scholarly journals In mice and humans, the brain's blood vessels mature postnatally to acquire barrier and contractile properties

2021 ◽  
Author(s):  
Leila Slaoui ◽  
Alice Gilbert ◽  
Laetitia Federici ◽  
Armelle Rancillac ◽  
Antoinette Gelot ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Blood Vessels ◽  
Smooth Muscle Actin ◽  
Brain Perfusion ◽  
Neural Cells ◽  
Glycoprotein P ◽  
Mural Cells ◽  
Time Period ◽  
Essential Properties ◽  
Cell Type Specific

The brain dense vascular network is essential for distributing oxygen and nutrients to neural cells. The network develops during embryogenesis and leads to the formation of the endothelial blood-brain barrier (BBB). This barrier is surrounded by mural cells (pericytes and vascular smooth muscle cells (VSMCs)) and fibroblasts. Here, we compared the molecular and functional properties of brain vascular cells on postnatal day (P)5 vs. P15, via a transcriptomic analysis of purified mouse cortical microvessels (MVs) and the identification of vascular-cell-type-specific or -preferentially expressed transcripts. We found that endothelial cells (ECs), VSMCs and fibroblasts follow specific molecular maturation programs over this time period. In particular, ECs acquire P-glycoprotein (P-gP)-mediated efflux capacities. The arterial VSMC network expands, acquires contractile proteins (such as smooth muscle actin (SMA) and myosin heavy chain 11 (Myh11)) and becomes contractile. We also analyzed samples of human brain cortex from the early prenatal stage through to adulthood: the expression of endothelial P-gP increased at birth and Myh11 in VSMCs acts as a developmental switch (as in the mouse) at birth and up to the age of 2 of 5 years. Thus, in both mice and humans, the early postnatal phase is a critical period during which the essential properties of cerebral blood vessels (i.e. the endothelial efflux of xenobiotics and other molecules, and the VSMC contractility required for vessel tone and brain perfusion) are acquired and mature.

An Angiomyomatous Hamartoma With Features of Vascular Transformation of Sinuses in the Mediastinal Lymph Node of a Beagle Dog

2020 ◽  
Vol 48 (8) ◽  
pp. 1017-1024
Author(s):  
Sophie Nelissen ◽  
Ronnie Chamanza
Keyword(s):  
Smooth Muscle ◽  
Lymph Node ◽  
Lymph Nodes ◽  
Blood Vessels ◽  
Mediastinal Lymph Node ◽  
Smooth Muscle Actin ◽  
Fibrous Tissue ◽  
Vascular Lesions ◽  
Positive Staining ◽  
Beagle Dog

Two similar benign, nonneoplastic vascular lesions have been described in the lymph nodes of humans and animals: angiomyomatous hamartoma (AMH), which is characterized by the replacement of lymphoid tissue by blood vessels, smooth muscle, and fibrous tissue, and vascular transformation of sinuses (VTS), which is considered a reactive transformation of lymph node sinuses into capillary-like vascular channels. We hereby report a lesion with features common to both lesions in the mediastinal lymph nodes of a 1-year-old beagle dog in a 1-month toxicity study. Grossly, enlargement and red discoloration were observed, while microscopically, the lesion was characterized by effacement of the lymph node parenchyma with replacement by mature blood vessels, smooth muscle, and fibrous tissue, associated with lymphoid atrophy, which is consistent with AMH. However, multifocal areas of anastomosing or plexiform capillary-like channels lined by normal to slightly plump endothelium, similar to those described for VTS, were also present. Immunohistochemistry analysis revealed abundant positive staining for smooth muscle actin and endothelial cells (von Willebrand factor/factor VIII) and the absence of proliferation (Ki67). In conclusion, these lesions most likely represent a mixture of both AMH and VTS.

scholarly journals Organizational Hierarchy and Structural Diversity of Microvascular Pericytes in Adult Mouse Cortex

2017 ◽  
Author(s):  
Roger I. Grant ◽  
David A. Hartmann ◽  
Robert G. Underly ◽  
Andrée-Anne Berthiaume ◽  
Narayan R. Bhat ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Smooth Muscle Actin ◽  
Muscle Cells ◽  
Cell Types ◽  
Mural Cell ◽  
Mural Cells ◽  
Mouse Cortex ◽  
Transitional Cells ◽  
Brain Microvasculature

