Rafal Gulej, Boglarka Csik, Janet Faakye, Stefano Tarantini, Santny Shanmugarama, Siva Sai Chandragiri, Peter Mukli, Shannon Conley, Anna Csiszar, Zoltan Ungvari, Andriy Yabluchanskiy, Ádám Nyúl-Tóth
Introduction
Age-related blood–brain barrier (BBB) disruption, cerebromicrovascular senescence, and microvascular rarefaction substantially contribute to the pathogenesis of vascular cognitive impairment (VCI) and Alzheimer's disease (AD). Previous studies established a causal link between age-related decline in circulating levels of insulin-like growth factor-1 (IGF-1), cerebromicrovascular dysfunction, and cognitive decline. The aim of our study was to determine the effect of IGF-1 signaling on senescence, BBB permeability, and vascular density in middle-age and old brains.
Methods
Accelerated endothelial senescence was assessed in senescence reporter mice (VE-Cadherin-CreERT2/Igf1rfl/fl × p16-3MR) using flow cytometry. To determine the functional consequences of impaired IGF-1 input to cerebromicrovascular endothelial cells, BBB integrity and capillary density were studied in mice with endothelium-specific knockout of IGF1R (VE-Cadherin-CreERT2/Igf1rfl/fl) using intravital two-photon microscopy.
Results
In VE-Cadherin-CreERT2/Igf1rfl/fl mice: (1) there was an increased presence of senescent endothelial cells; (2) cumulative permeability of the microvessels to fluorescent tracers of different molecular weights (0.3–40 kDa) is significantly increased, as compared to that of control mice, whereas decline in cortical capillary density does not reach statistical significance.
Conclusions
These findings support the notion that IGF-1 signaling plays a crucial role in preserving a youthful cerebromicrovascular endothelial phenotype and maintaining the integrity of the BBB.
{"title":"Endothelial deficiency of insulin-like growth factor-1 receptor leads to blood–brain barrier disruption and accelerated endothelial senescence in mice, mimicking aspects of the brain aging phenotype","authors":"Rafal Gulej, Boglarka Csik, Janet Faakye, Stefano Tarantini, Santny Shanmugarama, Siva Sai Chandragiri, Peter Mukli, Shannon Conley, Anna Csiszar, Zoltan Ungvari, Andriy Yabluchanskiy, Ádám Nyúl-Tóth","doi":"10.1111/micc.12840","DOIUrl":"10.1111/micc.12840","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>Age-related blood–brain barrier (BBB) disruption, cerebromicrovascular senescence, and microvascular rarefaction substantially contribute to the pathogenesis of vascular cognitive impairment (VCI) and Alzheimer's disease (AD). Previous studies established a causal link between age-related decline in circulating levels of insulin-like growth factor-1 (IGF-1), cerebromicrovascular dysfunction, and cognitive decline. The aim of our study was to determine the effect of IGF-1 signaling on senescence, BBB permeability, and vascular density in middle-age and old brains.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Accelerated endothelial senescence was assessed in senescence reporter mice (<i>VE-Cadherin-Cre</i><sup><i>ERT2</i></sup><i>/Igf1r</i><sup><i>fl/fl</i></sup> × <i>p16-3MR</i>) using flow cytometry. To determine the functional consequences of impaired IGF-1 input to cerebromicrovascular endothelial cells, BBB integrity and capillary density were studied in mice with endothelium-specific knockout of IGF1R (<i>VE-Cadherin-Cre</i><sup><i>ERT2</i></sup><i>/Igf1r</i><sup><i>fl/fl</i></sup>) using intravital two-photon microscopy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In <i>VE-Cadherin-Cre</i><sup><i>ERT2</i></sup><i>/Igf1r</i><sup><i>fl/fl</i></sup> mice: (1) there was an increased presence of senescent endothelial cells; (2) cumulative permeability of the microvessels to fluorescent tracers of different molecular weights (0.3–40 kDa) is significantly increased, as compared to that of control mice, whereas decline in cortical capillary density does not reach statistical significance.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These findings support the notion that IGF-1 signaling plays a crucial role in preserving a youthful cerebromicrovascular endothelial phenotype and maintaining the integrity of the BBB.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138685229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Abstracts from the 48th Annual Meeting of Japanese Society for Microcirculation","authors":"","doi":"10.1111/micc.12836","DOIUrl":"10.1111/micc.12836","url":null,"abstract":"","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138587930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jacques DuToit, Peter Brothers, Matthew Stephens, Keith Keane, Flavia Neto de Jesus, Simon Roizes, Pierre-Yves von der Weid
Objectives
The objective of our study is to evaluate the involvement of the transient receptor potential vanilloid 4 (TRPV4) in the alteration of lymphatic pumping in response to flow and determine the signaling pathways involved.
