The intermediate filament protein nestin occurs transiently in differentiating testis of rat and mouse

Nestin is a marker of unipotent embryonic and adult progenitors differentiating into an epithelial cell lineage of the hair follicles

Nestin is an intermediate filament protein transiently expressed in neural stem/progenitor cells. We previously demonstrated that outer root sheath (ORS) keratinocytes of adult hair follicles (HFs) in mice descend from nestin-expressing cells, despite being an epithelial cell lineage. This study determined the exact stage when nestin-expressing ORS stem/precursor cells or their descendants appear during HF morphogenesis, and whether they are present in adult HFs. Using Nes-Cre/CAG-CAT-EGFP mice, in which enhanced green fluorescent protein (EGFP) is expressed following Cre-based recombination driven by the nestin promoter, we found that EGFP⁺ cells appeared in the epithelial layer of embryonic HFs as early as the peg stage. EGFP⁺ cells in hair pegs were positive for keratin 14 (K14) and K5, but not vimentin, SOX2, SOX10, or S100 alpha 6. Tracing of tamoxifen-induced EGFP⁺ cells in postnatal Nes-CreERT2/CAG-CAT-EGFP mice revealed labeling of some isthmus HF epithelial cells in the first anagen stage. EGFP⁺ cells in adult HFs were not immunolabeled for K15, an HF multipotent stem cell marker. However, when hairs were depilated in Nes-CreERT2/CAG-CAT-EGFP mice to induce the anagen stage after tamoxifen injection, the majority of ORS keratinocytes in depilation-induced anagen HFs were labeled for EGFP. Our findings indicate that nestin-expressing unipotent progenitor cells capable of differentiating into ORS keratinocytes are present in HF primordia and adult HFs.

Human Primary Odontoblast-like Cell Cultures—A Focused Review Regarding Cell Characterization

Cell cultures can provide useful in vitro models. Since odontoblasts are postmitotic cells, they cannot be expanded in cell cultures. Due to their extension into the dentin, injuries are inevitable during isolation. Therefore, “odontoblast-like” cell culture models have been established. Nowadays, there is no accepted definition of odontoblast-like cell cultures, i.e., isolation, induction, and characterization of cells are not standardized. Furthermore, no quality-control procedures are defined yet. Thus, the aim of this review was to evaluate both the methods used for establishment of cell cultures and the validity of molecular methods used for their characterization. An electronic search was performed in February 2022 using the Medline, Scopus, and Web of Science database identifying publications that used human primary odontoblast-like cell cultures as models and were published between 2016 and 2022. Data related to (I) cell culture conditions, (II) stem cell screening, (III) induction media, (IV) mineralization, and (V) cell characterization were analyzed. The included publications were not able to confirm an odontoblast-like nature of their cell cultures. For their characterization, not only a similarity to dentin but also a distinction from bone must be demonstrated. This is challenging, due to the developmental and evolutionary proximity of these two tissue types.

Visual Defects and Ageing

Many diseases are related to age, among these neurodegeneration is particularly important. Alzheimer's disease Parkinson's and Glaucoma have many common pathogenic events including oxidative damage, Mitochondrial dysfunction, endothelial alterations and changes in the visual field. These are well known in the case of glaucoma, less in the case of neurodegeneration of the brain. Many other molecular aspects are common, such as the role of endoplasmic reticulum autophagy and neuronal apoptosis while others have been neglected due to lack of space such as inflammatory cytokine or miRNA. Moreover, the loss of specific neuronal populations, the induction of similar mechanisms of cell injury and the deposition of protein aggregates in specific anatomical areas are very similar events between these diseases. Intracellular and/or extracellular accumulation of protein aggregates is a key feature of many neurodegenerative disorders. The existence of abnormal protein aggregates has been documented in the RGCs of glaucomatous patients such as the anomalous Tau protein or the β-amyloid accumulations. Intra-cell catabolic processes also appear to be common in both glaucoma and neurodegeneration. They also help us to understand how the basis between these diseases is common and how the visual aspects can be a serious problem for those who are affected.

Implications of nestin in breast cancer pathogenesis (Review)

The aim of the present review was to summarize the current knowledge of the involvement of nestin in breast cancer (BC) pathogenesis. Nestin is a member of the class VI family of intermediate filament proteins, originally identified as a marker of neural stem cells and subsequently demonstrated to be expressed in BC and other cancer types. In normal breast tissue, nestin is expressed in the basal/myoepithelial cells of the mammary gland. In BC, nestin identifies basal-like tumours and predicts aggressive behaviour and poor prognosis. Nestin expression has also been detected in BC stem cells and newly-formed tumour vessels, being a factor in promoting invasion and metastasis. The present review provides an up-to-date overview of the involvement of nestin in processes facilitating BC pathogenesis and progression.

Hepatic stellate cells derived from the nestin-positive cells in septum transversum during rat liver development

Hepatic stellate cells (HSCs) play a principal role in Vitamin A metabolism and are considered the major matrix-producing cell type in the diseased liver. Rat HSCs are identified by immunohistochemistry with myogenic or mesenchymal (desmin, vimentin, and alpha-smooth muscle actin) or neural (e.g., GFAP or neuronal cell adhesion molecule) markers. Embryonic origin of rat HSCs was determined using these markers. Nestin, an intermediate filament protein originally identified in neuronal stem or progenitor cells, is widely used as a stem cell marker, including hepatic stem cells in adult rat livers. Additionally, nestin is reportedly expressed in activated HSCs during liver injury and hepatic regeneration. However, little is known about nestin expression in rat fetal liver HSCs. The present study aimed to clarify nestin-positive HSC expression during rat liver development. At embryonic day (ED) 10.5, nestin expression in mesenchymal cells adjacent to the liver bud was detected by immunohistochemistry. At ED 11.5, nestin-positive cells were also detected in desmin-positive cells appearing and increasing in intensity by ED 16.5. However, nestin-positive cells in the parenchyma decreased by ED 20.5 or later. These findings reveal that the nestin-positive HSCs during rat liver development originate from nestin-positive mesenchymal cells in the septum transversum.

