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We have recently demonstrated that exosomal communication between endothelial progenitor cells (EPCs) and brain endothelial cells is compromised in hypertensive conditions, which might contribute to the poor outcomes of stroke subjects with hypertension. The present study investigated whether exercise intervention can regulate EPC-exosome (EPC-EX) functions in hypertensive conditions. Bone marrow EPCs from sedentary and exercised hypertensive transgenic mice were used for generating EPC-EXs, denoted as R-EPC-EXs and R-EPC-EX ET . The exosomal microRNA profile was analyzed, and EX functions were determined in a co-culture system with N2a cells challenged by angiotensin II (Ang II) plus hypoxia. EX-uptake efficiency, cellular survival ability, reactive oxygen species (ROS) production, mitochondrial membrane potential, and the expressions of cytochrome c and superoxide-generating enzyme (Nox4) were assessed. We found that (1) exercise intervention improves the uptake efficiency of EPC-EXs by N2a cells. (2) exercise intervention restores miR-27a levels in R-EPC-EXs. (3) R-EPC-EX ET improved the survival ability and reduced ROS overproduction in N2a cells challenged with Ang II and hypoxia. (4) R-EPC-EX ET improved the mitochondrial membrane potential and decreased cytochrome c and Nox4 levels in Ang II plus hypoxia-injured N2a cells. All these effects were significantly reduced by miR-27a inhibitor. Together, these data have demonstrated that exercise-intervened EPC-EXs improved the mitochondrial function of N2a cells in hypertensive conditions, which might be ascribed to their carried miR-27a.

Background: Stem cell-released exosomes (EXs) have shown beneficial effects on regenerative diseases. Our previous study has revealed that EXs of endothelial progenitor cells (EPC-EXs) can elicit favorable effects on endothelial function. EXs may vary greatly in size, composition, and cargo uptake rate depending on the origins and stimulus; notably, EXs are promising vehicles for delivering microRNAs (miRs). Since miR-210 is known to protect cerebral endothelial cell mitochondria by reducing oxidative stress, here we study the effects of miR-210-loaded EPC-EXs (miR210-EPC-EXs) on ischemic brain damage in acute ischemic stroke (IS)., Methods: The miR210-EPC-EXs were generated from EPCs transfected with miR-210 mimic. Middle cerebral artery occlusion (MCAO) surgery was performed to induce acute IS in C57BL/6 mice. EPC-EXs or miR210-EPC-EXs were administrated via tail vein injection 2 hrs after IS. To explore the potential mechanisms, inhibitors of the vascular endothelial growth factor receptor 2 (VEGFR2)/PI3 kinase (PI3K) or tyrosine receptor kinase B (TrkB)/PI3k pathways were used. The brain tissue was collected after treatments for infarct size, cell apoptosis, oxidative stress, and protein expression (VEGFR2, TrkB) analyses on day two. The neurological deficit score (NDS) was evaluated before collecting the samples., Results: 1) As compared to EPC-EXs, miR210-EPC-EXs profoundly reduced the infarct volume and improved the NDS on day two post-IS. 2) Fewer apoptosis cells were detected in the peri-infarct brain of mice treated with miR210-EPC-EXs than in EPC-EXs-treated mice. Meanwhile, the oxidative stress was profoundly reduced by miR210-EPC-EXs. 3) The ratios of p-PI3k/PI3k, p- VEGFR2/VEGFR2, and p-TrkB/TrkB in the ipsilateral brain were raised by miR210-EPC-EXs treatment. These effects could be significantly blocked or partially inhibited by PI3k, VEGFR2, or TrkB pathway inhibitors., Conclusion: These findings suggest that miR210-EPC-EXs protect the brain from acute ischemia- induced cell apoptosis and oxidative stress partially through the VEGFR2/PI3k and TrkB/PI3k signal pathways., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The cancer-promoting function of the long non-coding RNA (lncRNA) LPP-AS2 has been documented in different cancers. Nonetheless, its role in thyroid carcinoma (THCA) remains unestablished. Reverse transcription quantitative polymerase chain reaction and Western blotting were conducted to estimate the expressions of lncRNA LPP-AS2, miR-132-3p, and OLFM1. The THCA cells' functions were assessed through CCK8 assays, Transwell invasion assays, scratch wound-healing migration assays, and quantification of caspase-3 activity. The in vivo assays were also implemented to assess tumor growth. Luciferase reporter and RNA immuno-precipitation assay (RIPA) experiments were executed to elucidate the