Cardioprotective and proangiogenic activities of small extracellular vesicles released by amniotic fluid stem cells

Protection against myocardial ischaemia/reperfusion injury and regeneration of the damaged myocardium are long-sought goals. The use of small extracellular vesicles (sEVs) released by mesenchymal stem cells (MSCs) was shown to be of benefit in the myocardial infarction setting. However, MSCs are frequently harvested from aged or diseased patients and suboptimal sEV isolation methods are used. A subtype of young, foetal MSCs, namely spindle-shaped amniotic fluid stem cells (SS-AFSCs), is known to possess better expansion and functional capacity than its adult counterparts. Here, sEVs released by SS-AFSCs were isolated using size-exclusion chromatography (SEC) – an isolation technique that yields vesicles of superior purity – and their cardioprotective and proangiogenic activities were studied. Firstly, using rat blood plasma, it was demonstrated that SEC isolates higher sEV yields with significantly compromised purity, mostly due to the presence of lipoproteins. To overcome this, a serum-free environment was used for sEVs isolation from SS-AFSC-conditioned medium. Comprehensive characterisation experiments showed that the harvested SS-AFSC sEVs are of high purity. Functionally, SS-AFSC sEVs protected the rat myocardium from ischaemia/reperfusion injury in vivo, but not isolated cardiomyocytes in vitro, indicative of indirect cardioprotective effects. Additionally, SS-AFSC sEVs promoted migration of endothelial cells in vitro and recapitulated the promigratory effects of the SS-AFSC-conditioned medium. Using pharmacological inhibition, it was shown that PI3K pathway, a known player in cell migration, mediates the sEV effects, while a series of potential candidates in the sEV cargo were excluded. Finally, cellular sEV uptake was studied by use of lipophilic dye-labelling experiments. Surprisingly, this commonly used approach was found to be unsuitable for sEV tracking due to non-specific dye retention by non-sEV contaminants. Overall, SEC-isolated SS-AFSC sEVs possess cardioprotective potential manifested only in vivo, and promigratory activity which requires PI3K signalling. These data indicate that SS-AFSC sEVs have multifactorial beneficial effects in a myocardial infarction setting

Postmodernism vis-a-vis African Traditional Cultures: Rethinking the Pathways to Authenticity

Globalization in the current epoch has often had among its trends to use western cultural paradigms and western cultural values to critique non-western indigenous cultures and their values This attitude unfortunately has sometimes given the false impression not only of racial superiority of Western peoples over non-western peoples but also of the cultural superiority of western cultures and their values over indigenous cultures and cultural values of nonwestern provenance This has been the issue with the Western culture of postmodernism when viewed from its encounter with indigenous African cultures Postmodernism comes across as an imperialistic culture with the intent to effect radical shifts in the very fabric of indigenous cultures and to transform these cultures and their values from the roots This article examines the tenets of this postmodern culture which often evades the possibility of being captured in a definition We argue that postmodernism can cause radical but destructive shifts in traditional African cultures and the indigenous values that these cultures define and uphol

Exosomes and Cardiovascular Protection

Most, if not all, cells of the cardiovascular system secrete small, lipid bilayer vesicles called exosomes. Despite technical challenges in their purification and analysis, exosomes from various sources have been shown to be powerfully cardioprotective. Indeed, it is possible that much of the so-called "paracrine" benefit in cardiovascular function obtained by stem cell therapy can be replicated by the injection of exosomes produced by stem cells. However, exosomes purified from plasma appear to be just as capable of activating cardioprotective pathways. We discuss the potential roles of endogenous exosomes in the cardiovascular system, how this is perturbed in cardiovascular disease, and evaluate their potential as therapeutic agents to protect the heart

Small extracellular vesicles secreted from human amniotic fluid mesenchymal stromal cells possess cardioprotective and promigratory potential