Nestin-positive microvessel density is an independent prognostic factor in breast cancer

The process of angiogenesis based on new vessel formation within the tumour area plays a significant role in the progression of breast cancer. Nestin is an intermediate filament protein and participates in the cytoskeleton organization. Nestin expression in the endothelium of blood vessels is mainly limited to newly forming vessels, thus being a more specific marker of angiogenesis than the commonly used vascular antigens. The aim of this study was to determine the prognostic value of nestin-positive microvessel density (Nes+MVD) in breast cancer patients and to confirm that nestin expression is related to newly forming tumour vessels. In this study, 137 cases of ductal breast carcinoma and 19 cases of non-malignant breast tissue lesions (NBTLs) were examined. Immunohistochemical reactions were performed on paraffin sections using antibodies against nestin, CD34 and CD31 antigens. For each marker, the microvessel density (MVD) was determined. Nestin expression was also examined in human endothelial cell lines (HUVEC-SVT, HMEC-1 and HEPC-CB.1) representing a different level of endothelial cell maturity. HUVEC-SVT and HMEC-1 cells represent the endothelium of mature vessels, whereas HEPC-CB.1 cells represent the early endothelial progenitor cells (EPCs). We have demonstrated that high Nes+MVD may be associated with a more aggressive course of the disease and a poorer prognosis. We have also found a higher Nes+MVD in the cases with lymph node metastases, with higher histological grade, with advanced-stage disease and with the triple-negative (TN) breast cancer. In addition, nestin expression in vessels was associated with a shorter overall survival (OS) and earlier relapse, and in the case of OS nestin was an independent prognostic factor. Finally, we further confirmed that nestin expression in endothelial cells reflects a progenitor nature of newly forming vessels.

Expression of Epithelial and Mesenchymal Differentiation Markers in the Early Human Gonadal Development

Expressions of cytokeratin 8 (CK8), vimentin, nestin, and alpha-smooth-muscle-actin (alpha-SMA) were analyzed in the developing gonads of 12, 5-9 week old (W) human conceptuses by immunohistochemistry and immunofluorescence. During the investigated period, the number of CK8 positive cells increased from 56% to 92% in the gonadal surface epithelium, from 50% to 60% in the stroma, and from 23% to 42% in the medulla. In the early fetal period, the cell expression of CK8 increased in all gonadal parts, whereas primordial germ cells (PGC) remained negative. The expression of vimentin increased in the gonad stroma (gs) from 73% to 88%, and in the surface epithelium from 18% to 97% until ninth W. The medulla had the highest expression of vimentin in the seventh to eighth W (93%). Vimentin and CK8 colocalized in the somatic cells, while some PGCs showed vimentin expression only. Initially, nestin was positive in the gonad surface epithelium (8%) and stroma (52%), however during further development it decreased to 1% and 33%, respectively. In the early fetal period, the nestin positive cells decreased from 44% to 31% in the gonad medulla. Alpha-SMA was positive only in the blood vessels and mesonephros. The described pattern of expression of intermediate filaments (IF) in developing human gonads suggests their role in the control of PGC apoptosis, early differentiation of gs cells and cell migration. Both epithelial and mesenchymal origins of follicular cells and possible epithelial-to-mesenchymal transition of somatic cells is proposed. Lastly, IF intensity expression varies depending on the cell type and developmental period analyzed. Anat Rec, 300:1315-1326, 2017. © 2017 Wiley Periodicals, Inc.

Phenotype and distribution pattern of nestin-GFP-expressing cells in murine myenteric plexus

The enteric nervous system has to adapt to altering dietary or environmental conditions and presents an enormous plasticity that is conserved over the whole lifespan. It harbours neural-crest-derived neurons, glial cells and their precursors. Based on a nestin-green fluorescent protein (NGFP) transgenic model, a histological inventory has been performed to deliver an overview of neuronal and glial markers for the various parts of the gastrointestinal tract in newborn (postnatal day 7) and adult mice under homeostatic conditions. Whereas NGFP-positive glial cells can be found in all parts of the gut at any individual age, a specific NGFP population is present with both neuronal morphology and marker expression in the myenteric plexus (nNGFP). These cells appear in variable quantities, depending on age and location. Their overall abundance decreases from newborn to adults and their spatial distribution is also age-dependent. In newborn gut, nNGFP cells are found in similar quantities throughout the gut, with a significantly lower presence in the duodenum. Their expression increases in the adult mouse from the stomach to the colon. All of these nNGFP cells expressed either (but not both) of the glia markers S100 or glial fibrillary acidic protein (GFAP). In the S100-positive glia population, a subset of cells also shows a neuronal morphology (nS100), without expressing nestin. Thus, the presence of premature neurons that express NGFP demonstrates that neurogenesis takes place far beyond birth. In enteric neurons, NGFP acts as a marker for neuronal plasticity showing the differentiation and change in the phenotype of neuronal precursor cells.

Cancer stem cells and epithelial-mesenchymal transition: Novel therapeutic targets for cancer

Despite the development of various therapeutic approaches, recurrence and metastasis remain major problems for patients with advanced cancer. Recent studies have shown that cancer stem cells (CSCs) play an important role in cancer aggressiveness. In cancer tissues, a small number of CSCs are able to self-renew and differentiate into heterogeneous cancer cells. CSCs usually remain in the resting phase of the cell cycle and possess efficient drug efflux pathways. Thus, they are resistant to chemoradiotherapy and surviving CSCs contribute to recurrence. During cancer metastasis, CSCs undergo epithelial-mesenchymal transition (EMT), thereby acquiring mesenchymal features, migrating to adjacent stromal tissues, and invading blood or lymph vessels. Recent studies showed that EMT-inducible factors also enhance or induce CSC-like features in cancer cells. These findings suggest that EMT is closely correlated with cancer recurrence and metastasis. Inhibition of nestin, a CSC marker, reduces the aggressiveness of several types of cancer. Suppression of the mesenchymal variant of fibroblast growth factor (FGFR)-2, FGFR-2 IIIc, and regulation of the EMT using epithelial splicing regulatory protein 1 (ESRP1) are effective in the treatment of immunodeficient mice with pancreatic cancer. The roles of CSCs and EMT in cancer and possible therapies are discussed in this review.

In utero exposure to di-(2-ethylhexyl) phthalate induces testicular effects in neonatal rats that are antagonized by genistein cotreatment

Fetal exposure to endocrine disruptors (EDs) is believed to predispose males to reproductive abnormalities. Although males are exposed to combinations of chemicals, few studies have evaluated the effects of ED mixtures at environmentally relevant doses. Our previous work showed that fetal exposure to a mixture of the phytoestrogen genistein (GEN) and the plasticizer di-(2-ethylhexyl) phthalate (DEHP) induced unique alterations in adult testis. In this follow-up study, we examined Postnatal Day 3 (PND3) and PND6 male offspring exposed from Gestational Day 14 to parturition to corn oil, 10mg/kg GEN, DEHP, or their combination, to gain insight into the early molecular events driving long-term alterations. DEHP stimulated the mRNA and protein expression of the steroidogenic enzyme HSD3B, uniquely at PND3. DEHP also increased the mRNA expression of Nestin, a Leydig progenitor/Sertoli cell marker, and markers of Sertoli cell (Wt1), gonocyte (Plzf, Foxo1), and proliferation (Pcna) at PND3, while these genes were unchanged by the mixture. Redox (Nqo1, Sod2, Sod3, Trx, Gst, Cat) and xenobiotic transporter (Abcb1b, Abcg2) gene expression was also increased by DEHP at PND3, while attenuated when combined with GEN, suggesting the involvement of cellular stress in short-term DEHP effects and a protective effect of GEN. The direct effects of GEN and mono-(2-ethylhexyl) phthalate, the principal bioactive metabolite of DEHP, on testis were investigated in PND3 organ cultures, showing a stimulatory effect of 10 μM mono-(2-ethylhexyl) phthalate on basal testosterone production that was normalized by GEN. These effects contrasted with previous reports of androgen suppression and decreased gene expression in perinatal rat testis by high DEHP doses, implying that neonatal effects are not predictive of adult effects. We propose that GEN, through an antioxidant action, normalizes reactive oxygen species-induced neonatal effects of DEHP. The notion that these EDs do not follow classical dose-response effects and involve different mechanisms of toxicity from perinatal ages to adulthood highlights the importance of assessing impacts across a range of doses and ages.

