL-13, IL-17, TNF-α, IFN-γ), chemokines (e.g., CCL3, CCL4, CCL12, CXCL2, CXCL9, CXCL12) and adhesion molecules (i.e., ICAM-1) were increased in the ischemic brain tissue of socially isolated compared with paired housing mice, whereas levels of selected cytokines (IL-5, IL-6, IL-16) and colony-stimulating factors (G-CSF, GM-CSF) were reduced. The activity of the transcription factor nuclear factor-ĸB (NF-ĸB), which promotes cell injury via pro-inflammatory responses, was increased by social isolation, whereas that of nuclear factor erythroid related factor-2 (Nrf-2), which mediates anti-oxidative responses under oxidative stress conditions, was reduced. Our study shows that social isolation profoundly alters post-ischemic cell signaling in a way promoting pro-inflammatory responses. Our results highlight the importance of social support in preventing deleterious health effects of social isolation.

Knockdown of NEAT1 prevents post-stroke lipid droplet agglomeration in microglia by regulating autophagy

BACKGROUND

Lipid droplets (LD), lipid-storing organelles containing neutral lipids like glycerolipids and cholesterol, are increasingly accepted as hallmarks of inflammation. The nuclear paraspeckle assembly transcript 1 (NEAT1), a long non-coding RNA with over 200 nucleotides, exerts an indispensable impact on regulating both LD agglomeration and autophagy in multiple neurological disorders. However, knowledge as to how NEAT1 modulates the formation of LD and associated signaling pathways is limited.

METHODS

In this study, primary microglia were isolated from newborn mice and exposed to oxygen-glucose-deprivation/reoxygenation (OGD/R). To further explore NEAT1-dependent mechanisms, an antisense oligonucleotide (ASO) was adopted to silence NEAT1 under in vitro conditions. Studying NEAT1-dependent interactions with regard to autophagy and LD agglomeration under hypoxic conditions, the inhibitor and activator of autophagy 3-methyladenine (3-MA) and rapamycin (RAPA) were used, respectively. In a preclinical stroke model, mice received intraventricular injections of ASO NEAT1 or control vectors in order to yield NEAT1 knockdown. Analysis of readout parameters included qRT-PCR, immunofluorescence, western blot assays, and behavioral tests.

RESULTS

Microglia exposed to OGD/R displayed a temporal pattern of NEAT1 expression, peaking at four hours of hypoxia followed by six hours of reoxygenation. After effectively silencing NEAT1, LD formation and autophagy-related proteins were significantly repressed in hypoxic microglia. Stimulating autophagy in ASO NEAT1 microglia under OGD/R conditions by means of RAPA reversed the downregulation of LD agglomeration and perilipin 2 (PLIN2) expression. On the contrary, application of 3-MA promoted repression of both LD agglomeration and expression of the LD-associated protein PLIN2. Under in vivo conditions, NEAT1 was significantly increased in mice at 24 h post-stroke. Knockdown of NEAT1 significantly alleviated LD agglomeration and inhibited autophagy, resulting in improved cerebral perfusion, reduced brain injury and increased neurological recovery.

CONCLUSION

NEAT1 is a key player of LD agglomeration and autophagy stimulation, and NEAT1 knockdown provides a promising therapeutic value against stroke.

A highly bioavailable curcumin formulation ameliorates inflammation cytokines and neurotrophic factors in mice with traumatic brain injury

A novel curcumin formulation increases relative absorption by 46 times (CurcuWIN®) of the total curcuminoids over the unformulated standard curcumin form. However, the exact mechanisms by which curcumin demonstrates its neuroprotective effects are not fully understood. This study aimed to investigate the impact of a novel formulation of curcumin on the expression of brain-derived neurotrophic factor (BDNF), glial fibrillary acidic protein (GFAP), a main component of the glial scar and growth-associated protein-43 (GAP-43), a signaling molecule in traumatic brain injury (TBI). Mice (adult, male, C57BL/6j) were randomly divided into three groups as follows: TBI group (TBI-induced mice); TBI + CUR group (TBI mice were injected i.p. curcumin just after TBI); TBI+ CurcuWIN® group (TBI mice were injected i.p. CurcuWIN® just after TBI). Brain injury was induced using a cold injury model. Injured brain tissue was stained with Cresyl violet to evaluate infarct volume and brain swelling, analyzed, and measured using ImageJ by Bethesda (MD, USA). Western blot analysis was performed to determine the protein levels related to injury. While standard curcumin significantly reduced brain injury, CurcuWIN® showed an even greater reduction associated with reductions in glial activation, NF-κB, and the inflammatory cytokines IL-1β and IL-6. Additionally, both standard curcumin and CurcuWIN® led to increased BDNF, GAP-43, ICAM-1, and Nrf2 expression. Notably, CurcuWIN® enhanced their expression more than standard curcumin. This data suggests that highly bioavailable curcumin formulation has a beneficial effect on the traumatic brain in mice.

Preconditioned extracellular vesicles from hypoxic microglia reduce poststroke AQP4 depolarization, disturbed cerebrospinal fluid flow, astrogliosis, and neuroinflammation

Background: Stroke stimulates reactive astrogliosis, aquaporin 4 (AQP4) depolarization and neuroinflammation. Preconditioned extracellular vesicles (EVs) from microglia exposed to hypoxia, in turn, reduce poststroke brain injury. Nevertheless, the underlying mechanisms of such effects are elusive, especially with regards to inflammation, AQP4 polarization, and cerebrospinal fluid (CSF) flow. Methods: Primary microglia and astrocytes were exposed to oxygen-glucose deprivation (OGD) injury. For analyzing the role of AQP4 expression patterns under hypoxic conditions, a co-culture model of astrocytes and microglia was established. Further studies applied a stroke model, where some mice also received an intracisternal tracer infusion of rhodamine B. As such, these in vivo studies involved the analysis of AQP4 polarization, CSF flow, astrogliosis, and neuroinflammation as well as ischemia-induced brain injury. Results: Preconditioned EVs decreased periinfarct AQP4 depolarization, brain edema, astrogliosis, and inflammation in stroke mice. Likewise, EVs promoted postischemic CSF flow and cerebral blood perfusion, and neurological recovery. Under in vitro conditions, hypoxia stimulated M2 microglia polarization, whereas EVs augmented M2 microglia polarization and repressed M1 microglia polarization even further. In line with this, astrocytes displayed upregulated AQP4 clustering and proinflammatory cytokine levels when exposed to OGD, which was reversed by preconditioned EVs. Reduced AQP4 depolarization due to EVs, however, was not a consequence of unspecific inflammatory regulation, since LPS-induced inflammation in co-culture models of astrocytes and microglia did not result in altered AQP4 expression patterns in astrocytes. Conclusions: These findings show that hypoxic microglia may participate in protecting against stroke-induced brain damage by regulating poststroke inflammation, astrogliosis, AQP4 depolarization, and CSF flow due to EV release.

Nanodrugs for the Treatment of Ischemic Stroke: A Systematic Review

Ischemic stroke, a significant neurovascular disorder, currently lacks effective restorative medication. However, recently developed nanomedicines bring renewed promise for alleviating ischemia's effects and facilitating the healing of neurological and physical functions. The aim of this systematic review was to evaluate the efficacy of nanotherapies in animal models of stroke and their potential impact on future stroke therapies. We also assessed the scientific quality of current research focused on nanoparticle-based treatments for ischemic stroke in animal models. We summarized the effectiveness of nanotherapies in these models, considering multiple factors such as their anti-inflammatory, antioxidant, and angiogenetic properties, as well as their safety and biodistribution. We conclude that the application of nanomedicines may reduce infarct size and improve neurological function post-stroke without causing significant organ toxicity.