interactions of miR-132-3p with lncRNA LPP-AS2 and OLFM1. THCA tissues and cells exhibited poor lncRNA LPP-AS2 and OLFM1 expressions and a robust expression of miR-132-3p. Overexpressing lncRNA LPP-AS2 constrained THCA cell proliferation, migration, and invasion and improved caspase-3 activity. The anti-tumor function of lncRNA LPP-AS2 was also validated in vivo. miR-132-3p had an interplay with lncRNA LPP-AS2 and OLFM1. Functionally, overexpressing miR-132-3p promoted the malignant THCA cell phenotypes. However, that tumor promotion was abolished by the additional overexpression of lncRNA LPP-AS2. The in vitro experiments also demonstrated that the repressive effect of OLFM1 overexpression on THCA cell malignant action could be offset by the miR-132-3p mimic. lncRNA LPP-AS2 impedes THCA progression via the miR-132-3p/OLFM1 axis. Our findings contribute a potential strategy in interfering with THCA progression.

We have previously demonstrated that endothelial progenitor cells (EPCs) provide beneficial effects on ischemic stroke by reducing oxidative stress, which could be through EPCs-released exosomes (EPC-EXs). EXs are emerging as a bioagent for mediating cell-cell communications via their carried microRNAs (miR). miR-210 is shown to provide a neuroprotection effect against ischemic stroke. Here, we aimed to determine whether the combination of EPC-EXs and miR-210 would provide an enhanced protective effect on neurons. The hypoxia and reoxygenation (H/R) model were applied to neurons to mimic the ischemic injury of neurons. EPCs were transfected with miR-210 mimic to elevate the level of miR-210 in cells and EPC-EXs (miR210-EPC-EXs). For functional studies, EPC-EXs were co-incubated with H/R-injured neurons, then the cell viability and reactive oxygen species (ROS) production were determined. The results showed 1) H/R induced apoptosis and ROS overproduction in neurons; 2) miR-210 mimic increased the level of miR-210 in both EPCs and EPC-EXs; 3) EPCs cultured in serum-free medium released more exosomes in comparison with cells grown in complete growth media, suggesting serum starving induce the release of EXs; 4) After transfection, EPCs grown in complete media had almost 50 times higher miR-210 level than EPCs had in serum-free media, while the EPCs-EXs isolated from the complete media has lower miR-210 expression than from the serum-free media in a time-dependent manner, suggesting the transfer of miR-210 through EXs; 5) After co-incubation, EPC-EXs and miR210-EPC-EXs were uptaken by neurons, and the miR-210 level in neurons was elevated by miR210-EPC-EXs; 6) miR210-EPC-EXs were more effective in promoting cell viability and decreasing apoptosis and ROS production than EPC-EXs. The present study demonstrated that EPCs-carried miR-210 could be released and transferred to neurons in a time-dependent manner and that miR-210 loading can enhance the protective effects of EPC-EXs on H/R-induced neuron apoptosis, oxidative stress, and decreased viability., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Published by Elsevier Inc.)

Ultraviolet B (UVB) stimulates the generation of extracellular vesicles, which elicit systemic effects. Here, we studied whether UVB affects the release and microRNA (miR) content of keratinocyte exosomes (EXs) in diabetic conditions. In vitro, we examined the UVB effects on affecting EX release from keratinocyte HaCaT cells (HaCaT-EX) pretreated with high glucose. HaCaT-EX functions were evaluated on Schwann cells (SCs). In vivo, UVB-induced miR change in skin EXs of diabetic db/db mice was analyzed. The miRs of interest were validated in HaCaT-EXs. We found that: (1) UVB promoted HaCaT-EX generation in dose- and time-dependent manners; 100 and 1800 J m -2 of UVB had the most prominent effect and were selected as effective low- and high-fluence UVB in vitro. (2) A total of 13 miRs were differentially expressed >3-fold in skin EXs in UVB-treated db/db mice; miR-126 was the most up-regulated by low-fluence UVB. (3) Functional studies revealed that the SC viability was improved by low-fluence UVB HaCaT-EXs, while worsened by high-fluence UVB HaCaT-EXs. (4) MiR-126 inhibitor attenuated the effects induced by low-fluence UVB HaCaT-EXs. Our data have demonstrated that low- and high-fluence UVBs promote HaCaT-EX generation but differentially affect exosomal miR levels and functions under diabetic conditions., (© 2021 The Authors. Photochemistry and Photobiology published by Wiley Periodicals LLC on behalf of American Society for Photobiology.)

