Acupuncture promotes angiogenesis after myocardial ischemia through H3K9 acetylation regulation at VEGF gene

Activation of ERK pathway is required for 15-HETE-induced angiogenesis in human umbilical vascular endothelial cells

Angiogenesis plays a critical role in the progression of cardiovascular disease, retinal ischemia, or tumorigenesis. The imbalance of endothelial cell proliferation and apoptosis disturbs the establishment of the vasculogenesis, which is affected by several arachidonic acid metabolites. 15-Hydroxyeicosatetraenoic acid (15-HETE) is one of the metabolites. However, the underlying mechanisms of angiogenesis induced by 15-HETE in human umbilical vascular endothelial cells (HUVECs) are still poorly understood. Since extracellular signal-regulated kinase (ERK) is a critical regulator of cell proliferation, there may be a crosstalk between 15-HETE-regulating angiogenic process and ERK-proliferative effect in HUVECs. To test this hypothesis, we study the effect of 15-HETE on cell proliferation, angiogenesis, and apoptosis using cell viability measurement, cell cycle analysis, western blot, scratch-wound, tube formation assay, and nuclear morphology determination. We found that 15-HETE promoted HUVEC angiogenesis, which were mediated by ERK. Moreover, 15-HETE-induced proliferation and cell cycle transition from the G(0)/G(1) phase to the G(2)/M + S phase. All these effects were reversed after blocking ERK with PD98059 (an ERK inhibitor). In addition, HUVEC apoptosis was relieved by 15-HETE through the ERK pathway. Thus, ERK is necessary for the effects of 15-HETE in the regulation of HUVEC angiogenesis, which may be a novel potential target for the treatment of angiogenesis-related diseases.

A protocol of histone modification-based mechanistic study of acupuncture in patients with stable angina pectoris

Background

Angina pectoris (Angina) is a medical condition related to myocardial ischemia. Although acupuncture has been widely accepted as a clinical approach for angina, there is no sufficient evidence of its effectiveness against this syndrome, and its mechanisms have not yet been well elucidated. We develop this protocol to confirm the clinical efficacy of electro-acupuncture on stable angina pectoris by needling on acupoint Neiguan (PC6). Furthermore, we employ high-throughput sequencing technology to investigate the gene expression profiling and determine involvement of histone modifications in the regulation of genes after electro-acupuncture treatment.

Methods/Design

A randomized, controlled, double-blinded (assessor and patients) trial will be carried out. Sixty participants will be randomly assigned to two acupuncture treatment groups and one control group in a 1:1:1 ratio. Participants in acupuncture groups will receive 12 sessions of electro-acupuncture treatment across 4 weeks, followed by a 12-week randomization period. The acupuncture groups are divided into Neiguan (PC6) on Pericardium Meridian of Hand-jueyin or a non-acupoint. The primary clinical measure of effect is the frequency of angina attacks between these groups for four weeks after randomization. RNAs are extracted from peripheral neutrophils collected from all participants on day 0, day 30, and week 16, and are processed to RNA-Seq. We then investigate profiles of histone modifications by ChIP-Seq, for H3 Lysine 4 (H3K4me) and acetylation of H3 Lysine 27 (H3K27ac), in the presence or absence of acupuncture treatment.

Discussion

This study determines the efficacy and mechanisms of electro-acupuncture on stable angina pectoris. We focus on effectiveness of acupuncture on alleviating symptoms of myocardial ischemia and the gene regulation and the chromatin remodeling marks, including H3K4me1, H3K4me2, and H3K27ac, which could be key factors for regulating gene expressions caused by electro-acupuncture treatment at Neiguan. This is the first genome-wide study of electro-acupuncture treatment in angina patients, and will provide valuable information for future studies in the fields of acupuncture and its underlying mechanisms.

Fourteen patients have been recruited since recruitment opened in November of 2012. This study is scheduled to end in November of 2014.