Type-1 pericytes accumulate after tissue injury and produce collagen in an organ-dependent manner

Introduction

Fibrosis, or scar formation, is a pathological condition characterized by excessive production and accumulation of collagen, loss of tissue architecture, and organ failure in response to uncontrolled wound healing. Several cellular populations have been implicated, including bone marrow-derived circulating fibrocytes, endothelial cells, resident fibroblasts, epithelial cells, and recently, perivascular cells called pericytes. We previously demonstrated pericyte functional heterogeneity in skeletal muscle. Whether pericyte subtypes are present in other tissues and whether a specific pericyte subset contributes to organ fibrosis are unknown.

Methods

Here, we report the presence of two pericyte subtypes, type-1 (Nestin-GFP-/NG2-DsRed+) and type-2 (Nestin-GFP+/NG2-DsRed+), surrounding blood vessels in lungs, kidneys, heart, spinal cord, and brain. Using Nestin-GFP/NG2-DsRed transgenic mice, we induced pulmonary, renal, cardiac, spinal cord, and cortical injuries to investigate the contributions of pericyte subtypes to fibrous tissue formation in vivo.

Results

A fraction of the lung’s collagen-producing cells corresponds to type-1 pericytes and kidney and heart pericytes do not produce collagen in pathological fibrosis. Note that type-1, but not type-2, pericytes increase and accumulate near the fibrotic tissue in all organs analyzed. Surprisingly, after CNS injury, type-1 pericytes differ from scar-forming PDGFRβ + cells.

Conclusions

Pericyte subpopulations respond differentially to tissue injury, and the production of collagen by type-1 pericytes is organ-dependent. Characterization of the mechanisms underlying scar formation generates cellular targets for future anti-fibrotic therapeutics.

Electronic supplementary material

The online version of this article (doi:10.1186/scrt512) contains supplementary material, which is available to authorized users.

Prognostic significance of neural stem cell markers, Nestin and Musashi-1, in oral squamous cell carcinoma: expression pattern of Nestin in the precancerous stages of oral squamous epithelium

BACKGROUND

Besides the tissue-specific stem cell markers, neural and hematopoietic stem cell markers were found to play an important role in carcinogenesis. Based on this background, we have investigated the expression pattern and prognostic significance of neural stem cell markers, Nestin and Musashi-1, in oral cancer.

METHODS

We used immunohistochemistry and immunofluorescence analyses to study the expression pattern and correlation between Nestin and Musashi-1 in oral squamous cell carcinoma. The Kaplan-Meier method was used to construct overall and disease-free survival curves, and the differences were calculated using log-rank test.

RESULTS

Nestin expression was gradually increased in the transformation stages of oral cancer. Both Nestin and Musashi-1 expressions were associated with higher stage and poorly differentiated status of oral carcinoma. Interestingly, Nestin and Musashi-1 double positive cases showed statistically highly significant correlation with poorer survival of oral carcinoma patients.

CONCLUSIONS

Expression of Nestin in the preneoplastic lesions indicates its role in the transformation of oral squamous epithelium. Clinicopathological and survival analyses suggest that Nestin and Musashi-1 might be associated with invasion, differentiation and poorer survival in oral squamous cell carcinoma. In addition to their role as independent prognostic indicators, Nestin and Musashi-1 double positivity can be used to select high-risk cases for effective therapy and this is the novel finding of this study.

CLINICAL RELEVANCE

Nestin and Musashi-1 are found to be independent prognostic markers of oral cancer, and they might be used as molecular targets for effective therapy.

Depletion of intermediate filament protein Nestin, a target of microRNA-940, suppresses tumorigenesis by inducing spontaneous DNA damage accumulation in human nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a major malignant tumor of the head and neck region in southern China. The understanding of its underlying etiology is essential for the development of novel effective therapies. We report for the first time that microRNA-940 (miR-940) significantly suppresses the proliferation of a variety of cancer cell lines, arrests cells cycle, induces caspase-3/7-dependent apoptosis and inhibits the formation of NPC xenograft tumors in mice. We further show that miR-940 directly binds to the 3′-untranslated regions of Nestin mRNA and promotes its degradation. Likewise, depletion of Nestin inhibits tumor cell proliferation, arrest cells at G2/M, induces apoptosis and suppresses xenograft tumor formation in vivo. These functions of miR-940 can be reversed by ectopic expression of Nestin, suggesting that miR-940 regulates cell proliferation and survival through Nestin. Notably, we observed reduced miR-940 and increased Nestin levels in NPC patient samples. Protein microarray revealed that knockdown of Nestin in 5-8F NPC cells alters the phosphorylation of proteins involved in the DNA damage response, suggesting a mechanism for the miR-940/Nestin axis. Consistently, depletion of Nestin induced spontaneous DNA damage accumulation, delayed the DNA damage repair process and increased the sensitivity to irradiation and the chemotherapeutic agent doxorubicin. Collectively, our findings indicate that Nestin, which is downregulated by miR-940, can promote tumorigenesis in NPC cells through involvement in the DNA damage response. The levels of microRNA-940 and Nestin may serve as indicators of cancer status and prognosis.

Muscle glycogen synthase isoform is responsible for testicular glycogen synthesis: glycogen overproduction induces apoptosis in male germ cells

Glycogen is the main source of glucose for many biological events. However, this molecule may have other functions, including those that have deleterious effects on cells. The rate-limiting enzyme in glycogen synthesis is glycogen synthase (GS). It is encoded by two genes, GYS1, expressed in muscle (muscle glycogen synthase, MGS) and other tissues, and GYS2, primarily expressed in liver (liver glycogen synthase, LGS). Expression of GS and its activity have been widely studied in many tissues. To date, it is not clear which GS isoform is responsible for glycogen synthesis and the role of glycogen in testis. Using RT-PCR, Western blot and immunofluorescence, we have detected expression of MGS but not LGS in mice testis during development. We have also evaluated GS activity and glycogen storage at different days after birth and we show that both GS activity and levels of glycogen are higher during the first days of development. Using RT-PCR, we have also shown that malin and laforin are expressed in testis, key enzymes for regulation of GS activity. These proteins form an active complex that regulates MGS by poly-ubiquitination in both Sertoli cell and male germ cell lines. In addition, PTG overexpression in male germ cell line triggered apoptosis by caspase3 activation, proposing a proapoptotic role of glycogen in testis. These findings suggest that GS activity and glycogen synthesis in testis could be regulated and a disruption of this process may be responsible for the apoptosis and degeneration of seminiferous tubules and possible cause of infertility.

