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The lower cell survival and retention in the hostile microenvironment after transplantation has been implicated as a major bottleneck in the advancement of stem cell therapy for myocardial infarction (MI). In this study, we designed a novel self-assembling peptide (SAP) by attaching prosurvival peptide QHREDGS derived from angiopoeitin-1 to the known SAP, RADA16-I. The mesenchymal stem cells (MSCs) were harvested from male rats and cytoprotective effect of this designer SAP (DSAP) on cultured MSCs was detected by Hoechst 33342 staining after being exposed to oxygen and glucose deprivation (OGD). The cytoprotective effect of MSCs seeded in DSAP (DSAP-MSCs) on OGD treated cardiomyocytes was examined by TUNEL staining, phosphorylated (p-) protein kinase B (Akt) level, and ELISA. The therapeutic potential of MSC transplantation carried in DSAP was evaluated in a female rat MI model. PBS, MSCs alone, MSCs seeded in SAP (SAP-MSCs), or DSAP-MSCs were transplanted into the border of the infarcted area, respectively. DSAP not only increased the proliferation of MSCs and decreased apoptosis of MSCs after OGD treatment but also promoted the secretion of IGF-1 and HGF in MSCs. Treatment with culture supernatant of DSAP-MSCs markedly reduced the percentage of apoptotic cardiomyocytes and increased the level of p-Akt. Compared with the MSC group and SAP-MSC group, DSAP-MSC injection improved cardiac function and reduced infarct size, collagen content, and cell apoptosis. The number of Y chromosome-positive cells and microvessels in the DSAP-MSC group was higher than those in the MSC group and SAP-MSC group. Moreover, DSAP-MSC transplantation down-regulated the expression of IL-6 and IL-1ß and up-regulated the level of VEGF and HGF. Interestingly, miR-21 was enriched in DSAP-MSC-derived exosomes (DSAP-MSC-Exos) and the protection against cardiomyocyte apoptosis by DSAP-MSC-Exos was inhibited when miR-21 was knocked down. Furthermore, miR-21 contributed to the improvement of cardiac function after DSAP-MSC-Exo injection in a rat model of MI. Additionally, the combination of DSAP and cardiotrophin-1 (Ctf1) pretreatment further improved the survival of MSCs and the efficiency of MSC transplantation. We proposed QHREDGS-modified SAP as an effective cell delivery system and demonstrated that MSC transplantation in this DSAP promoted angiogenesis and paracrine, thereby reducing scar size and cell apoptosis as well as improving cardiac function probably via exosome-mediated miR-21 after MI. Furthermore, for the first time, we proposed that DSAP, especially working together with Ctf1 pretreatment, could be a valuable way to improve the survival of MSCs and the efficiency of MSC transplantation after MI.-Cai, H., Wu, F.-Y., Wang, Q.-L., Xu, P., Mou, F.-F., Shao, S.-J., Luo, Z.-R., Zhu, J., Xuan, S.-S., Lu, R., Guo, H.-D. Self-assembling peptide modified with QHREDGS as a novel delivery system for mesenchymal stem cell transplantation after myocardial infarction.
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Citoprotección/efectos de los fármacos , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/metabolismo , Infarto del Miocardio , Péptidos , Aloinjertos , Animales , Supervivencia Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Femenino , Masculino , Células Madre Mesenquimatosas/patología , MicroARNs/metabolismo , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/terapia , Péptidos/química , Péptidos/farmacología , Ratas , Ratas Sprague-DawleyRESUMEN
Although the benefits of electroacupuncture (EA) for peripheral nerve injury (PNI) are well accepted in clinical practice, the underlying mechanism remains incompletely elucidated. In our study, we observed that EA intervention led to a reduction in the expression of the long non-coding RNA growth-arrest-specific transcript 5 (GAS5) and an increased in miR-21 levels within the injured nerve, effectively promoting functional recovery and nerve regeneration following sciatic nerve injury (SNI). In contrast, administration of adeno-associated virus expressing GAS5 (AAV-GAS5) weakened the therapeutic effect of EA. On the other hand, both silencing GAS5 and introducing a miR-21 mimic prominently enhanced the proliferation activity and migration ability of Schwann cells (SCs), while also inhibiting SCs apoptosis. On the contrary, inhibition of SCs apoptosis was found to be mediated by miR-21. Additionally, overexpression of GAS5 counteracted the effects of the miR-21 mimic on SCs. Moreover, SCs that transfected with the miR-21 mimic promoted neurite growth in hypoxia/reoxygenation-induced neurons, which might be prevented by overexpressing GAS5. Furthermore, GAS5 was found to be widely distributed in the cytoplasm and was negatively regulated by miR-21. Consequently, the targeting of GAS5 by miR-21 represents a potential mechanism through which EA enhances reinnervation and functional restoration following SNI. Mechanistically, the GAS5/miR-21 axis can modulate the proliferation, migration, and apoptosis of SCs while potentially influencing the neurite growth of neurons.
