Cerebral microvascular dysfunction in metabolic syndrome is exacerbated by ischemia-reperfusion injury

Bridging metabolic syndrome and cognitive dysfunction: role of astrocytes

Metabolic syndrome (MetS) and cognitive dysfunction pose significant challenges to global health and the economy. Systemic inflammation, endocrine disruption, and autoregulatory impairment drive neurodegeneration and microcirculatory damage in MetS. Due to their unique anatomy and function, astrocytes sense and integrate multiple metabolic signals, including peripheral endocrine hormones and nutrients. Astrocytes and synapses engage in a complex dialogue of energetic and immunological interactions. Astrocytes act as a bridge between MetS and cognitive dysfunction, undergoing diverse activation in response to metabolic dysfunction. This article summarizes the alterations in astrocyte phenotypic characteristics across multiple pathological factors in MetS. It also discusses the clinical value of astrocytes as a critical pathologic diagnostic marker and potential therapeutic target for MetS-associated cognitive dysfunction.

Elevated PDGF-BB from Bone Impairs Hippocampal Vasculature by Inducing PDGFRβ Shedding from Pericytes

Evidence suggests a unique association between bone aging and neurodegenerative/cerebrovascular disorders. However, the mechanisms underlying bone-brain interplay remain elusive. Here platelet-derived growth factor-BB (PDGF-BB) produced by preosteoclasts in bone is reported to promote age-associated hippocampal vascular impairment. Aberrantly elevated circulating PDGF-BB in aged mice and high-fat diet (HFD)-challenged mice correlates with capillary reduction, pericyte loss, and increased blood-brain barrier (BBB) permeability in their hippocampus. Preosteoclast-specific Pdgfb transgenic mice with markedly high plasma PDGF-BB concentration faithfully recapitulate the age-associated hippocampal BBB impairment and cognitive decline. Conversely, preosteoclast-specific Pdgfb knockout mice have attenuated hippocampal BBB impairment in aged mice or HFD-challenged mice. Persistent exposure of brain pericytes to high concentrations of PDGF-BB upregulates matrix metalloproteinase 14 (MMP14), which promotes ectodomain shedding of PDGF receptor β (PDGFRβ) from pericyte surface. MMP inhibitor treatment alleviates hippocampal pericyte loss and capillary reduction in the conditional Pdgfb transgenic mice and antagonizes BBB leakage in aged mice. The findings establish the role of bone-derived PDGF-BB in mediating hippocampal BBB disruption and identify the ligand-induced PDGFRβ shedding as a feedback mechanism for age-associated PDGFRβ downregulation and the consequent pericyte loss.

Accelerated amyloid angiopathy and related vascular alterations in a mixed murine model of Alzheimer´s disease and type two diabetes

BACKGROUND

While aging is the main risk factor for Alzheimer´s disease (AD), emerging evidence suggests that metabolic alterations such as type 2 diabetes (T2D) are also major contributors. Indeed, several studies have described a close relationship between AD and T2D with clinical evidence showing that both diseases coexist. A hallmark pathological event in AD is amyloid-β (Aβ) deposition in the brain as either amyloid plaques or around leptomeningeal and cortical arterioles, thus constituting cerebral amyloid angiopathy (CAA). CAA is observed in 85-95% of autopsy cases with AD and it contributes to AD pathology by limiting perivascular drainage of Aβ.

METHODS

To further explore these alterations when AD and T2D coexist, we have used in vivo multiphoton microscopy to analyze over time the Aβ deposition in the form of plaques and CAA in a relevant model of AD (APPswe/PS1dE9) combined with T2D (db/db). We have simultaneously assessed the effects of high-fat diet-induced prediabetes in AD mice. Since both plaques and CAA are implicated in oxidative-stress mediated vascular damage in the brain, as well as in the activation of matrix metalloproteinases (MMP), we have also analyzed oxidative stress by Amplex Red oxidation, MMP activity by DQ™ Gelatin, and vascular functionality.

RESULTS

We found that prediabetes accelerates amyloid plaque and CAA deposition, suggesting that initial metabolic alterations may directly affect AD pathology. T2D significantly affects vascular pathology and CAA deposition, which is increased in AD-T2D mice, suggesting that T2D favors vascular accumulation of Aβ. Moreover, T2D synergistically contributes to increase CAA mediated oxidative stress and MMP activation, affecting red blood cell velocity.