Skeletal muscle neural progenitor cells exhibit properties of NG2-glia

Reversing brain degeneration and trauma lesions will depend on cell therapy. Our previous work identified neural precursor cells derived from the skeletal muscle of Nestin-GFP transgenic mice, but their identity, origin, and potential survival in the brain are only vaguely understood. In this work, we show that Nestin-GFP+ progenitor cells share morphological and molecular markers with NG2-glia, including NG2, PDGFRα, O4, NGF receptor (p75), glutamate receptor-1(AMPA), and A2B5 expression. Although these cells exhibit NG2, they do not express other pericyte markers, such as α-SMA or connexin-43, and do not differentiate into the muscle lineage. Patch-clamp studies displayed outward potassium currents, probably carried through Kir6.1 channels. Given their potential therapeutic application, we compared their abundance in tissues and concluded that skeletal muscle is the richest source of predifferentiated neural precursor cells. We found that these cells migrate toward the neurogenic subventricular zone displaying their typical morphology and nestin-GFP expression two weeks after brain injection. For translational purposes, we sought to identify these neural progenitor cells in wild-type species by developing a DsRed expression vector under Nestin-Intron II control. This approach revealed them in nonhuman primates and aging rodents throughout the lifespan.

Nestin protein is phosphorylated in adult neural stem/progenitor cells and not endothelial progenitor cells

An intermediate filament protein, Nestin, is known as a neural stem/progenitor cell marker. It was shown to be required for the survival and self-renewal of neural stem cells according to the phenotypes of Nestin knockout mice. Nestin expression has also been reported in vascular endothelial cells, and we recently reported Nestin expression in proliferating endothelial progenitor cells, but not in mature endothelial cells. Using quantitative phosphoproteome analysis, we studied differences in phosphorylation levels between CNS Nestin in adult neural stem cells and vascular Nestin in adult bone-marrow-derived endothelial progenitor cells. We detected 495 phosphopeptides in the cell lysates of adult CNS stem/progenitor cells and identified 11 significant phosphorylated amino acid residues in the Nestin protein. In contrast, endothelial progenitor cells showed no significant phosphorylation of Nestin. We also measured neoplastic endothelial cells of the mouse brain and identified 13 phosphorylated amino acid residues in the Nestin protein. Among the 11 phosphorylated amino acids of adult CNS Nestin, five (S565, S570, S819, S883, and S886) were CNS Nestin-specific phosphorylation sites. Detection of the CNS-specific phosphorylation sites in Nestin, for example, by a phospho-specific Nestin antibody, may allow the expression of CNS Nestin to be distinguished from vascular Nestin.

Nestin and other putative cancer stem cell markers in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a high incidence of distant metastasis. Recent studies have shown that cancer stem cells (CSCs), which have the potential to self-renew and are pluripotent, are crucially important in cancer cell growth, invasion, metastasis, and recurrence. Recently, several CSC-specific markers for pancreatic cancer have been reported, including CD133, CD24, CD44, CXCR4, EpCAM, ABCG2, c-Met, ALDH-1, and nestin, but their use is controversial. Nestin is one of the class VI intermediate filament proteins and a marker of exocrine progenitors of normal pancreatic tissue. Activated mutations of K-ras in nestin-positive progenitors of pancreatic tissue have been reported to induce cell growth in vitro and induce the formation of precancerous pancreatic lesions. We have reported that downregulation of nestin in PDAC cells inhibits liver metastasis in vivo. Nestin may modulate the invasion and metastasis of nestin-positive progenitor cells during PDAC development and may serve as a novel target for suppressing invasion and metastasis in PDAC. In this review, we summarize what is known about the correlation between PDAC and CSC markers, including nestin.

Expression and role of nestin in human cervical intraepithelial neoplasia and cervical cancer

Nestin expression reportedly correlates with aggressive growth, metastasis, poor prognosis and presence of cancer stem cells (CSCs) in various tumors. In this study, we determined the expression and role of nestin in cervical intraepithelial neoplasia (CIN) and cervical cancer. We performed immunohistochemical and in situ hybridization analyses of nestin in 26 cases for each stage of CIN and 55 cervical cancer tissue samples. To examine the role of nestin in cervical cancer cells, we stably transfected expression vectors containing nestin cDNA into ME-180 cells. We studied the effects of increased nestin expression on cell proliferation, cell motility, invasion as well as sphere and soft agar formation. Nestin was not localized in the squamous epithelium in normal cervical tissues, but it was weakly expressed in the basal squamous epithelium of CIN 1. In CIN 2, nestin was localized to the basal to lower 2/3 of the squamous epithelium, whereas in CIN 3, it was localized to the majority of the squamous epithelium. Nestin was detected in all cases of invasive cervical cancer. Nestin mRNA was expressed in both ME-180 and CaSki cells. Growth rate, cell motility and invasion ability of stably nestin-transfected ME-180 cells were not different from empty vector-transfected ME-180 (mock cells). However, the nestin-transfected ME-180 cells formed more colonies and spheres compared to the mock cells. These findings suggest that nestin plays important roles in carcinogenesis and tumor formation of cervical cancer cells. Nestin may closely correlate with regulation of CSCs.

Aorta-derived mesoangioblasts differentiate into the oligodendrocytes by inhibition of the Rho kinase signaling pathway

Mesoangioblasts are vessel-derived stem cells that differentiate into mesodermal derivatives. We have isolated postnatal aorta-derived mesoangioblasts (ADMs) that differentiate into smooth, skeletal, and cardiac muscle, and adipocytes, and regenerate damaged skeletal muscle in a murine model for Duchenne muscular dystrophy. We report that the marker profile of ADM is similar to that of mesoangioblasts isolated from embryonic dorsal aorta, postnatal bone marrow, and heart, but distinct from mesoangioblasts derived from skeletal muscle. We also demonstrate that ADM differentiate into myelinating glial cells. ADM localize to peripheral nerve bundles in regenerating muscles and exhibit morphology and marker expression of mature Schwann cells, and myelinate axons. In vitro, ADM spontaneously express markers of oligodendrocyte progenitors, including the chondroitin sulphate proteoglycan NG2, nestin, platelet-derived growth factor (PDGF) receptor α, the A2B5 antigen, thyroid hormone nuclear receptor α, and O4. Pharmacological inhibition of Rho kinase (ROCK) initiated process extension by ADM, and when combined with insulin-like growth factor 1, PDGF, and thyroid hormone, enhanced ADM expression of oligodendrocyte precursor markers and maturation into the oligodendrocyte lineage. ADM injected into the right lateral ventricle of the brain migrate to the corpus callosum, and cerebellar white matter, where they express components of myelin. Because ADM differentiate or mature into cell types of both mesodermal and ectodermal origin, they may be useful for treatment of a variety of degenerative diseases, or repair and regeneration of multiple cell types in severely damaged tissue.