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Electroacupuntura , MicroARNs , Traumatismos de los Nervios Periféricos , ARN Largo no Codificante , Neuropatía Ciática , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Traumatismos de los Nervios Periféricos/terapia , Traumatismos de los Nervios Periféricos/metabolismo , Neuropatía Ciática/metabolismo , Regeneración Nerviosa/fisiología , Nervio Ciático/metabolismoRESUMEN
OBJECTIVE: The aim of this study was to explore the role and mechanisms of electroacupuncture (EA) in the regulation of chemokines in endogenous stem cell mobilization and myocardial regeneration after myocardial infarction (MI). METHODS: An MI model was constructed in adult male Sprague-Dawley rats by ligating the left anterior descending coronary artery. After 4 weeks of treatment, echocardiography was used to detect changes in cardiac function, and Masson's trichrome staining was used to detect collagen deposition. In addition, immunofluorescence staining was applied to examine von Willebrand factor (vWF)-positive vessels, the expression of cardiac troponin T (cTnT) and proliferation marker Ki67, and the number of c-kit-positive, C-X-C chemokine receptor type 4 (CXCR4)-positive, and Sca-1-positive endogenous stem cells in the infarcted area. In addition, the expression of stromal cell-derived factor (SDF)-1 and stem cell factor (SCF) was detected. RESULTS: EA increased the ejection fraction after MI, reduced collagen deposition and cellular apoptosis, and increased the number of blood vessels compared with an untreated model group. EA significantly promoted cellular proliferation, except for myocardial cells, and significantly increased the number of c-kit-, CXCR4- and Sca-1-positive stem cells. Moreover, the expression of SDF-1 and SCF in myocardial tissue in the EA group was significantly higher than that in the (untreated) MI group. CONCLUSIONS: EA appears to promote angiogenesis and reduce collagen deposition, thus improving the cardiac function of rats with MI. The underlying mechanism of action may involve endogenous stem cell mobilization mediated by SDF-1/CXCR4 and SCF/c-kit.
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Electroacupuntura , Infarto del Miocardio , Ratas , Masculino , Animales , Ratas Sprague-Dawley , Infarto del Miocardio/terapia , Células Madre/metabolismo , ColágenoRESUMEN
Poor vascularization and insufficient oxygen supply are detrimental to the survival of residual cardiomyocytes or transplanted stem cells after myocardial infarction. To prolong and slow the release of angiogenic factors, which stimulate both angiogenesis and vasculogenesis, we constructed a novel self-assembling peptide by attaching the heparin-binding domain sequence LRKKLGKA to the self-assembling peptide RADA16. This designer self-assembling peptide self-assembled into nanofiber scaffolds under physiological conditions, as observed by atomic force microscopy. The injection of designer self-assembling peptides can efficiently provide the sustained delivery of VEGF for at least 1 month. At 4 weeks after transplantation, cardiac function was improved, and scar size and collagen deposition were markedly reduced in the group receiving VEGF with the LRKKLGKA scaffolds compared with groups receiving VEGF alone, LRKKLGKA scaffolds alone or VEGF with RADA16 scaffolds. The microvessel density in the VEGF with LRKKLGKA group was higher than that in the VEGF with RADA16 group. TUNEL and cleaved caspase-3 expression assays showed that the transplantation of VEGF with LRKKLGKA enhanced cell survival in the infarcted heart. These results present the tailor-made peptide scaffolds as a new generation of sustained-release biomimetic biomaterials and suggest that the use of angiogenic factors along with designer self-assembling peptides can lead to myocardial protection, sufficient angiogenesis, and improvement in cardiac function.
