• 한국축산식품학회지
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• 제37권6호
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• pp.917-925
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• 2017

Whey protein, a by-product of milk curdling, exhibits diverse biological activities and is used as a dietary supplement. However, its effects on stress-induced vascular aging have not yet been elucidated. In this study, we found that whey protein significantly inhibited the Ang II-primed premature senescence of vascular smooth muscle cells (VSMCs). In addition, we observed a marked dose- and time-dependent increase in SIRT1 promoter activity and mRNA in VSMCs exposed to whey protein, accompanied by elevated SIRT1 protein expression. Ang II-mediated repression of SIRT1 level was dose-dependently reversed in VSMCs treated with whey protein, suggesting that SIRT1 is involved in preventing senescence in response to this treatment. Furthermore, resveratrol, a well-defined activator of SIRT1, potentiated the effects of whey protein on Ang II-primed premature senescence, whereas sirtinol, an inhibitor of SIRT1, exerted the opposite. Taken together, these results indicated that whey protein-mediated upregulation of SIRT1 exerts an anti-senescence effect, and can thus ameliorate Ang II-induced vascular aging as a dietary supplement.

• The Korean Journal of Physiology and Pharmacology
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• 제26권5호
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• pp.347-355
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• 2022

Abdominal aortic aneurysm (AAA) is a life-threatening disorder worldwide. Fibroblast growth factor 21 (FGF21) was shown to display a high level in the plasma of patients with AAA; however, its detailed functions underlying AAA pathogenesis are unclear. An in vitro AAA model was established in human aortic vascular smooth muscle cells (HASMCs) by angiotensin II (Ang-II) stimulation. Cell counting kit-8, wound healing, and Transwell assays were utilized for measuring cell proliferation and migration. RT-qPCR was used for detecting mRNA expression of FGF21 and activating transcription factor 4 (ATF4). Western blotting was utilized for assessing protein levels of FGF21, ATF4, and markers for the contractile phenotype of HASMCs. ChIP and luciferase reporter assays were implemented for identifying the binding relation between AFT4 and FGF21 promoters. FGF21 and ATF4 were both upregulated in Ang-II-treated HASMCs. Knocking down FGF21 attenuated Ang-II-induced proliferation, migration, and phenotype switch of HASMCs. ATF4 activated FGF21 transcription by binding to its promoter. FGF21 overexpression reversed AFT4 silencing-mediated inhibition of cell proliferation, migration, and phenotype switch. ATF4 transcriptionally upregulates FGF21 to promote the proliferation, migration, and phenotype switch of Ang-II-treated HASMCs.

• The Korean Journal of Physiology
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• 제29권1호
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• pp.91-102
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• 1995

The role of neurohumoral mechanisms in the regulation of cardiovascular functions and the effects of ethanol (EOH) on these mechanisms were examined in hemorrhaged conscious Wistar rats. The rats were bled at a constant rate (2 ml/kg/min) through the femoral artery until mean arterial pressure (MAP) was reduced by 30 mmHg. We studied the responses to hemorrhage 1) under normal conditions (Normal), and after pretreatments with 2) neural blockade (NB), pentolinium, 3) arginine vasopressin V1-receptor antagonist (AVPX) + NB, 4) angiotensin II ATI-receptor antagonist (AngIIX) + NB, 5) combined humoral blockade (HB), and 6) neurohumoral blockade. Intravenous administration of 30% EOH (6.3 ml/kg) attenuated the baroreceptor reflex sensitivity, and enhanced the depressor action of AngIIX. During hemorrhage, NB produced a faster fall ill MAP than Normal both in the saline and EOH groups. However, HB accelerated the rate of fall in MAP only in the EOH group. The recovery from hemorrhagic hypotension was not different between NB and Normal rats, but was attenuated in HB rats in the saline group. Under NB, AngIIX, but not AVPX, retarded the recovery rate compared with NB alone. EOH attenuated the recovery of MAP after hemorrhage in Normal rats, but completely abolished the recovery in HB rats. We conclude that 1) the maintenance of MAP during hemorrhage is mediated almost entirely by the autonomic functions, 2) angiotensin II plays an important role in the recovery from hemorrhagic hypotension, but AVP assumes little importance, 3) AVP release largely depends on the changes in blood volume, whereas renin release depends on the changes in blood pressure rather than blood volume, and 4) EOH increases the dependence of cardiovascular regulation on angiotensin II and impairs the recovery from hemorrhagic hypotension through the attenuation of autonomic functions.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.252-252
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• 2004