Methods
We used immunofluorescence imaging and western blotting to assess TRPV4 expression in rat mesenteric lymphatic vessels. We examined inhibition of TRPV4 with HC067047, nitric oxide synthase (NOS) with L-NNA and cyclooxygenases (COXs) with indomethacin on the contractile response of pressurized lymphatic vessels to flow changes induced by a stepwise increase in pressure gradients, and the functionality of endothelial TRPV4 channels by measuring the intracellular Ca2+ response of primary lymphatic endothelial cell cultures to the selective agonist GSK1016790A.
Results
TRPV4 protein was expressed in both the endothelial and the smooth muscle layer of rat mesenteric lymphatics with high endothelial expression around the valve sites. When maintained under constant transmural pressure, most lymphatic vessels displayed a decrease in contraction frequency under conditions of flow and this effect was ablated through inhibition of NOS, COX or TRPV4.
Conclusions
Our findings demonstrate a critical role for TRPV4 in the decrease in contraction frequency induced in lymphatic vessels by increases in flow rate via the production and action of nitric oxide and dilatory prostanoids.
{"title":"Flow-dependent regulation of rat mesenteric lymphatic vessel contractile response requires activation of endothelial TRPV4 channels","authors":"Jacques DuToit, Peter Brothers, Matthew Stephens, Keith Keane, Flavia Neto de Jesus, Simon Roizes, Pierre-Yves von der Weid","doi":"10.1111/micc.12839","DOIUrl":"10.1111/micc.12839","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>The objective of our study is to evaluate the involvement of the transient receptor potential vanilloid 4 (TRPV4) in the alteration of lymphatic pumping in response to flow and determine the signaling pathways involved.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used immunofluorescence imaging and western blotting to assess TRPV4 expression in rat mesenteric lymphatic vessels. We examined inhibition of TRPV4 with HC067047, nitric oxide synthase (NOS) with L-NNA and cyclooxygenases (COXs) with indomethacin on the contractile response of pressurized lymphatic vessels to flow changes induced by a stepwise increase in pressure gradients, and the functionality of endothelial TRPV4 channels by measuring the intracellular Ca<sup>2+</sup> response of primary lymphatic endothelial cell cultures to the selective agonist GSK1016790A.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>TRPV4 protein was expressed in both the endothelial and the smooth muscle layer of rat mesenteric lymphatics with high endothelial expression around the valve sites. When maintained under constant transmural pressure, most lymphatic vessels displayed a decrease in contraction frequency under conditions of flow and this effect was ablated through inhibition of NOS, COX or TRPV4.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our findings demonstrate a critical role for TRPV4 in the decrease in contraction frequency induced in lymphatic vessels by increases in flow rate via the production and action of nitric oxide and dilatory prostanoids.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138478062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cells have an incredible ability to physically interact with neighboring cells and their environment. They can detect and respond to mechanical forces by converting mechanical stimuli into biochemical signals in a process known as mechanotransduction. This is a key process for the adaption of vascular smooth muscle and endothelial cells to altered flow and pressure conditions. Mechanical stimuli, referring to a physical force exerted on cells, are primarily sensed by transmembrane proteins and the actin cytoskeleton, which initiate a cascade of intracellular events, including the activation of signaling pathways, ion channels, and transcriptional regulators. Recent work has highlighted an important role of the transcriptional coactivators YAP/TAZ for mechanotransduction in vascular cells. Interestingly, the activity of YAP/TAZ decreases with age, providing a potential mechanism for the detrimental effects of aging in the vascular wall. In this review, we summarize the current knowledge on the functional role of YAP and TAZ in vascular endothelial and smooth muscle cells for mechanotransduction in homeostasis and disease. In particular, the review is focused on in vivo observations from conditional knockout (KO) models of YAP/TAZ and the potential implications these studies may have for our understanding of vascular disease development.