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Inductores de la Angiogénesis/administración & dosificación , Materiales Biomiméticos/administración & dosificación , Corazón/efectos de los fármacos , Contracción Miocárdica/efectos de los fármacos , Infarto del Miocardio/fisiopatología , Factor A de Crecimiento Endotelial Vascular/administración & dosificación , Disfunción Ventricular Izquierda/fisiopatología , Secuencia de Aminoácidos , Inductores de la Angiogénesis/química , Animales , Materiales Biomiméticos/química , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Diseño de Fármacos , Femenino , Fibrosis , Heparina/química , Microscopía de Fuerza Atómica , Infarto del Miocardio/patología , Nanofibras/administración & dosificación , Nanofibras/química , Estructura Terciaria de Proteína , Ratas , Ratas Sprague-Dawley , Factor A de Crecimiento Endotelial Vascular/química , Disfunción Ventricular Izquierda/patologíaRESUMEN
Stem cell-based therapeutic strategies have obtained a significant breakthrough in the treatment of cardiovascular diseases, particularly in myocardial infarction (MI). Nevertheless, limited retention and poor migration of stem cells are still problems for stem cell therapeutic development. Hence, there is an urgent need to develop new strategies that can mobilize stem cells to infarcted myocardial tissues effectively. Electroacupuncture (EA) intervention can improve cardiac function and alleviate myocardial injury after MI, but its molecular mechanism is still unclear. This study is aimed at observing the effects of EA treatment on the stem cell mobilization and revealing possible mechanisms in the MI model of mice. EA treatment at Neiguan (PC6) and Xinshu (BL15) acupoints was conducted on the second day after the ligation surgery. Then, the number of stem cells in peripheral blood after EA in MI mice and their cardiac function, infarct size, and collagen deposition was observed. We found that the number of CD34-, CD117-, Sca-1-, and CD90-positive cells increased at 6 h and declined at 24 h after EA intervention in the blood of MI mice. The expression of CXC chemokine receptor-4 (CXCR4) protein was upregulated at 6 h after EA treatment, while the ratio of LC3B II/I or p-ERK/ERK showed a reverse trend. In addition, there was obvious difference in EF and FS between wild-type mice and CXCR4+/- mice. The infarct size, collagen deposition, and apoptosis of the injured myocardium in CXCR4+/- mice increased but could be ameliorated by EA. In a word, our study demonstrates that EA alleviates myocardial injury via stem cell mobilization which may be regulated by the SDF-1/CXCR4 axis.
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Quimiocina CXCL12 , Electroacupuntura , Infarto del Miocardio , Receptores CXCR4 , Animales , Quimiocina CXCL12/metabolismo , Movilización de Célula Madre Hematopoyética , Ratones , Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Receptores CXCR4/metabolismoRESUMEN
As a common complication of diabetes, the pathogenesis of diabetic peripheral neuropathy (DPN) is closely related to high glucose but has not been clarified. Exosomes can mediate crosstalk between Schwann cells (SC) and neurons in the peripheral nerve. Herein, we found that miR-21 in serum exosomes from DPN rats was decreased. SC proliferation was inhibited, cell apoptosis was increased, and the expression of miR-21 in cells and exosomes was downregulated when cultured in high glucose. Increasing miR-21 expression reversed these changes, while knockdown of miR-21 led to the opposite results. When co-cultured with exosomes derived from SC exposed to high glucose, neurite outgrowth was inhibited. On the contrary, neurite outgrowth was accelerated when incubated with exosomes rich in miR-21. We further demonstrated that the SC-derived exosomal miR-21 participates in neurite outgrowth probably through the AKT signaling pathway. Thus, SC-derived exosomal miR-21 contributes to high glucose regulation of neurite outgrowth.
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PURPOSE: Our study is aimed at investigating the mechanism by which electroacupuncture (EA) promoted nerve regeneration by regulating the release of exosomes and exosome-mediated miRNA-21 (miR-21) transmission. Furthermore, the effects of Schwann cells- (SC-) derived exosomes on the overexpression of miR-21 for the treatment of PNI were investigated. METHODS: A sciatic nerve injury model of rat was constructed, and the expression of miR-21 in serum exosomes and damaged local nerves was detected using RT-qPCR after EA treatment. The exosomes were identified under a transmission electron microscope and using western blotting analysis. Then, the exosome release inhibitor, GW4869, and the miR-21-5p-sponge used for the knockdown of miR-21 were used to clarify the effects of exosomal miR-21 on nerve regeneration promoted by EA. The nerve conduction velocity recovery rate, sciatic nerve function index, and wet weight ratio of gastrocnemius muscle were determined to evaluate sciatic nerve function recovery. SC proliferation and the level of neurotrophic factors were assessed using immunofluorescence staining, and the expression levels of SPRY2 and miR-21 were detected using RT-qPCR analysis. Subsequently, the transmission of exosomal miR-21 from SC to the axon was verified in vitro. Finally, the exosomes derived from the SC infected with the miR-21 overexpression lentivirus were collected and used to treat the rat SNI model to explore the therapeutic role of SC-derived exosomes overexpressing miR-21. RESULTS: We found that EA inhibited the release of serum exosomal miR-21 in a PNI model of rats during the early stage of PNI, while it promoted its release during later stages. EA enhanced the accumulation of miR-21 in the injured nerve and effectively promoted the recovery of nerve function after PNI. The treatment effect of EA was attenuated when the release of circulating exosomes was inhibited or when miR-21 was downregulated in local injury tissue via the miR-21-5p-sponge. Normal exosomes secreted by SC exhibited the ability to promote the recovery of nerve function, while the overexpression of miR-21 enhanced the effects of the exosomes. In addition, exosomal miR-21 secreted by SC could promote neurite outgrowth in vitro. CONCLUSION: Our results demonstrated the mechanism of EA on PNI from the perspective of exosome-mediated miR-21 transport and provided a theoretical basis for the use of exosomal miR-21 as a novel strategy for the treatment of PNI.
