Prominin-1 expression in the testis/epididymis and fertility.

The contribution of Prominin-1 (aka CD133) to male fertility has recently been (re)investigated, with contradictory results. Early findings, essential for deciphering its role, have unfortunately been neglected. Here, the authors present what is currently known about its expression in the male reproductive system of rodents and men so that its involvement in male fertility can be re-examined and discussed in the light of these elements.

Induction of vascular endothelial growth factor-A in human retinal and endothelial cells in response to glyoxal.

Low-density lipoprotein (LDL) apheresis is effective and safe for patients with diabetes, proteinuria, and dyslipidemia. Diabetes mellitus is accompanied by ocular microvascular complications like retinal neovascularization or diabetic macular edema. These are leading causes of blindness and can be mediated by abnormal vessel growth and increased vascular permeability due to elevated levels of vascular endothelial growth factor (VEGF) in diabetic patients.

VEGF-Trap Modulates Retinal Inflammation in the Murine Oxygen-Induced Retinopathy (OIR) Model.

Anti-Vascular Endothelial Growth Factor (VEGF) agents are the first-line treatment for retinal neovascular diseases, which represent the most prevalent causes of acquired vision loss world-wide. VEGF-Trap (Aflibercept, AFL), a recombinant decoy receptor recognizing ligands of both VEGFR-1 and -2, was recently reported to be highly efficient in improving visual acuity and preserving retinal anatomy in individuals affected by diabetic macular edema. However, the precise molecular and cell biological mechanisms underlying the beneficial effects of this novel tool have yet to be elucidated.

Gene expression profile of the murine ischemic retina and its response to Aflibercept (VEGF-Trap).

Ischemic retinal dystrophies are leading causes of acquired vision loss. Although the dysregulated expression of the hypoxia-responsive VEGF-A is a major driver of ischemic retinopathies, implication of additional VEGF-family members in their pathogenesis has led to the development of multivalent anti-angiogenic tools. Designed as a decoy receptor for all ligands of VEGFR1 and VEGFR2, Aflibercept is a potent anti-angiogenic agent.

Prominins control ciliary length throughout the animal kingdom: New lessons from human prominin-1 and zebrafish prominin-3.

Prominins (proms) are transmembrane glycoproteins conserved throughout the animal kingdom. They are associated with plasma membrane protrusions, such as primary cilia, as well as extracellular vesicles derived thereof. Primary cilia host numerous signaling pathways affected in diseases known as ciliopathies.

VEGF-Trap is a potent modulator of vasoregenerative responses and protects dopaminergic amacrine network integrity in degenerative ischemic neovascular retinopathy.

Retinal hypoxia triggers abnormal vessel growth and microvascular hyper-permeability in ischemic retinopathies. Whereas vascular endothelial growth factor A (VEGF-A) inhibitors significantly hinder disease progression, their benefits to retinal neurons remain poorly understood. Similar to humans, oxygen-induced retinopathy (OIR) mice exhibit severe retinal microvascular malformations and profound neuronal dysfunction.

Trends and Challenges in Tumor Anti-Angiogenic Therapies.

Excessive abnormal angiogenesis plays a pivotal role in tumor progression and is a hallmark of solid tumors. This process is driven by an imbalance between pro- and anti-angiogenic factors dominated by the tissue hypoxia-triggered overproduction of vascular endothelial growth factor (VEGF). VEGF-mediated signaling has quickly become one of the most promising anti-angiogenic therapeutic targets in oncology.

Expression of the transcription factor Hes3 in the mouse and human ocular surface, and in pterygium.

Purpose: In this work we examined the presence of the neural stem cell biomarker Hairy and Enhancer of Split 3 (Hes3) in the anterior eye segment and in the aberrant growth condition of the conjunctiva pterygium. Further, we studied the response of Hes3 to irradiation.

Materials And Methods: Adult mouse and human corneoscleral junction and conjunctiva, as well as human pterygium were prepared for immunohistochemical detection of Hes3 and other markers.