Reduced folate carrier 1 is present in retinal microvessels and crucial for the inner blood retinal barrier integrity

BACKGROUND

Reduced folate carrier 1 (RFC1; SLC19a1) is the main responsible transporter for the B9 family of vitamins named folates, which are essential for normal tissue growth and development. While folate deficiency resulted in retinal vasculopathy, the expression and the role of RFC1 in blood-retinal barrier (BRB) are not well known.

METHODS

We used whole mount retinas and trypsin digested microvessel samples of adult mice. To knockdown RFC1, we delivered RFC1-targeted short interfering RNA (RFC1-siRNA) intravitreally; while, to upregulate RFC1 we delivered lentiviral vector overexpressing RFC1. Retinal ischemia was induced 1-h by applying FeCl₃ to central retinal artery. We used RT-qPCR and Western blotting to determine RFC1. Endothelium (CD31), pericytes (PDGFR-beta, CD13, NG2), tight-junctions (Occludin, Claudin-5 and ZO-1), main basal membrane protein (Collagen-4), endogenous IgG and RFC1 were determined immunohistochemically.

RESULTS

Our analyses on whole mount retinas and trypsin digested microvessel samples of adult mice revealed the presence of RFC1 in the inner BRB and colocalization with endothelial cells and pericytes. Knocking down RFC1 expression via siRNA delivery resulted in the disintegration of tight junction proteins and collagen-4 in twenty-four hours, which was accompanied by significant endogenous IgG extravasation. This indicated the impairment of BRB integrity after an abrupt RFC1 decrease. Furthermore, lentiviral vector-mediated RFC1 overexpression resulted in increased tight junction proteins and collagen-4, confirming the structural role of RFC1 in the inner BRB. Acute retinal ischemia decreased collagen-4 and occludin levels and led to an increase in RFC1. Besides, the pre-ischemic overexpression of RFC1 partially rescued collagen-4 and occludin levels which would be decreased after ischemia.

CONCLUSION

In conclusion, our study clarifies the presence of RFC1 protein in the inner BRB, which has recently been defined as hypoxia-immune-related gene in other tissues and offers a novel perspective of retinal RFC1. Hence, other than being a folate carrier, RFC1 is an acute regulator of the inner BRB in healthy and ischemic retinas.

Age-Associated Resilience Against Ischemic Injury in Mice Exposed to Transient Middle Cerebral Artery Occlusion

Ischemic stroke is the leading cause of death and disability. Although stroke mainly affects aged individuals, animal research is mostly one on young rodents. Here, we examined the development of ischemic injury in young (9-12-week-old) and adult (72-week-old) C57BL/6 and BALB/c mice exposed to 30 min of intraluminal middle cerebral artery occlusion (MCAo). Post-ischemic reperfusion did not differ between young and adult mice. Ischemic injury assessed by infarct area and blood-brain barrier (BBB) integrity assessed by IgG extravasation analysis was smaller in adult compared with young mice. Microvascular viability and neuronal survival assessed by CD31 and NeuN immunohistochemistry were higher in adult than young mice. Tissue protection was associated with stronger activation of cell survival pathways in adult than young mice. Microglial/macrophage accumulation and activation assessed by F4/80 immunohistochemistry were more restricted in adult than young mice, and pro- and anti-inflammatory cytokine and chemokine responses were reduced by aging. By means of liquid chromatography-mass spectrometry, we identified a hitherto unknown proteome profile comprising the upregulation of glycogen degradation-related pathways and the downregulation of mitochondrial dysfunction-related pathways, which distinguished post-ischemic responses of the aged compared with the young brain. Our study suggests that aging increases the brain's resilience against ischemic injury.

Hyperthermia alters neurobehavior by affecting cell proliferation and neuronal survival in young male rats

Maintenance of body temperature within physiological range is critical for the fetal and neonatal development. Hyperthermia is one of the most frequently encountered pediatric complaints and may cause neurological disorders due to neuronal injury. In this study, we aimed to investigate the effects of hyperthermia on behavioral alterations, neuronal survival, apoptosis, and cell proliferation in young male Sprague-Dawley rats. Twenty-one 13-day-old rats were randomly divided into three groups (n = 7 per group). Body temperature was increased to 39°C and 41°C in a hyperthermia induction chamber for 30 min, whereas the animals in control group were maintained at 36°C. Twenty-four hours after hyperthermia, animals were subjected to the open field test, elevated-O-maze test, and grip strength test to assess the locomotor activity, anxiety, and motor function. Neuronal survival, apoptosis, and cell proliferation were investigated in cortex, hippocampal dentate gyrus (DG) and CA1 regions, and corpus callosum (CC). Decreased locomotor activity and motor function and increased anxiety were observed in the hyperthermia groups, and these were more pronounced in the 41°C group. Neuronal survival was significantly decreased in DG, CA1, and CC in the hyperthermia groups (**p < 0.01). Apoptosis was significantly induced in cortex, DG, and CC of the animals exposed to heat (*p < 0.05). In addition, cell proliferation positivity decreased significantly only in DG and CC of the animals exposed to heat (*p < 0.05). Our results suggest that neurobehavioral deficits caused by hyperthermia may be due to the increased apoptosis and neuronal cell death and decreased cell proliferation in the brain of postnatal developing rats.

The Unconventional Growth Factors Cerebral Dopamine Neurotrophic Factor and Mesencephalic Astrocyte-Derived Neurotrophic Factor Promote Post-ischemic Neurological Recovery, Perilesional Brain Remodeling, and Lesion-Remote Axonal Plasticity

Considerable efforts are currently made to develop strategies that boost endogenous recovery once a stroke has occurred. Owing to their restorative properties, neurotrophic factors are attractive candidates that capitalize on endogenous response mechanisms. Non-conventional growth factors cerebral dopamine neurotrophic factor (CDNF) and mesencephalic astrocyte-derived neurotrophic factor (MANF) promote neuronal survival and reduce neurological deficits in the acute phase of ischemic stroke in mice. Their effects on endogenous repair and recovery mechanisms in the stroke recovery phase were so far unknown. By intracerebroventricular delivery of CDNF or MANF starting 3 days post-stroke (1 µg/day for 28 days via miniosmotic pumps), we show that delayed CDNF and MANF administration promoted functional neurological recovery assessed by a battery of behavioral tests, increased long-term neuronal survival, reduced delayed brain atrophy, glial scar formation, and, in case of CDNF but not MANF, increased endogenous neurogenesis in the perilesional brain tissue. Besides, CDNF and MANF administration increased long-distance outgrowth of terminal axons emanating from the contralesional pyramidal tract, which crossed the midline to innervate ipsilesional facial nucleus. This plasticity promoting effect was accompanied by downregulation of the axonal growth inhibitor versican and the guidance molecules ephrin B1 and B2 in the previously ischemic hemisphere at 14 dpi, which represents a sensitive time-point for axonal growth. CDNF and MANF reduced the expression of the proinflammatory cytokines IL1β and TNFα in both hemispheres. The effects of non-conventional growth factors in the ischemic brain should further be examined since they might help to identify targets for restorative stroke therapy.