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Electroacupuntura/métodos , Exosomas/metabolismo , MicroARNs/genética , Traumatismos de los Nervios Periféricos/sangre , Traumatismos de los Nervios Periféricos/terapia , Recuperación de la Función/genética , Nervio Ciático/lesiones , Transducción de Señal/genética , Compuestos de Anilina/farmacología , Animales , Compuestos de Bencilideno/farmacología , Línea Celular Transformada , Modelos Animales de Enfermedad , Expresión Génica , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen/métodos , Masculino , Regeneración Nerviosa/efectos de los fármacos , Regeneración Nerviosa/genética , Proteínas del Tejido Nervioso/genética , Ratas , Ratas Wistar , Recuperación de la Función/efectos de los fármacos , Células de Schwann/metabolismo , Transducción de Señal/efectos de los fármacos , TransfecciónRESUMEN
Notoginsenoside R1 (NGR1) is the main monomeric component extracted from the dried roots and rhizomes of Panax notoginseng, and exerts pharmacological action against myocardial infarction (MI). Owing to the differences in compound distribution, absorption, and metabolism in vivo, exploring a more effective drug delivery system with a high therapeutic targeting effect is crucial. In the early stages of MI, CD11b-expressing monocytes and neutrophils accumulate at infarct sites. Thus, we designed a mesoporous silica nanoparticle-conjugated CD11b antibody with loaded NGR1 (MSN-NGR1-CD11b antibody), which allowed NGR1 precise targeted delivery to the heart in a noninvasively manner. By increasing targeting to the injured myocardium, intravenous injection of MSN-NGR1-CD11b antibody nanoparticle in MI mice improved cardiac function and angiogenesis, reduced cell apoptosis, and regulate macrophage phenotype and inflammatory factors and chemokines. In order to further explore the mechanism of NGR1 protecting myocardium, cell oxidative stress model and oxygen-glucose deprivation (OGD) model were established. NGR1 protected H9C2 cells and primary cardiomyocytes against oxidative injury induced by H2O2 and OGD treatment. Further network pharmacology and molecular docking analyses suggested that the AKT, MAPK and Hippo signaling pathways were involved in the regulation of NGR1 in myocardial protection. Indeed, NGR1 could elevate the levels of p-Akt and p-ERK, and promote the nuclear translocation of YAP. Furthermore, LY294002 (AKT inhibitor), U0126 (ERK1/2 inhibitor) and Verteporfin (YAP inhibitor) administration in H9C2 cells indicated the involvement of AKT, MAPK and Hippo signaling pathways in NGR1 effects. Meanwhile, MSN-NGR1-CD11b antibody nanoparticles enhanced the activation of AKT and MAPK signaling pathways and the nuclear translocation of YAP at the infarcted site. Our research demonstrated that MSN-NGR1-CD11b antibody nanoparticle injection after MI enhanced the targeting of NGR1 to the infarcted myocardium and improved cardiac function. More importantly, our pioneering research provides a new strategy for targeting drug delivery systems to the ischemic niche.
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Infarto del Miocardio , Nanopartículas , Animales , Apoptosis , Ginsenósidos , Glucosa , Peróxido de Hidrógeno , Ratones , Simulación del Acoplamiento Molecular , Infarto del Miocardio/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Dióxido de SilicioRESUMEN
Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus that affects approximately half of patients with diabetes. Current treatment regimens cannot treat DPN effectively. Schwann cells (SCs) are very sensitive to glucose concentration and insulin, and closely associated with the occurrence and development of type 1 diabetic mellitus (T1DM) and DPN. Apoptosis of SCs is induced by hyperglycemia and is involved in the pathogenesis of DPN. This review considers the pathological processes of SCs apoptosis under high glucose, which include the following: oxidative stress, inflammatory reactions, endoplasmic reticulum stress, autophagy, nitrification and signaling pathways (PI3K/AKT, ERK, PERK/Nrf2, and Wnt/ß-catenin). The clarification of mechanisms underlying SCs apoptosis induced by high glucose will help us to understand and identify more effective strategies for the treatment of T1DM DPN.