Spatial distribution of prominin-1 (CD133)-positive cells within germinative zones of the vertebrate brain.

Background: In mammals, embryonic neural progenitors as well as adult neural stem cells can be prospectively isolated based on the cell surface expression of prominin-1 (CD133), a plasma membrane glycoprotein. In contrast, characterization of neural progenitors in non-mammalian vertebrates endowed with significant constitutive neurogenesis and inherent self-repair ability is hampered by the lack of suitable cell surface markers. Here, we have investigated whether prominin-1-orthologues of the major non-mammalian vertebrate model organisms show any degree of conservation as for their association with neurogenic geminative zones within the central nervous system (CNS) as they do in mammals or associated with activated neural progenitors during provoked neurogenesis in the regenerating CNS.

Immunohistochemical localization and characterization of putative mesenchymal stem cell markers in the retinal capillary network of rodents.

Perivascular cells of microvascular niches are the prime candidates for being a reservoire of mesenchymal stem cell (MSC)-like cells in many tissues and organs that could serve as a potential source of cells and a target of novel cell-based therapeutic approaches. In the present study, by utilising typical markers of pericytes (neuronal-glial antigen 2, NG2, a chondroitin sulphate proteoglycan) and those of MSCs (CD146 and CD105) and primitive pluripotent cells (sex-determining region Y-box 2, Sox2), the phenotypic traits and the distribution of murine and rat retinal perivascular cells were investigated in situ. Our findings indicate that retinal microvessels of juvenile rodents are highly covered by NG2-positive branching processes of pericytic (perivascular) cells that are less prominent in mature capillary networks of the adult retina.

Prominin-1 (CD133): Molecular and Cellular Features Across Species.

Our knowledge of the first member of the prominin family is growing rapidly as the clinical value of prominin-1 (CD133) increases with its ever-wider use as a stem cell marker in normal and cancer tissues. Although the physiological function of this evolutionally conserved pentaspan membrane glycoprotein remains elusive, several studies have revealed new biological features regarding stem cells, cancer stem cells, and photoreceptors. The wide expression of CD133 in terminally differentiated epithelial cells, long overlooked by many authors, has attracted significant interest through the extensive investigation of human PROMININ-1 as a potential target for cancer therapies in various organs.

CD133 and membrane microdomains: old facets for future hypotheses.

Understanding all facets of membrane microdomains in normal and cancerous cells within the digestive tract is highly important, not only from a clinical point of view, but also in terms of our basic knowledge of cellular transformation. By studying the normal and cancer stem cell-associated molecule CD133 (prominin-1), novel aspects of the organization and dynamics of polarized epithelial cells have been revealed during the last decade. Its association with particular membrane microdomains is highly relevant in these contexts and might also offer new avenues in diagnosis and/or targeting of cancer stem cells.

Distinct and conserved prominin-1/CD133-positive retinal cell populations identified across species.

Besides being a marker of various somatic stem cells in mammals, prominin-1 (CD133) plays a role in maintaining the photoreceptor integrity since mutations in the PROM1 gene are linked with retinal degeneration. In spite of that, little information is available regarding its distribution in eyes of non-mammalian vertebrates endowed with high regenerative abilities. To address this subject, prominin-1 cognates were isolated from axolotl, zebrafish and chicken, and their retinal compartmentalization was investigated and compared to that of their mammalian orthologue.

Prominin-2 is a novel marker of distal tubules and collecting ducts of the human and murine kidney.

Prominin-1 (CD133) and its paralogue, prominin-2, are pentaspan membrane glycoproteins that are strongly expressed in the kidney where they have been originally cloned from. Previously, we have described the localization of prominin-1 in proximal tubules of the nephron. The spatial distribution of prominin-2, however, has not yet been documented in the kidney.

Loss of the cholesterol-binding protein prominin-1/CD133 causes disk dysmorphogenesis and photoreceptor degeneration.