CONCLUSIONS

Our data support the cross-talk between metabolic disease and Aβ deposition that affects vascular integrity, ultimately contributing to AD pathology and related functional changes in the brain microvasculature.

Neuroprotective Effect of Polyherbal Recipe Containing Ginger, Chinese Date, and Wood Ear Mushroom against Ischemic Stroke with Metabolic Syndrome Condition via Epigenetic Modification of Inflammation and Oxidative Stress

Currently, the prevalence of stroke with metabolic syndrome (MetS) is increasing and the current therapeutic efficiency is still limited. Therefore, the applications of herbal recipes have gained much attention. The polyherbal recipe containing ginger, Chinese date, and wood ear mushroom is reputed for atherosclerosis and stroke prevention. It has been long-term consumed without scientific support. Therefore, this study was carried out to determine the neuroprotective effect and its mechanisms in animal model of ischemic stroke with MetS. Male Wistar rats weighing 180-220 g were exposed to a 16-week high-fat high-carbohydrate feeding. The rats with the MetS characteristic were exposed to a temporary occlusion of the right middle cerebral artery (MCAO) for 90 minutes. They were orally fed with the polyherbal recipe (GCJ) at the doses of 100, 200, and 300 mg/kg BW for 21 days and assessed the neurological deficit, ion volume, cortical neuron density in the cerebral cortex, oxidative stress status, inflammation, and expressions of histone deacetylase 3 (HDAC3) and DNA methyltransferase 1 (DNMT1). The results showed that GCJ significantly improved all mentioned parameters. Therefore, GCJ is the potential neuroprotectant against ischemic stroke with MetS. The underlying mechanisms may involve the reduction of oxidative stress, inflammation, and the modification of epigenetic mechanism via the reduction of HDAC3 and DNMT1. However, further clinical investigation is essential to confirm this positive modulation effect.

A robust quantitative approach for laser speckle contrast imaging perfusion analysis revealed anomalies in the brain blood flow in offspring mice of preeclampsia

Microcirculation analysis of the brain cortex is challenging because surface perfusion varies rapidly in small space-time regions and is bone protected. The laser speckle contrast imaging (LSCI) technique allows analyzing in vivo brain vascular perfusion generating a large amount of data that requires sophisticated data analytics, making researchers invest much effort in processing. Our research question was whether the reduced placental perfusion model (RUPP) of preeclampsia (PE) was associated with impaired blood perfusion in the offspring's brains. We aimed to develop a robust numerical approach that mainly consisted of applying a signal-processing tool for calculating optimal segmentation and piece-wise fits of the offspring's brain perfusion signals obtained from the LSCI technique. We combined this tool with the usual statistical analysis, implementing both in Matlab software. We performed brain perfusion measurements from offspring (five days postnatal, P5) of control pregnant dams (sham, n = 13) and of RUPP dams (RUPP, n = 7) using the Pericam® PSI-HR system at a basal condition and after thermal stimuli (warm and cold). We found that pups of RUPP mice exhibited significant differences in perfusion and vascular response to thermal stimuli compared to the sham mice. These differences were associated with high data variability in the Sham group, while in the RUPP group, perfusion looks "stiffer." Data also suggest sex-dimorphism in the vascular response since female pups in the Sham group but not male pups showed statistically significant differences in response to the warm stimulus. Again, this sex-related difference was absent in pups of RUPP mice. In conclusion, we present a robust quantitative approach for LSCI measurements that revealed anomalies in the brain blood flow in offspring of the RUPP model of PE.

Lipidomics Analysis Reveals a Protective Effect of Myriocin on Cerebral Ischemia/Reperfusion Model Rats