{"title":"Emerging role of YAP/TAZ in vascular mechanotransduction and disease","authors":"Olivia Ritsvall, Sebastian Albinsson","doi":"10.1111/micc.12838","DOIUrl":"10.1111/micc.12838","url":null,"abstract":"<p>Cells have an incredible ability to physically interact with neighboring cells and their environment. They can detect and respond to mechanical forces by converting mechanical stimuli into biochemical signals in a process known as mechanotransduction. This is a key process for the adaption of vascular smooth muscle and endothelial cells to altered flow and pressure conditions. Mechanical stimuli, referring to a physical force exerted on cells, are primarily sensed by transmembrane proteins and the actin cytoskeleton, which initiate a cascade of intracellular events, including the activation of signaling pathways, ion channels, and transcriptional regulators. Recent work has highlighted an important role of the transcriptional coactivators YAP/TAZ for mechanotransduction in vascular cells. Interestingly, the activity of YAP/TAZ decreases with age, providing a potential mechanism for the detrimental effects of aging in the vascular wall. In this review, we summarize the current knowledge on the functional role of YAP and TAZ in vascular endothelial and smooth muscle cells for mechanotransduction in homeostasis and disease. In particular, the review is focused on in vivo observations from conditional knockout (KO) models of YAP/TAZ and the potential implications these studies may have for our understanding of vascular disease development.</p>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/micc.12838","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138445281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nadim Naser, Chenchel K. Lonj, Matthew Rikard-Bell, Shaun L. Sandow, Timothy V. Murphy
Objective
This study investigated the actions of advanced glycated end-products (AGE), their receptors (RAGE), and NAD(P)H oxidase (Nox) subtypes 1, 2, and 4 on mechanisms of endothelium-dependent dilation of the rat cremaster muscle artery (CMA).
Methods
Immunofluorescence studies were used to examine expression of RAGE in rat arteries. ROS accumulation was measured using luminescence and fluorescence assays. Functional studies were performed using pressure myography.
Results
High levels of RAGE expression were shown in the endothelial cells of the CMA, compared with low endothelial expression in middle cerebral and mesenteric arteries and the aorta. Exogenous AGE (in vitro glycated bovine serum albumin) stimulated H2O2 accumulation in CMA, which was prevented by the RAGE antagonist FPS-ZM1, the NAD(P)H oxidase (Nox) inhibitor apocynin and inhibited by the Nox1/4 inhibitor setanaxib, but not the Nox2 inhibitor GSK2795039. In functional studies, AGE inhibited vasodilation of CMA stimulated by acetylcholine, sodium nitroprusside, and the BKCa activator NS1619, but not adenosine-induced dilation. FPS-ZM1, apocynin, and setanaxib prevented the inhibitory effects of AGE on responses to acetylcholine and NS-1619.
Conclusion
These observations suggest RAGE are constitutively expressed in the endothelium of the rat CMA and may be activated by AGE to stimulate Nox1/4 and ROS formation with resulting inhibition of NO and BKCa-mediated endothelium-dependent dilation.
