GDF11 promotes wound healing in diabetic mice via stimulating HIF-1ɑ-VEGF/SDF-1ɑ-mediated endothelial progenitor cell mobilization and neovascularization.

Non-healing diabetic wounds (DW) are a serious clinical problem that remained poorly understood. We recently found that topical application of growth differentiation factor 11 (GDF11) accelerated skin wound healing in both Type 1 DM (T1DM) and genetically engineered Type 2 diabetic db/db (T2DM) mice. In the present study, we elucidated the cellular and molecular mechanisms underlying the action of GDF11 on healing of small skin wound. Single round-shape full-thickness wound of 5-mm diameter with muscle and bone exposed was made on mouse dorsum using a sterile punch biopsy 7 days following the onset of DM. Recombinant human GDF11 (rGDF11, 50 ng/mL, 10 µL) was topically applied onto the wound area twice a day until epidermal closure (maximum 14 days). Digital images of wound were obtained once a day from D0 to D14 post-wounding. We showed that topical application of GDF11 accelerated the healing of full-thickness skin wounds in both type 1 and type 2 diabetic mice, even after GDF8 (a muscle growth factor) had been silenced. At the cellular level, GDF11 significantly facilitated neovascularization to enhance regeneration of skin tissues by stimulating mobilization, migration and homing of endothelial progenitor cells (EPCs) to the wounded area. At the molecular level, GDF11 greatly increased HIF-1ɑ expression to enhance the activities of VEGF and SDF-1ɑ, thereby neovascularization. We found that endogenous GDF11 level was robustly decreased in skin tissue of diabetic wounds. The specific antibody against GDF11 or silence of GDF11 by siRNA in healthy mice mimicked the non-healing property of diabetic wound. Thus, we demonstrate that GDF11 promotes diabetic wound healing via stimulating endothelial progenitor cells mobilization and neovascularization mediated by HIF-1ɑ-VEGF/SDF-1ɑ pathway. Our results support the potential of GDF11 as a therapeutic agent for non-healing DW.

Kanglexin delays heart aging by promoting mitophagy.

Heart aging is characterized by structural and diastolic dysfunction of the heart. However, there is still no effective drug to prevent and treat the abnormal changes in cardiac function caused by aging. Here, we present the preventive effects of emodin and its derivative Kanglexin (KLX) against heart aging. We found that the diastolic dysfunction and cardiac remodeling in mice with D-galactose (D-gal)-induced aging were markedly mitigated by KLX and emodin. In addition, the senescence of neonatal mouse cardiomyocytes induced by D-gal was also reversed by KLX and emodin treatment. However, KLX exhibited better anti-heart aging effects than emodin at the same dose. Dysregulated mitophagy was observed in aging hearts and in senescent neonatal mouse cardiomyocytes, and KLX produced a greater increase in mitophagy than emodin. The mitophagy-promoting effects of KLX and emodin were ascribed to their abilities to enhance the protein stability of Parkin, a key modulator in mitophagy, with different potencies. Molecular docking and SPR analysis demonstrated that KLX has a higher affinity for the ubiquitin-like (UBL) domain of Parkin than emodin. The UBL domain might contribute to the stabilizing effects of KLX on Parkin. In conclusion, this study identifies KLX and emodin as effective anti-heart aging drugs that activate Parkin-mediated mitophagy and outlines their putative therapeutic importance.

Mzb1 protects against myocardial infarction injury in mice via modulating mitochondrial function and alleviating inflammation.

