Molecular mechanisms underlying the anti-proliferative and anti-migratory effects of folate on homocysteine-challenged rat aortic smooth muscle cells

Folic acid enhances the cardiovascular protective effect of amlodipine in renal hypertensive rats with elevated homocysteine

OBJECTIVES

To investigate the actions of amlodipine-folic acid (amlodipine-FA) preparation on hypertension and cardiovascular in renal hypertensive rats with hyperhomocysteinemia (HHcy), so as to provide experimental basis for clinical research of amlodipine folic acid tablets.

METHODS

Rats model of renal hypertension with HHcy were established. The rats were randomly divided into groups of model, amlodipine, folic acid (FA) and amlodipine-FA of various dosages. Normal rats were used as normal control group. Blood pressure, Hcy as well as plasma NO, ET-1 and hemodynamics were assayed. Histological alterations of heart and abdominal aorta were also examined.

RESULTS

Compared with the normal group, blood pressure, plasma Hcy, and NO of the rats in model group were significantly increased, while the plasma ET-1 was decreased. Compared with the normal group, the animals in the model group had reduced cardiac function, thickened wall of the aorta and narrowed lumen. In FA group and amlodipine group, the rat plasma NO was increased while ET-1 was decreased, the protective effect of amlodipine-FA group on endothelial cells was further enhanced. In amlodipine group, the rat hemodynamics (LVSP, LVEDP and ±dp/dt_max, et al.) and vascular damage were significantly reduced, while in amlodipine-FA group, the heart function were further improved, and myocardial and vascular hypertrophy were significantly reduced.

CONCLUSIONS

As compared to amlodipine alone, amlodipine -FA can lower both blood pressure and plasma Hcy, significantly enhancing vascular endothelial function to protect the heart and blood vessel in renal hypertensive rats with HHcy.

Advances in the role of epigenetics in homocysteine-related diseases

Homocysteine has a wide range of biological effects. However, the specific molecular mechanism of its pathogenicity is still unclear. The diseases induced by hyperhomocysteinemia (HHcy) are called homocysteine-related diseases. Clinical treatment of HHcy is mainly through folic acid and B-complex vitamins, which are not effective in reducing the associated end point events. Epigenetics is the alteration of heritable genes caused by DNA methylation, histone modification, noncoding RNAs and chromatin remodeling without altering the DNA sequence. In recent years the role of epigenetics in homocysteine-associated diseases has been gradually discovered. This article summarizes the latest evidence on the role of epigenetics in HHcy, providing new directions for its prevention and treatment.

MULTIOMIC PATTERNS IN BODY FLUIDS: TECHNOLOGICAL CHALLENGE WITH A GREAT POTENTIAL TO IMPLEMENT THE ADVANCED PARADIGM OF 3P MEDICINE

Liquid biopsy (LB) is defined as a sample of any of body fluids (blood, saliva, tear fluid, urine, sweat, amniotic, cerebrospinal and pleural fluids, cervicovaginal secretion, and wound efflux, amongst others), which can be ex vivo analysed to detect and quantity the target(s) of interest. LB represents diagnostic approach relevant for organ-specific changes and systemic health conditions including both manifested diseases and their prestages such as suboptimal health. Further, experts emphasise that DNA-based analysis alone does not provide sufficient information for optimal diagnostics and effective treatments. Consequently, of great scientific and clinical utility are molecular patterns detected by hybrid technologies such as metabolomic tools and molecular imaging. Future proposed strategies utilise multiomic pillars (generally genome, tanscriptome, proteome, metabolome, epigenome, radiome, and microbiome), system-biological approach, and multivariable algorithms for diagnostic, prognostic, and therapeutic purposes. Current article analyses pros and cons of the mass spectrometry-based technologies, provides eminent examples of a success story "from discovery to clinical application," and demonstrates a "road-map" for the technology-driven paradigm change from reactive to predictive, preventive and personalised medical services as the medicine of the future benefiting the patient and healthcare at large. © 2019 The Authors. Mass Spectrometry Reviews published by John Wiley & Sons Ltd. Mass Spec Rev.

Effects of female sex hormones on folic acid-induced anti-angiogenesis

AIM

Pregnant women have been recommended to take FA daily to prevent birth defects in the brain and spinal cord. We previously showed that folic acid (FA) exerts an anti-angiogenic activity. As angiogenesis is important for endometrial reorganization and embryonic development, there should be some mechanisms to allow the pregnant mother and the foetus to escape from the FA-induced anti-angiogenesis. This study was designed to investigate the effect of female sex hormones on the FA-induced anti-angiogenic activity.

METHODS

The protein levels and protein-protein interaction were examined by Western blot analysis and immunoprecipitation assay respectively. The cell proliferation and migration were examined by MTT assay and wound healing assay respectively. The in vivo angiogenesis was evaluated by Matrigel angiogenesis assay.

RESULTS

In human umbilical venous endothelial cells (HUVEC), FA receptor (FR) formed a complex with progesterone receptor (PR), oestradiol receptor (ER) and cSrc. Pregnancy levels of progesterone (P4) or oestradiol (E2) prevented FA-induced inhibitions of proliferation and migration in HUVEC. Both E2 and P4 prevented the FA-induced anti-angiogenesis in vivo. Moreover, cotreatment with FA and P4 or E2 inhibited the signalling pathways involved in FA-induced inhibitions of proliferation and migration in HUVEC.