ABSTRACTSmooth muscle cells and pericytes, together called mural cells, coordinate many distinct vascular functions. Smooth muscle cells are ring-shaped and cover arterioles with circumferential processes, whereas pericytes extend thin processes that run longitudinally along capillaries. In between these canonical mural cell types are cells with mixed phenotype of both smooth muscle cells and pericytes. Recent studies suggest that these transitional cells are critical for controlling blood flow to the capillary bed during health and disease, but there remains confusion on how to identify them and where they are located in the brain microvasculature. To address this issue, we measured the morphology, vascular territory, and α-smooth muscle actin content of structurally diverse mural cells in adult mouse cortex. We first imaged intact 3-D vascular networks to establish the locations of major gradations in mural cell appearance as arterioles branched into capillaries. We then imaged individual mural cells occupying the regions within these gradations. This revealed two transitional cells that were often similar in appearance, but with sharply contrasting levels of α-smooth muscle actin. Our findings highlight the diversity of mural cell morphologies in brain microvasculature, and provide guidance for identification and categorization of mural cell types.

The Neurovascular Unit: Focus on the Regulation of Arterial Smooth Muscle Cells

2020 ◽  
Vol 16 (5) ◽  
pp. 502-515 ◽  
Author(s):  
Patrícia Quelhas ◽  
Graça Baltazar ◽  
Elisa Cairrao
Keyword(s):  
Blood Flow ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Blood Vessels ◽  
Neurovascular Unit ◽  
Muscle Cells ◽  
Cerebral Blood Vessels ◽  
Mural Cells ◽  
Brain Pericytes ◽  
The Brain

The neurovascular unit is a physiological unit present in the brain, which is constituted by elements of the nervous system (neurons and astrocytes) and the vascular system (endothelial and mural cells). This unit is responsible for the homeostasis and regulation of cerebral blood flow. There are two major types of mural cells in the brain, pericytes and smooth muscle cells. At the arterial level, smooth muscle cells are the main components that wrap around the outside of cerebral blood vessels and the major contributors to basal tone maintenance, blood pressure and blood flow distribution. They present several mechanisms by which they regulate both vasodilation and vasoconstriction of cerebral blood vessels and their regulation becomes even more important in situations of injury or pathology. In this review, we discuss the main regulatory mechanisms of brain smooth muscle cells and their contributions to the correct brain homeostasis.

Angiomyofibroblastoma of the Male Inguinal Region

2000 ◽  
Vol 124 (11) ◽  
pp. 1679-1681
Author(s):  
Makoto Ito ◽  
Hideyuki Yamaoka ◽  
Kenji Sano ◽  
Masao Hotchi
Keyword(s):  
Smooth Muscle ◽  
Blood Vessels ◽  
Immunohistochemical Staining ◽  
Smooth Muscle Actin ◽  
Inguinal Region ◽  
Fibrous Capsule ◽  
Muscle Actin ◽  
Spindle Cells ◽  
Pleomorphic Cells

Abstract We present a case of benign angiomyxoid tumor arising in the inguinal region of a 27-year-old man. The tumor was a gelatinous mass completely encapsulated by a thin fibrous capsule with no hemorrhage or necrosis. Histologically, a proliferation of spindle cells as well as occasional pleomorphic cells was observed within the myxofibrous stroma, intermingled with abundant capillary-sized blood vessels. Immunohistochemical staining of the tumor demonstrated spindle, oval, and pleomorphic cells equally positive for vimentin, desmin, and CD34, but not for α-smooth muscle actin. Based on these histologic and immunophenotypic features, we conclude that this angiomyxoid tumor of the male inguinal region is indistinguishable from the female angiomyofibroblastoma of the pelvic and perineal regions.