Lithium promotes long-term neurological recovery after spinal cord injury in mice by enhancing neuronal survival, gray and white matter remodeling, and long-distance axonal regeneration

Spinal cord injury (SCI) induces neurological deficits associated with long-term functional impairments. Since the current treatments remain ineffective, novel therapeutic options are needed. Besides its effect on bipolar mood disorder, lithium was reported to have neuroprotective activity in different neurodegenerative conditions, including SCI. In SCI, the effects of lithium on long-term neurological recovery and neuroplasticity have not been assessed. We herein investigated the effects of intraperitoneally administered lithium chloride (LiCl) on motor coordination recovery, electromyography (EMG) responses, histopathological injury and remodeling, and axonal plasticity in mice exposed to spinal cord transection. At a dose of 0.2, but not 2.0 mmol/kg, LiCl enhanced motor coordination and locomotor activity starting at 28 days post-injury (dpi), as assessed by a set of behavioral tests. Following electrical stimulation proximal to the hemitransection, LiCl at 0.2 mmol/kg decreased the latency and increased the amplitude of EMG responses in the denervated hindlimb at 56 dpi. Functional recovery was associated with reduced gray and white matter atrophy rostral and caudal to the hemitransection, increased neuronal survival and reduced astrogliosis in the dorsal and ventral horns caudal to the hemitransection, and increased regeneration of long-distance axons proximal and distal to the lesion site in mice receiving 0.2 mmol/kg, but not 2 mmol/kg LiCl, as assessed by histochemical and immunohistochemical studies combined with anterograde tract tracing. Our results indicate that LiCl induces long-term neurological recovery and neuroplasticity following SCI.

Phosphodiesterase 10A deactivation induces long-term neurological recovery, Peri-infarct remodeling and pyramidal tract plasticity after transient focal cerebral ischemia in mice

The phosphodiesterase (PDE) superfamily comprises enzymes responsible for the cAMP and cGMP degradation to AMP and GMP. PDEs are abundant in the brain, where they are involved in several neuronal functions. High PDE10A abundance was previously observed in the striatum; however its consequences for stroke recovery were unknown. Herein, we evaluated the effects of PDE10A deactivation by TAK-063 (0.3 or 3 mg/kg, initiated 72 h post-stroke) in mice exposed to intraluminal middle cerebral artery occlusion. We found that PDE10A deactivation over up to eight weeks dose-dependently increased long-term neuronal survival, angiogenesis, and neurogenesis in the peri-infarct striatum, which represents the core of the middle cerebral artery territory, and reduced astroglial scar formation, whole brain atrophy and, more specifically, striatal atrophy. Functional motor-coordination recovery and the long-distance plasticity of pyramidal tract axons, which originate from the contralesional motor cortex and descend through the contralesional striatum to innervate the ipsilesional facial nucleus, were enhanced by PDE10A deactivation. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed a set of dopamine receptor-related and neuronal plasticity-related PDE10A targets, which were elevated (e.g., protein phosphatase-1 regulatory subunit 1B) or reduced (e.g., serine/threonine protein phosphatase 1α, β-synuclein, proteasome subunit α2) by PDE10A deactivation. Our results identify PDE10A as a therapeutic target that critically controls post-ischemic brain tissue remodeling and plasticity.

Effect of a Novel Valerian Extract on Sleep Duration, Latency, Pro-sleep Neurotransmitters and Neuronal Receptors in a Pentobarbital-Induced Sleep Model in Mice

Objectives

Insomnia and sleep associated disorders continue to remain one of the significant health challenges affecting more than 30% of adult population. Valeriana officinalis is being used since ancient times for treatment of conditions associated with sleep. The current study aimed to validate the effect of a novel valerian (VA) extract on sleep quality and molecular mechanisms of action using pentobarbital-induced sleep model in mice.

Methods

Thirty-five male BALB/c mice were divided into 5 groups: 1) Control, 2) Pentobarbital (42 mg/kg), 3) Pentobarbital + melatonin (2 mg/kg BW) 4) Pentobarbital + VA1 (100 mg/kg BW), 5) Pentobarbital + VA2 (300 mg/kg BW). Forty-five minutes following oral treatment, mice were injected with a hypotonic dose of pentobarbital into the left side of abdomen. Sleep duration was measured as the time elapsed between reflex loss and recovery. Sleep latency was measured as the period between pentobarbital injection and sleep onset. Melatonin was used as reference in the study. Animals were euthanized at the end of the study and analyzed for serum neurotransmitter levels and various neurotransmitter receptor levels in the brain tissues.

Results

Melatonin and VA extract increased the sleep duration and decreased the sleep latency as compared to Pentobarbital group (P &lt; 0.05), wherein the VA2 group showed significantly higher improvements in sleep latency compared to VA1 and melatonin groups (P &lt; 0.05). Further, both groups of valerian (VA1 & VA2) and melatonin increased the serum levels of pro-sleep neurotransmitters; serotonin, melatonin, and dopamine along with increased expression of their receptors (GABAA R2, GABAB R1- R2, serotonin receptor, Glutamate receptors GluA1, GluN2A, and GluN1) in the brain tissues. We also observed increased expression of modulators of apoptotic pathway and reduced oxidative stress in valerian as well as melatonin groups.

Conclusions

Valerian extract 2% powder prolongs sleep duration and decreases sleep latency in a pentobarbital-induced sleep model in mice. Further valerian extract modulated the serum levels of all three pro-sleep neurotransmitters and enhanced the expression of various sleep promoting neuronal receptors of brain involved in sleep biology in a dose-dependent manner.

Funding Sources

OmniActive Health Technologies (India) and partially by the Turkish Academy of Sciences (Turkey).

A Novel Theanine Complex, Mg-L-Theanine Improves Sleep Quality via Regulating Brain Electrochemical Activity

L-Theanine is commonly used to improve sleep quality through inhibitory neurotransmitters. On the other hand, Mg²⁺, a natural NMDA antagonist and GABA agonist, has a critical role in sleep regulation. Using the caffeine-induced brain electrical activity model, here we investigated the potency of L-theanine and two novel Mg-L-theanine compounds with different magnesium concentrations on electrocorticography (ECoG) patterns, GABAergic and serotonergic receptor expressions, dopamine, serotonin, and melatonin levels. Furthermore, we evaluated the sleep latency and duration in the pentobarbital induced sleep model. We herein showed that L-theanine, particularly its various complexes with magnesium increases the expression of GABAergic, serotonergic, and glutamatergic receptors, which were associated with decreased ECoG frequency, increased amplitude, and enhanced delta wave powers. Besides increased dopamine, serotonin, and melatonin; decreased MDA and increased antioxidant enzyme levels were also observed particularly with Mg-complexes. Protein expression analyses also showed that Mg-L-theanine complexes decrease inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) levels significantly. In accordance with these results, Mg complexes improved the sleep latency and duration even after caffeine administration. As a result, our data indicate that Mg-L-theanine compounds potentiate the effect of L-theanine on sleep by boosting slow-brain waves, regulating brain electrical activity, and increasing neurotransmitter and GABA receptor levels.