Thyroid cancer (THCA) is a leading endocrine cancer and becomes the fifth most commonly diagnosed malignancy in females. It is confirmed that circular RNAs (circRNAs) perform regulatory potencies in the pathological progress of THCA. Our purpose was to certify the trait of hsa_circ_0000285 (circ_0000285) and investigate its modulatory mechanism in THCA progression. We identified the expression profile of hsa_circ_0000285 in THCA by conducting qRT-PCR assay. Therewith, the potential of hsa_circ_0000285 in THCA development was determined with a set of functional experiments, including CCK-8, wound healing assay, Western blot, and xenograft model. The molecular mechanism underlying hsa_circ_0000285 was investigated with bioinformatic analysis, RIP and dual-luciferase reporter experiments. As opposed to normal samples and cells, hsa_circ_0000285 level was overtly increased in THCA specimens and cells. The downregulation of hsa_circ_0000285 weakened the proliferative and migratory capacity of THCA cells and promoted cell apoptosis. In addition, hsa_circ_0000285 silence suppressed the tumor growth of xenograft model mice in vivo. Notably, we demonstrated that hsa_circ_0000285 might target miR-127-5p/CDH2 axis in THCA. Afterward, our findings manifested that miR-127-5p attenuation blocked the function of hsa_circ_0000285 depletion in THCA cells. In the final step, CDH2 was proven to mediate the repressive potency of miR-127-5p in the malignant behaviors of THCA. Mechanistically, hsa_circ_0000285 induced the development of THCA via functioning as a competing endogenous RNA (ceRNA) of miR-127-5p to enhance CDH2 expression, which provided a new perspective for THCA therapy., (© 2022 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Background: Hyperglycemia contributes to cardiovascular complications in patients with type 2 diabetes. We confirmed that high glucose (HG) induces endothelial dysfunction and cerebral ischemic injury is enlarged in diabetic mice. Stem cell-released exosomes have been shown to protect the brain from ischemic stroke. We have previously shown that endothelial progenitor cells (EPCs)-released exosomes (EPC-EXs) can protect endothelial cells from hypoxia/reoxygenation (H/R) and HG-induced injury. Here, we aim to investigate the effects of EPC-EXs on astrocytes under H/R and HG-induced injury and whether miR-126 enriched EPC-EXs (miR126-EPC-EXs) have enhanced efficacy., Methods: EPC-EX uptake and co-localization were measured by fluorescent microscopy using PKH26 and DAPI staining. miR-126 enrichment was achieved by transfecting with miR-126 mimics and quantified with real-time PCR. After co-incubation, cell death or injury was measured by using LDH (Lactate Dehydrogenase) assay. Oxidative stress/ROS (reactive oxygen species) generation was measured by DHE (Dihydroethidium) staining and lipid peroxidation assay., Results: The EPC-EXs were effectively taken up by the astrocytes in a concentration as well as time-dependent manners and were co-localized within the nucleus as well as the cytoplasm. Pathway uptake inhibitors revealed that the EPC-EXs are effectively taken up by the clathrin-mediated, caveolin-dependent, and micropinocytosis via PI3K/Akt pathway. H/R and HG-induced a cell injury which could be protected by EPC-EXs evidenced by decreased cell cytotoxicity, oxidative stress, and lipid peroxidation. Moreover, miR-126 overexpression could increase the level of miR-126 in astrocytes and enhance the protective effects of EPC-EXs., Conclusions: These results collectively indicate that the EPC-EXs could protect astrocytes against the HG plus H/R-induced damage., (© 2022. The Author(s).)

