scholarly journals Cardiac Remodeling in Obesity-Resistance Model is not Related to Collagen I and III Protein Expression

2021 ◽  
Author(s):  
Scarlet Marques de Oliveira ◽  
Jéssica Leite Garcia ◽  
Danielle Fernandes Vileigas ◽  
Dijon Henrique Salomé de Campos ◽  
Fabiane Valentini Francisqueti-Ferron ◽  
...  
Keyword(s):  
Protein Expression ◽  
Cardiac Remodeling ◽  
Collagen I ◽  
Resistance Model ◽  
Obesity Resistance

Investigation of activin A in inflammatory responses of the testis and its role in the development of testicular fibrosis

2019 ◽  
Vol 34 (8) ◽  
pp. 1536-1550 ◽  
Author(s):  
A Christine Kauerhof ◽  
Nour Nicolas ◽  
Sudhanshu Bhushan ◽  
Eva Wahle ◽  
Kate A Loveland ◽  
...  
Keyword(s):  
Protein Expression ◽  
Activin A ◽  
Collagen I ◽  
3T3 Cells ◽  
Qrt Pcr ◽  
3T3 Fibroblasts ◽  
Total Collagen ◽  
Severity Of The Disease ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

Abstract STUDY QUESTION Does activin A contribute to testicular fibrosis under inflammatory conditions? SUMMARY ANSWER Our results show that activin A and key fibrotic proteins are increased in human testicular biopsies with leukocytic infiltrates and impaired spermatogenesis and in murine experimental autoimmune orchitis (EAO) and that activin A stimulates fibrotic responses in peritubular cells (PTCs) and NIH 3T3 fibroblasts. WHAT IS KNOWN ALREADY Fibrosis is a feature of EAO. Activin A, a regulator of fibrosis, was increased in testes of mice with EAO and its expression correlated with severity of the disease. STUDY DESIGN, SIZE, DURATION This is a cross-sectional and longitudinal study of adult mice immunized with testicular homogenate (TH) in adjuvant to induce EAO, collected at 30 (n = 6), 50 (n = 6) and 80 (n = 5) days after first immunization. Age-matched mice injected with adjuvant alone (n = 14) and untreated mice (n = 15) were included as controls. TH-immunized mice with elevated endogenous follistatin, injected with a non-replicative recombinant adeno-associated viral vector carrying a gene cassette of follistatin (rAAV-FST315; n = 3) or vector with an empty cassette (empty vector controls; n = 2) 30 days prior to the first immunization, as well as appropriate adjuvant (n = 2) and untreated (n = 2) controls, were also examined. Human testicular biopsies showing focal inflammatory lesions associated with impaired spermatogenesis (n = 7) were included. Biopsies showing intact spermatogenesis without inflammation, from obstructive azoospermia patients, served as controls (n = 7). Mouse primary PTC and NIH 3T3 fibroblasts were stimulated with activin A and follistatin 288 (FST288) to investigate the effect of activin A on the expression of fibrotic markers. Production of activin A by mouse primary Sertoli cells (SCs) was also investigated. PARTICIPANTS/MATERIALS, SETTING, METHODS Testicular RNA and protein extracts collected from mice at days 30, 50 and 80 after first immunization were used for analysis of fibrotic marker genes and proteins, respectively. Total collagen was assessed by hydroxyproline assay and fibronectin; collagen I, III and IV, α-smooth muscle actin (α-SMA) expression and phosphorylation of suppressor of mothers against decapentaplegic (SMAD) family member 2 were measured by western blot. Immunofluorescence was used to detect fibronectin. Fibronectin (Fn), αSMA (Acta2), collagen I (Col1a2), III (Col3a1) and IV (Col4a1) mRNA in PTC and NIH 3T3 cells treated with activin A and/or FST288 were measured by quantitative RT-PCR (qRT-PCR). Activin A in SC following tumour necrosis factor (TNF) or FST288 stimulation was measured by ELISA. Human testicular biopsies were analysed by qRT-PCR for PTPRC (CD45) and activin A (INHBA), hydroxyproline assay and immunofluorescence. MAIN RESULTS AND THE ROLE OF CHANCE Production of activin A by SC was stimulated by 25 and 50 ng/ml TNF (P < 0.01, P < 0.001, respectively) as compared to untreated cells. INHBA mRNA was increased in human testicular biopsies with leukocytic infiltrates and impaired spermatogenesis, compared with control biopsies (P < 0.05), accompanied by increased total collagen (P < 0.01) and fibronectin deposition. Total testicular collagen (P < 0.0001) and fibronectin protein expression (P < 0.05) were also increased in EAO, and fibronectin expression was correlated with the severity of the disease (r = 0.9028). In animals pre-treated with rAAV-FST315 prior to immunization with TH, protein expression of fibronectin was comparable to control. Stimulation of PTC and NIH 3T3 cells with activin A increased fibronectin mRNA (P < 0.05) and the production of collagen I (P < 0.001; P < 0.01) and fibronectin (P < 0.05). Moreover, activin A also increased collagen IV mRNA (P < 0.05) in PTC, while αSMA mRNA (P < 0.01) and protein (P < 0.0001) were significantly increased by activin A in NIH 3T3 cells. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION A limited number of human testicular specimens was available for the study. Part of the study was performed in vitro, including NIH 3T3 cells as a surrogate for testicular fibroblasts. WIDER IMPLICATIONS OF THE FINDINGS Resident fibroblasts and PTC may contribute to the progression of testicular fibrosis following inflammation, and activin A is implicated as a key mediator of this process. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the National Health and Medical Research Council of Australia, the Victorian Government’s Operational Infrastructure Support Program and the International Research Training Group between Justus Liebig University (Giessen) and Monash University (Melbourne) (GRK 1871/1–2) on `Molecular pathogenesis on male reproductive disorders’ funded by the Deutsche Forschungsgemeinschaft and Monash University. The authors declare no competing financial interests.