Phosphorylation of PI3K/Akt at Thr308, but not MAPK kinase, mediates lithium-induced neuroprotection against cerebral ischemia in mice

Lithium, in addition to its effect on acute and long-term bipolar disorder, is involved in neuroprotection after ischemic stroke. Yet, its mechanism of action is still poorly understood, which was only limited to its modulatory effect on GSK pathway. Therefore, we initially analyzed the dose-dependent effects of lithium on neurological deficits, infarct volume, brain edema and blood-brain barrier integrity, along with neuronal injury and survival in mice subjected to focal cerebral ischemia. Thereafter, we investigated the involvement of the PI3K/Akt and MEK signal transduction pathways and their components. Our observations revealed that 2 mmol/kg lithium significantly improved post-ischemic brain tissue survival. Although, 2 mmol/kg lithium had no negative effect on brain microcirculation, 5 and 20 mmol/kg lithium reduced brain perfusion. Furthermore, supratherapeutic dose of lithium in 20 mmol/kg lead to animal death. In addition, improvement of brain perfusion with L-arginine, did not change the effect of 5 mmol/kg lithium on brain injury. Additionally, post-stroke blood-brain barrier leakage, hemodynamic impairment and apoptosis have been reversed by lithium treatment. Interestingly, lithium-induced neuroprotection was associated with increased phosphorylation of Akt at Thr308 and suppressed GSK-3β phosphorylation at Ser9 residue. Lithium upregulated Erk-2 and downregulated JNK-2 phosphorylation. To distinguish whether neuroprotective effects of lithium are modulated by PI3K/Akt or MEK, we sequentially blocked these pathways and demonstrated that the neuroprotective activity of lithium persisted during MEK/ERK inhibition, whereas PI3K/Akt inhibition abolished neuroprotection. Collectively, we demonstrated lithium exerts its post-stroke neuroprotective activity via the PI3K/Akt pathway, specifically via Akt phosphorylation at Thr308, but not via MEK/ERK.

Right ventricle early inflow-outflow index may inform about the severity of pneumonia in patients with COVID-19

BACKGROUND

Echocardiography is generally used in our daily practice to detect cardiovascular complications in COVID-19 patients and for etiological research in the case of worsened clinical status. Many echocardiographic parameters have been the subject of investigation in previous studies on COVID-19. Recently, the right ventricle early inflow-outflow (RVEIO) index has been identified as a possible and indirect marker of the severity of tricuspid regurgitation and right ventricular dysfunction in pulmonary embolism. In this study, we aimed to investigate the relationship between the severity of pneumonia in COVID-19 patients and the RVEIO index.

METHODS

A total of 54 patients diagnosed with COVID-19 pneumonia were enrolled in this study. Our study population was separated into two groups as severe pneumonia and nonsevere pneumonia based on computed tomography imaging.

RESULTS

Saturation O₂ , C-reactive protein, D-dimer, deceleration time, tricuspid annular plane systolic excursion, tricuspid lateral annular systolic velocity, and RVEIO index values were found to be significantly different between severe and nonsevere pneumonia groups. The result of the multivariate logistic regression test revealed that saturation O2, D-dimer, Sm, and RVEIO index were the independent predictive parameters for severe pneumonia. Receiver operating characteristic curve analysis demonstrated that RVEIO index >4.2 predicted severe pneumonia with 77% sensitivity and 79% specificity.

CONCLUSION

The RVEIO index can be used as a bedside, noninvasive, easily accessible, and useful marker to identify the COVID-19 patient group with widespread pneumonia and, therefore high risk of complications, morbidity, and mortality.

Can Carpobrotus edulis, heal incisional and excisional wounds on the skin?

OBJECTIVES

This study aimed to investigate the wound healing activity of liposomal Carpobrotus edulis powder extract (CEPE) formulation on incisional and excisional wounds in rat.

BACKGROUND

In the event of any damage, the damaged tissue undergoes a process of regenerating itself, which is called wound healing.

METHODS

Centella asiatica extract (CAE) was used as the reference molecule in the study. The wound healing process was tested by using the excisional and incisional wound model. On the 12th day of the study, maximum stress, stress, % of elongation values were evaluated in the incisional wound. Also; histological parameters and macroscopic photographic analyses were evaluated in the excisional wound.

RESULTS

In the photo evaluations, the improvement was more prominent in both CAE and CEPE groups than in the control group. Histological evaluation showed that CEPE group had significant wound healing activity compared to the control and CAE groups. Axial tensile-elongation experiments in incisional wound tissue show that there was no significant difference between CAE and CEPE groups.

CONCLUSION

Liposomal formulations of C.edulis extract were found to have positive effects on the healing process, both on excisional and incisional wound tissues (Tab. 2, Fig. 3, Ref. 30).

Extracellular vesicles from hypoxia-preconditioned microglia promote angiogenesis and repress apoptosis in stroke mice via the TGF-β/Smad2/3 pathway

Systemic transplantation of oxygen-glucose deprivation (OGD)-preconditioned primary microglia enhances neurological recovery in rodent stroke models, albeit the underlying mechanisms have not been sufficiently addressed. Herein, we analyzed whether or not extracellular vesicles (EVs) derived from such microglia are the biological mediators of these observations and which signaling pathways are involved in the process. Exposing bEnd.3 endothelial cells (ECs) and primary cortical neurons to OGD, the impact of EVs from OGD-preconditioned microglia on angiogenesis and neuronal apoptosis by the tube formation assay and TUNEL staining was assessed. Under these conditions, EV treatment stimulated both angiogenesis and tube formation in ECs and repressed neuronal cell injury. Characterizing microglia EVs by means of Western blot analysis and other techniques revealed these EVs to be rich in TGF-β1. The latter turned out to be a key compound for the therapeutic potential of microglia EVs, affecting the Smad2/3 pathway in both ECs and neurons. EV infusion in stroke mice confirmed the aforementioned in vitro results, demonstrating an activation of the TGF-β/Smad2/3 signaling pathway within the ischemic brain. Furthermore, enriched TGF-β1 in EVs secreted from OGD-preconditioned microglia stimulated M2 polarization of residing microglia within the ischemic cerebral environment, which may contribute to a regulation of an early inflammatory response in postischemic hemispheres. These observations are not only interesting from the mechanistic point of view but have an immediate therapeutic implication as well, since stroke mice treated with such EVs displayed a better functional recovery in the behavioral test analyses. Hence, the present findings suggest a new way of action of EVs derived from OGD-preconditioned microglia by regulating the TGF-β/Smad2/3 pathway in order to promote tissue regeneration and neurological recovery in stroke mice.

Phosphodiesterase 10A Is a Critical Target for Neuroprotection in a Mouse Model of Ischemic Stroke

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/β 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.

Inflammatory Cytokines are in Action: Brain Plasticity and Recovery after Brain Ischemia Due to Delayed Melatonin Administration

OBJECTIVES

Post-ischemic inflammation leads to apoptosis as an indirect cause of functional disabilities after the stroke. Melatonin may be a good candidate for the stroke recovery because of its anti-inflammatory effects. Therefore, we investigated the effect of melatonin on inflammation in the functional recovery of brain by evaluating ipsilesional and contralesional alterations.

MATERIALS AND METHODS

Melatonin (4 mg/kg/day) was intraperitoneally administered into the mice from the 3^rd to the 55^th day of the post-ischemia after 30 min of middle cerebral artery occlusion.

RESULTS

Melatonin produced a functional recovery by reducing the emigration of the circulatory leukocytes and the local microglial activation within the ischemic brain. Overall, the expression of the inflammation-related genes reduced upon melatonin treatment in the ischemic hemisphere. On the other hand, the expression level of the inflammatory cytokine genes raised in the contralateral hemisphere at the 55^th day of the post-ischemia. Furthermore, melatonin triggers an increase in the iNOS expression and a decrease in the nNOS expression in the ipsilateral hemisphere at the earlier times in the post-ischemic recovery. At the 55^th day of the post-ischemic recovery, melatonin administration enhanced the eNOS and nNOS protein expressions.