Increased expression of nestin in the major pelvic ganglion following cavernous nerve injury

In an effort to identify neuronal repair mechanisms of the major pelvic ganglion (MPG), we evaluated changes in the expression of nestin, an intermediate filament protein and neural stem cell marker following cavernous nerve crush injury (CNI). We utilized two groups of Sprague Dawley rats: (i) sham and (ii) bilateral CNI. Erectile responses to cavernous nerve stimulation (CNS) were determined at 48 h in a subset of rats. The MPG was isolated and removed at 48 h after CNI, and nestin immunolocalization, protein levels and RNA expression were evaluated. At 48 h, erectile responses to CNS in CNI rats were substantially reduced (P<0.05; ∼70% decrease in intracavernous pressure/mean arterial pressure) compared with sham surgery controls. This coincided with a dramatic 10-fold increase (P<0.05) in nestin messenger RNA expression and protein levels in the MPG of rats with CNI. Immunoflourescence microscopy demonstrated that nestin upregulation after CNI occurred within the ganglion cell bodies and nerve fibers of the MPG. In conclusion, CNI induces nestin in the MPG. These data suggest that nestin may be involved in the regenerative process of the cavernous nerve following crush injury.

Nestin is not essential for development of the CNS but required for dispersion of acetylcholine receptor clusters at the area of neuromuscular junctions

Nestin is expressed in many different progenitors during development including those of the CNS, heart, skeletal muscle, and kidney. The adult expression is mainly restricted to the subependymal zone and dentate gyrus of the brain, the neuromuscular junction, and renal podocytes. In addition, this intermediate filament protein has served as a marker of neural stem/progenitor cells for close to 20 years. Therefore it is surprising that its function in development and adult physiology is still poorly understood. Here we report that nestin deficiency is compatible with normal development of the CNS. The mutant mice, however, show impaired motor coordination. Furthermore, we found that the number of acetylcholine receptor clusters, the nerve length, and the endplate bandwidth are significantly increased in neuromuscular junction area of nestin-deficient mice. This is similar to the phenotype described for deficiency of cyclin-dependent kinase 5 (Cdk5), a candidate downstream affecter of nestin. Moreover, we demonstrate that nestin deficiency can rescue maintenance of acetylcholine receptor clusters in the absence of agrin, similar to Cdk5/agrin double knock-outs, suggesting that the observed nestin deficiency phenotype is the consequence of aberrant Cdk5 activity.

Nestin is a novel target for suppressing pancreatic cancer cell migration, invasion and metastasis

Nestin, is a class VI intermediate filament (IF) that is expressed in 30% of pancreatic ductal adenocarcinoma (PDAC) cases, and its expression in PDAC positively correlates with peripancreatic invasion. An expression vector carrying a short hairpin RNA (shRNA) targeting nestin was stably transfected into PANC-1 and PK-45H human pancreatic cancer cells, which express high nestin levels. Alterations in morphology and alignment of actin filaments and α-tubulin were examined by phase-contrast and immunocytochemistry. Effects on cell growth, migration in scratch and Boyden chamber assays, invasion, cell adhesion, and in vivo growth were determined. Differences in mRNA levels were examined by arrays. Nestin shRNA-transfected cells exhibited decreased nestin expression, a sheet-like appearance with tight cell-cell adhesion, increased expression of filamentous F-actin and E-cadherin, and attenuated migration and invasion, both of which were enhanced following nestin re-expression. Expression of α-tubulin, and in vitro cell growth and adhesion were not altered by nestin down-regulation, whereas hepatic metastases were decreased. Thus, nestin plays important roles in pancreatic cancer cell migration, invasion and metastasis by selectively modulating the expression of actin and cell adhesion molecules, and may therefore be a novel therapeutic target in PDAC.

Nestin in gastrointestinal and other cancers: Effects on cells and tumor angiogenesis

Nestin is a class VI intermediate filament protein that was originally described as a neuronal stem cell marker during central nervous system (CNS) development, and is currently widely used in that capacity. Nestin is also expressed in non-neuronal immature or progenitor cells in normal tissues. Under pathological conditions, nestin is expressed in repair processes in the CNS, muscle, liver, and infarcted myocardium. Furthermore, increased nestin expression has been reported in various tumor cells, including CNS tumors, gastrointestinal stromal tumors, pancreatic cancer, prostate cancer, breast cancer, malignant melanoma, dermatofibrosarcoma protuberances, and thyroid tumors. Nestin is reported to correlate with aggressive growth, metastasis, and poor prognosis in some tumors; however, the roles of nestin in cancer cells have not been well characterized. Furthermore, nestin is more specifically expressed in proliferating small-sized tumor vessels in glioblastoma and gastric, colorectal, and prostate cancers than are other tumor vessel markers. These findings indicate that nestin may be a marker for newly synthesized tumor vessels and a therapeutic target for tumor angiogenesis. It has received a lot of attention recently as a cancer stem cell marker in various cancer cells including brain tumors, malignant rhabdoid tumors, and uterine, cervical, prostate, bladder, head and neck, ovarian, testicular, and pancreatic cancers. The purpose of this review is to clarify the roles of nestin in cancer cells and in tumor angiogenesis, and to examine the association between nestin and cancer stem cells. Nestin has the potential to serve as a molecular target for cancers with nestin-positive cancer cells and nestin-positive tumor vasculature.

Adult human CD133/1(+) kidney cells isolated from papilla integrate into developing kidney tubules

Approximately 60,000 patients in the United States are waiting for a kidney transplant due to genetic, immunologic and environmentally caused kidney failure. Adult human renal stem cells could offer opportunities for autologous transplant and repair of damaged organs. Current data suggest that there are multiple progenitor types in the kidney with distinct localizations. In the present study, we characterize cells derived from human kidney papilla and show their capacity for tubulogenesis. In situ, nestin(+) and CD133/1(+) cells were found extensively intercalated between tubular epithelia in the loops of Henle of renal papilla, but not of the cortex. Populations of primary cells from the renal cortex and renal papilla were isolated by enzymatic digestion from human kidneys unsuited for transplant and immuno-enriched for CD133/1(+) cells. Isolated CD133/1(+) papillary cells were positive for nestin, as well as several human embryonic stem cell markers (SSEA4, Nanog, SOX2, and OCT4/POU5F1) and could be triggered to adopt tubular epithelial and neuronal-like phenotypes. Isolated papillary cells exhibited morphologic plasticity upon modulation of culture conditions and inhibition of asymmetric cell division. Labeled papillary cells readily associated with cortical tubular epithelia in co-culture and 3-dimensional collagen gel cultures. Heterologous organ culture demonstrated that CD133/1(+) progenitors from the papilla and cortex became integrated into developing kidney tubules. Tubular epithelia did not participate in tubulogenesis. Human renal papilla harbor cells with the hallmarks of adult kidney stem/progenitor cells that can be amplified and phenotypically modulated in culture while retaining the capacity to form new kidney tubules. This article is part of a Special Issue entitled: Polycystic Kidney Disease.