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Apoptosis/efectos de los fármacos , Neuropatías Diabéticas/genética , Glucosa/farmacología , Hiperglucemia/genética , Células de Schwann/efectos de los fármacos , Animales , Apoptosis/genética , Autofagia/efectos de los fármacos , Autofagia/genética , Neuropatías Diabéticas/complicaciones , Neuropatías Diabéticas/metabolismo , Neuropatías Diabéticas/patología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Regulación de la Expresión Génica , Glucosa/metabolismo , Humanos , Hiperglucemia/complicaciones , Hiperglucemia/metabolismo , Hiperglucemia/patología , Insulina/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Células de Schwann/metabolismo , Células de Schwann/patología , Transducción de Señal , beta Catenina/genética , beta Catenina/metabolismoRESUMEN
Growing evidence indicates that electroacupuncture (EA) has a definite effect on the treatment of peripheral nerve injury (PNI), but its mechanism is not completely clear. MicroRNAs (miRNAs) are involved in the regulation of a variety of biological processes, and EA may enhance PNI repair by regulating miRNAs. In this study, the rat sciatic nerve injury model was treated with EA for 4 weeks. Acupoints Huantiao (GB30) and Zusanli (ST36) were stimulated by EA 20 min once a day, 6 days a week for 4 weeks. We found that EA treatment downregulated the expression of miR-1b in the local injured nerve. In vitro experiments showed that overexpression of miR-1b inhibited the expression of brain-derived neurotrophic factor (BDNF) in rat Schwann cell (SC) line, while BDNF knockdown inhibited the proliferation, migration, and promoted apoptosis of SCs. Subsequently, the rat model of sciatic nerve injury was treated by EA treatment and injection of agomir-1b or antagomir-1b. The nerve conduction velocity ratio (NCV), sciatic functional index (SFI), and S100 immunofluorescence staining were examined and showed that compared with the model group, NCV, SFI, proliferation of SC, and expression of BDNF in the injured nerves of rats treated with EA or EA + anti-miR-1b were elevated, while EA + miR-1b was reduced, indicating that EA promoted sciatic nerve function recovery and SC proliferation through downregulating miR-1b. To summarize, EA may promote the proliferation, migration of SC, and nerve repair after PNI by regulating miR-1b, which targets BDNF.
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OBJECTIVE: To investigate the effect of electroacupuncture (EA) at "Baihui "(GV20) and "Shenshu "(BL23) on activation of glial cells, expression of inflammatory factor proteins and aquaporin 4 (AQP4)in the hippocampus of amyloid precursor protein/presenilin-1 (APP/PS1) transgenic mice, so as to explore its mechanisms underlying improvement of Alzheimer's disease(AD). METHODS: Twenty C57/BL6 background male APP695/PS1-dE9(APP/PS1) double transgenic mice (model group) and 20 wild type (WT) C57/BL6 mice (blank group) were respectively randomized into control and EA groups. EA (2 Hz/15 Hz, 1ï¼2 mA) was applied to GV20 and bilateral BL23 for 30 min, once daily, 6 days a week for 4 weeks. The recognition memory ability was detected by novel object recognition tests in a behavior test box. The percentage of time spent in close interaction with novel object (C) relative to the total time was used to generate preference index. The contents of hippocampal ß amyloid protein (Aß)1-40 and Aß1-42 were assayed using ELISA, and the expression levels of glial fibrillary acidic protein (GFAP), ionic calcium binding receptor molecule-1 (Iba-1), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) proteins in the hippocampus measured by Western blot. The activities of hippocampal astrocytes (GFAP-labelled cells), microglia (Iba-1-labelled cells) and the polarity expression of AQP4 (for removing Aß) were measured by immunohistochemistry. RESULTS: The preference index was significantly decreased in the model group relatively to the blank control group (P<0.05) and considerably increased in the modelï¼EA group relatively to the model group (P<0.05), suggesting an improvement of the recognition memory after EA. The contents of Aß1-40 and Aß1-42, immunoactivity of GFAP and Iba-1, expression levels of GFAP, Iba-1, IL-1ß, IL-6 and TNF-α proteins were significantly higher in the model group than in the blank control group (P<0.01ï¼P<0.05), while the AQP4 immunoactivity was notably lower in the model group than in the blank control group (P<0.05). Compared with the model group, the levels of Aß1-40 and Aß1-42, GFAP, Iba-1, IL-1ß, IL-6 and TNF-α proteins, and the percentage of Aß plaque area were significantly decreased in the modelï¼EA group (P<0.01ï¼P<0.05), and the immunoactivity of AQP4 was significantly increased in the mo-delï¼EA group (P<0.05). No significant changes were found in the above-mentioned indexes in the blankï¼EA group relevant to the blank control group (P>0.05)ï¼. CONCLUSION: EA at GV20 and BL23 can reduce inflammatory reaction and Aß level, suppress activation of astrocytes and microglia, and up-regulate expression of AQP4 in the hippocampus tissue in APP/PS1 transgenic mice, which may contribute to its effect in improving recognition memory ability, suggesting a role of EA intervention in delaying the development of AD via promoting the drainage of Aß by the glymphatic system in the brain.
