Cells, Cultured ; Humans ; Neovascularization, Physiologic ; immunology ; Pericytes ; metabolism ; physiology

Pericyte, also known as mural cell or Rouget cell, is one of the main cells that make up the wall of capillaries. Pericytes play important roles not only in the maturation, stability, and function maintenance of blood vessels, but also in the growth and development of tissues and organs, wound repair, and other physiological and pathological processes. Researches on the functions of pericytes are mainly concentrated on their multipotency, adjustment of vascular functions, and process of fibrosis, as well as on renal fibrosis, renal blood flow regulation, and glomerular filtration in urology, but are quite insufficient in andrology. This article reviews the location, origin, distribution, morphology, markers, and functions of pericytes, aiming to induce further studies of pericytes in andrology.
Fibrosis ; pathology ; Humans ; Pericytes ; physiology ; Urogenital System ; cytology

Cerebral pericytes are perivascular cells that stabilize blood vessels. Little is known about the plasticity of pericytes in the adult brain in vivo. Recently, using state-of-the-art technologies, including two-photon microscopy in combination with sophisticated Cre/loxP in vivo tracing techniques, a novel role of pericytes was revealed in vascular remodeling in the adult brain. Strikingly, after pericyte ablation, neighboring pericytes expand their processes and prevent vascular dilatation. This new knowledge provides insights into pericyte plasticity in the adult brain.
Animals ; Brain ; blood supply ; physiology ; physiopathology ; Brain Diseases ; physiopathology ; Capillaries ; physiology ; Cellular Microenvironment ; Diabetic Retinopathy ; physiopathology ; Endothelial Cells ; physiology ; Humans ; Pericytes ; physiology ; Vascular Remodeling

Although hepatic stellate cells, which are liver specific pericytes, have been recognized within the vasculature of the sinusoid for more than one hundred years, the biology and function of these cells is unclear. Recent studies have highlighted the key role of stellate cells in a number of fundamental processes that include wound healing/fibrosis, vasoregulation, and vascular remodeling/angiogenesis. In the liver, these processes are particularly important in the development of cirrhosis, portal hypertension and cancer. This article highlights the recent advances in our understanding of the biology of hepatic stellate cells and discusses some of the recently-ascribed functions that are relevant to liver fibrosis, portal hypertension and cancer angiogenesis.
Cell Communication/physiology ; Humans ; Hypertension, Portal/*etiology ; Kupffer Cells/*physiology ; Liver Cirrhosis/*etiology ; Liver Neoplasms/blood supply/*etiology ; Neovascularization, Pathologic/etiology ; Pericytes/*physiology

Angiopoietins ; metabolism ; physiology ; Animals ; Cell Proliferation ; Endothelial Cells ; cytology ; physiology ; Humans ; Neoplasms ; blood supply ; Neovascularization, Pathologic ; physiopathology ; Neovascularization, Physiologic ; physiology ; Pericytes ; cytology ; metabolism ; physiology ; Proto-Oncogene Proteins c-sis ; metabolism ; physiology ; Receptor, Platelet-Derived Growth Factor beta ; metabolism ; physiology ; Receptor, TIE-2 ; metabolism ; physiology ; Signal Transduction

BACKGROUNDCorneal neovascular leakage can lead to edema and secondary scarring. Previous studies have shown that pericytes play a key role in maturation of angiogenesis. The present studies investigate the relationship between vascular permeability and pericyte coverage of endothelial cells in rat corneal neovascular induced by alkali burns.

METHODSCorneal neovascular vessels induced by alkali burns was performed in Sprague-Dawley rats. Corneas were excised on 1, 2, 3, 5, 7 and 10 days after cauterization. The vascular permeability rate was measured by the Evans blue method. The microvessel pericyte coverage index (MPI) was applied to quantify the pericyte coverage through double immunofluorescent staining of frozen sections of corneas with CD31 as the endothelial and alpha-smooth muscle actin (alpha-SMA) as the pericyte markers. The correlation between permeability rate and MPI was analyzed. Pericyte coverage was confirmed ultrastructually using transmission electron microscopy.

RESULTSThe vascular permeability rate was (1.14 +/- 0.17), (0.24 +/- 0.08), (0.29 +/- 0.16), (0.14 +/- 0.10), (0.09 +/- 0.06) and (0.05 +/- 0.04) microg x ml(-1) x mm(-2) respectively on 1, 2, 3, 5, 7 and 10 days after cauterization. The MPI was 0, 16.07%, 11.95%, 43.84%, 73.97% and 86.21% respectively at the above mentioned time points. The correlation coefficient between MPI and the permeability rate was -0.943 (P = 0.005).

CONCLUSIONSPericyte recruitment was significantly correlated with the permeability of corneal neovascularization induced by alkali burns in rats. Therapeutic strategies aiming at anti-leakage should be most effective if they promote pericytes proliferation in the course of corneal neovascularization.

Alkalies ; Animals ; Burns, Chemical ; physiopathology ; Capillary Permeability ; Cell Movement ; Cornea ; blood supply ; ultrastructure ; Corneal Neovascularization ; physiopathology ; Eye Burns ; chemically induced ; physiopathology ; Female ; Fluorescent Antibody Technique ; Pericytes ; physiology ; Rats ; Rats, Sprague-Dawley

When adipose-derived stem cells (ASCs) are retrieved from the stromal vascular portion of adipose tissue, a large amount of mature adipocytes are often discarded. However, by modified ceiling culture technique based on their buoyancy, mature adipocytes can be easily isolated from the adipose cell suspension and dedifferentiated into lipid-free fibroblast-like cells, named dedifferentiated fat (DFAT) cells. DFAT cells re-establish active proliferation ability and undertake multipotent capacities. Compared with ASCs and other adult stem cells, DFAT cells showed unique advantages in their abundance, isolation and homogeneity. In this concise review, the establishment and culture methods of DFAT cells are introduced and the current profiles of their cellular nature are summarized. Under proper induction culture in vitro or environment in vivo, DFAT cells could demonstrate adipogenic, osteogenic, chondrogenic and myogenic potentials. In angiogenic conditions, DFAT cells could exhibit perivascular characteristics and elicit neovascularization. Our preliminary findings also suggested the pericyte phenotype underlying such cell lineage, which supported a novel interpretation about the common origin of mesenchymal stem cells and tissue-specific stem cells within blood vessel walls. Current research on DFAT cells indicated that this alternative source of adult multipotent cells has great potential in tissue engineering and regenerative medicine.
Adipocytes ; physiology ; Adult Stem Cells ; Animals ; Cell Culture Techniques ; Cell Dedifferentiation ; Cell Lineage ; Gene Expression Profiling ; Humans ; Mesenchymal Stromal Cells ; Multipotent Stem Cells ; Neovascularization, Physiologic ; Pericytes ; cytology ; Tissue Engineering ; methods