The neural stem/progenitor cell marker nestin is expressed in proliferative endothelial cells, but not in mature vasculature

Nestin is an intermediate filament protein that is known as a neural stem/progenitor cell marker. It is expressed in undifferentiated central nervous system (CNS) cells during development, but also in normal adult CNS and in CNS tumor cells. Additionally, nestin is expressed in endothelial cells (ECs) of CNS tumor tissues and of adult tissues that replenish by angiogenesis. However, the regulation of nestin expression in vascular endothelium has not been analyzed in detail. This study showed that nestin expression was observed in proliferating endothelial progenitor cells (EPCs), but not in mature ECs. In adherent cultured cells derived from bone marrow cells, EPCs that highly expressed nestin also expressed the endothelial marker CD31 and the proliferation marker Ki67. ECs cultured without growth factors showed attenuated nestin immunoreactivity as they matured. Transgenic mice that carried the enhanced green fluorescent protein under the control of the CNS-specific second intronic enhancer of the nestin gene showed no reporter gene expression in EPCs. This indicated that the mechanisms of nestin gene expression were different in EPCs and CNS cells. Immunohistochemistry showed nestin expression in neovascular cells from two distinct murine models. Our results demonstrate that nestin can be used as a marker protein for neovascularization.

The Sertoli cell cytoskeleton

The cytoskeleton of terminally differentiated mammalian Sertoli cells is one of the most elaborate of those that have been described for cells in tissues. Actin filaments, intermediate filaments and microtubules have distinct patterns of distribution that change during the cyclic process of spermatogenesis. Each of the three major cytoskeletal elements is either concentrated at or related in part to intercellular junctions. Actin filaments are concentrated in unique structures termed ectoplasmic specializations that function in intercellular adhesion, and at tubulobulbar complexes that are thought to be involved with junction internalization during sperm release and movement of spermatocytes through basal junctions between neighboring Sertoi cells. Intermediate filaments occur in a perinuclear network which has peripheral extensions to desmosome-like junctions with adjacent cells and to small hemidesmosome-like attachments to the basal lamina. Unlike in most other epithelia where the intermediate filaments are of the keratin type, intermediate filaments in mature Sertoli cells are of the vimentin type. The function of intermediate filaments in Sertoli cells in not entirely clear; however, the pattern of filament distribution and the limited experimental data available are consistent with a role in maintaining tissue integrity when the epithelium is mechanically stressed. Microtubules are abundant in Sertoli cells and are predominantly oriented parallel to the long axis of the cell. Microtubules are involved with maintaining the columnar shape of Sertoli cells, with transporting and positioning organelles in the cytoplasm, and with secreting seminiferous tubule fluid. In addition, microtubule-based transport machinery is coupled to intercellular junctions to translocate and position adjacent spermatids in the epithelium. Although the cytoskeleton of Sertoli cells has structural and functional properties common to cells generally, there are a number of properties that are unique and that appear related to processes fundamental to spermatogenesis and to interfacing somatic cells both with similar neighboring somatic cells and with differentiating cells of the germ cell line.

In utero exposure to di-(2-ethylhexyl) phthalate decreases mineralocorticoid receptor expression in the adult testis

In utero exposure to di-(2-ethylhexyl) phthalate (DEHP) has been shown to result in decreased androgen formation by fetal and adult rat testes. In the fetus, decreased androgen is accompanied by the reduced expression of steroidogenic enzymes. The mechanism by which in utero exposure results in reduced androgen formation in the adult, however, is unknown. We hypothesized that deregulation of the nuclear steroid receptors might explain the effects of in utero DEHP exposure on adult testosterone production. To test this hypothesis, pregnant Sprague Dawley dams were gavaged with 100-950 mg DEHP per kilogram per day from gestational d 14-19, and testes were collected at gestational d 20 and postnatal days (PND) 3, 21, and 60. Among the nuclear receptors studied, the mineralocorticoid receptor (MR) mRNA and protein levels were reduced in PND60 interstitial Leydig cells, accompanied by reduced mRNA expression of MR-regulated genes. Methylation-sensitive PCR showed effects on the nuclear receptor subfamilies NR3A and -3C, but only MR was affected at PND60. Pyrosequencing of two CpG islands within the MR gene promoter revealed a loss of methylation in DEHP-treated animals that was correlated with reduced MR. Because MR activation is known to stimulate Leydig cell testosterone formation, and MR inhibition to be repressive, our results are consistent with the hypothesis that in utero exposure to DEHP leads to MR dysfunction and thus to depressed testosterone production in the adult. We suggest that decreased MR, possibly epigenetically mediated, is a novel mechanism by which phthalates may affect diverse functions later in life.

Epigenetic hierarchy governing Nestin expression

Nestin is an intermediate filament protein expressed specifically in neural stem cells and progenitor cells of the central nervous system. DNA demethylation and histone modifications are two types of epigenetic modifications working in a coordinate or synergistic manner to regulate the expression of various genes. This study investigated and elucidated the epigenetic regulation of Nestin gene expression during embryonic differentiation along the neural cell lineage. Nestin exhibits differential DNA methylation and histone acetylation patterns in Nestin-expressing and nonexpressing cells. In P19 embryonic carcinoma cells, activation of Nestin expression is mediated by both trichostatin A and 5-aza-2'-deoxycytidine treatment, concomitant with histone acetylation, but not with DNA demethylation. Nestin transcription is also mediated by treatment with retinoic acid, again in the absence of DNA demethylation. Thus, histone acetylation is sufficient to mediate the activation of Nestin transcription. This study proposed that the regulation of Nestin gene expression can be used as a model to study the epigenetic regulation of gene expression mediated by histone acetylation, but not by DNA demethylation.

