Capillary refill: a technique for obtaining histology-grade OCT angiography maps of human dermal vasculature in vivo (Conference Presentation)

Although microvascular dysfunction accompanies cognitive decline in aging, vascular dementia, and Alzheimer's disease, tools to study microvasculature longitudinally in vivo are lacking. Here, we use Doppler optical coherence tomography (OCT) and angiography for noninvasive, longitudinal imaging of mice with chronic cerebral hypoperfusion for up to 1 month. In particular, we optimized the OCT angiography method to selectively image red blood cell (RBC)-perfused capillaries, leading to a novel way of assessing capillary supply heterogeneity in vivo. After bilateral common carotid artery stenosis (BCAS), cortical blood flow measured by Doppler OCT dropped to half of baseline throughout the imaged tissue acutely. Microscopic imaging of the capillary bed with OCT angiography further revealed local heterogeneities in cortical flow supply during hypoperfusion. The number of RBC-perfused capillaries decreased, leading to increased oxygen diffusion distances in the days immediately after BCAS. Linear regression showed that RBC-perfused capillary density declined by 0.3% for a drop in flow of 1 mL/100 g per minute, and decreases in RBC-perfused capillary density as high as 25% were observed. Taken together, these results demonstrate the existence of local supply heterogeneity at the capillary level even at nonischemic global flow levels, and demonstrate a novel imaging method to assess this heterogeneity.

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In vivo imaging of retinal hemodynamics with OCT angiography and Doppler OCT

Biomedical Optics Express ◽

10.1364/boe.7.000663 ◽

2016 ◽

Vol 7 (2) ◽

pp. 663 ◽

Cited By ~ 17

Author(s):

Shenghai Huang ◽

Meixiao Shen ◽

Dexi Zhu ◽

Qi Chen ◽

Ce Shi ◽

...

Keyword(s):

In Vivo Imaging ◽

Oct Angiography ◽

Doppler Oct

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Doppler OCT and OCT Angiography for In Vivo Imaging of Vascular Physiology

Selected Topics in Optical Coherence Tomography ◽

10.5772/29378 ◽

2012 ◽

Author(s):

Vivek J. ◽

Aaron C. ◽

Edmund Y.

Keyword(s):

In Vivo Imaging ◽

Oct Angiography ◽

Doppler Oct ◽

Vascular Physiology

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Spatio-temporal dynamics of cerebral capillary segments with stalling red blood cells

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x17743877 ◽

2017 ◽

Vol 39 (5) ◽

pp. 886-900 ◽

Cited By ~ 20

Author(s):

Şefik Evren Erdener ◽

Jianbo Tang ◽

Amir Sajjadi ◽

Kıvılcım Kılıç ◽

Sreekanth Kura ◽

...

Keyword(s):

Temporal Dynamics ◽

Oct Angiography ◽

Label Free ◽

Systematic Analysis ◽

Volumetric Imaging ◽

Cerebral Capillary ◽

Spatio Temporal ◽

The Brain

Optical coherence tomography (OCT) allows label-free imaging of red blood cell (RBC) flux within capillaries with high spatio-temporal resolution. In this study, we utilized time-series OCT-angiography to demonstrate interruptions in capillary RBC flux in mouse brain in vivo. We noticed ∼7.5% of ∼200 capillaries had at least one stall in awake mice with chronic windows during a 9-min recording. At any instant, ∼0.45% of capillaries were stalled. Average stall duration was ∼15 s but could last over 1 min. Stalls were more frequent and longer lasting in acute window preparations. Further, isoflurane anesthesia in chronic preparations caused an increase in the number of stalls. In repeated imaging, the same segments had a tendency to stall again over a period of one month. In awake animals, functional stimulation decreased the observance of stalling events. Stalling segments were located distally, away from the first couple of arteriolar-side capillary branches and their average RBC and plasma velocities were lower than nonstalling capillaries within the same region. This first systematic analysis of capillary RBC stalls in the brain, enabled by rapid and continuous volumetric imaging of capillaries with OCT-angiography, will lead to future investigations of the potential role of stalling events in cerebral pathologies.