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Enfermedad de Alzheimer , Electroacupuntura , Precursor de Proteína beta-Amiloide , Animales , Acuaporina 4 , Modelos Animales de Enfermedad , Hipocampo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Presenilina-1RESUMEN
Cardiovascular disease has been established as a major cause of morbidity and mortality worldwide, resulting in a huge burden to patients, families, and society. Traditional Chinese Medicine (TCM) presents several advantages for the prevention and treatment of cardiovascular diseases including multitargets, multi-ingredients, fewer side effects, and low cost. In this study, a rat model of myocardial infarction (MI) was established by ligating the anterior descending branch of the left coronary artery, and the effect of the Taohong Siwu decoction (THSWD) on cardiac function was evaluated in MI rats. Following the intragastric administration of THSWD, the cardiac function was examined using echocardiography. The infarct size and collagen deposition in the infarct area were measured using Masson's trichrome staining, and the number of CD31- and α-SMA-positive blood vessels in the peri-infarct and infarct area was evaluated by immunofluorescent staining. The mRNA expression of bFGF, IGF-1, and HGF was detected using RT-PCR assay. Cell apoptosis in the infarcted area was assessed by TUNEL staining, and the p-Akt level was detected using the western blot assay. The mitochondrial ROS production was measured using MitoSOX staining, and mitochondrial dynamics and mitophagy were evaluated with western blotting 7 days after THSWD treatment. THSWD increased the ejection fraction (EF) and fractional shortening (FS) values in the rat hearts; however, no statistical difference was found between the THSWD and MI groups 4 weeks after treatment. Furthermore, THSWD significantly decreased the value of the left ventricular end-systolic volume (LVESV). Compared with the model group, THSWD significantly increased the expression of IGF-1 and bFGF, reduced collagen deposition, promoted angiogenesis, reduced cell apoptosis, and activated the PI3K/Akt signaling pathway. Notably, THSWD significantly decreased mitochondrial ROS production and Fis1 expression. No statistical differences were observed in the expression of mitochondrial LC3B and Mfn1 between the THSWD and control groups. In summary, THSWD may possess a beneficial effect on cardiac function by improving the local ischemic microenvironment and by decreasing mitochondrial fission after MI. Hence, this may present a promising auxiliary strategy in the treatment of ischemic cardiomyopathy such as MI.
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Using electroacupuncture and moxibustion to treat peripheral nerve injury is highly efficient with low side effects. However, the electroacupuncture- and moxibustion-based mechanisms underlying nerve repair are still unclear. Here, in vivo and in vitro experiments uncovered one mechanism through which electroacupuncture and moxibustion affect regeneration after peripheral nerve injury. We first established rat models of sciatic nerve injury using neurotomy. Rats were treated with electroacupuncture or moxibustion at acupoints Huantiao (GB30) and Zusanli (ST36). Each treatment lasted 15 minutes, and treatments were given six times a week for 4 consecutive weeks. Behavioral testing was used to determine the sciatic functional index. We used electrophysiological detection to measure sciatic nerve conduction velocity and performed hematoxylin-eosin staining to determine any changes in the gastrocnemius muscle. We used immunohistochemistry to observe changes in the expression of S100-a specific marker for Schwann cells-and an enzyme-linked immunosorbent assay to detect serum level of nerve growth factor. Results showed that compared with the model-only group, sciatic functional index, recovery rate of conduction velocity, diameter recovery of the gastrocnemius muscle fibers, number of S100-immunoreactive cells, and level of nerve growth factor were greater in the electroacupuncture and moxibustion groups. The efficacy did not differ between treatment groups. The serum from treated rats was collected and used to stimulate Schwann cells cultured in vitro. Results showed that the viability of Schwann cells was much higher in the treatment groups than in the model group at 3 and 5 days after treatment. These findings indicate that electroacupuncture and moxibustion promoted nerve regeneration and functional recovery; its mechanism might be associated with the enhancement of Schwann cell proliferation and upregulation of nerve growth factor.