Aims: We previously showed that the protective effects of endothelial progenitor cells (EPCs)-released exosomes (EPC-EXs) on endothelium in diabetes. However, whether EPC-EXs are protective in diabetic ischemic stroke is unknown. Here, we investigated the effects of EPC-EXs on diabetic stroke mice and tested whether miR-126 enriched EPC-EXs (EPC-EXs miR126 ) have enhanced efficacy., Methods: The db/db mice subjected to ischemic stroke were intravenously administrated with EPC-EXs 2 hours after ischemic stroke. The infarct volume, cerebral microvascular density (MVD), cerebral blood flow (CBF), neurological function, angiogenesis and neurogenesis, and levels of cleaved caspase-3, miR-126, and VEGFR2 were measured on day 2 and 14., Results: We found that (a) injected EPC-EXs merged with brain endothelial cells, neurons, astrocytes, and microglia in the peri-infarct area; (b) EPC-EXs miR126 were more effective than EPC-EXs in decreasing infarct size and increasing CBF and MVD, and in promoting angiogenesis and neurogenesis as well as neurological functional recovery; (c) These effects were accompanied with downregulated cleaved caspase-3 on day 2 and vascular endothelial growth factor receptor 2 (VEGFR2) upregulation till day 14., Conclusion: Our results indicate that enrichment of miR126 enhanced the therapeutic efficacy of EPC-EXs on diabetic ischemic stroke by attenuating acute injury and promoting neurological function recovery., (© 2020 The Authors. CNS Neuroscience & Therapeutics Published by John Wiley & Sons Ltd.)

Background: We have previously verified the beneficial effects of exosomes from endothelial progenitor cells (EPC-EXs) in ischemic stroke. However, the effects of EPC-EXs in hemorrhagic stroke have not been investigated. Additionally, miR-137 is reported to regulate ferroptosis and to be involved in the neuroprotection against ischemic stroke. Hence, the present work explored the effects of miR-137-overexpressing EPC-EXs on apoptosis, mitochondrial dysfunction, and ferroptosis in oxyhemoglobin (oxyHb)-injured SH-SY5Y cells., Methods: The lentiviral miR-137 was transfected into EPCs and then the EPC-EXs were collected. RT-PCR was used to detect the miR-137 level in EPCs, EXs, and neurons. The uptake mechanisms of EPC-EXs in SH-SY5Y cells were explored by the co-incubation of Dynasore, Pitstop 2, Ly294002, and Genistein. After the transfection of different types of EPC-EXs, flow cytometry and expression of cytochrome c and cleaved caspase-3 were used to detect the apoptosis of oxyHb-injured neurons. Neuronal mitochondrial function was assessed by reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP) depolarization, and cellular ATP content. Cell ferroptosis was measured by lipid peroxidation, iron overload, degradation of glutathione, and glutathione peroxidase 4. Additionally, recombinational PGE2 was used to detect if activation of COX2/PGE2 pathway could reverse the protection of miR-137 overexpression., Results: The present work showed (1) EPC-EXs could be taken in by SH-SY5Y cells via caveolin-/clathrin-mediated pathways and macropinocytosis; (2) miR-137 was decreased in neurons after oxyHb treatment, and EXs miR-137 could restore the miR-137 levels; (3) EXs miR-137 worked better than EXs in reducing the number of apoptotic neurons and pro-apoptotic protein expression after oxyHb treatment; (4) EXs miR-137 are more effective in improving the cellular MMP, ROS, and ATP level; (5) EXs miR-137 , but not EXs, protected oxyHb-treated SH-SY5Y cells against lipid peroxidation, iron overload, degradation of glutathione, and glutathione peroxidase 4; and (6) EXs miR-137 suppressed the expression of the COX2/PGE2 pathway, and activation of the pathway could partially reverse the neuroprotective effects of EXs miR-137 ., Conclusion: miR-137 overexpression boosts the neuroprotective effects of EPC-EXs against apoptosis and mitochondrial dysfunction in oxyHb-treated SH-SY5Y cells. Furthermore, EXs miR-137 rather than EXs can restore the decrease in miR-137 levels and inhibit ferroptosis, and the protection mechanism might involve the miR-137-COX2/PGE2 signaling pathway.