Myocardial infarction (MI) leads to the loss of cardiomyocytes, left ventricle dilation and cardiac dysfunction, eventually developing into heart failure. Mzb1 (Marginal zone B and B1 cell specific protein 1) is a B-cell-specific and endoplasmic reticulum-localized protein. Mzb1 is an inflammation-associated factor that participates a series of inflammatory processes, including chronic periodontitis and several cancers. In this study we investigated the role of Mzb1 in experimental models of MI. MI was induced in mice by ligation of the left descending anterior coronary artery, and in neonatal mouse ventricular cardiomyocytes (NMVCs) by H2O2 treatment in vitro. We showed that Mzb1 expression was markedly reduced in the border zone of the infarct myocardium of MI mice and in H2O2-treated NMVCs. In H2O2-treated cardiomyocytes, knockdown of Mzb1 decreased mitochondrial membrane potential, impaired mitochondrial function and promoted apoptosis. On contrary, overexpression of Mzb1 improved mitochondrial membrane potential, ATP levels and mitochondrial oxygen consumption rate (OCR), and inhibited apoptosis. Direct injection of lentiviral vector carrying Len-Mzb1 into the myocardial tissue significantly improved cardiac function and alleviated apoptosis in MI mice. We showed that Mzb1 overexpression significantly decreased the levels of Bax/Bcl-2 and cytochrome c and improved mitochondrial function in MI mice via activating the AMPK-PGC1α pathway. In addition, we demonstrated that Mzb1 recruited the macrophages and alleviated inflammation in MI mice. We conclude that Mzb1 is a crucial regulator of cardiomyocytes after MI by improving mitochondrial function and reducing inflammatory signaling pathways, implying a promising therapeutic target in ischemic cardiomyopathy.

Interleukin-17 upregulation participates in the pathogenesis of heart failure in mice via NF-κB-dependent suppression of SERCA2a and Cav1.2 expression.

Interleukin-17 (IL-17), also called IL-17A, is an important regulator of cardiac diseases, but its role in calcium-related cardiac dysfunction remains to be explored. Thus, we investigated the influence of IL-17 on calcium handling process and its contribution to the development of heart failure. Mice were subjected to transaortic constriction (TAC) to induce heart failure. In these mice, the levels of IL-17 in the plasma and cardiac tissue were significantly increased compared with the sham group. In 77 heart failure patients, the plasma level of IL-17 was significantly higher than 49 non-failing subjects, and was negatively correlated with cardiac ejection fraction and fractional shortening. In IL-17 knockout mice, the shortening of isolated ventricular myocytes was increased compared with that in wild-type mice, which was accompanied by significantly increased amplitude of calcium transient and the upregulation of SERCA2a and Cav1.2. In cultured neonatal cardiac myocytes, treatment of with IL-17 (0.1, 1 ng/mL) concentration-dependently suppressed the amplitude of calcium transient and reduced the expression of SERCA2a and Cav1.2. Furthermore, IL-17 treatment increased the expression of the NF-κB subunits p50 and p65, whereas knockdown of p50 reversed the inhibitory effects of IL-17 on SERCA2a and Cav1.2 expression. In mice with TAC-induced mouse heart, IL-17 knockout restored the expression of SERCA2a and Cav1.2, increased the amplitude of calcium transient and cell shortening, and in turn improved cardiac function. In addition, IL-17 knockout attenuated cardiac hypertrophy with inhibition of calcium-related signaling pathway. In conclusion, upregulation of IL-17 impairs cardiac function through NF-κB-mediated disturbance of calcium handling and cardiac remodeling. Inhibition of IL-17 represents a potential therapeutic strategy for the treatment of heart failure.

eNOS-Nitric Oxide System Contributes to a Novel Antiatherogenic Effect of Leonurine via Inflammation Inhibition and Plaque Stabilization.

Leonurine (LEO) is a bioactive small molecular compound that has protective effects on the cardiovascular system and prevents the early progression of atherosclerosis; however, it is not clear whether LEO is effective for plaque stability. A novel mouse atherosclerosis model involving tandem stenosis (TS) of the right carotid artery combined with western diet (WD) feeding was used. Apolipoprotein E gene-deficient mice were fed with a WD and received LEO administration daily for 13 weeks. TS was introduced 6 weeks after the onset of experiments. We found that LEO enhanced plaque stability by increasing fibrous cap thickness and collagen content while decreasing the population of CD68-positive cells. Enhanced plaque stability by LEO was associated with the nitric oxide synthase (NOS)-nitric oxide (NO) system. LEO restored the balance between endothelial NOS(E)- and inducible NOS(iNOS)-derived NO production; suppressed the NF-κB signaling pathway; reduced the level of the inflammatory infiltration in plaque, including cytokine interleukin 6; and downregulated the expression of adhesion molecules. These findings support the distinct role of LEO in plaque stabilization. In vitro studies with oxidized low-density lipoprotein-challenged human umbilical vein endothelial cells revealed that LEO balanced NO production and inhibited NF-κB/P65 nuclear translocation, thus mitigating inflammation. In conclusion, the restored balance of the NOS-NO system and mitigated inflammation contribute to the plaque-stabilizing effect of LEO. SIGNIFICANCE STATEMENT: LEO restored the balance between endothelial NOS and inducible NOS in NO production and inhibited excessive inflammation in atherosclerotic "unstable" and rupture-prone plaques in apolipoprotein E gene-deficient mice. The protective effect of LEO for stabilizing atherosclerotic plaques was due to improved collagen content, increased fibrous cap thickness, and decreased accumulation of macrophages/foam cells. So far, LEO has passed the safety and feasibility test of phase I clinical trial.