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Peripheral nerve injury (PNI) is a global problem that leads to severe disability and high healthcare expenditure. Accumulating evidence suggested that the phenotypes of Schwann cells (SCs) could be regulated by microRNAs (miRNAs) and expressions of various miRNAs are altered after PNI. In this study, the expression of miR-1b in the injured nerve and hypoxia-treated SCs was detected through qRT-PCR. The target genes of miR-1b were predicted by bioinformatics prediction and dual-luciferase reporter assay and verified through qRT-PCR and western blot. The effects of miR-1b and its specific target gene on the proliferation, migration and apoptosis of SCs were determined and the regulation of miR-1b on peripheral nerve regeneration after PNI was further investigated in vivo. We found that miR-1b was obviously downregulated in the injured nerve in a rat sciatic nerve transection model and directly targeted N-myc downstream-regulated gene 3 (NDRG3) by binding to its 3'-UTR and caused both mRNA degradation and translation suppression of NDRG3. Overexpression of miR-1b or knockdown of NDRG3 decreased the proliferation and migration as well as increased the apoptosis of SCs. NDRG3 reversed the effects of miR-1b overexpression on proliferation/migration/apoptosis of RSC96. In addition, injection of miR-1b antagomir promoted the expression of NDRG3 in the injured nerve following sciatic nerve injury. Compared to the model group, the rats treated with miR-1b agomir had lower functional recovery rate, and downregulation of miR-1b through injection of specific antagomir improved the functional recovery rate according to the results of sciatic functional index and nerve conduction velocity. Overall, our results will contribute to the development of novel targets for promoting nerve regeneration after PNI.
Asunto(s)
Apoptosis/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/genética , MicroARNs/farmacología , Animales , Células Cultivadas , Masculino , Regeneración Nerviosa/genética , Traumatismos de los Nervios Periféricos/metabolismo , Estabilidad del ARN/genética , Ratas Wistar , Células de Schwann/metabolismo , Nervio Ciático/efectos de los fármacos , Nervio Ciático/lesiones , Neuropatía Ciática/metabolismoRESUMEN
The neuropathological hallmarks of Alzheimer's disease (AD) include the presence of extracellular amyloid-ß peptide (Aß) in the form of amyloid plaques and neuronal loss. Neural stem cell (NSC) is being scrutinized as a promising cell replacement therapy for various neurodegenerative diseases. However, the unfavorable niche at the site of degenerative disease is hostile to the survival and differentiation of transplanted cells. Here, we undertook in vitro and in vivo works to examine whether a designer self-assemble peptide (DSP), which contains one functional domain Tyr-Ile-Gly-Ser-Arg (YIGSR) derived from laminin, promotes the survival and neuronal differentiation of NSC and behavioral improvement. We found that DSP could undergo spontaneous assembly into well-ordered nanofibers, and it not only facilitated the cell viability in normal culture condition, but also decreased the number of apoptotic cells induced by Aß in vitro. NSC seeded in DSP showed much more neuronal differentiation than that seeded in self-assemble peptide (SP) or alone. In the AD model, NSC transplantation in DSP-treated AD rats demonstrated much more obvious cognitive rescue with restoration of learning/memory function compared with NSC transplantation in SP, NSC alone, or DSP alone treated ones. Interestingly, DSP enhanced the survival and neuronal differentiation of transplanted NSC. Apoptosis levels in the CA1 region and Aß level in the hippocampus were significantly decreased in the group of NSC transplantation in DSP. Moreover, synaptic function, indicated by the expression of pre-synaptic protein synapsin-1, was restored and the secretion of anti-inflammatory and neurotrophic factors were increased, such as IL-10, brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), and insulin-like growth factor 1 (IGF-1), while the expression of pro-inflammatory factors were decreased, such as TNF-α and IL-1ß. These data firstly unveiled that the biomaterial DSP can maximize the therapeutic benefits of NSC transplantation for AD through improving the survival and differentiation of transplanted stem cells and promoting the effects of neuroprotection, anti-neuroinflammatory and paracrine action. Our results may have important clinical implications for the design of future NSC-based strategies using the biomaterials for various neurodegenerative diseases including AD.