Ceramide accumulation has been associated with ischemic stroke. Myriocin is an effective serine palmitoyltransferase (SPT) inhibitor that reduces ceramide levels by inhibiting the de novo synthesis pathway. However, the role of myriocin in cerebral ischemia/reperfusion (I/R) injury and its underlying mechanism remain unknown. The present study established an experimental rat model of middle cerebral artery occlusion (MCAO). We employed ultra-performance liquid chromatograph quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based lipidomic analysis to identify the disordered lipid metabolites and the effects of myriocin in cerebral cortical tissues of rats. In this study, we found 15 characterized lipid metabolites involved in sphingolipid and glycerophospholipid metabolism in cerebral I/R-injured rats, and these alterations were significantly alleviated by myriocin. Specifically, the mRNA expression of metabolism-related enzyme genes was detected by real-time quantitative polymerase chain reaction (RT-qPCR). We demonstrated that myriocin could regulate the mRNA expression of ASMase, NSMase, SGMS1, SGMS2, ASAH1, ACER2, and ACER3, which are involved in sphingolipid metabolism and PLA2, which is involved in glycerophospholipid metabolism. Moreover, TUNEL and Western blot assays showed that myriocin plays a key role in regulating neuronal cell apoptosis. In summary, the present work provides a new perspective for the systematic study of metabolic changes in ischemic stroke and the therapeutic applications of myriocin.

Effects of acute and chronic oxidative stress on the blood-brain barrier in 2D and 3D in vitro models

Oxidative stress is a shared pathology of neurodegenerative disease and brain injuries, and is derived from perturbations to normal cell processes by aging or environmental factors such as UV exposure and air pollution. As oxidative cues are often present in systemic circulation, the blood-brain barrier (BBB) plays a key role in mediating the effect of these cues on brain dysfunction. Therefore, oxidative damage and disruption of the BBB is an emergent focus of neurodegenerative disease etiology and progression. We assessed barrier dysfunction in response to chronic and acute oxidative stress in 2D and 3D in vitro models of the BBB with human iPSC-derived brain microvascular endothelial-like cells (iBMECs). We first established doses of hydrogen peroxide to induce chronic damage (modeling aging and neurodegenerative disease) and acute damage (modeling the response to traumatic brain injury) by assessing barrier function via transendothelial electrical resistance in 2D iBMEC monolayers and permeability and monolayer integrity in 3D tissue-engineered iBMEC microvessels. Following application of these chronic and acute doses in our in vitro models, we found local, discrete structural changes were the most prevalent responses (rather than global barrier loss). Additionally, we validated unique functional changes in response to oxidative stress, including dysfunctional cell turnover dynamics and immune cell adhesion that were consistent with changes in gene expression.

Oxycodone relieves permeability damage and apoptosis of oxygen-glucose deprivation/reoxygenation-induced brain microvascular endothelial cells through ras homolog family member A (RhoA)/ Rho-associated coiled-coil containing kinases (ROCK)/ myosin light chain 2 (MLC2) signal

Cerebrovascular disease, an important cause of acute ischemic stroke, has attracted worldwide attention. Oxycodone has been widely used to treat various painful disorders. This study was designed to explore the mechanism of oxycodone in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced brain microvascular endothelial cell model. For the reliability of the results in the following experiments, the viability was firstly detected using CCK-8. With the application of LDH, TEER and TUNEL assays, the LDH expression, permeability and apoptosis of brain microvascular endothelial cells were detected, respectively. Besides, the mRNA and protein expressions of tight junction proteins and RhoA were measured using RT-qPCR and Western blot. Moreover, RT-qPCR was employed to evaluate the expressions of inflammatory cytokines. Western blot was adopted to measure the levels of RhoA, ROCK, MLC2 and apoptosis-related proteins. The results revealed that oxycodone attenuated permeability damage, inflammatory factor release and apoptosis of OGD/R-induced brain microvascular endothelial cells in a dose-dependent manner. It was also found that oxycodone could reduce the expressions of RhoA, ROCK and MLC2 in brain microvascular endothelial cells induced by OGD/R. More importantly, oxycodone exhibited desirable effects on OGD/R-induced brain microvascular endothelial cells through RhoA/ROCK/MLC2 signal. In conclusion, oxycodone relieved permeability damage and apoptosis of OGD/R-induced brain microvascular endothelial cells through RhoA/ROCK/MLC2 signal, suggesting that oxycodone might be an effective method for the improvement of cerebral ischemia-reperfusion injury.

Potentially undiagnosed cognitive impairment in patients with peripheral arterial disease: A systematic review of the literature

INTRODUCTION

It is purported that patients with peripheral arterial disease (PAD) may have impaired cognitive function due to concomitant cerebrovascular disease. Such disease may be clinically unrecognized but can impact on a patient's recovery and prognosis. The purpose of this systematic review was to interrogate the body of published evidence on undiagnosed cognitive impairment in PAD patients.