Sporadic Uterine Cervical Angiomyolipoma with Concurrent Endometrial Adenocarcinoma

2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S75-S76
Author(s):  
M A Masoud ◽  
E Wei
Keyword(s):  
Smooth Muscle ◽  
Blood Vessels ◽  
Smooth Muscle Actin ◽  
Endometrial Adenocarcinoma ◽  
White Female ◽  
Anterior Surface ◽  
Stromal Invasion ◽  
Common Location ◽  
Mesenchymal Neoplasm ◽  
Cervical Stromal Invasion

Abstract Introduction/Objective Angiomyolipoma is a benign mesenchymal neoplasm composed of variable admixture of thick dysmorphic blood vessels, smooth muscle cells, and fat cells that commonly arises in the kidney. It is strongly associated with tuberous sclerosis but it can also occur as sporadic. Extra renal angiomyolipomas have been reported with the liver being the most common location. Few cases of angiomyolipoma in the female genital have been reported where the uterus being the most common site. Uterine cervical angiomyolipoma has rarely been reported. Methods/Case Report We reported a case of 64-year-old white female with postmenopausal bleeding. Endometrial biopsy revealed endometrioid type endometrial adenocarcinoma. MRI showed endometrium was thickened, and the cervix was enlarged with disruption of the cervical fibrous stroma on the anterior surface concerning for cervical stromal invasion. Grossly, besides the polypoid mass that involved the endometrial cavity, there was a firm nodule with whorled cut surface noted on the anterior surface of the cervix. Microscopic examination of the cervical nodule revealed a classic variant of angiomyolipoma with mature adipocytes, spindle shaped smooth myocytes and anomalous thick-walled blood vessels with hyalinization. The spindle cells were positive for smooth muscle actin and caldesmon. CD34 highlighted the thick walled blood vessels. The stain for HMB- 45 was negative in contrast to renal counterpart. These findings are consistent with cervical angiomyolipoma. In addition, there was endometrioid endometrial adenocarcinoma, FIGO grade 1, with microsatellite stable phenotype, with only superficial invasion of myometrium, without involvement of cervical stroma. Results (if a Case Study enter NA) NA Conclusion This is a rare and probably the only presentation of cervical angiomyolipoma concurrently occurring with endometrial adenocarcinoma. It is uncertain if these two disease entities have genetic or pathogenesis association. The imaging studies were very concerning for cervical stromal invasion or questionable cervical cancer with local invasion. Cervical angiomyolipomas, though, extremely rare, may also be included in dysfunctional uterine bleeding differential diagnosis.

scholarly journals An α-Smooth Muscle Actin (acta2/αsma) Zebrafish Transgenic Line Marking Vascular Mural Cells and Visceral Smooth Muscle Cells

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e90590 ◽  
Author(s):  
Thomas R. Whitesell ◽  
Regan M. Kennedy ◽  
Alyson D. Carter ◽  
Evvi-Lynn Rollins ◽  
Sonja Georgijevic ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Transgenic Line ◽  
Smooth Muscle Actin ◽  
Muscle Cells ◽  
Muscle Actin ◽  
Mural Cells ◽  
Visceral Smooth Muscle

scholarly journals Organizational hierarchy and structural diversity of microvascular pericytes in adult mouse cortex

2017 ◽  
Vol 39 (3) ◽  
pp. 411-425 ◽  
Author(s):  
Roger I Grant ◽  
David A Hartmann ◽  
Robert G Underly ◽  
Andrée-Anne Berthiaume ◽  
Narayan R Bhat ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Smooth Muscle Actin ◽  
Muscle Cells ◽  
Cell Types ◽  
Mural Cell ◽  
Mural Cells ◽  
Mouse Cortex ◽  
Transitional Cells ◽  
Brain Microvasculature

Smooth muscle cells and pericytes, together called mural cells, coordinate many distinct vascular functions. Canonically, smooth muscle cells are ring-shaped and cover arterioles with circumferential processes, whereas pericytes extend thin processes that run longitudinally along capillaries. In between these canonical mural cell types are cells with features of both smooth muscle cells and pericytes. Recent studies suggest that these transitional cells are critical for controlling blood flow to the capillary bed during health and disease, but there remains confusion on how to identify them and where they are located in the brain microvasculature. To address this issue, we measured the morphology, vascular territory, and α-smooth muscle actin content of structurally diverse mural cells in adult mouse cortex. We first imaged intact 3D vascular networks to establish the locations of major gradations in mural cell appearance as arterioles branched into capillaries. We then imaged individual mural cells occupying the regions within these gradations. This revealed two transitional cells that were often similar in appearance, but with sharply contrasting levels of α-smooth muscle actin. Our findings highlight the diversity of mural cell morphologies in brain microvasculature, and provide guidance for identification and categorization of mural cell types.