1. The concentrations of Ang. Ⅱ were 7.2±0.91 × 10³, 3.8±0.34 × 10³, 3.5±0.30 × 10³, 2.8±0.22 × 10³ pg/㎖ in bovine follicular fluids from 1∼3 ㎜, 3∼5 ㎜, 5∼7 ㎜ and 8∼10 ㎜ follicles, respectively. However, the concentrations of Ang. Ⅱ decreased in follicular fluids from large follicles. (omitted)

• BMB Reports
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• 제52권10호
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• pp.595-600
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• 2019

Cardiac fibrosis is a common feature in chronic hypertension patients with advanced heart failure, and endothelial-to-mesenchymal transition (EndMT) is known to promote Angiotensin II (Ang II)-mediated cardiac fibrosis. Previous studies have suggested a potential role for the transcription factor, ETS-1, in Ang II-mediated cardiac remodeling, however the mechanism are not well defined. In this study, we found that mice with endothelial Ets-1 deletion showed reduced cardiac fibrosis and hypertrophy following Ang II infusion. The reduced cardiac fibrosis was accompanied by decreased expression of fibrotic matrix genes, reduced EndMT with decreased Snail, Slug, Twist, and ZEB1 expression, as well as reduced cardiac hypertrophy and expression of hypertrophy-associated genes was observed. In vitro studies using cultured H5V cells further confirmed that ETS-1 knockdown inhibited $TGF-{\beta}1$-induced EndMT. This study revealed that deletion of endothelial Ets-1 attenuated Ang II-induced cardiac fibrosis via inhibition of EndMT, indicating an important ETS-1 function in mediating EndMT. Inhibition of ETS-1 could be a potential therapeutic strategy for treatment of heart failure secondary to chronic hypertension.

• Molecules and Cells
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• 제42권3호
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• pp.218-227
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• 2019

This study was designed to determine the effects of the long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) on vascular smooth muscle cell (VSMC) apoptosis and extracellular matrix (ECM) disruption in a murine abdominal aortic aneurysm (AAA) model. After injection of PVT1-silencing lentiviruses, AAA was induced in Apolipoprotein E-deficient ($ApoE^{-/-}$) male mice by angiotensin II (Ang II) infusion for four weeks. After Ang II infusion, mouse serum levels of pro-inflammatory cytokines were analysed, and aortic tissues were isolated for histological, RNA, and protein analysis. Our results also showed that PVT1 expression was significantly upregulated in abdominal aortic tissues from AAA patients compared with that in controls. Additionally, Ang II treatment significantly increased PVT1 expression, both in cultured mouse VSMCs and in AAA murine abdominal aortic tissues. Of note, the effects of Ang II in facilitating cell apoptosis, increasing matrix metalloproteinase (MMP)-2 and MMP-9, reducing tissue inhibitor of MMP (TIMP)-1, and promoting switching from the contractile to synthetic phenotype in cultured VSMCs were enhanced by overexpression of PVT1 but attenuated by knockdown of PVT1. Furthermore, knockdown of PVT1 reversed Ang II-induced AAA-associated alterations in mice, as evidenced by attenuation of aortic diameter dilation, marked adventitial thickening, loss of elastin in the aorta, enhanced aortic cell apoptosis, elevated MMP-2 and MMP-9, reduced TIMP-1, and increased pro-inflammatory cytokines. In conclusion, our findings demonstrate that knockdown of lncRNA PVT1 suppresses VSMC apoptosis, ECM disruption, and serum pro-inflammatory cytokines in a murine Ang II-induced AAA model.