Kanglexin, a novel anthraquinone compound, protects against myocardial ischemic injury in mice by suppressing NLRP3 and pyroptosis.

Pyroptosis is a form of inflammatory cell death that could be driven by the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation following myocardial infarction (MI). Emerging evidence suggests the therapeutic potential for ameliorating MI-induced myocardial damages by targeting NLRP3 and pyroptosis. In this study, we investigated the myocardial protection effect of a novel anthraquinone compound (4,5-dihydroxy-7-methyl-9,10-anthraquinone-2-ethyl succinate) named Kanglexin (KLX) in vivo and in vitro. Male C57BL/6 mice were pre-treated either with KLX (20, 40 mg· kg-1per day, intragastric gavage) or vehicle for 7 consecutive days prior to ligation of coronary artery to induce permanent MI. KLX administration dose-dependently reduced myocardial infarct size and lactate dehydrogenase release and improved cardiac function as compared to vehicle-treated mice 24 h after MI. We found that MI triggered NLRP3 inflammasome activation leading to conversion of interleukin-1ß (IL-1ß) and IL-18 into their active mature forms in the heart, which could expand the infarct size and drive cardiac dysfunction. We also showed that MI induced pyroptosis, as evidenced by increased DNA fragmentation, mitochondrial swelling, and cell membrane rupture, as well as increased levels of pyroptosis-related proteins, including gasdermin D, N-terminal GSDMD, and cleaved caspase-1. All these detrimental alterations were prevented by KLX. In hypoxia- or lipopolysaccharide (LPS)-treated neonatal mouse ventricular cardiomyocytes, we showed that KLX (10 µM) decreased the elevated levels of terminal deoxynucleotidyl transferase dUTP nick end labeling- and propidium iodide-positive cells, and pyroptosis-related proteins. We conclude that KLX prevents MI-induced cardiac damages and cardiac dysfunction at least partly through attenuating NLRP3 and subsequent cardiomyocyte pyroptosis, and it is worthy of more rigorous investigations for its potential for alleviating ischemic heart disease.

New ingol-type diterpenes from the latex of Euphorbia resinifera.

Two new ingol-type diterpenes, euphoresins A-B (1-2), have been isolated from the methanol extract of Euphorbium, the latex of Euphorbia resinifera Berg. Their structures were established on the basis of extensive analyses of their HR-ESI-MS, IR, UV, 1D, and 2D NMR spectra. The absolute configurations were confirmed by Mosher's method and circular dichroism (CD) analyses. The two compounds were tested for their cytotoxic activities against MCF-7, U937, and C6 cancer cell lines, but they both exhibited little cytotoxic effect.

Ablation of interleukin-17 alleviated cardiac interstitial fibrosis and improved cardiac function via inhibiting long non-coding RNA-AK081284 in diabetic mice.

Interleukin 17 (IL-17) plays an important role in the pathogenesis of cardiac interstitial fibrosis. In this study, we explored the role of interleukin-17 in the development of diabetic cardiomyopathy and the underlying mechanisms. The level of IL-17 increased in both the serum and cardiac tissue of diabetic mice. Knockout of IL-17 improved cardiac function of diabetic mice induced by streptozotocin (STZ), and significantly alleviated interstitial fibrosis as manifested by reduced collagen mRNA expression and collagen deposition evaluated by Masson's staining. High glucose treatment induced collagen production were abolished in cultured IL-17 knockout cardiac fibroblasts (CFs). The levels of long noncoding RNA-AK081284 were increased in the CFs treated with high glucose or IL-17. Knockout of IL-17 abrogated high glucose induced upregulation of AK081284. Overexpression of AK081284 in cultured CFs promoted the production of collagen and TGFß1. Both high glucose and IL-17 induced collagen and TGFß1 production were mitigated by the application of the siRNA for AK081284. In summary, deletion of IL-17 is able to mitigate myocardial fibrosis and improve cardiac function of diabetic mice. The IL-17/AK081284/TGFß1 signaling pathway mediates high glucose induced collagen production. This study indicates the therapeutic potential of IL-17 inhibition on diabetic cardiomyopathy disease associated with fibrosis.