METHODS

A search strategy encompassing MEDLINE, Scopus, and the Cochrane database was developed to identify peer-reviewed articles examining rates of undiagnosed cognitive impairment in patients with PAD. The following search terms were used: 'PAD'; 'PVD'; 'dementia'; 'peripheral arterial disease'; 'peripheral vascular disease'; 'cognitive impairment'; 'alzheimer's disease' and 'cogniti∗'. Our primary outcome was the incidence of previously undiagnosed cognitive impairment in patients with PAD.

RESULTS

The initial search yielded 1492 titles. After removal of duplicates, 961 abstracts were screened to ascertain if they were eligible for inclusion. Abstract review yielded 62 full texts for further evaluation. Eight case-control studies consisting of 1161 patients were included. Analysis of these studies revealed that PAD patients performed significantly worse than controls on a variety of neuropsychological measures.

CONCLUSION

Our review indicated that PAD patients are more likely to suffer with undiagnosed cognitive impairment than healthy controls.

The Effect of High Fat Diet on Cerebrovascular Health and Pathology: A Species Comparative Review

In both humans and animal models, consumption of a high-saturated-fat diet has been linked to vascular dysfunction and cognitive impairments. Laboratory animals provide excellent models for more invasive high-fat-diet-related research. However, the physiological differences between humans and common animal models in terms of how they react metabolically to high-fat diets need to be considered. Here, we review the factors that may affect the translatability of mechanistic research in animal models, paying special attention to the effects of a high-fat diet on vascular outcomes. We draw attention to the dissociation between metabolic syndrome and dyslipidemia in rodents, unlike the state in humans, where the two commonly occur. We also discuss the differential vulnerability between species to the metabolic and vascular effects of macronutrients in the diet. Findings from animal studies are better interpreted as modeling specific aspects of dysfunction. We conclude that the differences between species provide an opportunity to explore why some species are protected from the detrimental aspects of high-fat-diet-induced dysfunction, and to translate these findings into benefits for human health.

MicroRNA mediated regulation of the major redox homeostasis switch, Nrf2, and its impact on oxidative stress-induced ischemic/reperfusion injury

Ischemia/reperfusion injury (IRI) initiates from oxidative stress caused by lack of blood supply and subsequent reperfusion. It is often associated with sterile inflammation, cell death and microvascular dysfunction, which ultimately results in myocardial, cerebral and hepatic IRIs. Reportedly, deregulation of Nrf2 pathway plays a significant role in the oxidative stress-induced IRIs. Further, microRNAs (miRNAs/miRs) are proved to regulate the expression and activation of Nrf2 by targeting either the 3'-UTR or the upstream regulators of Nrf2. Additionally, compounds (crocin, ZnSO4 and ginsenoside Rg1) that modulate the levels of the Nrf2-regulating miRNAs were found to exhibit a protective effect against IRIs of different organs. Therefore, the current review briefs the impact of ischemia reperfusion (I/R) pathogenesis in various organs, role of miRNAs in the regulation of Nrf2 and the I/R protective effect of compounds that alter their expression.

Diagnostic Criteria for Metabolic Syndrome in Diet-Induced Rodent Models: A Systematic Review

BACKGROUND

Thousands of publications in recent years have addressed the induction of metabolic syndrome (MetS) in rodents. However, the criteria and the reference values for diagnosing this disease have not been defined.

OBJECTIVE

Our main objective was to carry out a systematic review to gather evidence about the criteria for biochemical and anthropometric parameters in which scientific studies have relied on to report that rats developed MetS from a previous dietary manipulation.

METHODS

We compiled characteristics and findings of diet-induced MetS with high-fat, high-carbohydrate, high-fat/high-carbohydrates, and cafeteria diet from PubMed and Science Direct databases published in the last 5 years.

RESULTS

The results on the principal determinants for the syndrome, published in the reviewed articles, were chosen to propose reference values in the rat models of food induction.

CONCLUSION

The values obtained will serve as reference cut-of points in the development of the disease; in addition, the compilation of data will be useful in planning and executing research protocols in animal models.