The role of miR-503 in brain endothelium and ischemic stroke (IS) remains unclear. We aimed to study the relationship between plasma miR-503 and the onset time, severity, subtypes, and von Willebrand Factor (vWF) level in IS patients and to investigate the roles and underlying mechanisms of miR-503 in middle cerebral artery occlusion (MCAO) mice and cultured cerebral vascular endothelial cells (ECs). In MCAO mice, the effects of plasma from acute severe IS patients (ASS) with or without miR-503 antagomir on brain and ECs damage were determined. In cultured human ECs, the effects of miR-503 overexpression or knockdown on the monolayer permeability, apoptosis, ROS, and NO generation were investigated. For mechanism study, the PI3K/Akt/eNOS pathway, cleaved caspase-3, and bcl-2 were analyzed. Results showed that plasma miR-503 was significantly increased in IS patients, especially in acute period and severe cases and subtypes of LAA and TACI, and was positively correlated with vWF. Logistic analysis indicated that miR-503 was an independent risk factor for IS, with the area under curve of 0.796 in ROC analysis. In MCAO mice, ASS pretreatment aggravated neurological injury, BBB damage, brain edema, CBF reduction, and decreased NO production while increased apoptosis and ROS generation in brain ECs, which were partly abolished by miR-503 antagomir. In cultured ECs, miR-503 overexpression and knockdown confirmed its effects on regulating monolayer permeability, cell apoptosis, NO, and ROS generation via PI3K/Akt/eNOS pathway or bcl-2 and cleaved caspase-3 proteins. These together indicate that miR-503 is a promising biomarker and novel therapeutic target for IS.

Exosomes (EXs) are emerging as novel players in the beneficial effects induced by exercise on vascular diseases. We have recently revealed that moderate exercise enhances the function of circulating endothelial progenitor cell-derived EXs (cEPC-EXs) on protecting endothelial cells against hypoxia injury. However, the relationship between the changes of cEPC-EXs and the effects of exercise on ischemic stroke (IS) is unknown. Here, we investigated whether exercise-regulated EPC-EXs contribute to the beneficial effects of exercise on IS. C57BL/6 mice received moderate treadmill exercise (10 m/min) for 4-wks and then were subjected to middle cerebral artery occlusion (MCAO) stroke. The neurologic deficit score (NDS), infarct volume, microvessel density, cell apoptosis, angiogenesis/neurogenesis, sensorimotor functions were determined on day 2 (acute stage) and/or day 28 (chronic stage) post-stroke. The miR-126 and EPC-EX levels were analyzed by RT-PCR or nanoparticle tracking analysis combined with microbeads and used for correlation analyses. The function of EPC-EXs from exercised mice was detected in a hypoxia neuron model. Cell apoptosis, axon growth ability and gene expressions (cas-3 and Akt) were measured. Our data showed that: i) On day 2, exercised mice had decreased NDS and infarct volume, reduced cell apoptosis rate and cleaved cas-3 level, and a higher microvessel density than those in control (no-exercise) mice. The levels of EPC-EXs in plasma and brain tissue were raised and positively correlated in exercised mice. Meanwhile, the miR-126 level in cEPC-EXs and in ischemic tissue were upregulated in exercised mice. The EPC-EXs and their carried miR-126 levels negatively correlated with the infarct volume and cell apoptosis, whereas positively correlated with microvessel density. In addition, cEPC-EXs from exercised mice elicited protective effects on neurons against hypoxia-induced apoptosis and compromised axon growth ability which were blocked by miR-126 and PI3k inhibitors in vitro. ii) On day 28, exercised mice had less infarct volume, higher microvessel density, angiogenesis/neurogenesis and better sensorimotor functions. The levels of BDNF, p-TrkB/TrkB and p-Akt/Akt were upregulated in the