Manipulating PML SUMOylation via Silencing UBC9 and RNF4 Regulates Cardiac Fibrosis.

The promyelocytic leukemia protein (PML) is essential in the assembly of dynamic subnuclear structures called PML nuclear bodies (PML-NBs), which are involved in regulating diverse cellular functions. However, the possibility of PML being involved in cardiac disease has not been examined. In mice undergoing transverse aortic constriction (TAC) and arsenic trioxide (ATO) injection, transforming growth factor ß1 (TGF-ß1) was upregulated along with dynamic alteration of PML SUMOylation. In cultured neonatal mouse cardiac fibroblasts (NMCFs), ATO, angiotensin II (Ang II), and fetal bovine serum (FBS) significantly triggered PML SUMOylation and the assembly of PML-NBs. Inhibition of SUMOylated PML by silencing UBC9, the unique SUMO E2-conjugating enzyme, reduced the development of cardiac fibrosis and partially improved cardiac function in TAC mice. In contrast, enhancing SUMOylated PML accumulation, by silencing RNF4, a poly-SUMO-specific E3 ubiquitin ligase, accelerated the induction of cardiac fibrosis and promoted cardiac function injury. PML colocalized with Pin1 (a positive regulator for TGF-ß1 mRNA expression in PML-NBs) and increased TGF-ß1 activity. These findings suggest that the UBC9/PML/RNF4 axis plays a critical role as an important SUMO pathway in cardiac fibrosis. Modulating the protein levels of the pathway provides an attractive therapeutic target for the treatment of cardiac fibrosis and heart failure.

[Triterpenoids from Uygur medicine latex of Euphorbia resinifera].

Ten triterpenes compounds were isolated from the methanol extraction of the latex of Euphorbia resinifera by means of various chromatographic methods such as silica gel, ODS and semi-preparative HPLC, Their structures were identified by spectroscopic methods and physicochemical properties. These isolated compounds were identified as 3ß-hydroxy-25,26,27-trinor eupha-8-ene-24-oate (1), iso-maticadienediol (2), 25,26,27-trinorTirucall-8-ene-3ß-ol-4-acid (3), dammarendiol Ⅱ (4), eupha-8,24-diene-3-ol-26-al (5), lnonotusane C (6), eupha-8,24-diene-3ß-ol-7,11-dione (7), inoterpene A (8), inoterpene B (9), and eupha-24-methylene-8-ene-3ß-ol-7,11-dione (10). Among them, compound 1 was a new natural product, compounds 2-4 were firstly isolated from the Euphorbiaceae and compounds 5 and 6 were isolated from the genus Euphorbia for the first time. The cytotoxicity of the compounds 1-10 against MCF-7, U937 and C6 cancer cell lines was evaluated, but none of the compounds was active.

Circulating long non-coding RNAs NRON and MHRT as novel predictive biomarkers of heart failure.

This study sought to evaluate the potential of circulating long non-coding RNAs (lncRNAs) as biomarkers for heart failure (HF). We measured the circulating levels of 13 individual lncRNAs which are known to be relevant to cardiovascular disease in the plasma samples from 72 HF patients and 60 non-HF control participants using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) methods. We found that out of the 13 lncRNAs tested, non-coding repressor of NFAT (NRON) and myosin heavy-chain-associated RNA transcripts (MHRT) had significantly higher plasma levels in HF than in non-HF subjects: 3.17 ± 0.30 versus 1.0 ± 0.07 for NRON (P < 0.0001) and 1.66 ± 0.14 versus 1.0 ± 0.12 for MHRT (P < 0.0001). The area under the ROC curve was 0.865 for NRON and 0.702 for MHRT. Univariate and multivariate analyses identified NRON and MHRT as independent predictors for HF. Spearman's rank correlation analysis showed that NRON was negatively correlated with HDL and positively correlated with LDH, whereas MHRT was positively correlated with AST and LDH. Hence, elevation of circulating NRON and MHRT predicts HF and may be considered as novel biomarkers of HF.