Inhibition of MiR-122 Decreases Cerebral Ischemia-reperfusion Injury by Upregulating DJ-1-Phosphatase and Tensin Homologue Deleted on Chromosome 10 (PTEN)/Phosphonosinol-3 Kinase (PI3K)/AKT

BACKGROUND Ischemia-reperfusion injury is caused by a blood reperfusion injury in ischemic brain tissue, and usually occurs in the treatment stage of ischemic disease, which can aggravate brain tissue injury. MiR-122 is closely related to ischemia-reperfusion injury in the myocardium, kidney, and liver; however, the role in cerebral ischemia-reperfusion injury has not been established. MATERIAL AND METHODS In this study, cerebral ischemia-reperfusion injury was established in a rat model, and the control group was a sham-operated group. After ischemia-reperfusion injury for 6, 12, and 24 hours, brain tissue specimens were collected and the expression of miR-122 and DJ-1 were determined using quantitative real-time polymerase chain reaction. Flow cytometry was used to determine the reactive oxygen species (ROS) content. The modified Neurological Severity Score (mNSS) scale was used to evaluate the sensory and motor function defects of the rats. The malondialdehyde (MDA), superoxide dismutase (SOD), and enzyme activity were determined. The rats in the cerebral ischemia-reperfusion injury model were divided into 2 groups (antagomir-NC group and antagomir miR-122 group). Brain neuron RN-c cells were divided into the following 4 groups: antagomir-NC, antagomir miR-122, pIRES2-blank, and pIRES2-DJ-1. Seventy-two hours after transfection, ischemia-reperfusion treatment was carried out and conventional cultured RN-c cells were used as the control group. Flow cytometry was used to detect apoptosis and western blot was used to detect the expression of DJ-1, PTEN, AKT, and p-AKT. RESULTS The expression of miR-122 increased significantly in the process of ischemia-reperfusion damage after cerebral infarction, while the expression of DJ-1 decreased significantly. Downregulation of miR-122 significantly increased the expression of DJ-1, enhanced the activity of the PTEN/PI3K/AKT pathway, reduced cell apoptosis, and alleviated cerebral ischemia-reperfusion injury. CONCLUSIONS Inhibition of miR-122 can decrease cerebral ischemia-reperfusion injury by upregulating DJ-1-PTEN/PI3K/AKT pathway.

Shifted vascular optimization: the emergence of a new arteriolar behaviour with chronic metabolic disease

NEW FINDINGS

What is the topic of this review? Altered perfusion distribution at skeletal muscle arteriolar bifurcations and how this is modified by development of chronic metabolic disease. What advances does it highlight? The outcome created is a distribution of erythrocytes in the distal microcirculation that is characterized by increased spatial heterogeneity and reduced flexibility such that mass transport/exchange within the network is impaired, with limited ability to respond to imposed challenges. This advances our understanding of how altered vascular structure and function with metabolic disease impairs perfusion to skeletal muscle at a level of resolution that would not be identified through bulk flow responses.

ABSTRACT

This review is based on the presentation 'Shifted vascular optimization: the emergence of a new arteriolar behaviour with chronic metabolic disease', given at the Symposium 'Understanding Complex Behaviours in the Microcirculation: from Blood Flow to Oxygenation' during the Annual Meeting of the Physiological Society at the Aberdeen Exhibition and Conference Centre in Aberdeen, UK in July 2019. The past years of dedicated investigation on linkages between vascular (dys)function under conditions of elevated cardiovascular disease risk and tissue/organ performance have produced results and insights that frequently suffer from limited correlation and causation. Reaching out from this challenge, it was proposed that this may reflect a 'level of resolution' argument and that altered haemodynamic behaviour in vascular networks could be a stronger predictor of functional outcomes than higher resolution measures. Using this approach, we have determined that an attractor that describes the spatial and temporal shift in perfusion distribution at successive arteriolar bifurcations within the skeletal muscle is a strong predictor of functional outcomes within animals and provides novel insight into fundamental mechanistic contributors to altered patterns of intra-muscular perfusion. This article focuses on the applicability and utility of the attractor in models of cardiovascular and metabolic disease risk of increasing severity. We will also discuss the utility of the attractor in terms of understanding the effectiveness of aggressive interventions for reversing established vasculopathy and perfusion impairments.