{"title":"Advanced glycated end-products inhibit dilation through constitutive endothelial RAGE and Nox1/4 in rat isolated skeletal muscle arteries","authors":"Nadim Naser, Chenchel K. Lonj, Matthew Rikard-Bell, Shaun L. Sandow, Timothy V. Murphy","doi":"10.1111/micc.12837","DOIUrl":"10.1111/micc.12837","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>This study investigated the actions of advanced glycated end-products (AGE), their receptors (RAGE), and NAD(P)H oxidase (Nox) subtypes 1, 2, and 4 on mechanisms of endothelium-dependent dilation of the rat cremaster muscle artery (CMA).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Immunofluorescence studies were used to examine expression of RAGE in rat arteries. ROS accumulation was measured using luminescence and fluorescence assays. Functional studies were performed using pressure myography.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>High levels of RAGE expression were shown in the endothelial cells of the CMA, compared with low endothelial expression in middle cerebral and mesenteric arteries and the aorta. Exogenous AGE (in vitro glycated bovine serum albumin) stimulated H2O2 accumulation in CMA, which was prevented by the RAGE antagonist FPS-ZM1, the NAD(P)H oxidase (Nox) inhibitor apocynin and inhibited by the Nox1/4 inhibitor setanaxib, but not the Nox2 inhibitor GSK2795039. In functional studies, AGE inhibited vasodilation of CMA stimulated by acetylcholine, sodium nitroprusside, and the BKCa activator NS1619, but not adenosine-induced dilation. FPS-ZM1, apocynin, and setanaxib prevented the inhibitory effects of AGE on responses to acetylcholine and NS-1619.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>These observations suggest RAGE are constitutively expressed in the endothelium of the rat CMA and may be activated by AGE to stimulate Nox1/4 and ROS formation with resulting inhibition of NO and BKCa-mediated endothelium-dependent dilation.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/micc.12837","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138176586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summer N. Horchler, Patrick C. Hancock, Mingjie Sun, Alexander T. Liu, Sameer Massand, Jessica C. El-Mallah, Dana Goldenberg, Olivia Waldron, Mary E. Landmesser, Shailaja Agrawal, Srinivas V. Koduru, Dino J. Ravnic
Objective
The success of engineered tissues continues to be limited by time to vascularization and perfusion. Recently, we described a simple microsurgical approach, termed micropuncture (MP), which could be used to rapidly vascularize an adjacently placed scaffold from the recipient macrovasculature. Here we studied the long-term persistence of the MP-induced microvasculature.
Methods
Segmental 60 μm diameter MPs were created in the recipient rat femoral artery and vein followed by coverage with a simple Type 1 collagen scaffold. The recipient vasculature and scaffold were then wrapped en bloc with a silicone sheet to isolate intrinsic vascularization. Scaffolds were harvested at 28 days post-implantation for detailed analysis, including using a novel artificial intelligence (AI) approach.
Results
MP scaffolds demonstrated a sustained increase of vascular density compared to internal non-MP control scaffolds (p < 0.05) secondary to increases in both vessel diameters (p < 0.05) and branch counts (p < 0.05). MP scaffolds also demonstrated statistically significant increases in red blood cell (RBC) perfused lumens.
Conclusions
This study further highlights that the intrinsic MP-induced vasculature continues to persist long-term. Its combination of rapid and stable angiogenesis represents a novel surgical platform for engineered scaffold and graft perfusion.
{"title":"Vascular persistence following precision micropuncture","authors":"Summer N. Horchler, Patrick C. Hancock, Mingjie Sun, Alexander T. Liu, Sameer Massand, Jessica C. El-Mallah, Dana Goldenberg, Olivia Waldron, Mary E. Landmesser, Shailaja Agrawal, Srinivas V. Koduru, Dino J. Ravnic","doi":"10.1111/micc.12835","DOIUrl":"10.1111/micc.12835","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>The success of engineered tissues continues to be limited by time to vascularization and perfusion. Recently, we described a simple microsurgical approach, termed micropuncture (MP), which could be used to rapidly vascularize an adjacently placed scaffold from the recipient macrovasculature. Here we studied the long-term persistence of the MP-induced microvasculature.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Segmental 60 μm diameter MPs were created in the recipient rat femoral artery and vein followed by coverage with a simple Type 1 collagen scaffold. The recipient vasculature and scaffold were then wrapped <i>en bloc</i> with a silicone sheet to isolate intrinsic vascularization. Scaffolds were harvested at 28 days post-implantation for detailed analysis, including using a novel artificial intelligence (AI) approach.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>MP scaffolds demonstrated a sustained increase of vascular density compared to internal non-MP control scaffolds (<i>p</i> < 0.05) secondary to increases in both vessel diameters (<i>p</i> < 0.05) and branch counts (<i>p</i> < 0.05). MP scaffolds also demonstrated statistically significant increases in red blood cell (RBC) perfused lumens.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study further highlights that the intrinsic MP-induced vasculature continues to persist long-term. Its combination of rapid and stable angiogenesis represents a novel surgical platform for engineered scaffold and graft perfusion.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/micc.12835","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72014693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
PKD1 (polycystin 1) and PKD2 (polycystin 2) are expressed in a variety of different cell types, including arterial smooth muscle and endothelial cells. PKD1 is a transmembrane domain protein with a large extracellular N-terminus that is proposed to act as a mechanosensor and receptor. PKD2 is a member of the transient receptor potential (TRP) channel superfamily which is also termed TRPP1. Mutations in the genes which encode PKD1 and PKD2 lead to autosomal dominant polycystic kidney disease (ADPKD). ADPKD is one of the most prevalent monogenic disorders in humans and is associated with extrarenal and vascular complications, including hypertension. Recent studies have uncovered mechanisms of activation and physiological functions of PKD1 and PKD2 in arterial smooth muscle and endothelial cells. It has also been found that PKD function is altered in the vasculature during ADPKD and hypertension. We will summarize this work and discuss future possibilities for this area of research.
