laser-doppler-tool-for-measuring-pancreatic-islet-microvascular

Laser Doppler: A Tool for Measuring Pancreatic Islet Microvascular Vasomotion <em>In Vivo</em>

As a functional status of microcirculation, microvascular vasomotion is important for the delivery of oxygen and nutrients and the removal of carbon ...

Chinese Academy of Medical Sciences & Peking Union Medical College

Pericytes, located on microvessels, help to maintain vascular stability and blood-brain barrier integrity. The influence of pericytes on microvessels after spinal cord injury (SCI) is less clear. Therefore, the aim of this study was to investigate whether pericytes took a protective effect on microvessels in melatonin-treated SCI.

Microvascular protective role of pericytes in melatonin-treated spinal cord injury in the C57BL/6 mice.

The spinal cord microcirculation plays a critically important role in maintaining the normal function of spinal cord neurons, glial cells, and axons. Previous researches were largely focused on improved neurological manifestations of spinal cord injury (SCI) while ignoring to improve spinal cord microcirculation disorder after melatonin treatment. Therefore, the mechanism of melatonin that affects blood spinal cord barrier (BSCB) integrity and microcirculation in SCI remains unclear. The present study was performed to investigate the effect of melatonin on the BSCB in a SCI mice model. Melatonin (5, 10, 25, 50, 100 mg/kg i.p.) was administered to mice immediately following SCI. Compared to the 48 h post-SCI group, mice treated with melatonin (50 mg/kg) exhibited significantly reduced BSCB permeability. Additionally, melatonin treatment restrained microvessel loss; attenuated edema; protected the tight junction proteins, endothelial cells, and pericytes; decreased the number of cell apoptosis; and reduced MMP3/AQP4/HIF-1α/VEGF/VEGFR2 expression after SCI. Above all, our results clearly demonstrated that melatonin could stabilize microvascular barrier function and microcirculation of SCI, whose mechanism was to promote the repair of the damaged BSCB.

Melatonin treatment protects against acute spinal cord injury-induced disruption of blood spinal cord barrier in mice.

Accumulating evidence indicates that circulating pericyte progenitor cells (CPPCs) may be angiogenic biomarkers in cancer and diabetes. Their validity as biomarkers depends on the accuracy of techniques used for enumeration. In this report, absolute CPPC counts were performed by 2 single-platform technologies. The reliability of the 2 methods, including retest reliability and intraobserver and interobserver variability, was assessed according to the intraclass correlation coefficient (ICC). The linear correlation and agreement among both methods were assessed, and the stability of CPPC numbers in blood samples was analyzed.

Absolute circulating pericyte progenitor cell counts in mice by flow cytometry: comparison of 2 single-platform technologies.

Accumulating evidence demonstrates that microcirculation plays a role in the pathogenesis of hypertension. In the current study, we demonstrated that pancreatic islet microvascular vasomotion of spontaneously hypertensive rats (SHRs) lost the ability to regulate blood flow perfusion and exhibited a lower microvascular blood perfusion pattern which was negative correlated with blood glucose level. SHRs administrated with insulin revealed an improvement of pancreatic islet microvascular vasomotion and blood perfusion pattern. In vitro, the expressions of endothelial nitric oxide synthase (eNOS) and phospho-eNOS(p-eNOS) were significantly decreased in high glucose exposed islet endothelial cells (iECs), accompanied with a higher ratio of eNOS monomer to eNOS dimer and a significantly increased malondialdehyde and nitrite levels. Meanwhile, barrier function, tube formation and migration capacities of high glucose exposed iECs were significantly inhibited. In contrast, iECs dysfunction induced by glucose toxicity and oxidative stress was attenuated or improved by supplement with insulin, L-arginine and β-mercaptoethanol. In summary, our findings suggest that functional status of pancreatic islet microvascular vasomotion is impaired in SHRs and provide evidence that treatment with insulin, L-arginine and β-mercaptoethanol improves endothelium-dependent microvascular vasomotion and meliorates iECs function due to anti-hyperglycemic and anti-oxidative effects, partly through mechanism involving regulation of eNOS and p-eNOS.

Article	Year
Microvascular protective role of pericytes in melatonin-treated spinal cord injury in the C57BL/6 mice. Chinese medical journal\| PubMed ID: 25146619	2014
Melatonin treatment protects against acute spinal cord injury-induced disruption of blood spinal cord barrier in mice. Journal of molecular neuroscience : MN\| PubMed ID: 25303856	2014
Absolute circulating pericyte progenitor cell counts in mice by flow cytometry: comparison of 2 single-platform technologies. The International journal of biological markers\| PubMed ID: 26109365	2015
Functional status of microvascular vasomotion is impaired in spontaneously hypertensive rat. Scientific reports\| PubMed ID: 29213078	2017

Qingbin Wu

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