Nestin modulates glucocorticoid receptor function by cytoplasmic anchoring

Nestin is the characteristic intermediate filament (IF) protein of rapidly proliferating progenitor cells and regenerating tissue. Nestin copolymerizes with class III IF-proteins, mostly vimentin, into heteromeric filaments. Its expression is downregulated with differentiation. Here we show that a strong nestin expression in mouse embryo tissue coincides with a strong accumulation of the glucocorticoid receptor (GR), a key regulator of growth and differentiation in embryonic development. Microscopic studies on cultured cells show an association of GR with IFs composed of vimentin and nestin. Cells lacking nestin, but expressing vimentin, or cells expressing vimentin, but lacking nestin accumulate GR in the nucleus. Completing these networks with an exogenous nestin, respectively an exogenous vimentin restores cytoplasmic anchoring of GR to the IF system. Thus, heteromeric filaments provide the basis for anchoring of GR. The reaction pattern with phospho-GR specific antibodies and the presence of the chaperone HSC70 suggest that specifically the unliganded receptor is anchored to the IF system. Ligand addition releases GR from IFs and shifts the receptor into the nucleus. Suppression of nestin by specific shRNA abolishes anchoring of GR, induces its accumulation in the nucleus and provokes an irreversible G1/S cell cycle arrest. Suppression of GR prior to that of nestin prevents entry into the arrest. The data give evidence that nestin/vimentin specific anchoring modulates growth suppression by GR. We hypothesize that expression of nestin is a major determinant in suppression of anti-proliferative activity of GR in undifferentiated tissue and facilitates activation of this growth control in a precise tissue and differentiation dependent manner.

Nestin expression correlates with nerve and retroperitoneal tissue invasion in pancreatic cancer

Nestin was first described as an intermediate filament protein expressed in neuroepithelial stem cells. Nestin expression has also been reported in brain tumors, schwannomas, gastrointestinal stromal tumors, and melanomas. In the pancreas, Nestin expression has been detected in exocrine and mesenchymal cells, including stellate cells, pericytes, and endothelial cells. In the present study, we examined Nestin expression in human pancreatic ductal adenocarcinoma and sought to determine its role in this malignancy. Reverse transcription-polymerase chain reaction analysis demonstrated the presence of Nestin mRNA in all 10 tested pancreatic cancer cell lines, and quantitative reverse transcription-polymerase chain reaction revealed that Nestin mRNA levels were highest in PANC-1 cells and lowest in PK-8 cells. Immunofluorescent analysis revealed that Nestin localized in the outer cytoplasm of PANC-1 cells. Nestin immunoreactivity was present in the cancer cells in 20 (33.3%) of 60 cancer cases, and its expression was confirmed by in situ hybridization. Nestin expression was also increased in peripheral nerve fibers adjacent to cancer cells and in peripheral nerve fibers invaded by cancer cells. Clinicopathologically, there was a statistically significant association between Nestin expression in pancreatic cancer cells and nerve invasion (P = .010) and the presence of cancer cells in the tumor resection margins (P = .003). Nestin-positive cases exhibited similar survival after resection by comparison with Nestin-negative cases, irrespective of whether they were given adjuvant therapy. These findings indicate that Nestin expression in pancreatic cancer cells may contribute to nerve and stromal invasion in this malignancy.

Nestin in central nervous system cells

This literature review reflects current knowledge on the intermediate filament protein nestin, which most authors regard as a marker of "neural stem/progenitor cells." The structural-functional characteristics of nestin and its presence in various central nervous system cells at different stages of ontogenesis in normal and pathological conditions are discussed.

Sertoli cell development and function in an animal model of testicular dysgenesis syndrome

Pregnancy exposure to di(n-butyl) phthalate (DBP) in rats induces a testicular dysgenesislike syndrome (TDS) in male offspring. Earlier studies suggested altered Sertoli cell development/maturation may result, especially in testes that become cryptorchid. This study quantitatively assessed Sertoli cell numerical and functional development in DBP-exposed rats and compared (unilaterally) cryptorchid and scrotal testes. Pregnant rats were gavaged with 500 mg/kg/day DBP or corn oil from embryonic (E) Days 13.5 to 21.5. Male offspring were sampled on E21.5 or Postnatal Day 6, 10, 15, 25, or 90. Sertoli cell number in DBP-exposed males was reduced by approximately 50% at E21.5 but recovered to normal by Days 25-90, accompanied by significant changes in plasma inhibin B and testosterone levels. Sertoli cell maturational development in DBP-exposed males, assessed using five protein markers (anti-müllerian hormone, cytokeratin, androgen receptor, CDKN1B, and Nestin), was largely normal, with some evidence of delayed maturation. However, in adulthood, Sertoli cells (SC) in areas lacking germ cells (Sertoli cell-only [SCO] tubules) often exhibited immature features, especially in cryptorchid testes. Sertoli cells in DBP-exposed animals supported fewer germ cells during puberty, but this normalized in scrotal testes by adulthood. Scrotal and especially cryptorchid testes from DBP-exposed animals exhibited abnormalities (SCO tubules, focal dysgenetic areas) at all postnatal ages. Cryptorchid testes from DBP-exposed animals exhibited more Sertoli cell abnormalities at Day 25 compared with scrotal testes, perhaps indicating more severe underlying Sertoli cell malfunction in these testes. Our findings support the concept of altered Sertoli cell development in TDS, especially in cryptorchid testes, but show that maturational defects in Sertoli cells in adulthood most commonly reflect secondary dedifferentiation in absence of germ cells.

Functional association of the morphogenic factors with the clusterin for the pancreatic beta-cell differentiation

Several differentiation or morphogenic factors have known to be involved in the developmental process of endocrine pancreas. However, mechanism of action and functional relation of these molecules are not well elucidated particularly in beta-cell formation from adult pancreatic stem cells. We hypothesized that adult pancreatic stem cells could be activated by the functional resumption of the morphogenic factors that were involved in embryonic development of pancreas in the duct system under the specific conditions such as tissue injuries. Besides the well-established genes including Pdx-1 and Ngn-3, we propose the nestin and clusterin as the new morphogenic factors for beta-cell neogenesis and their functional associations. We found extensive in vivo formation of ductules showing a higher replicating ability following the experimental tissue injury. These neogenic ductules were lined with low epithelial cells positive for the nestin, which has been known as neuronal stem cell marker. In in vitro culture, the nestin-rich epithelial cells of the neogenic ductules also displayed extensive self-replication leading to monolayer of epithelial cell explants and transformed into the insulin secreting beta cells as well as duct cells. Thus, we depicted them as nestin-positive duct stem (NPDS) cells. We found a neogenesis specific protein 'clusterin' in the regenerating pancreatic tissues with concomitant increase of Pdx-1 and Ngn-3 expression. The protein is expressed predominantly in the neogenic pancreas undergoing differentiation. In vitro over-expression of the clusterin gene strongly induces beta-cell transformation from neogenic ductal cells. Insulin expression, both insulin mRNA and peptide levels, was increased and showed glucose dependent manner by ectopic expression of clusterin upon the culture of neogenic ductules when compared to the mock-transfected control, implying that the duct cells transformed functional beta cells. We observed that clusterin over-expression led to up-regulation of Pdx-1 and Ngn-3, and clusterin levels were increased upon the transfection of cDNAs of Pdx-1 or Ngn-3, suggesting a close functional association of these morphogenic factors. In conclusion, we suggest that adult pancreatic stem cells can be recapitulated for neogenesis of insulin secreting beta cells not only by reactivation Pdx-1 and Ngn-3, the classical differentiation factors for pancreas development, but also by the intervention of new morphogenic factors including nestin and clusterin. In particular, by modulation of Pdx-1 and Ngn-3, clusterin induces remarkable differentiation of the functional beta cells secreting insulin in response to glucose stimulation.