Prominin-1/CD133 (Prom-1) is a commonly used marker of neuronal, vascular, hematopoietic and other stem cells, yet little is known about its biological role and importance in vivo. Here, we show that loss of Prom-1 results in progressive degeneration of mature photoreceptors with complete loss of vision. Despite the expression of Prom-1 on endothelial progenitors, photoreceptor degeneration was not attributable to retinal vessel defects, but caused by intrinsic photoreceptor defects in disk formation, outer segment morphogenesis, and associated with visual pigment sorting and phototransduction abnormalities.

Expression of distinct splice variants of the stem cell marker prominin-1 (CD133) in glial cells.

Prominin-1 (CD133) is a cholesterol-interacting pentaspan membrane glycoprotein specifically associated with plasma membrane protrusions. Prominin-1 is expressed by various stem and progenitor cells, notably neuroepithelial progenitors found in the developing embryonic brain. Here, we further investigated its expression in the murine brain.

The stem cell marker CD133 (Prominin-1) is expressed in various human glandular epithelia.

Human prominin-1 (CD133) is expressed by various stem and progenitor cells originating from diverse sources. In addition to stem cells, its mouse ortholog is expressed in a broad range of adult epithelial cells, where it is selectively concentrated in their apical domain. The lack of detection of prominin-1 in adult human epithelia might be explained, at least in part, by the specificity of the widely used AC133 antibody, which recognizes an epitope that seems dependent on glycosylation.

Robust expression of Prominin-2 all along the adult male reproductive system and urinary bladder.

Although the male reproductive system seems to be enriched in transcripts encoding for both Prominin genes, little is known about their spatial distribution in distinct segments of this organ system. This is especially true for the less-characterized second Prominin paralogue, Prominin-2. The present study, therefore, mainly examines the expression of Prominin-2 in male mice and reveals the existence of some crucial differences in the tissue compartmentalization of the two Prominin paralogues in the testis, epididymis, seminal vesicle, prostate and urinary bladder.

New insights into the cell biology of hematopoietic progenitors by studying prominin-1 (CD133).

Prominin-1 (alias CD133) has received considerable interest because of its expression by several stem and progenitor cells originating from various sources, including the neural and hematopoietic systems. As a cell surface marker, prominin-1 is now used for somatic stem cell isolation. Its expression in cancer stem cells has broadened its clinical value, as it might be useful to outline new prospects for more effective cancer therapies by targeting tumor-initiating cells.

The stem cell marker prominin-1/CD133 on membrane particles in human cerebrospinal fluid offers novel approaches for studying central nervous system disease.

Cerebrospinal fluid (CSF) is routinely used for diagnosing and monitoring neurological diseases. The CSF proteins used so far for diagnostic purposes (except for those associated with whole cells) are soluble. Here, we show that human CSF contains specific membrane particles that carry prominin-1/CD133, a neural stem cell marker implicated in brain tumors, notably glioblastoma.

Differential expression of Prominin-1 (CD133) and Prominin-2 in major cephalic exocrine glands of adult mice.

The major cephalic exocrine glands share many morphological and functional features and so can be simultaneously affected in certain autoimmune- and inherited disorders leading to glandular hypofunction. Phenotypic characterization of these exocrine glands is not only an interesting biological issue, but might also be of considerable clinical relevance. The major salivary and lacrimal glands might therefore be potential subjects of future cell-based regenerative/tissue engineering therapeutic approaches.

Isthmus-to-midbrain transformation in the absence of midbrain-hindbrain organizer activity.

In zebrafish acerebellar (ace) embryos, because of a point mutation in fgf8, the isthmic constriction containing the midbrain-hindbrain boundary (MHB) organizer fails to form. The mutants lack cerebellar development by morphological criteria, and they appear to have an enlarged tectum, showing no obvious reduction in the tissue mass at the dorsal mesencephalic/metencephalic alar plate. To reveal the molecular identity of the tissues located at equivalent rostrocaudal positions along the neuraxis as the isthmic and cerebellar primordia in wild-types, we undertook a detailed analysis of ace embryos.