CONCLUSIONS

The present molecular, biological, and histological data have revealed broad anti-inflammatory effects of melatonin in both hemispheres with distinct temporal and spatial patterns at different phases of post-stroke recovery. These outcomes also established that melatonin act recruitment of contralesional rather than of ipsilesional.

Inhibition of Fatty Acid Synthesis Aggravates Brain Injury, Reduces Blood-Brain Barrier Integrity and Impairs Neurological Recovery in a Murine Stroke Model

Inhibition of fatty acid synthesis (FAS) stimulates tumor cell death and reduces angiogenesis. When SH-SY5Y cells or primary neurons are exposed to hypoxia only, inhibition of FAS yields significantly enhanced cell injury. The pathophysiology of stroke, however, is not only restricted to hypoxia but also includes reoxygenation injury. Hence, an oxygen-glucose-deprivation (OGD) model with subsequent reoxygenation in both SH-SY5Y cells and primary neurons as well as a murine stroke model were used herein in order to study the role of FAS inhibition and its underlying mechanisms. SH-SY5Y cells and cortical neurons exposed to 10 h of OGD and 24 h of reoxygenation displayed prominent cell death when treated with the Acetyl-CoA carboxylase inhibitor TOFA or the fatty acid synthase inhibitor cerulenin. Such FAS inhibition reduced the reduction potential of these cells, as indicated by increased NADH₂ ⁺/NAD⁺ ratios under both in vitro and in vivo stroke conditions. As observed in the OGD model, FAS inhibition also resulted in increased cell death in the stroke model. Stroke mice treated with cerulenin did not only display increased brain injury but also showed reduced neurological recovery during the observation period of 4 weeks. Interestingly, cerulenin treatment enhanced endothelial cell leakage, reduced transcellular electrical resistance (TER) of the endothelium and contributed to poststroke blood-brain barrier (BBB) breakdown. The latter was a consequence of the activated NF-κB pathway, stimulating MMP-9 and ABCB1 transporter activity on the luminal side of the endothelium. In conclusion, FAS inhibition aggravated poststroke brain injury as consequence of BBB breakdown and NF-κB-dependent inflammation.

Neural Progenitor Cell-Derived Extracellular Vesicles Enhance Blood-Brain Barrier Integrity by NF-κB (Nuclear Factor-κB)-Dependent Regulation of ABCB1 (ATP-Binding Cassette Transporter B1) in Stroke Mice

Supplemental Digital Content is available in the text.

Objective:

Extracellular vesicles (EVs) derived from neural progenitor cells enhance poststroke neurological recovery, albeit the underlying mechanisms remain elusive. Since previous research described an enhanced poststroke integrity of the blood-brain barrier (BBB) upon systemic transplantation of neural progenitor cells, we examined if neural progenitor cell-derived EVs affect BBB integrity and which cellular mechanisms are involved in the process.

Approach and Results:

Using in vitro models of primary brain endothelial cell (EC) cultures as well as co-cultures of brain ECs (ECs) and astrocytes exposed to oxygen glucose deprivation, we examined the effects of EVs or vehicle on microvascular integrity. In vitro data were confirmed using a mouse transient middle cerebral artery occlusion model. Cultured ECs displayed increased ABCB1 (ATP-binding cassette transporter B1) levels when exposed to oxygen glucose deprivation, which was reversed by treatment with EVs. The latter was due to an EV-induced inhibition of the NF-κB (nuclear factor-κB) pathway. Using a BBB co-culture model of ECs and astrocytes exposed to oxygen glucose deprivation, EVs stabilized the BBB and ABCB1 levels without affecting the transcellular electrical resistance of ECs. Likewise, EVs yielded reduced Evans blue extravasation, decreased ABCB1 expression as well as an inhibition of the NF-κB pathway, and downstream matrix metalloproteinase 9 (MMP-9) activity in stroke mice. The EV-induced inhibition of the NF-κB pathway resulted in a poststroke modulation of immune responses.

Conclusions:

Our findings suggest that EVs enhance poststroke BBB integrity via ABCB1 and MMP-9 regulation, attenuating inflammatory cell recruitment by inhibition of the NF-κB pathway.

The Association between HbA1c Levels, Olfactory Memory and Cognition in Normal, Pre-Diabetic and Diabetic Persons

BACKGROUND AND AIM

Recent data have shown that olfactory dysfunction is strongly related to Alzheimer's Disease (AD) that is often preceded by olfactory deficits suggesting that olfactory dysfunction might represent an early indicator of future cognitive in prediabetes.

METHODS

We have applied to a group of normal (n=15), prediabetic (n=16) and type 2 diabetic outpatients (n=15) olfactory testing, 1.5-T MRI scanner and detailed cognitive evaluation including the standard Mini-Mental State Examination (MMSE) form, Short Blessed Test (SBT), Letter Fluency Test (LFT) and the category fluency test with animal, Fruit and Vegetable Naming (CFT).

RESULTS

We have shown that Odour Threshold (OT), Discrimination (OD), and Identification (OI) scores and most cognitive test results were significantly different in the prediabetes and diabetes group compared to those in the control group. OD and OT were significantly different between the prediabetes and diabetes group, although the cognitive test results were only significantly different in the prediabetes and diabetes group compared to those in the control group. In evaluating the association between OI, OT, OD scores and specific cognitive tests, we have found, that impaired olfactory identification was the only parameter that correlated significantly with the SBT both in the pre-diabetes and diabetes group. Although spot glucose values were only correlated with OT, HbA1c levels were correlated with OT, OD, and OI, as well as results of the letter fluency test suggesting that HbA1c levels rather than the spot glucose values play a critical role in specific cognitive dysfunction.

CONCLUSION

To the best of our knowledge, this is the first prospective study to demonstrate a strong association between olfactory dysfunction and specific memory impairment in a population with prediabetes and diabetes suggesting that impaired olfactory identification might play an important role as a specific predictor of memory decline.

Adipose-derived mesenchymal stem cells reduce autophagy in stroke mice by extracellular vesicle transfer of miR-25

Grafted mesenchymal stem cells (MSCs) yield neuroprotection in preclinical stroke models by secreting extracellular vesicles (EVs). The neuroprotective cargo of EVs, however, has not yet been identified. To investigate such cargo and its underlying mechanism, primary neurons were exposed to oxygen‐glucose‐deprivation (OGD) and cocultured with adipose‐derived MSCs (ADMSCs) or ADMSC‐secreted EVs. Under such conditions, both ADMSCs and ADMSC‐secreted EVs significantly reduced neuronal death. Screening for signalling cascades being involved in the interaction between ADMSCs and neurons revealed a decreased autophagic flux as well as a declined p53‐BNIP3 activity in neurons receiving either treatment paradigm. However, the aforementioned effects were reversed when ADMSCs were pretreated with the inhibitor of exosomal secretion GW4869 or when Hrs was knocked down. In light of miR‐25‐3p being the most highly expressed miRNA in ADMSC‐EVs interacting with the p53 pathway, further in vitro work focused on this pathway. Indeed, a miR‐25‐3p oligonucleotide mimic reduced cell death, whereas the anti‐oligonucleotide increased autophagic flux and cell death by modulating p53‐BNIP3 signalling in primary neurons exposed to OGD. Likewise, native ADMSC‐EVs but not EVs obtained from ADMSCs pretreated with the anti‐miR‐25‐3p oligonucleotide (ADMSC‐EVs^{anti‐miR‐25‐3p}) confirmed the aforementioned in vitro observations in C57BL/6 mice exposed to cerebral ischemia. The infarct size was reduced, and neurological recovery was increased in mice treated with native ADMSC‐EVs when compared to ADMSC‐EVs^{anti‐miR‐25‐3p}. ADMSCs induce neuroprotection by improved autophagic flux through secreted EVs containing miR‐25‐3p. Hence, our work uncovers a novel key factor in naturally secreted ADMSC‐EVs for the regulation of autophagy and induction of neuroprotection in a preclinical stroke model.