brain of exercised mice. These recovery indexes correlated with the levels of cEPC-EXs and their miR-126. In conclusion, our data suggest that moderate exercise intervention has protective effects on the brain against MCAO-induced ischemic injury in both acute and chronic stages which might via the release of miR-126 enriched EPC-EXs., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Backgrounds/aims: Mesenchymal stromal cell-derived exosomes (MSC-EXs) could exert protective effects on recipient cells by transferring the contained microRNAs (miRs), and miR-132-3p is one of angiogenic miRs. However, whether the combination of MSC-EXs and miR-132-3p has better effects in ischemic cerebrovascular disease remains unknown., Methods: Mouse MSCs transfected with scrambler control or miR-132-3p mimics were used to generate MSC-EXs and miR-132-3p-overexpressed MSC-EXs (MSC-EXs miR-132-3p ). The effects of EXs on hypoxia/reoxygenation (H/R)-injured ECs in ROS generation, apoptosis, and barrier function were analyzed. The levels of RASA1, Ras, phosphorylations of PI3K, Akt and endothelial nitric oxide synthesis (eNOS), and tight junction proteins (Claudin-5 and ZO-1) were measured. Ras and PI3K inhibitors were used for pathway analysis. In transient middle cerebral artery occlusion (tMCAO) mouse model, the effects of MSC-EXs on the cerebral vascular ROS production and apoptosis, cerebral vascular density (cMVD), Evans blue extravasation, brain water content, neurological deficit score (NDS), and infarct volume were determined., Results: MSC-EXs could deliver their carried miR-132-3p into target ECs, which functionally downregulated the target protein RASA1, while upregulated the expression of Ras and the downstream PI3K phosphorylation. Compared to MSC-EXs, MSC-EXs miR-132-3p were more effective in decreasing ROS production, apoptosis, and tight junction disruption in H/R-injured ECs. These effects were associated with increased levels of phosphorylated Akt and eNOS, which could be abolished by PI3K inhibitor (LY294002) or Ras inhibitor (NSC 23766). In the tMCAO mouse model, the infusion of MSC-EXs miR-132-3p was more effective than MSC-EXs in reducing cerebral vascular ROS production, BBB dysfunction, and brain injury., Conclusion: Our results suggest that miR-132-3p promotes the beneficial effects of MSC-EXs on brain ischemic injury through protecting cerebral EC functions.

Endothelial cells (ECs) released microvesicles (EMVs) could modulate the functions of target cells by transferring their microRNAs (miRs). We have reported that miR-125a-5p protected EC function. In this study, we determined whether EMVs provided beneficial effects on ECs by transferring miR-125a-5p. Human brain microvessel ECs were transfected with miR-125a-5p mimic or miR-125a-5p short hairpin RNA to obtain miR-125a-5p overexpressing ECs and miR-125a-5p knockdown ECs, and their derived EMVs. For the functional study, ECs or hypoxia/reoxygenation injured ECs were coincubated with various EMVs. The survival and angiogenic function of ECs were measured. Western blot and quantitative real time polymerase chain reaction (qRT-PCR) were used for measuring the levels of phosphoinositide 3-kinase (PI3K), phosphorylation-Akt (p-Akt)/Akt, p-endothelial nitric oxide synthase (p-eNOS), cleaved caspase-3, and miR-125a-5p. PI3K inhibitor was used for pathway analysis. EMVs promoted the proliferation, migration, and tube formation ability of ECs, and alleviated the apoptotic rate of ECs. These effects were associated by an increase in p-Akt/Akt and p-eNOS, and a decrease in cleaved caspase-3 could be abolished by LY294002. Overexpression or downregulation of miR-125a-5p in EMVs promoted or inhibited those effects of EMVs. EMVs could enhance the survival and angiogenic function of ECs via delivering miR-125a-5p to modulate the expression of PI3K/Akt/eNOS pathway and caspase-3., (© 2018 Wiley Periodicals, Inc.)