• Asian-Australasian Journal of Animal Sciences
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• 제17권11호
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• pp.1570-1574
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• 2004

A flock of AA breed chickens were reared in peterstme brood-vait chamber and were provided with high energy pelleted feed. At 14 d of age, a total of 350 birds were randomly divided into 3 groups as follows: 100 birds were exposed to normal ambient temperature of 20$^{\circ}C$ for control group; 150 birds were exposed to lower ambient temperature of 11$^{\circ}C$ to induce ascites (treatment I); and another group of 100 birds were exposed to lower ambient temperature of 11$^{\circ}C$ and fed diet containing 1% L-arginine for ascitic prophylactic treatment (treatment II). Samples were collected from blood and abdominal fluid of chicken at 3, 4, 5, 6 and 7 wk of age subsequently, to analysis the contents of plasma endothelin (ET-1), angiotensin II (Ang II), cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP). The results indicated that the contents of cAMP, cGMP, and Ang II in reatment I and ascitic broilers were higher than the corresponding control group (p<0.01, p<0.05), ET-1 of preascitic broilers were control group (p<0.05), while there was an insignificant difference with later ascitic broilers. The contents of cAMP and cGMP in treatment II were higher than the treatment I and control groups (p<0.01, p<0.05), whereas, the contents of Ang II were gradually decreased compared to the control group (p<0.05), the contents of ET-1 were insignificantly different. On further analysis, the increased plasma Ang II at low ambient temperature condition in broilers made endothelium cell secretion of increased ET-1, cAMP, cGMP and decreased NO. Therefore, low temperature accelerated ascites syndrome in broilers. Supplemently L-arginine can decrease ET-1, and increase cAMP and cGMP. It is concluded that cAMP mediated in broilers pulmonary hypertension syndrome.

• The Korean Journal of Physiology and Pharmacology
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• 제8권2호
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• pp.89-94
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• 2004

The arterial pressure is regulated by the nervous and humoral mechanisms. The neuronal regulation is mostly carried out by the autonomic nervous system through the rostral ventrolateral medulla (RVLM), a key area for the cardiovascular regulation, and the humoral regulation is mediated by a number of substances, including the angiotensin (Ang) II and vasopressin. Recent studies suggest that central interleukin-1 (IL-1) activates the sympathetic nervous system and produces hypertension. The present study was undertaken to elucidate whether IL-1 and Ang II interact in the regulation of cardiovascular responses to the stress of hemorrhage. Thus, Sprague-Dawley rats were anesthetized and both femoral arteries were cannulated for direct measurement of arterial pressure and heart rate (HR) and for inducing hemorrhage. A guide cannula was placed into the lateral ventricle for injection of IL-1 $(0.1,\;1,\;10,\;20\;ng/2\;{\mu}l)$ or Ang II $(600\;ng/10\;{\mu}l)$. A glass microelectrode was inserted into the RVLM to record the single unit spike potential. Barosensitive neurons were identified by an increased number of single unit spikes in RVLM following intravenous injection of nitroprusside. I.c.v. $IL-1\;{\beta}$ increased mean arterial pressure (MAP) in a dose-dependent fashion, but HR in a dose-independent pattern. The baroreceptor reflex sensitivity was not affected by i.c.v. $IL-1\;{\beta}$. Both i.c.v. $IL-1\;{\alpha}\;and\;{\beta}$ produced similar increase in MAP and HR. When hemorrhage was induced after i.c.v. injection of $IL-1\;{\beta}$, the magnitude of MAP fall was not different from the control. The $IL-1\;{\beta}$ group showed a smaller decrease in HR and a lower spike potential count in RVLM than the control. MAP fall in response to hemorrhage after i.c.v. injection of Ang II was not different from the control. When both IL-1 and Ang II were simultaneously injected i.c.v., however, MAP fall was significantly smaller than the control, and HR was increased rather than decreased. These data suggest that IL-1, a defense immune mediator, manifests a hypertensive action in the central nervous system and attenuates the hypotensive response to hemorrhage by interaction with Ang II.