Mesenchymal stromal cells (MSCs) exhibit antiapoptotic and proangiogenic functions in models of myocardial infarction which may be mediated by secreted small extracellular vesicles (sEVs). However, MSCs have frequently been harvested from aged or diseased patients, while the isolated sEVs often contain high levels of impurities. Here, we studied the cardioprotective and proangiogenic activities of size-exclusion chromatography-purified sEVs secreted from human foetal amniotic fluid stem cells (SS-hAFSCs), possessing superior functional potential to that of adult MSCs. We demonstrated for the first time that highly pure (up to 1.7 × 1010 particles/µg protein) and thoroughly characterised SS-hAFSC sEVs protect rat hearts from ischaemia–reperfusion injury in vivo when administered intravenously prior to reperfusion (38 ± 9% infarct size reduction, p < 0.05). SS-hAFSC sEVs did not protect isolated primary cardiomyocytes in models of simulated ischaemia–reperfusion injury in vitro, indicative of indirect cardioprotective effects. SS-hAFSC sEVs were not proangiogenic in vitro, although they markedly stimulated endothelial cell migration. Additionally, sEVs were entirely responsible for the promigratory effects of the medium conditioned by SS-hAFSC. Mechanistically, sEV-induced chemotaxis involved phosphatidylinositol 3-kinase (PI3K) signalling, as its pharmacological inhibition in treated endothelial cells reduced migration by 54 ± 7% (p < 0.001). Together, these data indicate that SS-hAFSC sEVs have multifactorial beneficial effects in a myocardial infarction setting

Comparison of small extracellular vesicles isolated from plasma by ultracentrifugation or size-exclusion chromatography: yield, purity and functional potential

Interest in small extracellular vesicles (sEVs) as functional carriers of proteins and nucleic acids is growing continuously. There are large numbers of sEVs in the blood, but lack of standardised methods for sEV isolation greatly limits our ability to study them. In this report, we use rat plasma to systematically compare two commonly used techniques for isolation of sEVs: ultracentrifugation (UC-sEVs) and size-exclusion chromatography (SEC-sEVs). SEC-sEVs had higher particle number, protein content, particle/protein ratios and sEV marker signal than UC-sEVs. However, SEC-sEVs also contained greater amounts of APOB+ lipoproteins and large quantities of non-sEV protein. sEV marker signal correlated very well with both particle number and protein content in UC-sEVs but not in all of the SEC-sEV fractions. Functionally, both UC-sEVs and SEC-sEVs isolates contained a variety of proangiogenic factors (with endothelin-1 being the most abundant) and stimulated migration of endothelial cells. However, there was no evident correlation between the promigratory potential and the quantity of sEVs added, indicating that non-vesicular co-isolates may contribute to the promigratory effects. Overall, our findings suggest that UC provides plasma sEVs of lower yields, but markedly higher purity compared to SEC. Furthermore, we show that the functional activity of sEVs can depend on the isolation method used and does not solely reflect the sEV quantity. These findings are of importance when working with sEVs isolated from plasma- or serum-containing conditioned medium

Ефект на Beauveria bassiana (щам ATCC 74040) върху два вида листояди вредители по царевицата в лабораторни условия