[Research advances of M3 receptor: a new target for treating and preventing cardiovascular disease].

Cardiovascular disease, with high morbidity and mortality, has been threatening the health of human beings. Therefore, expecting to find a more effective therapeutic method, a plenty of researchers devote themselves to the study of the cardiovascular disease all the time. Since discovered on the heart, M3 receptor of muscarinic acetylcholine receptor (mAchR, M receptor) became a new starting point of the research of the cardiovascular disease. With more and more investigation, many people found that M3 receptor could protect the heart from kinds of cardiovascular disease, which may make it a new hopeful therapeutic point. So, expecting to give support to the reference and encouragement for the study of disease related to M3 receptor in future, this review expounds M3 receptor on the heart from the main following aspects: the effect on the heart, the influence on the cardiovascular disease and the mechanism of M3 receptor involved.

[Progress in the treatment of diabetic wound healing via stem cells transplant].

The morbidity of diabetes has been increasing rapidly in recent years. Delayed wound healing has become a common complication in diabetes, which seriously affects the orthobiosis of patients. Exploring and finding the molecular mechanisms of diabetic wound healing and the effective therapies to promote wound healing have important clinical significances. Stem cells transplant has become a research hotspot in accelerating diabetic wound healing. This article reviewed the present approaches concerning stem cells transplant in diabetic wound healing both at domestic and abroad, and looked forward the clinical therapy of stem cells on diabetic wound healing.

MicroRNA-195 protects against dementia induced by chronic brain hypoperfusion via its anti-amyloidogenic effect in rats.

Previous studies have demonstrated that chronic brain hypoperfusion (CBH) causes Aß aggregation by upregulating expression of amyloid precursor protein (APP) and ß-site APP cleaving enzyme 1 (BACE1) protein, which is accompanied by cognitive impairment, but the mechanisms are not fully understood. In this study, we evaluated the effect of microRNA on memory impairment in rats induced by CBH. We show here that CBH generated by bilateral common carotid artery occlusion (2VO) significantly decreased the learning and memory ability in rats, as assessed by Morris water maze, and upregulated expression of APP and BACE1 proteins in the hippocampus and cortex of rats, as evaluated by Western blot and immunofluorescence. In reciprocal, qRT-PCR analysis showed that microRNA-195 (miR-195) was downregulated in both the hippocampus and cortex of rats following CBH, and in the plasma of dementia patients. APP and BACE1 proteins were downregulated by miR-195 overexpression, upregulated by miR-195 inhibition, and unchanged by binding-site mutation or miR-masks, indicating that APP and BACE1 are two potential targets for miR-195. Knockdown of endogenous miR-195 by lentiviral vector-mediated overexpression of its antisense molecule (lenti-pre-AMO-miR-195) elicited dementia in rats, whereas overexpression of miR-195 using lenti-pre-miR-195 reduced dementia vulnerability triggered by 2VO. Additionally, chromatin immunoprecipitation analysis showed that NFκB was bound to the promoter region of miR-195 and inhibited its expression. We conclude that miR-195 may play a key role in determining dementia susceptibility in 2VO rats by regulating APP and BACE1 expression at the post-transcriptional level, and exogenous complement of miR-195 may be a potentially valuable anti-dementia approach.

MicroRNA-23a mediates mitochondrial compromise in estrogen deficiency-induced concentric remodeling via targeting PGC-1α.