Abstract 17853: Activation of AMP-activated Protein Kinase (AMPKα) by AICAR Attenuates Klotho Deficiency-induced Endothelial Dysfunction, Arterial Stiffening and Hypertension

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Yi Lin ◽  
Zhongjie Sun
Keyword(s):  
Blood Pressure ◽  
Blood Glucose ◽  
Endothelial Dysfunction ◽  
Protein Expression ◽  
Normal Diet ◽  
Collagen I ◽  
Daily Injection ◽  
Arterial Stiffening ◽  
Glucose Levels ◽  
Amp Activated Protein Kinase

Background: Arterial stiffening and hypertension are progressive aging-related disorders. Klotho (KL) is a recently-discovered anti-aging gene but its role in the pathogenesis of endothelial dysfunction, arterial stiffening and hypertension is not fully understood. Methods and Results: Heterozygous Klotho deficiency ( KL +/- ) mice and WT littermate mice were fed on high fat diet (HFD) or normal diet (ND). Plasma KL in KL heterozygeous mice (+/-) is about a half of that of the WT mice. Pulse wave velocity (PWV), an index of arterial stiffening, was increased in KL +/- mice but not in WT mice fed on HFD for 4 weeks. Systolic blood pressure and blood glucose levels were increased earlier with greater magnitudes in KL +/- mice than in WT mice fed on HFD. Notably, protein expression of collagen I, Runx2, and TGFβ1 were increased but protein expression of phosphorylated AMPKα (pAMPKα), phosphorylated eNOS (peNOS), and Mn-SOD were decreased in aortas of KL +/- mice fed on HFD for 5 weeks. Interestingly, daily injection of AICAR, an activator of AMPK, abolished the increases in PWV, blood pressure, and blood glucose in KL +/- mice fed on HFD. AICAR not only abolished the downregulation of pAMPKα, peNOS, and Mn-SOD levels but also attenuated the increased levels of collagen I, Runx2, TGFβ1 and superoxide, elastic lamellae breaks, and calcification in aortas in KL +/- mice fed on HFD. Conclusions: Klohto deficiency promotes HFD-induced endothelial dysfunction, arterial stiffening and hypertension. The promoting effects of klotho deficiency on arterial stiffening may be due to downregulation of endothelial AMPKα activity.