Lithium modulates miR-1906 levels of mesenchymal stem cell-derived extracellular vesicles contributing to poststroke neuroprotection by toll-like receptor 4 regulation

Lithium is neuroprotective in preclinical stroke models. In addition to that, poststroke neuroregeneration is stimulated upon transplantation of mesenchymal stem cells (MSCs). Preconditioning of MSCs with lithium further enhances the neuroregenerative potential of MSCs, which act by secreting extracellular vesicles (EVs). The present work analyzed whether MSC preconditioning with lithium modifies EV secretion patterns, enhancing the therapeutic potential of such derived EVs (Li‐EVs) in comparison with EVs enriched from native MSCs. Indeed, Li‐EVs significantly enhanced the resistance of cultured astrocytes, microglia, and neurons against hypoxic injury when compared with controls and to native EV‐treated cells. Using a stroke mouse model, intravenous delivery of Li‐EVs increased neurological recovery and neuroregeneration for as long as 3 months in comparison with controls and EV‐treated mice, albeit the latter also showed significantly better behavioral test performance compared with controls. Preconditioning of MSCs with lithium also changed the secretion patterns for such EVs, modifying the contents of various miRNAs within these vesicles. As such, Li‐EVs displayed significantly increased levels of miR‐1906, which has been shown to be a new regulator of toll‐like receptor 4 (TLR4) signaling. Li‐EVs reduced posthypoxic and postischemic TLR4 abundance, resulting in an inhibition of the nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) signaling pathway, decreased proteasomal activity, and declined both inducible NO synthase and cyclooxygenase‐2 expression, all of which culminated in reduced levels of poststroke cerebral inflammation. Conclusively, the present study demonstrates, for the first time, an enhanced therapeutic potential of Li‐EVs compared with native EVs, interfering with a novel signaling pathway that yields both acute neuroprotection and enhanced neurological recovery.

Neuroprotective effect of lithium in cold- induced traumatic brain injury in mice

Apart from its well-established therapeutic activity on bipolar disorder and depression, lithium exerts neuroprotective activity upon neurodegenerative disorders, such as traumatic brain injury (TBI). However, the cellular signaling mechanisms mediating lithium's neuroprotective activity and long-term dose- and time-dependent effects on close and remote proximity are largely unknown. Herein, we tested prophylactic and acute effects of lithium (2 mmol/kg) after cold- induced TBI. In both conditions, treatments with lithium resulted in reduced infarct volume and apoptosis. Its acute treatment resulted in the increase of Akt, ERK-1/2 and GSK-3 α/β phosphoylations. Interestingly, its prophylactic treatment instead resulted in decreased phosphorylations of Akt, ERK-1/2, p38, JNK-1 moderately and GSK-3 α/β significantly. Then, we tested subacute (35-day follow-up) role of low (0.2 mmol/kg) and high dose (2 mmol/kg) lithium and revealed that high dose lithium group was the most mobile so the least depressed in the tail suspension test. Anxiety level was assessed by light-dark test, all groups' anxiety levels were decreased with time, but lithium had no effect on anxiety like behavior. When subacute effects of injury and drug treatment were evaluated on the defined brain regions, infarct volume was decreased in the high dose lithium group significantly. In contrast to other brain regions, hippocampal atrophies were observed in both lithium treatment groups, which were significant in the low dose lithium group in both hemispheres, which was associated with the reduced cell proliferation and neurogenesis. Our data demonstrate that lithium treatment protects neurons from TBI. However, long term particularly low-dose lithium causes hippocampal atrophy and decreased neurogenesis.

Lentivirally administered glial cell line-derived neurotrophic factor promotes post-ischemic neurological recovery, brain remodeling and contralesional pyramidal tract plasticity by regulating axonal growth inhibitors and guidance proteins

Owing to its potent longterm neuroprotective and neurorestorative properties, glial cell line-derived neurotrophic factor (GDNF) is currently studied in neurodegenerative disease clinical trials. However, little is known about the longterm effect of GDNF on neurological recovery, brain remodeling and neuroplasticity in the post-acute phase of ischemic stroke. In a comprehensive set of experiments, we examined the effects of lentiviral GDNF administration after ischemic stroke. GDNF reduced neurological deficits, neuronal injury, blood-brain barrier permeability in the acute phase in mice. As compared with control, enhanced motor-coordination and spontaneous locomotor activity were noted in GDNF-treated mice, which were associated with increased microvascular remodeling, increased neurogenesis and reduced glial scar formation in the peri-infarct tissue. We observed reduced brain atrophy and increased plasticity of contralesional pyramidal tract axons that crossed the midline in order to innervate denervated neurons in the ipsilesional red and facial nuclei. Contralesional axonal plasticity by GDNF was associated with decreased abundance of the axonal growth inhibitors brevican and versican in contralesional and ipsilesional brain tissue, reduced abundance of the growth repulsive guidance molecule ephrin b1 in contralesional brain tissue, increased abundance of the midline growth repulsive protein Slit1 in contralesional brain tissue and reduced abundance of Slit1's receptor Robo2 in ipsilesional brain tissue. These data indicate that GDNF potently induces longterm neurological recovery, peri-infarct brain remodeling and contralesional neuroplasticity, which are associated with the fine-tuned regulation of axonal growth inhibitors and guidance molecules that facilitate the growth of contralesional corticofugal axons in the direction to the ipsilesional hemisphere.

The effect of systemic rifampicin treatment on inferior alveolar nerve regeneration in rats following crush injury

Axonal regeneration of the inferior alveolar nerve (IAN) is a therapeutic target for functional recovery after peripheral nerve injury. Rifampicin exerts anti-apoptotic, anti-inflammatory, and anti-oxidant effects on nerve tissues that may enhance functional recovery after peripheral nerve injury. The aim of the present study was to evaluate the therapeutic effects of systemic rifampicin following IAN crush injury. Following the nerve crush injuries of the IAN, 24 Sprague-Dawley rats were randomly divided into three groups to receive daily intraperitoneal injections of either vehicle, 5 mg kg^-1 rifampicin, or 20 mg kg^-1 rifampicin. Twenty-four days after induction of nerve injuries, Fluorogold (FG) was injected over the mental foramen for the evaluation of neuronal survival. At the end of the four-week period, histologic and histomorphometric examination of IAN samples were performed and FG positive cells were counted in the trigeminal ganglion sections. FG positive cells were significantly more frequent in the 20 and 5 mg kg^-1 rifampicin groups than in the vehicle-treated group. Electron microscopic analyses revealed that the percentage of axons with optimum g-ratio was significantly lower in the vehicle group than in both treatment groups. In conclusion, systemic rifampicin treatment can enhance peripheral nerve regeneration.

Melatonin affects the release of exosomes and tau-content in in vitro amyloid-beta toxicity model

BACKGROUND

Recent studies have been revealed that oxidative damage is the main cause of aging and age-related neurodegenerative diseases like Alzheimer's disease (AD). Melatonin is secreted from the pineal gland and its secretion has been found to be altered in AD. In the last decade the role of exosomes in spreading toxic proteins and inducing the propagation of diseases like AD has been discussed. However, it is not known how melatonin affects the amount of exosomes released from the cells and the content of the exosomes.