Trials registration

ChiCTR-TRC-12002668

Involvement of activation of C-met signaling pathway in CD151-induced HUVECs angiogenesis

CD151 is a member of the tetraspanin family that is implicated as a promoter of pathological or physiological angiogenesis. C-Met is expressed on a variety of cells including vascular endothelial cells (VECs) and up-regulated during angiogenesis. In this study, we investigated whether CD151 regulated migration, proliferation, tube formation and angiogenesis of human umbilical VECs (HUVECs) with activation of C-Met. Moreover, we studied whether CD151 could affect the angiogenic molecules such as nitric oxide (NO), vascular cell adhesion molecule-1 (VCAM-1) and vascular endothelial growth factor (VEGF). The expression of CD151 was determined by Western blotting. The cell proliferation assay was performed using the cell counting kit-8 (CCK-8) method and cell migration was assessed in microchemotaxis chambers by using fetal bovine serum (FBS) as the chemotactic stimulus. The angiogenic molecules were evaluated using ELISA. The NO level was detected using NO detection kit. The potential involvement of various signaling pathways was explored using relevant antibodies. We found that proliferation, migration and tube formation of HUVECs were promoted by CD151 with activation of C-Met, FAK and CDC42, while they were suppressed with CD151 knockdown by RNAi. Similarly, the levels of NO, VCAM-1 and VEGF in HUVECs were increased by CD151, but they were inhibited with CD151 knockdown by RNAi. These data suggested that CD151 could promote migration, proliferation, tube formation and angiogenesis of HUVECs, which was possibly related to the C-Met signaling pathways.

Electro-acupuncture at Neiguan pretreatment alters genome-wide gene expressions and protects rat myocardium against ischemia-reperfusion

This study investigated genome-wide gene expressions and the cardioprotective effects of electro-acupuncture pretreatment at the PC6 Neiguan acupoint on myocardial ischemia reperfusion (I/R) injury. Male SD rats were randomly divided into four groups: sham operation (SO), I/R, electro-acupuncture at the PC6 Neiguan acupoint pretreatment (EA) and electro-acupuncture at non-acupoint pretreatment (NA). Compared with the I/R group, the survival rate of the EA group was significantly increased, the arrhythmia score, infarction area, serum concentrations of CK, LDH and CK-Mb and plasma level of cTnT were significantly decreased. RNA-seq results showed that 725 genes were up-regulated and 861 genes were down-regulated under I/R conditions compared to the SO group; both EA and NA reversed some of these gene expression levels (592 in EA and 238 in NA group). KEGG pathway analysis indicated that these genes were involved in multiple pathways, including ECM, MAPK signaling, apoptosis, cytokine and leukocyte pathways. In addition, some pathways were uniquely regulated by EA, but not NA pretreatment, such as oxidative stress, cardiac muscle contraction, gap junction, vascular smooth muscle contraction, hypertrophic, NOD-like receptor, and P53 and B-cell receptor pathways. This study was first to reveal the gene expression signatures of acute myocardial I/R injury and electro-acupuncture pretreatment in rats.

miR-21 in ischemia/reperfusion injury: a double-edged sword?

MicroRNAs (miRNAs or miRs) are endogenous, small RNA molecules that suppress expression of targeted mRNA. miR-21, one of the most extensively studied miRNAs, is importantly involved in divergent pathophysiological processes relating to ischemia/reperfusion (I/R) injury, such as inflammation and angiogenesis. The role of miR-21 in renal I/R is complex, with both protective and pathological pathways being regulated by miR-21. Preconditioning-induced upregulation of miR-21 contributes to the protection against subsequent renal I/R injury through the targeting of genes such as the proapoptotic gene programmed cell death 4 and interactions between miR-21 and hypoxia-inducible factor. Conversely, long-term elevation of miR-21 may be detrimental to the organ by promoting the development of renal interstitial fibrosis following I/R injury. miR-21 is importantly involved in several pathophysiological processes related to I/R injury including inflammation and angiogenesis as well as the biology of stem cells that could be used to treat I/R injury; however, the effect of miR-21 on these processes in renal I/R injury remains to be studied.

A feedback regulatory loop between HIF-1α and miR-21 in response to hypoxia in cardiomyocytes

Accumulating evidence suggests that hypoxia-inducible factor 1α (HIF-1α) regulates numerous miRNAs and is crucial for cellular response to hypoxia. However, the relationship between HIF-1α and miR-21 in hypoxic cardiomyocytes is little known. We found that hypoxia induced HIF-1α and miR-21 expression. HIF-1α knockdown increased cell apoptosis and reduced miR-21 expression. Furthermore, we found that HIF-1α transcriptionally enhanced miR-21 promoter activity by binding to its promoter, which required the recruitment of CBP/p300. In addition, we found that miR-21 inhibition increased cell apoptosis and reduced HIF-1α expression, and modulated the PTEN/Akt pathway. Our results indicate that HIF-1α-miR-21 feedback contributes to the adaptation of cardiomyocytes to hypoxia, and has potential as therapeutic target for myocardial ischemia.