Extracellular matrix proteins differentially regulate airway smooth muscle phenotype and function

2007 ◽  
Vol 292 (6) ◽  
pp. L1405-L1413 ◽  
Author(s):  
Bart G. J. Dekkers ◽  
Dedmer Schaafsma ◽  
S. Adriaan Nelemans ◽  
Johan Zaagsma ◽  
Herman Meurs
Keyword(s):  
Smooth Muscle ◽  
Protein Expression ◽  
Airway Smooth Muscle ◽  
Airway Remodeling ◽  
Negative Control ◽  
Collagen I ◽  
Contractile Protein ◽  
Chronic Obstructive ◽  
Ecm Proteins ◽  
And Function

Changes in the ECM and increased airway smooth muscle (ASM) mass are major contributors to airway remodeling in asthma and chronic obstructive pulmonary disease. It has recently been demonstrated that ECM proteins may differentially affect proliferation and expression of phenotypic markers of cultured ASM cells. In the present study, we investigated the functional relevance of ECM proteins in the modulation of ASM contractility using bovine tracheal smooth muscle (BTSM) preparations. The results demonstrate that culturing of BSTM strips for 4 days in the presence of fibronectin or collagen I depressed maximal contraction (Emax) both for methacholine and KCl, which was associated with decreased contractile protein expression. By contrast, both fibronectin and collagen I increased proliferation of cultured BTSM cells. Similar effects were observed for PDGF. Moreover, PDGF augmented fibronectin- and collagen I-induced proliferation in an additive fashion, without an additional effect on contractility or contractile protein expression. The fibronectin-induced depression of contractility was blocked by the integrin antagonist Arg-Gly-Asp-Ser (RGDS) but not by its negative control Gly-Arg-Ala-Asp-Ser-Pro (GRADSP). Laminin, by itself, did not affect contractility or proliferation but reduced the effects of PDGF on these parameters. Strong relationships were found between the ECM-induced changes in Emax in BTSM strips and their proliferative responses in BSTM cells and for Emax and contractile protein expression. Our results indicate that ECM proteins differentially regulate both phenotype and function of intact ASM.

scholarly journals Valsartan ameliorates high glucose-induced peritoneal fibrosis by blocking mTORC1 signaling

2020 ◽  
Vol 245 (11) ◽  
pp. 983-993 ◽  
Author(s):  
Jing Liu ◽  
Yuan Feng ◽  
Cheng Sun ◽  
Wei Zhu ◽  
Qing-Yan Zhang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Peritoneal Dialysis ◽  
Protein Expression ◽  
High Glucose ◽  
Collagen I ◽  
Peritoneal Fibrosis ◽  
Dialysis Solution ◽  
Mtorc1 Pathway ◽  
Peritoneal Dialysis Solution

Our previous study demonstrated that the mammalian target of rapamycin complex 1 (mTORC1) pathway is activated in peritoneal fibrosis under high glucose condition. This study aimed to investigate whether valsartan inhibits high glucose-induced peritoneal fibrosis via decreasing the activity of the mTORC1 pathway. We used high glucose peritoneal dialysis solution in a mouse peritoneal dialysis model to induce peritoneal fibrosis in vivo and high glucose in human peritoneal mesothelial cells (HPMCs) to stimulate extracellular matrix accumulation in vitro. After injections of peritoneal dialysis solution containing 4.25% glucose for four weeks, mice showed typical features of peritoneal fibrosis, including markedly increased peritoneal thickness, excessive matrix deposition, increased peritoneal permeability, and higher expression of extracellular matrix proteins, such as α-smooth muscle actin (α-SMA) and collagen I. Oral gavage of valsartan significantly ameliorated these pathological changes at both week 6 and week 8. These effects of valsartan were closely correlated with a decrease in the activation of the mTORC1 signal, which was mediated by the downregulation of the protein expression of phosphorylated (p)-mTOR, p-eukaryotic initiation factor 4E-binding protein 1, and p-p70 S6 kinase 1. Further research showed that the protein expression of mTORC1 signal was positively correlated with the expression of both α-SMA and collagen I in the peritoneum. In vitro, high glucose increased the protein expression of α-SMA and collagen I in a dose-dependent manner, while valsartan significantly inhibited high glucose-induced extracellular matrix accumulation in HPMCs. The effect was also accompanied by a decrease in the activation of the mTORC1 signal. Furthermore, the mTOR agonist MHY1485 reversed the downregulation of extracellular matrix components in HPMCs, even in the presence of valsartan. We conclude that valsartan exerts a protective effect against high glucose-induced peritoneal fibrosis via suppressing the activity of the mTORC1 pathway. Impact statement Our study provided new insight into the mechanism underlying the preservation of the peritoneum by valsartan. The results demonstrated that the mice receiving chronic high glucose (HG) peritoneal dialysis solution infusion showed a typical feature of peritoneal fibrosis (PF), as well as higher expression of α-smooth muscle actin (α-SMA) and collagen I. In vitro, HG increased the protein expression of α-SMA and collagen I in a dose-dependent manner, while valsartan significantly ameliorated these pathological changes. Interestingly, there was a parallel decrease in the activity of mammalian target of rapamycin complex 1 (mTORC1) and the protein expression levels of α-SMA and collagen I upon treatment with valsartan in vivo and in vitro. Moreover, the mTOR agonist MHY1485 reversed the downregulation of α-SMA and collagen I in vitro, even in the presence of valsartan. Altogether, our findings reported for the first time that valsartan exerts a protective effect against HG-induced PF by inhibiting the activity of the mTORC1 pathway.