It is well known that menopause could worsen age-related ventricular concentric remodeling following estrogen (E2) deficiency. However the underlying mechanisms of such phenomena are not fully understood. Mitochondria, as the 'cellular power station' of hearts, play an important role in maintaining normal cardiac function and structure. Therefore, the present study aims to investigate whether mitochondrial compromise is responsible for E2 deficiency associated concentric remodeling and, if so, what is its underlying molecular mechanism. We found evident concentric remodeling pattern in both postmenopausal and ovariectomized (OVX) mice, which could be attenuated by E2 replacement. Further study showed mitochondrial structural damages and respiratory function impairment in myocardium of both postmenopausal and OVX mice and E2 supplement reversed mitochondrial dysfunction in OVX mice, suggesting that E2 deficiency could induce mitochondrial compromise in the heart. Then, peroxisome proliferator-activated receptor-γ co-activator 1-α (PGC-1α), a key mitochondrial function and biology regulator, was found significantly reduced in both postmenopausal and OVX mice. The reduction of PGC-1α protein level in OVX mice could be rescued by E2 delivery, indicating that E2 could positively regulate PGC-1α expression. Next, we found that microRNA-23a (miR-23a) could be negatively regulated by E2 in both myocardium and cultured cardiomyocytes. Moreover, miR-23a could directly downregulate PGC-1α expression in cardiomyocytes via binding to its 3'UTR which implied that miR-23a could be critical for the downregulation of PGC-1α under E2 deficiency. Overexpression of miR-23a was also found to damage mitochondria in cultured cardiomyocytes, ascribed to PGC-1α downregulation. Taken together, E2 deficiency may cause mitochondrial compromise through miR-23a-mediated PGC-1α downregulation, which may subsequently lead to the menopause-associated concentric remodeling.

Expression of amyloid-associated miRNAs in both the forebrain cortex and hippocampus of middle-aged rat.

BACKGROUND: Aging is associated with the gradual cognitive decline and shows the typical senile plaque formation in the brain, which results from the aggregation of beta amyloid (Aß) peptide following the abnormal proteolytic processing of amyloid precursor protein (APP) by ß-secretase (BACE1) and γ-secretase. Accumulating evidence indicates that several microRNAs (miRNAs) are involved in the Alzheimer's disease (AD) by regulating the expression of APP and BACE1 proteins. However, the cognitive ability and the expression profile of the APP- and BACE1-associated miRNAs in the middle-aged population are largely unknown. METHODS: The learning and memory ability in rats were determined by Morris Water Maze test. The protein levels of APP and BACE1 were detected by western blotting. The quantitative polymerase chain reaction was used to identify the miRNAs levels in forebrain cortex and the hippocampus. RESULTS: Middle-aged rats have declined learning ability without changes in the memory ability, and increased APP and BACE1 protein expression in the forebrain cortex. Computational analysis using Targetscan and Pictar databases reveals that totally 4 predicted miRNAs have conserved binding site with APP, namely miR-106b, -17-5p, -153, -101. All of them showed decreased expression in both the forebrain cortex and hippocampus. Among the 10 predicted miRNAs targeting BACE1, different expression profiles were identified in the forebrain cortex (decreased: miR-9, -19a, -135a, -15b, -16, -195, -29c, -214; increased: miR-124; no change: miR-141) and the hippocampus (decreased: miR-9, -15b, -16, -195, -29c, -124; increased: miR-19a, -135a, -214, -141) in the middle-aged rats compared with the young rats. CONCLUSION: Our results provided the first evidence that middle-aged rats have begun displaying cognitive disability with abnormal expression of APP- and BACE1-related miRNAs in the hippocampus and forebrain cortex.

Translational toxicology and rescue strategies of the hERG channel dysfunction: biochemical and molecular mechanistic aspects.

The human ether-à-go-go related gene (hERG) potassium channel is an obligatory anti-target for drug development on account of its essential role in cardiac repolarization and its close association with arrhythmia. Diverse drugs have been removed from the market owing to their inhibitory activity on the hERG channel and their contribution to acquired long QT syndrome (LQTS). Moreover, mutations that cause hERG channel dysfunction may induce congenital LQTS. Recently, an increasing number of biochemical and molecular mechanisms underlying hERG-associated LQTS have been reported. In fact, numerous potential biochemical and molecular rescue strategies are hidden within the biogenesis and regulating network. So far, rescue strategies of hERG channel dysfunction and LQTS mainly include activators, blockers, and molecules that interfere with specific links and other mechanisms. The aim of this review is to discuss the rescue strategies based on hERG channel toxicology from the biochemical and molecular perspectives.

Salvianolic acid A provides neuroprotective effects on cerebral ischemia-reperfusion injury in rats via PKA/CREB/c-Fos signaling pathway.