Increasing evidence shows that repetitive transcranial magnetic stimulation (rTMS) promotes neurogenesis and the expression of microRNA (miR)‑106b. The present study investigated whether rTMS promotes the proliferation of neural progenitor cells (NPCs) and whether the effect is associated with the expression of miR‑106b. NPCs were cultured from the rat hippocampus and exposed to rTMS daily, comprising 1,000 stimuli for 3 days at 10 Hz, with 1.75 T output. The proliferation ability of the NPCs was revealed by EdU staining, and the levels of miR‑106b and downstream gene p21 in the NPCs were measured by reverse transcription‑quantitative polymerase chain reaction and western blot analyses. For analysis of the mechanism, the NPCs were transfected with Lenti‑miR‑106b or small interfering RNAs prior to rTMS. The results showed that: i) rTMS increased NPC proliferation, as revealed by the increased proportion of EdU‑positive cells; ii) rTMS was able to upregulate the expression of miR‑106b and downregulate the level of p21 in NPCs; iii) overexpression of miR‑106b further enhanced the effects of rTMS, whereas knockdown of miR‑106b had the opposite effects. Taken together, these data indicated that rTMS can promote NPC proliferation by upregulating the expression of miR‑106b and possibly inhibiting the expression of p21.

Purpose: Exercise has cardiovascular benefits which might be related to endothelial progenitor cells (EPC). Meanwhile, there is evidence suggesting that EPC-derived exosomes (EPC-EX) promote vascular repair and angiogenesis through their carried microRNA (miR)-126. In this study, we investigated whether exercise could increase the levels of circulating EPC-EX and their miR-126 cargo, and by which promote the protective function of EPC-EX on endothelial cells (EC)., Methods: Plasma EPC-EX from sedentary, low, or moderate exercise mice, respectively, denoted as EPC-EX, EPC-EX, and EPC-EX, were isolated using microbead-based sorting techniques and characterized by nanoparticle tracking analysis, Western blot, and quantitative real-time polymerase chain reaction assessments of biomarkers and miR-126. High glucose (25 mM) with hypoxia (1% O2) was used for inducing an EC injury model. The injured EC were treated by coculturing with vehicle, EPC-EX, EPC-EX, EPC-EX, or EPC-EX + anti-miR-126. After that, EC were used for flow cytometry analysis of apoptosis, assessments of tube formation and migration, and measurements of miR-126 level and its downstream sprouty-related protein-1 (SPRED1) and vascular endothelial growth factor (VEGF)., Results: 1) Isolated EPC-EX positively expressed exosomal markers (CD63 and Tsg101) and EPC markers (CD34 and VEGFR2). 2) Exercise intensity dependently elevated plasma level of EPC, EPC-EX/EPC ratio, and miR-126 expression in EPC and EPC-EX. 3) Injured EC displayed apoptosis increment, angiogenic dysfunction and miR-126 reduction. 4) EPC-EX had better effects than EPC-EX and EPC-EX on alleviating those changes of injured EC, accompanied with SPRED1 downregulation and VEGF upregulation. 5) The effects of EPC-EX were abolished by miR-126 knockdown., Conclusions: Our data demonstrate that exercise can increase EPC-EX release and miR-126 level and enhance the effects of EPC-EX on protecting EC against injury through the SPRED1/VEGF pathway.