scholarly journals Alleviation of Inflammation and Oxidative Stress in Pressure Overload-Induced Cardiac Remodeling and Heart Failure via IL-6/STAT3 Inhibition by Raloxifene

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Shengqi Huo ◽  
Wei Shi ◽  
Haiyan Ma ◽  
Dan Yan ◽  
Pengcheng Luo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Protein Expression ◽  
Cardiac Remodeling ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Stat3 Signaling ◽  
H9c2 Myoblasts ◽  
And Oxidative Stress ◽  
Stat3 Inhibition

Background. Inflammation and oxidative stress are involved in the initiation and progress of heart failure (HF). However, the role of the IL6/STAT3 pathway in the pressure overload-induced HF remains controversial. Methods and Results. Transverse aortic constriction (TAC) was used to induce pressure overload-HF in C57BL/6J mice. 18 mice were randomized into three groups (Sham, TAC, and TAC+raloxifene, n = 6 , respectively). Echocardiographic and histological results showed that cardiac hypertrophy, fibrosis, and left ventricular dysfunction were manifested in mice after TAC treatment of eight weeks, with aggravation of macrophage infiltration and interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) expression in the myocardium. TAC (four and eight weeks) elevated the phosphorylation of signal transducer and activator of transcription 3 (p-STAT3) and prohibitin2 (PHB2) protein expression. Importantly, IL-6/gp130/STAT3 inhibition by raloxifene alleviated TAC-induced myocardial inflammation, cardiac remodeling, and dysfunction. In vitro, we demonstrated cellular hypertrophy with STAT3 activation and oxidative stress exacerbation could be elicited by IL-6 (25 ng/mL, 48 h) in H9c2 myoblasts. Sustained IL-6 stimulation increased intracellular reactive oxygen species, repressed mitochondrial membrane potential (MMP), decreased intracellular content of ATP, and led to decreased SOD activity, an increase in iNOS protein expression, and increased protein expression of Pink1, Parkin, and Bnip3 involving in mitophagy, all of which were reversed by raloxifene. Conclusion. Inflammation and IL-6/STAT3 signaling were activated in TAC-induced HF in mice, while sustained IL-6 incubation elicited oxidative stress and mitophagy-related protein increase in H9c2 myoblasts, all of which were inhibited by raloxifene. These indicated IL-6/STAT3 signaling might be involved in the pathogenesis of myocardial hypertrophy and HF.

scholarly journals Collagen I and III and metalloproteinase gene and protein expression in prostate cancer in relation to Gleason score

2012 ◽  
Vol 38 (3) ◽  
pp. 341-355 ◽  
Author(s):  
Antonio H. Duarte ◽  
Sicilia Colli ◽  
Jorge L. Alves-Pereira ◽  
Max P. Martins ◽  
Francisco J. B. Sampaio ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Protein Expression ◽  
Gleason Score ◽  
Collagen I ◽  
Gene And Protein Expression

scholarly journals MiRNA-1202 promotes the TGF-β1-induced proliferation, differentiation and collagen production of cardiac fibroblasts by targeting nNOS

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256066
Author(s):  
Jingwen Xiao ◽  
Yan Zhang ◽  
Yuan Tang ◽  
Hengfen Dai ◽  
Yu OuYang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Myocardial Fibrosis ◽  
Cardiac Fibroblasts ◽  
Collagen I ◽  
Luciferase Reporter ◽  
Control Group ◽  
Protein Levels ◽  
Collagen Iii ◽  
Human Cardiac Fibroblasts ◽  
Tgf Β1