Beneficial Effect of Exercise on Cognitive Function during Peripheral Arterial Disease: Potential Involvement of Myokines and Microglial Anti-Inflammatory Phenotype Enhancement

Peripheral arterial disease (PAD), leading to intermittent claudication, critical ischemia with rest pain, and/or tissue damage, is a public health issue associated with significant morbidity and mortality. Little is known about the link between PAD, cognitive function, and whether exercise might reduce cognitive dysfunction in PAD patients, as previously observed concerning both quality of life and prognosis. This review highlights the fact that patients suffering from PAD often demonstrate cognitive dysfunction characterized by reduced performance in nonverbal reasoning, reduced verbal fluency, and decreased information processing speed and a greater risk for progression toward dementia. Further, the data presented support that physical exercise, likely through myokine secretion and microglial anti-inflammatory phenotype enhancement, might participate in the cognition protection in common clinical settings.

Cerebroprotective Effect against Cerebral Ischemia of the Combined Extract of Oryza sativa and Anethum graveolens in Metabolic Syndrome Rats

The novel strategy against ischemic stroke in metabolic syndrome (MetS) targeting at oxidative stress and inflammation has gained attention due to the limitation of the current therapy. Due to the antioxidant and anti-inflammation of the combined extract of Oryza sativa and Anethum graveolens, the cerebroprotective effect against cerebral ischemia in MetS condition has been focused. Since no data were available, this study was set up to determine the effects of the combined extract of Oryza sativa L. and Anethum graveolens Linn. against ischemic stroke in the animal model of metabolic syndrome. The possible underlying mechanism was also further investigated. Male Wistar rats (180-220 g) were fed with high-carbohydrate high-fat diet (HCHF diet) to induce metabolic syndrome-like condition. Then, MetS rats were subjected to reperfusion injury at the right middle cerebral artery. The combined extract of O. sativa and A. graveolens (OA extract) at doses of 0.5, 5, and 50 mg/kg BW was fed once daily for 21 days. Neurological assessment was performed every 7 days throughout the experimental period. At the end of study, brain infarction volume, neuron and glial fibrillary acidic protein- (GFAP-) positive cell density, the oxidative stress status, the expressions of proinflammatory cytokines (NF-κB, IL-6), and eNOS in the cortical area together with the expression of VCAM-1 and the histological changes of common carotid artery were determined. It was found that OA extract decreased brain infarction, neurological score, oxidative stress status, and inflammatory mediators but increased eNOS expression in the cortical area; the increased VCAM-1 and intima-media thickness together with the reduction of lumen diameter of common carotid artery of MetS eats with MCAO were also mitigated by OA extract. These data suggest the cerebroprotective effect of OA, and the underlying mechanism may occur partly via the improvement of oxidative stress status, inflammation, and brain blood supply.

iTRAQ-Based Proteomics Analysis Reveals the Effect of Rhubarb in Rats with Ischemic Stroke

Background. Rhubarb, a traditional Chinese medicine, promotes viscera and remove blood stasis. Rhubarb is skilled in smoothening meridians, improving blood circulation which exhibits better efficacy on cerebral ischemic stroke. In this study, we aimed to analyze the underlying mechanisms of rhubarb which treated rats of middle cerebral artery occlusion (MCAO) model according to an iTRAQ-based proteomics and bioinformatics analysis. 30 rats were randomly allocated into three groups including sham group (SG), model group (MG), and rhubarb group (RG). Rhubarb group was given a gavage of rhubarb decoction at dose of 3 g/kg and the remaining groups were prepared with normal saline by gavage. Rats from MG and RG were induced into MCAO model. The effects of rhubarb were estimated by Modified Neurological Severity Score (mNSS) and cerebral infarct volume. The brain tissues were measured via the quantitative proteomic approach of iTRAQ coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, the bioinformatics analysis of overlapping differentially expression proteins (DEPs) was conducted by DAVID, KEGG, and Cytoscape. Specific selective DEPs were validated by Western blotting. Rats treated with rhubarb after MCAO showed a significant reduction on mNSS and cerebral infarct volume compared with MG. In MG versus SG and RG versus MG, we identified a total of 4578 proteins, of which 287 were DEPs. There were 76 overlapping DEPs between MG versus SG and RG versus MG. Through bioinformatics analysis, 14 associated pathways were searched including cGMP-PKG signaling pathway, tuberculosis, synaptic vesicle cycle, amyotrophic lateral sclerosis, long-term potentiation, and so on. 76 overlapping DEPs mainly involved synaptic vesicle cycling biological processes based on GO annotation. Further, the selective overlapping DEPs were verified at the protein level by using Western blotting. Our present study reveals that rhubarb highlights promising neuroprotective effect. Rhubarb exerts novel therapeutic action via modulating multiple proteins, targets, and pathways.