OBJECTIVE

Herein, we investigated the possible role of melatonin treatment in the releasing of exosomes and exosomal tau content in an in vitro Aβ toxicity model.

METHOD

SH-SY5Y cell line was used. The optimum concentration of Aβ was determined by cell viability and cell proliferation tests. Melatonin (100 µM) was applied before and after Aβ application. Total exosomes isolated from cell culture media were immunoprecipitated. The amount of released exosomes and their tau content were analyzed by Western blots.

RESULTS

Our data demonstrated for the first time that melatonin treatment clearly affected the amount of released exosomes. It would decrease the amyloid beta load and toxicity by inhibiting exosome release. We also demonstated that melatonin also affected the level of tau carried by exosomes depending on whether melatonin was applied before or after Aβ application.

CONCLUSION

It is considered that the effect of melatonin in the release of exosomes and exosomal tau content would contribute the development of therapeutic strategies in AD and related disorders.

Short-Term Diet Restriction but Not Alternate Day Fasting Prevents Cisplatin-Induced Nephrotoxicity in Mice

Cisplatin (CP) is one of the most preferred platinum-containing antineoplastic drugs. However, even in nontoxic plasma concentrations, it may cause kidney injury. To be able to increase its effective pharmacological dose, its side effects need to be regarded. Diet restriction (DR) has been demonstrated to improve cellular survival in a number of disorders. In this context, we investigated the role of DR in CP-induced nephrotoxicity (CPN). Besides alternate DR, animals were exposed to DR for 3 days prior or after CP treatment. Here, we observed that both 3 days of DR reverses the nephrotoxic effect of CP, which was associated with improved physiological outcomes, such as serum creatine, blood-urea nitrogen and urea. These treatments significantly increased phosphorylation of survival kinases PI3K/Akt and ERK-1/2 and decreased the level of stress kinase JNK were noted. In addition, the activation level of signal transduction mediator p38 MAPK phosphorylation was higher particularly in both three-day DR groups. Next, animals were fed with carbohydrate-, protein- or fat-enriched diets in the presence of CP. Results indicated that not only fasting but also dietary content itself may play a determinant role in the severity of CPN. Our data suggest that DR is a promising approach to reduce CPN by regulating metabolism and cell signaling pathways.

Interaction of melatonin and Bmal1 in the regulation of PI3K/AKT pathway components and cellular survival

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-3αβ, 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.

Normobaric oxygen treatment improves neuronal survival functional recovery and axonal plasticity after newborn hypoxia-ischemia

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.

Cinnamon Polyphenol Extract Exerts Neuroprotective Activity in Traumatic Brain Injury in Male Mice

BACKGROUND

Cinnamon polyphenol extract is a traditional spice commonly used in different areas of the world for the treatment of different disease conditions which are associated with inflammation and oxidative stress. Despite many preclinical studies showing the anti-oxidative and antiinflammatory effects of cinnamon, the underlying mechanisms in signaling pathways via which cinnamon protects the brain after brain trauma remained largely unknown. However, there is still no preclinical study delineating the possible molecular mechanism of neuroprotective effects cinnamon polyphenol extract in Traumatic Brain Injury (TBI). The primary aim of the current study was to test the hypothesis that cinnamon polyphenol extract administration would improve the histopathological outcomes and exert neuroprotective activity through its antioxidative and anti-inflammatory properties following TBI.

METHODS

To investigate the effects of cinnamon, we induced brain injury using a cold trauma model in male mice that were treated with cinnamon polyphenol extract (10 mg/kg) or vehicle via intraperitoneal administration just after TBI. Mice were divided into two groups: TBI+vehicle group and TBI+ cinnamon polyphenol extract group. Brain samples were collected 24 h later for analysis.

RESULTS

We have shown that cinnamon polyphenol extract effectively reduced infarct and edema formation which were associated with significant alterations in inflammatory and oxidative parameters, including nuclear factor-κB, interleukin 1-beta, interleukin 6, nuclear factor erythroid 2-related factor 2, glial fibrillary acidic protein, neural cell adhesion molecule, malondialdehyde, superoxide dismutase, catalase and glutathione peroxidase.

CONCLUSION

Our results identify an important neuroprotective role of cinnamon polyphenol extract in TBI which is mediated by its capability to suppress the inflammation and oxidative injury. Further, specially designed experimental studies to understand the molecular cross-talk between signaling pathways would provide valuable evidence for the therapeutic role of cinnamon in TBI and other TBI related conditions.

Curcumin Plays Neuroprotection Activity by Modulation of Neurotrophic Factor BDNF, GAP-43 and GFAP in Mice with Traumatic Brain Injury (P06-043-19)

Objectives

Curcumin, extracted from the rhizome Curcuma longa, has been shown to be beneficial for neuroprotection in previous studies. In a recent study, a novel formulation of curcumin resulted in an increased relative absorption by 46 times (CurcuWIN®) of the total curcuminoids over the unformulated standard curcumin form. However, the exact mechanisms by which curcumin demonstrates its neuroprotective effects are not fully understood. The present study aimed to investigate the effects of curcumin supplementation on the expression of brain-derived neurotrophic factor (BDNF), glial fibrillary acidic protein (GFAP), a main component of the glial scar, and growth-associated protein-43 (GAP-43), a signaling molecule in traumatic brain injury (TBI).

Methods

Brain injury was induced using a cold trauma model in male mice that were treated with curcumin (50 mg/kg) or vehicle via intraperitoneal administration just after TBI. Mice were divided into two groups: TBI + vehicle group and TBI + curcumin (CurcuWIN) group.

Results

The results show that curcumin treatment reduced the infarct volume in the brain. TBI induction increased inflammatory cytokines (IL-1β and IL-6), nuclear factor-κB (NF-κB) and GFAP, and reduced BDNF, GAP-43, neural cell adhesion molecule (ICAM) and nuclear factor erythroid 2-related factor 2 (Nrf2) levels in the brain. Interestingly, curcumin decreased the levels of NF-κB, IL-1β, IL-6, and GFAP, and increased BDNF, GAP-43, ICAM and Nrf2 levels in the brain.

Conclusions

In conclusion, these results showed that curcumin could increase the levels of BDNF, GAP-43, ICAM, and Nrf2 and attenuate brain injury in the model of TBI.

Funding Sources

This study was supported by OmniActive Health Technologies Inc. (NJ, USA). This work was also supported in part by the Turkish Academy of Sciences.

Supporting Tables, Images and/or Graphs

Acute and Post-acute Neuromodulation Induces Stroke Recovery by Promoting Survival Signaling, Neurogenesis, and Pyramidal Tract Plasticity

Repetitive transcranial magnetic stimulation (rTMS) has gained interest as a non-invasive treatment for stroke based on the data promoting its effects on functional recovery. However, the exact action mechanisms by which the rTMS exert beneficial effects in cellular and molecular aspect are largely unknown. To elucidate the effects of high- and low-frequency rTMS in the acute-ischemic brain, we examined how rTMS influences injury development, cerebral blood flow (CBF), DNA fragmentation, neuronal survival, pro- and anti-apoptotic protein activations after 30 and 90 min of focal cerebral ischemia. In addition, inflammation, angiogenesis, growth factors and axonal outgrowth related gene expressions, were analyzed. Furthermore, we have investigated the effects of rTMS on post-acute ischemic brain, particularly on spontaneous locomotor activity, perilesional tissue remodeling, axonal sprouting of corticobulbar tracts, glial scar formation and cell proliferation, in which rTMS was applied starting 3 days after the stroke onset for 28 days. In the high-frequency rTMS received animals reduced DNA fragmentation, infarct volume and improved CBF were observed, which were associated with increased Bcl-xL activity and reduced Bax, caspase-1, and caspase-3 activations. Moreover, increased angiogenesis, growth factors; and reduced inflammation and axonal sprouting related gene expressions were observed. These results correlated with reduced microglial activation, neuronal degeneration, glial scar formation and improved functional recovery, tissue remodeling, contralesional pyramidal tract plasticity and neurogenesis in the subacute rTMS treated animals. Overall, we propose that high-frequency rTMS in stroke patients can be used to promote functional recovery by inducing the endogenous repair and recovery mechanisms of the brain.