Background Atrial fibrillation (AF) is a clinically common arrhythmia that affects human health. Myocardial fibrosis serves as an important contributor to AF. Recently, miRNA-1202 have been reported to be up-regulated in AF. However, the role of miRNA-1202 and its mechanism in myocardial fibrosis remain unclear. Methods Human cardiac fibroblasts (HCFs) were used to construct a fibrosis model by TGF-β1 induction. The expression of miR-1202 was measured by qRT-PCR. Cell proliferation was assessed by CCK-8 assays. Protein expression levels were measured by western blot. Collagen accumulation was measured by ELISA. The relationship between miR-1202 and nNOS was investigated by luciferase reporter assays. Results MiR-1202 expression was obviously increased in HCFs and was both time- and dose-independent. MiR-1202 could increase the proliferation and collagen I, collagen III, and α-SMA levels with or without TGF-β1. MiR-1202 could also increase TGF-β1 and p-Smad2/3 protein levels in comparison to the control group. However, they were obviously decreased after inhibitor transfection. MiR-1202 targets nNOS for negative regulation of HCFs fibrosis by decreasing cell differentiation, collagen deposition and the activity of the TGF-β1/Smad2/3 pathway. Co-transfection of miR-1202 inhibitor and siRNA of nNOS inhibited nNOS protein expression, thereby enhancing the HCFs proliferation. Furthermore, co-transfection of the miR-1202 inhibitor and siRNA of nNOS significantly promoted collagen I, collagen III, TGF-β1, Smad2/3 and α-SMA protein expression and Smad2/3 protein phosphorylation. These findings suggested that miR-1202 promotes HCFs transformation to a pro-fibrotic phenotype by targeting nNOS through activating the TGF-β1/Smad2/3 pathway.

P4428Physical exercise during uncontrolled systemic arterial hypertension

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L Urbano Pagan ◽  
M J Gomes ◽  
R L Damatto ◽  
M D M Cezar ◽  
D R A Reyes ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Protein Expression ◽  
Antioxidant Enzyme ◽  
Cardiac Remodeling ◽  
Spontaneously Hypertensive Rats ◽  
Myocardial Function ◽  
Antioxidant Enzyme Activity ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Nadph Oxidase Activity

Abstract Introduction Physical exercise reduces systemic arterial blood pressure and improves cardiac remodeling. However, the effects of exercise during uncontrolled arterial hypertension remains poorly understood. This study evaluated the influence of physical training on cardiac remodeling in untreated spontaneously hypertensive rats (SHR). Methods Four experimental groups were used: sedentary (W-SED n=27) and trained (W-EX, n=31) normotensive Wistar rats, and sedentary (SHR-SED, n=27) and exercised (SHR-EX, n=32) hypertensive rats. At 13 months old, the exercise groups underwent treadmill exercise five days a week, for four months. Echocardiogram was performed to evaluate cardiac structures and function. In vitro myocardial function was analyzed in left ventricular (LV) papillary muscle preparations. Myocardial collagen was quantified by histology and hydroxyproline concentration and antioxidant enzyme activity was assessed by spectrophotometry. NADPH oxidase activity was analyzed by lucigenin reduction. Protein expression was quantified by Western blot. Matrix metalloproteinases (MMP) activity was evaluated by zymography. Statistical analyzes: two factor ANOVA and Bonferroni or Kruskal-Wallis and Dunn tests. Results Systolic blood pressure was higher in SHR groups. Exercised groups had greater physical capacity. Frequency of heart failure features was higher in hypertensive groups than controls; SHR-EX had a lower frequency of pleural effusion and tachypnea than SHR-SED. Echocardiogram showed lower LV wall thickness, LV relative wall thickness, left atrium diameter, and relaxation time in SHR-EX than SHR-SED. Myocardial function was better in SHR-EX (positive derivative of developed tension) than SHR-SED. SHR-EX had higher antioxidant enzyme activity than SHR-SED. Lipid hydroperoxide concentration, myocyte diameters, and phosphorylated JNK and total IkB protein expression were higher in hypertensive than control groups. Hydroxyproline, malondialdehyde, NADPH oxidase activity, and protein expression of collagen III, lysyl oxidase, TIMP-1, total JNK, phosphorylated p38, phosphorylated and total p65, and phosphorylated IkB did not differ between groups. Interstitial collagen fraction, MMP-2 activity, and protein expression of total p38, and total and phosphorylated ERK were higher in SHR-SED than W-SED. Exercise reduced MMP-2 activity and phosphorylated ERK in hypertensive rats. Conclusion Physical exercise improves physical capacity, reduces the frequency of heart failure features, and attenuates cardiac remodeling in spontaneously hypertensive rats. In addition, exercise increases antioxidant enzyme activity, decreases ERK phosphorylation and MMP-2 activity, and attenuates total ERK protein expression. Acknowledgement/Funding Fapesp, CNPq, Capes and UNESP

scholarly journals C/EBPβ Acetylation is Involved in Idiopathic Pulmonary Fibrosis

