It is now recognized that the heart can behave as a true endocrine organ, which can modulate the function of other tissues. Emerging evidence has shown that visceral fat is one such distant organ the heart communicates with. In fact, it appears that bi-directional crosstalk between adipose tissue and the myocardium is crucial to maintenance of normal function in both organs. In particular, factors secreted from the heart are now known to influence the metabolic activity of adipose tissue and other organs, as well as modulate the release of metabolic substrates and signaling molecules from the periphery. This review summarizes current knowledge regarding primary cardiokines and adipokines involved in heart-fat crosstalk, as well as implications of their dysregulation for cardiovascular health.
Adipocytes ; Adipokines ; Adipose Tissue ; Heart ; Intra-Abdominal Fat ; Myocardium ; Myocytes, Cardiac

It is now recognized that the heart can behave as a true endocrine organ, which can modulate the function of other tissues. Emerging evidence has shown that visceral fat is one such distant organ the heart communicates with. In fact, it appears that bi-directional crosstalk between adipose tissue and the myocardium is crucial to maintenance of normal function in both organs. In particular, factors secreted from the heart are now known to influence the metabolic activity of adipose tissue and other organs, as well as modulate the release of metabolic substrates and signaling molecules from the periphery. This review summarizes current knowledge regarding primary cardiokines and adipokines involved in heart-fat crosstalk, as well as implications of their dysregulation for cardiovascular health.

OBJECTIVETo study the activation of sterol regulatory element binding protein (SREBP) and its critical role in endothelial cell migration.

METHODSBovine aortic endothelial cells (ECs) were cultured. The expression of SREBP and Cdc42 were determined by Western blot and quantitative real-time PCR. Moreover, outward growth migration model and transwell chamber assay were used to detect ECs migration.

RESULTS(1) SREBP was activated during ECs migration. Western blot analysis demonstrated increased active form SREBP in migrating as compared to non-migrating ECs population. SREBP activation decreased as ECs migration slowed;(2) Coincidental with SREBP activation, mRNA expression of its target genes such as low density lipoprotein receptor, HMG-CoA reductase, and fatty acid synthase also increased in migrating ECs population as detected by real-time PCR; (3) Migration induced SREBP activation in ECs was inhibited by SREBP-acting protein RNAi and pharmacologically by 25-hydroxycholesterol; (4) Inhibition of SREBP led to decreased ECs migration in various models; (5) Cells genetically deficient in SREBP-acting protein, S1P, or S2P, phenotypically exhibited impaired migration; (6) SREBP inhibition in ECs suppressed the activity of small GTPase Cdc42, a key molecule for ECs motility.

CONCLUSIONSSREBP is activated during and plays a critical role in ECs migration. Targeting SREBP could become a novel approach in fighting diseases involving abnormal ECs migration.

Animals ; Aorta ; cytology ; CHO Cells ; Cattle ; Cell Movement ; Cells, Cultured ; Cricetinae ; Cricetulus ; Endothelial Cells ; Fatty Acid Synthases ; genetics ; metabolism ; Hydroxycholesterols ; pharmacology ; Hydroxymethylglutaryl CoA Reductases ; genetics ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; Receptors, LDL ; genetics ; metabolism ; Sterol Regulatory Element Binding Proteins ; metabolism ; physiology

BACKGROUND AND OBJECTIVES: β-arrestin2 (β-arr2) basically regulates multiple signaling pathways in mammalian cells by desensitization and internalization of G-protein coupled receptors (GPCRs). We investigated impacts of β-arr2 on survival, mobility, and tube formation of cardiac progenitor cells (CPCs) obtained from wild-type (WT) mouse (CPC-WT), and β-arr2 knock-out (KO) mouse (CPC-KO) cultured in presence or absence of serum and oxygen as non-canonical roles in GPCR system. METHODS: CPCs were cultured in Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12 -based media containing fetal bovine serum and growth factors. Survival of 2 types of CPCs in hypoxia and/or serum deprivation was measured by fluorescence-activated cell sorting. Wound healing ability, and tube formation ability on Matrigel of 2 kinds of CPCs were compared in normoxic and hypoxic cultures. Protein expression related to survival and mobility were measured with the Western blot for each culture conditions. RESULT: CPC-KO showed significantly worse mobility in the wound healing assay and in tube formation on Matrigel especially in hypoxic culture than did the CPC-WT. Also, CPC-KO showed significantly higher apoptosis fraction in both normoxic and hypoxic cultures than did the CPC-WT. Expression of proteins associated with cell survival and mobility, e.g., protein kinase B (Akt), β-catenin, and glycogen synthase kinase-3β (GSK-3β) was significantly worse in CPC-KO. CONCLUSIONS: The CPC-KO had significantly worse cell mobility, tube formation ability, and survival than the CPC-WT, especially in the hypoxic cultures. Apparently, β-arr2 is important on CPC survival by means of mobility and tube formation in myocardial ischemia.
Animals ; Anoxia ; Apoptosis ; Blotting, Western ; Cell Movement ; Cell Survival ; Eagles ; Flow Cytometry ; Glycogen Synthase ; GTP-Binding Proteins ; Intercellular Signaling Peptides and Proteins ; Mice ; Myocardial Ischemia ; Oxygen ; Proto-Oncogene Proteins c-akt ; Stem Cells ; Wound Healing

BACKGROUND AND OBJECTIVES: β-arrestin2 (β-arr2) basically regulates multiple signaling pathways in mammalian cells by desensitization and internalization of G-protein coupled receptors (GPCRs). We investigated impacts of β-arr2 on survival, mobility, and tube formation of cardiac progenitor cells (CPCs) obtained from wild-type (WT) mouse (CPC-WT), and β-arr2 knock-out (KO) mouse (CPC-KO) cultured in presence or absence of serum and oxygen as non-canonical roles in GPCR system. METHODS: CPCs were cultured in Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12 -based media containing fetal bovine serum and growth factors. Survival of 2 types of CPCs in hypoxia and/or serum deprivation was measured by fluorescence-activated cell sorting. Wound healing ability, and tube formation ability on Matrigel of 2 kinds of CPCs were compared in normoxic and hypoxic cultures. Protein expression related to survival and mobility were measured with the Western blot for each culture conditions.RESULT: CPC-KO showed significantly worse mobility in the wound healing assay and in tube formation on Matrigel especially in hypoxic culture than did the CPC-WT. Also, CPC-KO showed significantly higher apoptosis fraction in both normoxic and hypoxic cultures than did the CPC-WT. Expression of proteins associated with cell survival and mobility, e.g., protein kinase B (Akt), β-catenin, and glycogen synthase kinase-3β (GSK-3β) was significantly worse in CPC-KO. CONCLUSIONS The CPC-KO had significantly worse cell mobility, tube formation ability, and survival than the CPC-WT, especially in the hypoxic cultures. Apparently, β-arr2 is important on CPC survival by means of mobility and tube formation in myocardial ischemia.