Asunto(s)
Enfermedad de Alzheimer/terapia , Diferenciación Celular/efectos de los fármacos , Células-Madre Neurales/trasplante , Neuronas/patología , Comunicación Paracrina/efectos de los fármacos , Péptidos/uso terapéutico , Trasplante de Células Madre , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/fisiopatología , Secuencia de Aminoácidos , Péptidos beta-Amiloides/toxicidad , Animales , Apoptosis/efectos de los fármacos , Conducta Animal/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Citocinas/metabolismo , Inflamación/metabolismo , Inflamación/patología , Masculino , Trastornos de la Memoria/complicaciones , Trastornos de la Memoria/fisiopatología , Trastornos de la Memoria/terapia , Microscopía de Fuerza Atómica , Datos de Secuencia Molecular , Factores de Crecimiento Nervioso/metabolismo , Células-Madre Neurales/citología , Células-Madre Neurales/efectos de los fármacos , Neuronas/efectos de los fármacos , Péptidos/química , Péptidos/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas Sprague-Dawley , Recuperación de la Función/efectos de los fármacos , Sinapsis/efectos de los fármacos , Sinapsis/metabolismoRESUMEN
BACKGROUND: Acupuncture is a potential therapy for Alzheimer's disease (AD), but its clinical effects and underlying mechanisms are not fully understood. Emerging evidence suggests autophagy is involved in ß-amyloid (Aß) clearance. We hypothesised that electroacupuncture (EA) treatment of AD involves the autophagy pathway in rats. METHODS: We injected 2µl Aß1-40 bilaterally into the hippocampi of 42 rats to establish AD. Rats remained untreated (AD group, n=14) or received 24 EA treatments at GV20+BL23 over 28â days from day 7 post-injection with/without co-treatment with 3-methyladenine (3-MA), an autophagy inhibitor (AD+EA+3-MA and AD+EA groups, respectively, n=14 each). Cognitive function was evaluated by Morris water maze (MWM) testing. Hippocampi were examined by transmission electron microscopy (TEM) and stained with haematoxylin and eosin/transferase dUTP nick end labelling (TUNEL) to assess neuronal morphology/apoptosis, respectively. Protein expression of Beclin-1, LC3 and Aß1-40 was examined. RESULTS: In the MWM test, the AD+EA group showed an improvement in parameters consistent with improved learning/memory compared to untreated AD rats, and 3-MA attenuated these effects. EA mitigated cellular apoptosis resulting from Aß infusion in the CA1 region and enhanced LC3II/LC3I ratios and Beclin-1 expression. Numerous autophagosome precursors and enlarged autophagosomes were observed by TEM in the hippocampi of EA-treated rats. Reduced Aß levels, and co-localisation of Aß and LC3II, were observed following EA treatment by immunofluorescence staining. EA+3-MA treated rats had much higher TUNEL-positive neurons, lower LC3II/LC3I ratios and Beclin-1 expression, and elevated Aß levels compared with EA alone. CONCLUSIONS: EA reduces neuronal apoptosis, enhances degradation of Aß, and improves learning/memory in AD rats by upregulating the autophagy pathway.
Asunto(s)
Enfermedad de Alzheimer/terapia , Autofagia/fisiología , Electroacupuntura/métodos , Trastornos de la Memoria/terapia , Neuronas , Adenina/administración & dosificación , Adenina/análogos & derivados , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/metabolismo , Animales , Apoptosis/fisiología , Beclina-1/metabolismo , Modelos Animales de Enfermedad , Hipocampo/fisiopatología , Memoria/fisiología , Trastornos de la Memoria/etiología , Proteínas Asociadas a Microtúbulos/metabolismo , Fragmentos de Péptidos/metabolismo , RatasRESUMEN
Acupuncture is a potential strategy for the treatment of Alzheimer's disease (AD) and the possible mechanisms worth to be explored. In this study, we proposed and tested the hypothesis that whether Notch signaling pathway is involved in the effect of electroacupuncture (EA) treatment. Rats that received EA treatment on the acupoints of Baihui (Du 20) and Shenshu (BL 23) had shorter latency and remained in the original platform quadrant longer and crossed the former platform contained quadrant more frequently compared to the Aß injection rats without EA treatment. EA obviously alleviated the cell apoptosis resulted by Aß infusion in hippocampus CA1 regions through upregulating the expression of Bcl-2 and downregulating the expression of Bax. EA could further obviously promote the expression of synapsin-1 and synaptophysin in hippocampus. Aß injection significantly increased the expression of Notch1, Jag1, and Hes1 mRNA, while EA treatment downregulated the level of Notch1 and Hes1 mRNA in hippocampus, but not Jag1 mRNA. Our data suggested that EA treatment improved learning and memory function in the AD rat model partially through downregulating Notch signaling pathway.