scholarly journals Alpha-Smooth Muscle Actin-Positive Perivascular Cells in Diabetic Retina and Choroid

2020 ◽  
Vol 21 (6) ◽  
pp. 2158 ◽  
Author(s):  
Soo Jin Kim ◽  
Sang A. Kim ◽  
Yeong A. Choi ◽  
Do Young Park ◽  
Junyeop Lee
Keyword(s):  
Diabetic Retinopathy ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Smooth Muscle Actin ◽  
Muscle Cells ◽  
Higher Order ◽  
Muscle Actin ◽  
Diabetic Mice ◽  
Mural Cells ◽  
Retinal Capillaries

Structural alterations of pericytes in microvessels are important features of diabetic retinopathy. Although capillary pericytes had been known not to have α-smooth muscle actin (αSMA), a recent study revealed that a specific fixation method enabled the visualization of αSMA along retinal capillaries. In this study, we applied snap-fixation in wild type and streptozotocin-induced diabetic mice to evaluate the differences in vascular smooth muscle cells of the retina and the choroid. Mice eyeballs were fixed in ice-cold methanol to prevent the depolymerization of filamentous actin. Snap-fixated retina showed αSMA expression in higher-order branches along the capillaries as well as the arterioles and venules, which were not detected by paraformaldehyde fixation. In contrast, most choriocapillaris, except those close to the arterioles, were not covered with αSMA-positive perivascular mural cells. Large choroidal vessels were covered with more αSMA-positive cells in the snap-fixated eyes. Diabetes induced less coverage of αSMA-positive perivascular mural cells overall, but they reached higher-order branches of the retinal capillaries, which was prominent in the aged mice. More αSMA-positive pericytes were observed in the choroid of diabetic mice, but the αSMA-positive expression reduced with aging. This study suggests the potential role of smooth muscle cells in the pathogenesis of age-related diabetic retinopathy and choroidopathy.

Medial Smooth Muscle Cell Proliferation in the Balloon Injured Rabbit Aorta: Effect of a Thiazole Compound with Platelet Inhibitory Activity

1984 ◽  
Vol 51 (01) ◽  
pp. 075-078 ◽  
Author(s):  
R G Schaub ◽  
C A Simmons
Keyword(s):  
Smooth Muscle ◽  
Platelet Aggregation ◽  
Balloon Catheter ◽  
Rabbit Aorta ◽  
Surface Characteristics ◽  
Inhibitory Effect ◽  
Lesion Size ◽  
Blue Staining ◽  
Morphologic Characteristics ◽  
Time Period

SummaryTwenty-seven adult male New Zealand rabbits (3–4 kgs) were used in this study. Six rabbits received vehicle, 3 groups of 6 each received doses of 4,5-bis(p-methoxyphenyl)-2-(trifluoromethyl)- thiazole, (U-53,059), at 0.3 mg/kg, 3.0 mg/kg and 30.0 mg/kg/day respectively. Drug and vehicle doses were given orally each day starting 3 days before balloon injury and continuing for the entire 2 week time period. Three rabbits were used as nontreated sham controls. In the vehicle and U-53,059 treated groups aortae were denuded of endothelial cells by balloon catheter injury. Two weeks after injury platelet aggregation to collagen was measured and the aortae removed for analysis of surface characteristics by scanning electron microscopy and lesion size by morphometry. All doses of U-53,059 inhibited platelet aggregation. The 3.0 and 30.0 mg/kg groups had the greatest inhibitory effect. All balloon injured aortae had the same morphologic characteristics. All vessels had similar extent and intensity of Evan’s blue staining, similar areas of leukocyte/platelet adhesion, and a myointimal cell cover of transformed smooth muscle cells. The myointimal proliferative response was not inhibited at any of the drug doses studied.

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