The therapeutic role of minocycline in Parkinson's disease

Minocycline, a semisynthetic tetracycline-derived antibiotic, has been shown to exert anti-apoptotic, anti-inflammatory, and antioxidant effects. Furthermore, there is rapidly growing evidence suggesting that minocycline may have some neuroprotective activity in various experimental models such as cerebral ischemia, traumatic brain injury, amyotrophic lateral sclerosis, Parkinson's disease (PD), Huntington's disease, and multiple sclerosis. In this perspective review, we summarize the preclinical and clinical findings suggesting the neuroprotective role of minocycline in PD.

Minocycline Increases in-vitro Cortical Neuronal Cell Survival after Laser Induced Axotomy

Background

Antibiotic therapies targeting multiple regenerative mechanisms have the potential for neuroprotective effects, but the diversity of experimental strategies and analyses of non-standardised therapeutic trials are challenging. In this respect, there are no cases of successful clinical application of such candidate molecules when it comes to human patients.

Methods

After 24 hours of culturing, three different minocycline (Sigma-Aldrich, M9511, Germany) concentrations (1 µM, 10 µM and 100 µM) were added to the primary cortical neurons 15 minutes before laser axotomy procedure in order to observe protective effect of minocycline in these dosages.

Results

Here, we have shown that minocycline exerted a significant neuroprotective effect at 1 and 100μM doses. Beyond confirming the neuroprotective effect of minocycline in a more standardised and advanced in-vitro trauma model, our findings could have important implications for future studies that concentrate on the translational block between animal and human studies.

Conclusion

Such sophisticated approaches might also help to conquer the influence of human-made variabilities in critical experimental injury models. To the best of our knowledge, this is the first study showing that minocycline increases in-vitro neuronal cell survival after laser-axotomy.

Esthetic outcomes after immediate and late implant loading for a single missing tooth in the anterior maxilla

Objective

This study compared the esthetic outcomes of 1-year follow-up of immediate and late implant loading after implant restoration of a single tooth in the anterior maxilla.

Materials and Methods

A total of 33 patients with missing teeth in the anterior maxilla (Central = 8/lateral = 22/canine = 3) were enrolled in this study (18 immediate loading and 15 late loading). At after cementation, 1, 3, 6, and 12 months photographs were taken of anterior maxilla. The photographs were assessed using pink esthetic score (PES) which consists of seven variables. All PES data were analyzed with independent sample t-tests and repeated measures ANOVAs.

Results

PES values increased significantly in both groups at the 1-year follow-up (P > 0.05). There was no statistically significant difference between the immediate and late loading groups at any time point (P > 0.05).

Conclusions

Within the limitation of this study, immediate loading did not have a negative effect on esthetics.

Dose-dependent effects of vitamin 1,25(OH)2D3 on oxidative stress and apoptosis

Background The purpose of this study is to examine the dose-dependent effects of vitamin 1,25(OH)2D3 on apoptosis and oxidative stress. Methods In this study, 50 male Balb/c mice were used as control and experiment groups. The mice were divided into 5 groups each consisting of 10 mice. Calcitriol was intraperitoneally administered as low dose, medium dose, medium-high dose and high dose vitamin D groups (at 0.5, 1, 5 and 10 μg/kg, respectively), for three times a week during 14 days. At the end of the study, annexin V was measured by enzyme-linked immunosorbent assay method, and total antioxidant capacity and total oxidant status values were measured by colorimetric method in serum. Hematoxylin eosin staining was performed in liver tissues and periodic acid schiff staining was performed in kidney tissues. Results While comparing the results of medium-high dose (5 μg/kg) and high dose (10 μg/kg) vitamin D administration to that of the control group, it was observed that serum antioxidant status and annexin V levels decreased and glomerular mesenchial matrix ratio increased in kidney (p<0.05). In addition to these findings, in the group receiving high dose vitamin D (10 μg/kg), it was observed that the damage to the liver increased together with the the oxidative stress index values (p<0.05). Conclusions As a result, this study was the first in the literature to report that use of high-dose vitamin D (10 μg/kg) results in oxidant effect, rather than being an antioxidant, and causes severe histopathological toxicity in the liver and kidney.

Acute intensive care unit management of mustard gas victims: the Turkish experience. Cutan Ocul Toxicol 2018;37:332-337. [PMID: 29648477 DOI: 10.1080/15569527.2018.1464018]

PURPOSE

Sulphur mustard (SM) is an highly toxic and vesicant chemical weapon that was used in various military conflicts several times in the history. The severity of ocular, dermal, and pulmonary symptoms that may appear following a characteristic asymptomatic period are depending on the SM concentration and exposure duration. The aim of this study is to present the clinical features and share the intensive care unit (ICU) experiences for the medical management of mustard gas victims.

MATERIALS AND METHODS

Thirteen Free Syrian Army soldiers near Al-Bab region of North Syria were reportedly exposed to oily blackish smoke with garlic smell due to the explosion of a trapped bomb without causing any blast or thermal effect on 26th November 2016. None of them wore any chemical protective suits or gas masks during explosion. Since they observed skin lesions including bullous formation next day, they were admitted to the Turkish Field Hospital at the Turkish - Syrian border and then evacuated to the State Hospital of Gaziantep Province, Turkey for further management. Eight victims who were very close to point of explosion suffered burning eyes, sore throat, dry cough and dyspnoea after the chemical attack.

RESULTS

On admission to hospital, all cases had conjunctivitis, hoarseness and bullae on various body areas. Blepharospasm and opacity were found in 8 patients and 5 of them had corneal erosions and periorbital oedema. Temporary loss of vision in 4 cases lasted for 24 h. Multiple fluid-filled blisters were observed especially on the scalp, neck, arms and hands, where direct skin exposure to the agent occurred. A definitive clinical care and infection prophylaxis measures along with the burn treatment and bronchodilators for respiratory effects were applied in ICU. Two patients received granulocyte-colony-stimulating factor due to the SM-mediated bone marrow suppression on the 16th day of exposure and one of them died because of necrotic bronchial pseudomembrane obstruction resulting in cardiopulmonary arrest.

CONCLUSIONS

SM was first used during the First World War and it is still considered one of the major chemical weapons recently used by non-state actors in Syria and Iraq. In case of SM exposure, medical treatment of SM-induced lesions is symptomatic because no antidote or causal therapy does exist even though SM is very well known for over 100 years. However, clinical management in intensive care medicine of SM victims have improved since the 1980s, this study which is one of the largest recent SM-exposed case series since that time is important for the contribution to the clinical experience.

Time-of-Day Dependent Neuronal Injury After Ischemic Stroke: Implication of Circadian Clock Transcriptional Factor Bmal1 and Survival Kinase AKT

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.