{"title":"Vascular polycystin proteins in health and disease","authors":"Ulrich C. Mbiakop, Jonathan H. Jaggar","doi":"10.1111/micc.12834","DOIUrl":"10.1111/micc.12834","url":null,"abstract":"<p>PKD1 (polycystin 1) and PKD2 (polycystin 2) are expressed in a variety of different cell types, including arterial smooth muscle and endothelial cells. PKD1 is a transmembrane domain protein with a large extracellular N-terminus that is proposed to act as a mechanosensor and receptor. PKD2 is a member of the transient receptor potential (TRP) channel superfamily which is also termed TRPP1. Mutations in the genes which encode PKD1 and PKD2 lead to autosomal dominant polycystic kidney disease (ADPKD). ADPKD is one of the most prevalent monogenic disorders in humans and is associated with extrarenal and vascular complications, including hypertension. Recent studies have uncovered mechanisms of activation and physiological functions of PKD1 and PKD2 in arterial smooth muscle and endothelial cells. It has also been found that PKD function is altered in the vasculature during ADPKD and hypertension. We will summarize this work and discuss future possibilities for this area of research.</p>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41204763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims to examine the effect of sepsis on the dynamics of skeletal muscle partial oxygen pressure during muscle contractions as well as the effect of reactive oxygen species (ROS) scavenger (ascorbic acid, Asc).
Methods
Twenty-seven male Sprague–Dawley rats (2–3 months old) were randomly assigned to three groups; sham, cecal ligation and puncture (CLP), or CLP plus ascorbic acid treatment group (CLP + Asc). Electrical stimuli-induced muscle contractions and partial oxygen pressure measurements were performed at 3 h after CLP. The interstitial oxygen pressure (PO2is) in the spinotrapezius muscle was measured by the phosphorescence quenching method.
Results
The PO2is at rest was not different between the three groups. The PO2is decreased from rest to contraction in all groups. Compared to the sham, the time to decrease PO2is was significantly faster in CLP but not in CLP + Asc (p < .05). Compared to the sham, the PO2is during muscle contractions was significantly lower in both CLP and CLP + Asc (p < .05, respectively).
Conclusions
Our results suggest that CLP-induced sepsis accelerated the decay of PO2is at the onset of muscle contractions and maintained a low level of PO2is during muscle contractions.