Neuroprotection Targeting Protein Misfolding on Chronic Cerebral Hypoperfusion in the Context of Metabolic Syndrome

Metabolic syndrome (MetS) is a cluster of risk factors that lead to microvascular dysfunction and chronic cerebral hypoperfusion (CCH). Long-standing reduction in oxygen and energy supply leads to brain hypoxia and protein misfolding, thereby linking CCH to Alzheimer's disease. Protein misfolding results in neurodegeneration as revealed by studying different experimental models of CCH. Regulating proteostasis network through pathways like the unfolded protein response (UPR), the ubiquitin-proteasome system (UPS), chaperone-mediated autophagy (CMA), and macroautophagy emerges as a novel target for neuroprotection. Lipoxin A4 methyl ester, baclofen, URB597, N-stearoyl-L-tyrosine, and melatonin may pose potential neuroprotective agents for rebalancing the proteostasis network under CCH. Autophagy is one of the most studied pathways of proteostatic cell response against the decrease in blood supply to the brain though the role of the UPR-specific chaperones and the UPS system in CCH deserves further research. Pharmacotherapy targeting misfolded proteins at different stages in the proteostatic pathway might be promising in treating cognitive impairment following CCH.

[The state of microcirculation and platelet hemostasis in patients with ischemic stroke after systemic thrombolytic therapy]

AIM

The state of microcirculation and platelet hemostasis in patients with ischemic stroke after systemic thrombolytic therapy.

MATERIAL AND METHODS

Forty-two patients after systemic thrombolytic therapy (TLT) (mean age 64.26 [60.58; 68.06]) and 47 patients without TLT (54.52 [47.48; 60.83]) were studied. The study of platelet hemostasis was conducted with the determination of platelet aggregation (AT) on adrenaline, ADP, ristomycin, spontaneous aggregation on days 1, 7 and 14. Studies of the state of microcirculation of cerebral vessels were carried out using the laser Doppler flowmetry (LDF).

RESULTS AND CONCLUSION

Characteristics of changes in induced AT and parameters of the microcirculation system in patients after systemic TLT at 1, 7 and 14 days in comparison with the indices of patients without TLT were revealed that allowed to expand the understanding of pathological mechanisms of the microcirculatory bed, their connection with violations of central hemodynamics and to obtain additional markers of disease course and prognosis.

Metabolic Syndrome and Neuroprotection

Introduction: Over the years the prevalence of metabolic syndrome (MetS) has drastically increased in developing countries as a major byproduct of industrialization. Many factors, such as the consumption of high-calorie diets and a sedentary lifestyle, bolster the spread of this disorder. Undoubtedly, the massive and still increasing incidence of MetS places this epidemic as an important public health issue. Hereon we revisit another outlook of MetS beyond its classical association with cardiovascular disease (CVD) and Diabetes Mellitus Type 2 (DM2), for MetS also poses a risk factor for the nervous tissue and threatens neuronal function. First, we revise a few essential concepts of MetS pathophysiology. Second, we explore some neuroprotective approaches in MetS pertaining brain hypoxia. The articles chosen for this review range from the years 1989 until 2017; the selection criteria was based on those providing data and exploratory information on MetS as well as those that studied innovative therapeutic approaches.

Pathophysiology: The characteristically impaired metabolic pathways of MetS lead to hyperglycemia, insulin resistance (IR), inflammation, and hypoxia, all closely associated with an overall pro-oxidative status. Oxidative stress is well-known to cause the wreckage of cellular structures and tissue architecture. Alteration of the redox homeostasis and oxidative stress alter the macromolecular array of DNA, lipids, and proteins, in turn disrupting the biochemical pathways necessary for normal cell function.

Neuroprotection: Different neuroprotective strategies are discussed involving lifestyle changes, medication aimed to mitigate MetS cardinal symptoms, and treatments targeted toward reducing oxidative stress. It is well-known that the routine practice of physical exercise, aerobic activity in particular, and a complete and well-balanced nutrition are key factors to prevent MetS. Nevertheless, pharmacological control of MetS as a whole and pertaining hypertension, dyslipidemia, and endothelial injury contribute to neuronal health improvement.

Conclusion: The development of MetS has risen as a risk factor for neurological disorders. The therapeutic strategies include multidisciplinary approaches directed to address different pathological pathways all in concert.