BACKGROUND: Cerebral ischemia-reperfusion injury (CIRI) is a phenomenon that pathological injury of ischemic brain tissue is further aggravated after the restoration of blood supply. The complex pathological mechanism of CIRI has led to the failure of multiple neuroprotective agents in clinical studies. Salvianolic acid A (SAA) is a neuroprotective extract from Salvia miltiorrhiza Bge., with significant pharmacological activities in the treatment of brain injury. However, the neuroprotective mechanisms of SAA remain unclear. PURPOSE: To explore the potential protective effect of SAA on CIRI and its mechanism, and to provide experimental basis for the research of new drugs for CIRI. STUDY DESIGN: A model of transient middle cerebral artery occlusion (tMCAO) in rats was used to simulate clinical CIRI, and the neuroprotective effect of SAA on tMCAO rats was investigated within 14 days after reperfusion. The improvement effects of SAA on cognitive impairment of tMCAO rats were investigated by behavioral tests from days 7-14. Finally, the neuroprotective mechanism of SAA was investigated on day 14. METHODS: The neuroprotective effects and mechanism of SAA were investigated by behavioral tests, HE and TUNEL staining, RNA sequence (RNA-seq) analysis and Western blot in tMCAO rats. RESULTS: The brain protective effects of SAA were achieved by alleviating cerebral infarction, cerebral edema, cerebral atrophy and nerve injury in tMCAO rats. Meanwhile, SAA could effectively improve the cognitive impairment and pathological damage of hippocampal tissue, and inhibit cell apoptosis in tMCAO rats. Besides, SAA could provide neuroprotective effects by up-regulating the expression of Bcl-2, inhibiting the activation of Caspase 3, and regulating PKA/CREB/c-Fos signaling pathway. CONCLUSION: SAA can significantly improve brain injury and cognitive impairment in CIRI rats, and this neuroprotective effect may be achieved through the anti-apoptotic effect and the regulation of PKA/CREB/c-Fos signaling pathway.

MicroRNA transport: a new way in cell communication.

MicroRNAs (miRNAs) can efficiently regulate gene expression by targeting mRNA to cause mRNA cleavage or translational repression. Growing evidence indicates that miRNAs exist not only in cells but also in a variety of body fluids, which stimulates substantial interest in the transport mechanism and regulating process of extracellular miRNAs. This article reviews the basic biogenesis of miRNAs in detail to explore the origin of extracellular miRNAs. Different miRNA transporters have been summarized (e.g., exosomes, microvesicles, apoptosis bodies, and RNA-binding proteins). In addition, we discuss the regulators affecting miRNA transport (e.g., ATP and ceramide) and the selection mechanism for different miRNA transporters. Studies about miRNA transporters and the transport mechanism are new and developing. With the progress of the research, new functions of extracellular miRNAs may be uncovered in the future.

Blockage of peripheral NPY Y1 and Y2 receptors modulates barorefex sensitivity of diabetic rats.

BACKGROUND/AIMS: Abnormal baroreceptor reflex sensitivity (BRS) and elevated plasma neuropeptide Y (NPY) are prevalent in diabetic patients. The present study was conducted to determine whether NPY Y1 receptor (Y1R) and NPY Y2 receptor (Y2R) contribute to the regulatin of BRS in diabetic rats. METHODS: Diabetes mellitus (DM) rats with hyperlipidemia were developed by an emulsion diet enriched with fat, sucrose and fructose followed by streptozocin (STZ). Y1R and Y2R specific antagonists (BIBP 3226 and BIIE 0246) were administered by a mini-osmotic pump. Systolic blood pressure (SBP), heart rate (HR), BRS and heart functions, as well as the plasma NPY and lipid level were measured after treatment for 4 weeks. RESULTS: Both BIBP 3226 and BIIE 0246 treatment reversed the elevated total cholesterol (TC) and low density lipoprotein (LDL-C) level, and reduced high density lipoprotein (HDL-C) level in DM rats. BIIE 0246 may attenuate the increased triglyceride (TG) level in DM rats. In addition, neither BIBP 3226 nor BIIE 0246 treatment produced significant effects on BRS, SBP or HR (P>0.05) in DM rats, even after PE and SNP challenge. However, BIBP 3226 and BIIE 0246 further impaired LVSP, LVEDP, +dp/dtmax and -dp/dtmax. CONCLUSION: This study provided us with the evidence that the inhibition of peripheral Y1R and Y2R did not affect impaired BRS but amplified the deterioration of the compromised cardiac function in STZ-induced DM rats with hyperlipidemia.