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Upregulated hsa_circRNA_100269 inhibits the growth and metastasis of gastric cancer through inactivating PI3K/Akt axis

PLoS ONE ◽

10.1371/journal.pone.0250603 ◽

2021 ◽

Vol 16 (4) ◽

pp. e0250603

Author(s):

Zhongli Wang ◽

Chao Liu

Keyword(s):

Gastric Cancer ◽

Cell Cycle ◽

Cell Cycle Arrest ◽

Cell Apoptosis ◽

Akt Signaling ◽

Cell Models ◽

Cycle Arrest ◽

Histology Grade ◽

Multiple Signaling

The pathogenesis of GC involves the complex networking of multiple signaling pathways; however, the detailed mechanisms of tumorigenesis of GC remains largely unknown. Therefore, it is necessary to explore novel diagnostic/prognostic biomarkers for GC. In this study, the levels of hsa_circRNA_100269 in gastric cancer (GC) samples and cells were examined, and its effects on the biological functions of GC cells were elucidated. The levels of hsa_circRNA_100269 in specimens/cell lines were examined using RT-qPCR. Cell models with hsa_circRNA_100269 overexpression or knockdown were generated using lentiviral vectors. Cell viability was determined by MTT assay; cell migratory/invasive activity was evaluated using wound healing/Transwell assay. Cell cycle arrest and apoptosis were assessed by flow cytometry; expression of associated markers involved in cell apoptosis, EMT and the PI3K/Akt signaling were determined by RT-qPCR/immunoblotting. In vivo study was also performed using hsa_circRNA_100269 knockout mice. Our findings revealed downregulation of hsa_circRNA_100269 in GC tissues compared to non-cancerous control. Additionally, the levels of PI3K were remarkably elevated in GC tissues, where hsa_circRNA_100269 and PI3K was negatively correlated. Moreover, the expression of hsa_circRNA_100269 was associated with histology grade and occurrence of metastasis in GC patients. In addition, hsa_circRNA_100269 was downregulated in GC cells compared to normal gastric epithelial cells. Overexpressed hsa_circRNA_100269 notably inhibited the proliferation, migration, invasion and EMT of GC cells, whereas cell cycle arrest at G0/G1 phase was promoted and cell apoptosis was enhanced. Moreover, the PI3K/Akt signaling was involved in hsa_circRNA_100269-regulated GC cell proliferation, migration, invasion, EMT and apoptosis. Knockdown of hsa_circRNA_100269 also remarkably induced tumor growth in mouse model. In summary, our findings indicated that the levels of hsa_circRNA_100269 were reduced in GC. Furthermore, hsa_circRNA_100269 could suppress the development of GC by inactivating the PI3K/Akt pathway. More importantly, hsa_circRNA_100269/PI3K/Akt axis may be a novel therapeutic candidate for GC treatment.

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Functional OCT angiography reveals early physiological dysfunction of hyaloid vasculature in developing mouse eye

Experimental Biology and Medicine ◽

10.1177/1535370219850787 ◽

2019 ◽

Vol 244 (10) ◽

pp. 819-823 ◽

Cited By ~ 2

Author(s):

Tae-Hoon Kim ◽

Taeyoon Son ◽

Xincheng Yao

Keyword(s):

Optical Coherence Tomography ◽

Vascular System ◽

Eye Development ◽

Vision System ◽

Longitudinal Optical ◽

Oct Angiography ◽

Full Description ◽

Optical Coherence ◽

Hyaloid Vasculature

Hyaloid vascular system (HVS) is a transient capillary network nourishing developing eye. Better study of the HVS regression correlated with eye development is essential for in-depth understanding of the nature of vision system. In this study, we demonstrate the feasibility of longitudinal optical coherence tomography (OCT) and OCT angiography (OCTA) monitoring of the HVS in C57BL/6J mice. OCT enables morphological monitoring of the HVS regression, and OCTA allows physiological assessment of the HVS involution correlated with eye development. Functional OCTA reveals early physiological dysfunction before morphological regression of the hyaloid vasculature in developing mouse eye. We anticipate that noninvasive, simultaneous OCT/OCTA observation of morphological regression and physiological degradation in normal and diseased animal models will be valuable to unravel the complex mechanisms of the HVS regression correlated with normal eye development and abnormal persistent hyaloid conditions. Impact statement Hyaloid vascular system (HVS) is known to have an essential role in the eye development. However, established knowledge of the HVS largely relies on end-point studies with biochemically fixed tissues, lacking a full description of the natural dynamics of the HVS correlated with eye development. An imaging methodology for noninvasive, longitudinal, and high-resolution monitoring of the HVS is important not only for better understanding of the nature of the vision system and is also valuable for better study of abnormal eye conditions. Here, we report the feasibility of in vivo optical coherence tomography (OCT) and OCT angiography (OCTA) imaging of the HVS regression in developing mouse eye. OCT enables morphological imaging of the HVS structure, and OCTA allows functional assessment of the HVS physiology correlated with eye development.

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