• Clinical and Experimental Pediatrics
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• 제52권8호
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• pp.944-952
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• 2009

목 적 : Epithelial to mesenchymal transition (EMT)은 태생기에 있어 필수 불가결한 발달과정일 뿐 아니라, 신 섬유화에 있어서도 중요한 역할을 하며, nestin은 고전적인 줄기세포 표지자로 신 세뇨관 간질 손상에 있어 새로운 표지자로 밝혀지고 있다. 신생 백서 신장에서 Angiotensin (Ang) II가 EMT에 미치는 영향을 알아보고자, 안지오텐신 전환 효소 억제제를 투여한 신생 백서의 신장에서 EMT 표지자 및 nestin의 발현 양상을 조사하였다. 방 법 : 7일 동안 신생 백서에게 enalapril (30 mg/kg/d) 또는 vehicle을 투여하였으며, ${\alpha}-smooth$ muscle actin (SMA), E-cadherin, vimentin 및 nestin에 대한 면역 조직 화학 염색을 시행하였다. 결 과 : enalapril 투여군에서 대조군에 비해 신 피질 및 수질 모두에서 ${\alpha}-SMA$ 발현이 증가하였으며, 이는 확장된 세뇨관 상피 세포에서 뚜렷하였다(P<0.05). E-cadherin 발현은 enalapril 투여군의 신 피질 및 수질의 세뇨관 상피 세포에서 확연히 감소하였다(P<0.05). vimentin 및 nestin 발현은 신 피질에서는 양군간의 차이가 없었으나, 신 수질에서는 enalapril 투여군에서 세뇨관 간질 세포에서 발현이 의미있게 증가하였다(P<0.05). 결 론 : 신생 백서 신장에서 Ang II 억제는 ${\alpha}-SMA$ 발현을 증가시키고, E-cadherin 발현을 감소시킴으로써 발달하는 신장의 EMT를 증가시켰다. Enalapril 투여는 또한 신 수질에서 vimentin과 nestin의 발현을 증가시켰으며, 이는 신생 백서 신장에서의 Ang II 억제로 인한 EMT 과정 중 신 수질의 변화가 더욱 뚜렷한 것을 시사하며, Ang II 억제가 EMT 표지자들의 발현을 다르게 변화시키는 것으로 사료된다.

• Nutrition Research and Practice
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• 제18권2호
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• pp.210-222
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• 2024

BACKGROUND/OBJECTIVES: Chronic renal failure (CRF) is a complex pathological condition that lacks a cure. Certain Chinese medicines, such as melittin, a major component in bee venom, have shown efficacy in treating CRF patients. On the other hand, the mechanisms underlying the therapeutic effects of melittin are unclear. MATERIALS/METHODS: A 5/6 nephrectomy model (5/6 Nx) of renal failure was established on rats for in vivo assays, and mouse podocyte clone 5 (MPC5) mouse podocyte cells were treated with angiotensin II (AngII) to establish an in vitro podocyte damage model. The 24-h urine protein, serum creatinine, and blood urea nitrogen levels were evaluated after one, 2, and 4 weeks. Hematoxylin and eosin staining, Masson staining, and periodic acid-Schiff staining were used to examine the pathological changes in kidney tissues. A cell counting kit 8 assay was used to assess the cell viability. Reverse transcription polymerase chain reaction and Western blot were used to assess the mRNA and protein levels in the cells, respectively. RESULTS: In the rat 5/6 Nx, melittin reduced the 24-h urinary protein excretion and the serum creatinine and blood urea nitrogen levels. Furthermore, the renal pathology was improved in the melittin-treated 5/6 Nx rats. Melittin promoted podocin, nephrin, Beclin 1, and the LC3II/LC3I ratio and inhibited phosphorylated mammalian target of rapamycin (mTOR)/mTOR in 5/6 Nx-induced rats and AngII-induced MPC5 mouse podocyte cells. Moreover, inhibiting autophagy with 3-MA weakened the effects of melittin on podocin, nephrin, and the LC3II/LC3I ratio in podocytes. CONCLUSION: Melittin may offer protection against kidney injury, probably by regulating podocyte autophagy. These results provide the theoretical basis for applying melittin in CRF therapy.