{"title":"The effect of sepsis and reactive oxygen species on skeletal muscle interstitial oxygen pressure during contractions","authors":"Naoki Hitosugi, Kazuki Hotta, Yoshikazu Taketa, Ren Takamizawa, Yutaka Fujii, Ryo Ikegami, Hajime Tamiya, Tatsuro Inoue, Atsuhiro Tsubaki","doi":"10.1111/micc.12833","DOIUrl":"10.1111/micc.12833","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>This study aims to examine the effect of sepsis on the dynamics of skeletal muscle partial oxygen pressure during muscle contractions as well as the effect of reactive oxygen species (ROS) scavenger (ascorbic acid, Asc).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Twenty-seven male Sprague–Dawley rats (2–3 months old) were randomly assigned to three groups; sham, cecal ligation and puncture (CLP), or CLP plus ascorbic acid treatment group (CLP + Asc). Electrical stimuli-induced muscle contractions and partial oxygen pressure measurements were performed at 3 h after CLP. The interstitial oxygen pressure (<i>P</i>O<sub>2</sub>is) in the spinotrapezius muscle was measured by the phosphorescence quenching method.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The <i>P</i>O<sub>2</sub>is at rest was not different between the three groups. The <i>P</i>O<sub>2</sub>is decreased from rest to contraction in all groups. Compared to the sham, the time to decrease <i>P</i>O<sub>2</sub>is was significantly faster in CLP but not in CLP + Asc (<i>p</i> < .05). Compared to the sham, the <i>P</i>O<sub>2</sub>is during muscle contractions was significantly lower in both CLP and CLP + Asc (<i>p</i> < .05, respectively).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results suggest that CLP-induced sepsis accelerated the decay of <i>P</i>O<sub>2</sub>is at the onset of muscle contractions and maintained a low level of <i>P</i>O<sub>2</sub>is during muscle contractions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41179205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Essential hypertension (HT) is the global health problem and is a major risk factor for the development of cardiovascular and kidney disease. High salt intake has been associated with HT and impaired kidney sodium excretion is considered to be a major mechanism for the development of HT. Although kidney has a very important role in regulation of BP, this traditional view of BP regulation was challenged by recent findings suggesting that nonosmotic tissue sodium deposition is very important for BP regulation. This new paradigm indicates that sodium can be stored and deposited nonosmotically in the interstitium without water retention and without increased BP. One of the major determinants of this deposition is glycosaminoglycans (GAGs). By binding to GAGs found in the endothelial surface layer (ESL) which contains glycocalyx, sodium is osmotically inactivated and not induce concurrent water retention. Thus, GAGs has important function for homeostatic BP and sodium regulation. In the current review, we summarized the role of GAGs in ESL and BP regulation.
{"title":"The role of glycosaminoglycans in blood pressure regulation","authors":"Baris Afsar, Rengin Elsurer Afsar","doi":"10.1111/micc.12832","DOIUrl":"10.1111/micc.12832","url":null,"abstract":"<p>Essential hypertension (HT) is the global health problem and is a major risk factor for the development of cardiovascular and kidney disease. High salt intake has been associated with HT and impaired kidney sodium excretion is considered to be a major mechanism for the development of HT. Although kidney has a very important role in regulation of BP, this traditional view of BP regulation was challenged by recent findings suggesting that nonosmotic tissue sodium deposition is very important for BP regulation. This new paradigm indicates that sodium can be stored and deposited nonosmotically in the interstitium without water retention and without increased BP. One of the major determinants of this deposition is glycosaminoglycans (GAGs). By binding to GAGs found in the endothelial surface layer (ESL) which contains glycocalyx, sodium is osmotically inactivated and not induce concurrent water retention. Thus, GAGs has important function for homeostatic BP and sodium regulation. In the current review, we summarized the role of GAGs in ESL and BP regulation.</p>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41139652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Caitlin R. Francis, Makenzie L. Bell, Marina M. Skripnichuk, Erich J. Kushner
Objective
Endocytosis is a process vital to angiogenesis and vascular homeostasis. In pathologies where supraphysiological growth factor signaling underlies disease etiology, such as in diabetic retinopathy and solid tumors, strategies to limit chronic growth factor signaling by way of blunting endocytic processes have been shown to have tremendous clinical value. ADP ribosylation factor 6 (Arf6) is a small GTPase that promotes the assembly of actin necessary for clathrin-mediated and clathrin-independent endocytosis. In its absence, growth factor signaling is greatly diminished, which has been shown to ameliorate pathological signaling input in diseased vasculature. However, it is less clear if there are bystander effects related to loss of Arf6 on angiogenic behaviors. Our goal was to provide an analysis of Arf6's function in angiogenic endothelium, focusing on its role in actin and endocytosis as well as sprouting morphogenesis.
Methods
Primary endothelial cells were cultured in both 2D and 3D environments. Here, endothelial cells were fixed and stained for various proteins or transfected with fluorescently-tagged constructs for live-cell imaging.
Results
We found that Arf6 localized to both filamentous actin and sites of endocytosis in two-dimensional culture. Loss of Arf6 distorted both apicobasal polarity and reduced the total cellular filamentous actin content, which may be the primary driver underlying gross sprouting dysmorphogenesis in its absence.
Conclusions
Our findings highlight that endothelial Arf6 is a potent mediator of both actin regulation and endocytosis and is required for proper sprout formation.
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