CONCLUSION

Female sex hormones interrupt the FA-induced anti-angiogenic action through receptor-receptor interaction.

l-Homocysteine-induced cathepsin V mediates the vascular endothelial inflammation in hyperhomocysteinaemia

BACKGROUND AND PURPOSE

Vascular inflammation, including the expression of inflammatory cytokines in endothelial cells, plays a critical role in hyperhomocysteinaemia-associated vascular diseases. Cathepsin V, specifically expressed in humans, is involved in vascular diseases through its elastolytic and collagenolytic activities. The aim of this study was to determine the effects of cathepsin V on l-homocysteine-induced vascular inflammation.

EXPERIMENTAL APPROACH

A high methionine diet-induced hyperhomocysteinaemic mouse model was used to assess cathepsin V expression and vascular inflammation. Cultures of HUVECs were challenged with l-homocysteine and the cathepsin L/V inhibitor SID to assess the pro-inflammatory effects of cathepsin V. Transfection and antisense techniques were utilized to investigate the effects of cathepsin V on the dual-specificity protein phosphatases (DUSPs) and MAPK pathways.

KEY RESULTS

Cathepsin L (human cathepsin V homologous) was increased in the thoracic aorta endothelial cells of hyperhomocysteinaemic mice; l-homocysteine promoted cathepsin V expression in HUVECs. SID suppressed the activity of cathepsin V and reversed the up-regulation of inflammatory cytokines (IL-6, IL-8 and TNF-α), adhesion and chemotaxis of leukocytes and vascular inflammation induced by l-homocysteine in vivo and in vitro. Increased cathepsin V promoted the degradation of DUSP6 and DUSP7, phosphorylation and subsequent nuclear translocation of ERK1/2, phosphorylation of STAT1 and expression of IL-6, IL-8 and TNF-α.

CONCLUSIONS AND IMPLICATIONS

This study has identified a novel mechanism, which shows that l-homocysteine-induced upregulation of cathepsin V mediates vascular endothelial inflammation under high homocysteine condition partly via ERK_1/2 /STAT1 pathway. This mechanism could represent a potential therapeutic target in hyperaemia-associated vascular diseases.

LINKED ARTICLES

This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.

Folic acid inhibits dedifferentiation of PDGF-BB-induced vascular smooth muscle cells by suppressing mTOR/P70S6K signaling

OBJECTIVE

Folic acid (FA) supplementation reduces the risk of atherosclerosis and stroke. Phenotypic change from differentiated to dedifferentiated vascular smooth muscle cells (VSMCs) plays an important role in atherosclerosis development; however, the exact mechanisms remain unknown. This study aimed to assess whether FA through mammalian target of rapamycin (mTOR)/P70S6K signaling inhibits platelet derived growth factor (PDGF-BB) induced VSMC dedifferentiation.

METHODS

VSMCs from primary cultures were identified by morphological observation and α-smooth muscle actin (α-SM-actin, α-SMA) immunocytochemistry. Then, VSMCs were induced by PDGF-BB and treated with varying FA concentrations. Rapamycin and MHY-1485 were used to inhibit or activate the mTOR/P70S6K pathway, respectively. Next, MTT, Transwell, and wound healing assays were employed to assess proliferation and migration of VSMCs. In addition, Western blotting was used to evaluate protein levels of α-SMA, calponin, osteopontin, mTOR, p-mTOR, P70S6K and p-P70S6K in VSMCs.

RESULTS

VSMCs showed phenotypic alteration from differentiated to dedifferentiated cells in response to PDGF-BB. MTT, Transwell and wound healing assays showed that FA markedly inhibited proliferation and migration in PDGF-BB-induced VSMCs, in a time and concentration-dependent manner. FA treatment increased the expression levels of the contractile phenotype marker proteins α-SMA and calponin compared with VSMCs stimulated by PDGF-BB alone. Furthermore, FA significantly suppressed mTOR and P70S6K phosphorylation compared with PDGF-BB alone. Similar to FA, downregulation of mTOR signaling by rapamycin inhibited VSMC dedifferentiation. In contrast, upregulation of mTOR signaling by MHY-1485 reversed the FA-induced inhibition of VSMC dedifferentiation.

CONCLUSION

Folic acid inhibits dedifferentiation of PDGF-BB-induced VSMCs by suppressing mTOR/P70S6K signaling.

MiR-615 inhibited cell proliferation and cell cycle of human breast cancer cells by suppressing of AKT2 expression

MicroRNAs (miRNAs) have emerged as important regulators that potentially play critical roles in various biological processes. Previous studies have shown that miR-615 regulates proliferation and apoptosis in many types of cancers. The biological function of this microRNA in breast cancer remains largely unexplored. In the present study, we found that miR-615 expression was markedly downregulated in breast cancer tissues and breast cancer cells. The enforced expression of miR-615 was able to inhibite the proliferation and anchorage-independent growth of breast cancer cells, while miR-615-in showed the opposite effect. Bioinformatics analysis further revealed AKT2, a putative tumor promoter as a potential target of miR-615. Ectopic expression of miR-615 led to downregulation of AKT2 protein, which resulted in the upregulation of p27 and p21 and the downregulation of cyclin D1. In sum, these results suggest that miR-615 represents a potential anti-onco-miR and participates in breast cancer carcinogenesis by suppressing AKT2 expression.