Oxidative stress is one of the mechanisms of ageing-associated vascular dysfunction. Angiotensin-converting enzyme 2 (ACE2) and microRNA (miR)-18a have shown to be down-regulated in ageing cells. Our previous study has shown that ACE2-primed endothelial progenitor cells (ACE2-EPCs) have protective effects on endothelial cells (ECs), which might be due to their released exosomes (EXs). Here, we aimed to investigate whether ACE2-EPC-EXs could attenuate hypoxia/reoxygenation (H/R)-induced injury in ageing ECs through their carried miR-18a. Young and angiotensin II-induced ageing ECs were subjected to H/R and co-cultured with vehicle (medium), EPC-EXs, ACE2-EPCs-EXs, ACE2-EPCs-EXs + DX600 or ACE2-EPCs-EXs with miR-18a deficiency (ACE2-EPCs-EXs anti-miR-18a ). Results showed (1) ageing ECs displayed increased senescence, apoptosis and ROS production, but decreased ACE2 and miR-18a expressions and tube formation ability; (2) under H/R condition, ageing ECs showed higher rate of apoptosis, ROS overproduction and nitric oxide reduction, up-regulation of Nox2, down-regulation of ACE2, miR-18a and eNOS, and compromised tube formation ability; (3) compared with EPC-EXs, ACE2-EPC-EXs had better efficiencies on protecting ECs from H/R-induced changes; (4) The protective effects were less seen in ACE2-EPCs-EXs + DX600 and ACE2-EPCs-EXs anti-miR-18a groups. These data suggest that ACE-EPCs-EXs have better protective effects on H/R injury in ageing ECs which could be through their carried miR-18a and subsequently down-regulating the Nox2/ROS pathway., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Background/aims: Stem cell-derived exosomes (EXs) offer protective effects on various cells via their carried microRNAs (miRs). Meanwhile, miR-210 has been shown to reduce mitochondrial reactive oxygen species (ROS) overproduction. In this study, we determined the potential effects of endothelial progenitor cell-derived EXs (EPC-EXs) on hypoxia/ reoxygenation (H/R) injured endothelial cells (ECs) and investigated whether these effects could be boosted by miR-210 loading., Methods: Human EPCs were used to generate EPC-EXs, or transfected with scrambler control or miR-210 mimics to generate EPC-EXssc and EPC-EXsmiR-210. H/R-injured human ECs were used as a model for functional analysis of EXs on apoptosis, viability, ROS production and angiogenic ability (migration and tube formation) by flow cytometry, MTT, dihydroethidium and angiogenesis assay kits, respectively. For mechanism analysis, the mitochondrion morphology, membrane potential (MMP), ATP level and the expression of fission/fusion proteins (dynamin-related protein 1: drp1 and mitofusin-2: mfn2) were assessed by using JC-1 staining, ELISA and western blot, respectively., Results: 1) Transfection of miR-210 mimics into EPCs induced increase of miR-210 in EPC-EXsmiR-210 without change of average size; 2) EPC-EXsmiR-210, but not EPC-EXs or EPC-EXssc, significantly elevated miR-210 level in ECs; 3) EPC-EXsmiR-210 were more effective than EPC-EXs and EPC-EXssc in reducing H/R-induced EC apoptosis, ROS overproduction and angiogenic dysfunction; 4) EPC-EXs decreased mitochondrial fragmentation, elevated MMP and ATP level, as well as improved mitochondrial mfn2 and drp1 dysregulation, which were more effective in EPC-EXsmiR-210., Conclusion: Our results suggest that EPC-EXs protect ECs against H/R injury via improving mitochondrial function and miR-210 enrichment could boost their effects., (© 2018 The Author(s). Published by S. Karger AG, Basel.)

We have demonstrated that neural progenitor cells (NPCs) protect endothelial cells (ECs) from oxidative stress. Since exosomes (EXs) can convey the benefit of parent cells through their carried microRNAs (miRs) and miR-210 is ubiquitously expressed with versatile functions, we investigated the role of miR-210 in the effects of NPC-EXs on oxidative stress and dysfunction in ECs. NPCs were transfected with control and miR-210 scramble/inhibitor/mimic to generate NPC-EXs con , NPC-EXs sc , NPC-EXs anti-miR-210 , and NPC-EXs miR-210 . The effects of various NPC-EXs on angiotensin II- (Ang II-) induced reactive oxygen species (ROS) overproduction, apoptosis, and dysfunction, as well as dysregulation of Nox2, ephrin A3, VEGF, and p-VEGFR2/VEGFR2 in ECs were evaluated. Results showed (1) Ang II-induced ROS overproduction, increase in apoptosis, and decrease in tube formation ability, accompanied with Nox2 upregulation and reduction of p-VEGFR2/VEGFR2 in ECs. (2) Compared to NPC-EXs con or NPC-EXs sc , NPC-EXs anti-miR-210 were less whereas NPC-EXs miR-210 were more effective on attenuating these detrimental effects induced by Ang II in ECs. (3) These effects of NPC-EXs anti-miR-210 and NPC-EXs miR-210 were associated with the changes of miR-210, ephrin A3, VEGF, and p-VEGFR2/VEGFR2 ratio in ECs. Altogether, the protective effects of NPC-EXs on Ang II-induced endothelial injury through miR-210 which controls Nox2/ROS and VEGF/VEGFR2 signals were studied.