2021 ◽  
Author(s):  
Jingzhu Zhou ◽  
Xiuhai Ji ◽  
yan fen ◽  
Hui ding
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Protein Expression ◽  
Western Blot ◽  
Real Time Pcr ◽  
Lung Fibrosis ◽  
Collagen I ◽  
Fibroblast Foci ◽  
The Relationship ◽  
Control Samples

Abstract Background: IPF is a progressive lung disease, characterized by excessive deposition of ECM. C/EBPβ is involved in the development of pulmonary fibrosis. However, the regulation of C/EBPβ in the context of pulmonary fibrosis is not clear. The study is to identify the C/EBPβ acetylation in IPF．Methods: Lung from six IPF and six control samples were selected in this study. We investigated the expression of C/EBPβ in lungs with Immunochemistry. Moreover, the expression of C/EBPβ mRNA via Real Time-PCR and its protein expression via Western Blot were performed. Meanwhile, the levels of collagen-I and α-SMA as markers of pulmonary fibrosis were also determined by Western Blot. Furthermore, we confirmed the relationship between α-SMA and acetylated C/EBPβ by Co-Immunoprecipitation. Results: We found the elevated C/EBPβ mostly locating in fibroblast foci in lungs of IPF. And the expression of C/EBPβ RNA and protein were obviously increased in IPF (P <0.05), in which the proteins of α-SMA and collagen-I were enhanced (P <0.05). Furthermore, the stronger acetylation of C/EBPβ binging to the α-SMA gene was shown in lung fibrosis (P <0.05). Conclusions: The increased expression of C/EBPβ acetylation associated with α-SMA expression is involved in the development of pulmonary fibrosis.

scholarly journals Middle cerebral artery alterations in a rat chronic hypoperfusion model

2012 ◽  
Vol 112 (3) ◽  
pp. 511-518 ◽  
Author(s):  
Ana Márquez-Martín ◽  
Francesc Jiménez-Altayó ◽  
Ana P. Dantas ◽  
Laura Caracuel ◽  
Anna M. Planas ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Protein Expression ◽  
Western Blot ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Collagen I ◽  
Cerebral Hypoperfusion ◽  
Aging Brain ◽  
Mrna Levels ◽  
Cross Sectional

Chronic cerebral hypoperfusion (CHP) induces microvascular changes that could contribute to the progression of vascular cognitive impairment and dementia in the aging brain. This study aimed to analyze the effects of CHP on structural, mechanical, and myogenic properties of the middle cerebral artery (MCA) after bilateral common carotid artery occlusion (BCCAO) in adult male Wistar rats. Sham animals underwent a similar surgical procedure without carotid artery (CA) ligation. After 15 days of occlusion, MCA and CA were dissected and MCA structural, mechanical, and myogenic properties were assessed by pressure myography. Collagen I/III expression was determined by immunofluorescence in MCA and CA and by Western blot in CA. mRNA levels for 1A1, 1A2, and 3A1 collagen subunits were quantified by quantitative real-time PCR in CA. Matrix metalloproteinase (MMP-1, MMP-2, MMP-9, and MMP-13) and hypoxia-inducible factor-1α (HIF-1α) protein expression were determined in CA by Western blot. BCCAO diminished cross-sectional area, wall thickness, and wall-to-lumen ratio. Nevertheless, whereas wall stress was increased, stiffness was not modified and myogenic response was diminished. Hypoperfusion triggered HIF-1α expression. Collagen I/III protein expression diminished in MCA and CA after BCCAO, despite increased mRNA levels for 1A1 and 3A1 collagen subunits. Therefore, the reduced collagen expression might be due to proteolytic degradation, since the expression of MMP-1 and MMP-9 increased in the CA. These data suggest that BCCAO induces hypotrophic remodeling by a mechanism that involves a reduction of collagen I/III in association with increased MMP-1 and MMP-9 and that decreases myogenic tone in major arteries supplying the brain.

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