In some European countries, the Western corn rootworm, Diabrotica virgifera virgifera, and the cereal leaf beetle, Oulema melanopus, are present in maize stands in high population density, occasionally causing damage of the crops. Susceptibility of adults of these species and larvae of the cereal leaf beetle to the commercially available product Naturalis® based on Beauveria bassiana strain ATCC 74040 was explored in laboratory conditions. The results of the bioassays showed that the fungal strain caused the highest corrected mortality on O. melanopus larvae with average values above 95% for all conidia concentrations (from 2.3 × 102 to 2.3 × 107 conidia/ml) tested. For the adults of the two pests, the average mortality increased positively with concentration of conidia and the values ranges from 9.5% to 94.2% for O. melanopus (concentrations from 2.3 × 102 to 2.3 × 107 conidia/ml) and from 19.3% to 92.4% for D. v. virgifera (concentrations from 2.3 × 103 to 2.3 × 107 conidia/ml). Accordingly, the LC50 values for O. melanopus larvae and adults and D. v. virgifera adults were determined as 4.6, 8.3 × 104 and 4.3 × 105 conidia/ml, respectively. Further studies to confirm the susceptibility of the larvae of the cereal leaf beetle to Naturalis® under field conditions should be conducted.В някои европейски страни западният царевичен коренов червей Diabrotica virgifera virgifera и обикновената житна пиявица Oulema melanopus присъстват в царевичните площи във висока плътност, нанасяйки щети на културите. В лабораторни условия беше изследвана чувствителността на възрастните индивиди от тези видове и ларвите на обикновената житна пиявица към търговския продукт Naturalis®, който съдържа Beauveria bassiana (щам ATCC 74040). Резултатите от опитите показват, че гъбният щам причини най-високата коригирана смъртност на ларвите на O. melanopus със средни стойности над 95% за всички изпитани концентрации на конидиите (от 2.3 × 102 до 2.3 × 107 конидии/ml). За възрастните на двата вида вредители средната смъртност нараства с увеличаване на концентрацията на конидиите и стойностите варират от 9.5% до 94.2% за O. melanopus (концентрации от 2.3 x 102 до 2.3 × 107 конидии/ml) и от 19.3% до 92.4% за D. v. virgifera (концентрации от 2.3 × 103 до 2.3 × 107 конидии/ml). Cтойностите на LC50 за ларвите и възрастните на O. melanopus и възрастните индивиди на D. v. virgifera бяха съответно 4.6, 8.3 × 104 и 4.3 × 105 конидии/ml. Необходимо е да се проведат допълнителни изследвания за потвърждаване на високата чувствителност на ларвите на обикновената житна пиявица към Naturalis® в полеви условия

Pedestrian Infrastructure Audit Report: UP 494-Transportation Planning Workshop

This report was compiled by the students of UP 494: Transportation Workshop at UIUC. As part of this course, the students engaged with the policies and design of pedestrian infrastructure around Pace bus stops in suburban communities of the Chicago Metropolitan Area. Students designed a custom-made pedestrian infrastructure audit, tailored to the needs of the research as well as the infrastructure available at Pace stops. For the second portion of the workshop, the class focused on performing in-lab exercises and research that would allow the students to better understand policies surrounding pedestrian planning and construction in suburban communities, as well as to strengthen the students understanding of the assessed built environment.Ope

Cardioprotection mediated by exosomes is impaired in the setting of type II diabetes but can be rescued by the use of non-diabetic exosomes in vitro

Many patients with ischaemic heart disease also have diabetes. As myocardial infarction is a major cause of mortality and morbidity in these patients, treatments that increase cell survival in response to ischaemia and reperfusion are needed. Exosomes-nano-sized, lipid vesicles released from cells-can protect the hearts of non-diabetic rats. We previously showed that exosomal HSP70 activates a cardioprotective signalling pathway in cardiomyocytes culminating in ERK1/2 and HSP27 phosphorylation. Here, we investigated whether the exosomal cardioprotective pathway remains intact in the setting of type II diabetes. Exosomes were isolated by differential centrifugation from non-diabetic and type II diabetic patients, from non-diabetic and Goto Kakizaki type II diabetic rats, and from normoglycaemic and hyperglycaemic endothelial cells. Exosome size and number were not significantly altered by diabetes. CD81 and HSP70 exosome markers were increased in diabetic rat exosomes. However, exosomes from diabetic rats no longer activated the ERK1/2 and HSP27 cardioprotective pathway and were no longer protective in a primary rat cardiomyocytes model of hypoxia and reoxygenation injury. Hyperglycaemic culture conditions were sufficient to impair protection by endothelial exosomes. Importantly, however, exosomes from non-diabetic rats retained the ability to protect cardiomyocytes from diabetic rats. Exosomes from diabetic plasma have lost the ability to protect cardiomyocytes, but protection can be restored with exosomes from non-diabetic plasma. These results support the concept that exosomes may be used to protect cardiomyocytes against ischaemia and reperfusion injury, even in the setting of type II diabetes