Normal distribution and medullary-to-cortical shift of Nestin-expressing cells in acute renal ischemia

Nestin, a marker of multi-lineage stem and progenitor cells, is a member of intermediate filament family, which is expressed in neuroepithelial stem cells, several embryonic cell types, including mesonephric mesenchyme, endothelial cells of developing blood vessels, and in the adult kidney. We used Nestin-green fluorescent protein (GFP) transgenic mice to characterize its expression in normal and post-ischemic kidneys. Nestin-GFP-expressing cells were detected in large clusters within the papilla, along the vasa rectae, and, less prominently, in the glomeruli and juxta-glomerular arterioles. In mice subjected to 30 min bilateral renal ischemia, glomerular, endothelial, and perivascular cells showed increased Nestin expression. In the post-ischemic period, there was an increase in fluorescence intensity with no significant changes in the total number of Nestin-GFP-expressing cells. Time-lapse fluorescence microscopy performed before and after ischemia ruled out the possibility of engraftment by the circulating Nestin-expressing cells, at least within the first 3 h post-ischemia. Incubation of non-perfused kidney sections resulted in a medullary-to-cortical migration of Nestin-GFP-positive cells with the rate of expansion of their front averaging 40 microm/30 min during the first 3 h and was detectable already after 30 min of incubation. Explant matrigel cultures of the kidney and aorta exhibited sprouting angiogenesis with cells co-expressing Nestin and endothelial marker, Tie-2. In conclusion, several lines of circumstantial evidence identify a sub-population of Nestin-expressing cells with the mural cells, which are recruited in the post-ischemic period to migrate from the medulla toward the renal cortex. These migrating Nestin-positive cells may be involved in the process of post-ischemic tissue regeneration.

Functional Neuronal Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells

Recent results have shown the ability of bone marrow cells to migrate in the brain and to acquire neuronal or glial characteristics. In vitro, bone marrow-derived MSCs can be induced by chemical compounds to express markers of these lineages. In an effort to set up a mouse model of such differentiation, we addressed the neuronal potentiality of mouse MSCs (mMSCs) that we recently purified. These cells expressed nestin, a specific marker of neural progenitors. Under differentiating conditions, mMSCs display a distinct neuronal shape and express neuronal markers NF-L (neurofilament-light, or neurofilament 70 kDa) and class III beta-tubulin. Moreover, differentiated mMSCs acquire neuron-like functions characterized by a cytosolic calcium rise in response to various specific neuronal activators. Finally, we further demonstrated for the first time that clonal mMSCs and their progeny are competent to differentiate along the neuronal pathway, demonstrating that these bone marrow-derived stem cells share characteristics of widely multipotent stem cells unrestricted to mesenchymal differentiation pathways.

Sodium butyrate activates genes of early pancreatic development in embryonic stem cells

Embryonic stem (ES) cells can differentiate into any tissue, including pancreatic islet cell types. Protocols for the efficient generation of these cells in vitro could have therapeutic applications for type I diabetes. Here we describe a simple method for the differentiation of mouse ES cells into epithelial cells with a gene expression profile consistent with that expected of early pancreatic progenitors (PP). It is based on the addition of sodium butyrate, an agent known to induce chromatin rearrangements. Variations on the length of exposure to butyrate result in the generation of hepatocytes or PP-like cells. qRT-PCR indicates that butyrate induces mesendoderm/definitive endoderm, but not neuroectoderm differentiation. PPlike cells show a strong upregulation of Ipf1/Pdx1, p48, Isl-1 and Nkx6.1, but not Ngn3, NeuroD/ Beta2 or Pax4. PP-like cells also express the epithelial marker E-cadherin. Taken together, our observations suggest that butyrate stimulates early events of pancreatic specification, prior to the onset of endocrine differentiation. These findings are discussed in the context of the development of protocols for the in vitro differentiation of islets.

Presence of endocrine and exocrine markers in EGFP-positive cells from the developing pancreas of a nestin/EGFP mouse

In order to purify and characterize nestin-positive cells in the developing pancreas a transgenic mouse was generated, in which the enhanced green fluorescent protein (EGFP) was driven by the nestin second intronic enhancer and upstream promoter. In keeping with previous studies on the distribution of nestin, EGFP was expressed in the developing embryo in neurones in the brain, eye, spinal cord, tail bud and glial cells in the small intestine. In the pancreas there was no detectable EGFP at embryonic day 11.5 (E11.5). EGFP expression appeared at E12.5 and increased in intensity through E14.5, E18.5 and post-natal day 1. Flow cytometry was used to quantify and purify the EGFP positive population in the E15.5 pancreas. The purified (96%) EGFP-expressing cells, which represent 20% of the total cell population, were shown by RT/PCR to express exocrine cell markers (amylase and P48) and endocrine cell markers (insulin 1, insulin 2, and Ngn3). They also expressed, at a lower level, PDX-1, Isl-1, and the islet hormones pancreatic polypeptide, glucagon and somatostatin as well as GLUT2, the stem cell marker ABCG2 and PECAM, a marker of endothelial cells. It was further shown by immunocytochemistry of the E15.5 pancreas that EGFP colocalised in separate subpopulations of cells that expressed nestin, insulin and amylase. These results support the conclusion that nestin expressing cells can give rise to both endocrine and exocrine cells. The ability to purify these putative progenitor cells may provide further insights into their properties and function.

Nestin expression in odontoblasts and odontogenic ectomesenchymal tissue of odontogenic tumours

BACKGROUND

Nestin, one of the intermediate filaments constituting the cytoskeleton, is a marker of neural stem cells or progenitor cells. Its expression is also related to tooth development and repair of dentine.

AIMS

The aim of this study was to investigate nestin expression in various odontogenic tumours and evaluate its usefulness for histopathological diagnosis.

METHODS

We studied formalin fixed, paraffin embedded specimens from 129 cases of odontogenic tumours and 9 of mandibular intraosseous myxoma. After characterisation of odontogenic ectomesenchymal tissues in these tumours using antibodies to vimentin, desmin, neurofilament, and glial fibrillary acidic protein, we immunohistochemically examined nestin expression.

RESULTS

No differentiation towards muscle and nervous tissues was found in the odontogenic ectomesenchymal tissues. Although almost all the ameloblastomas and malignant ameloblastomas were negative for nestin, odontogenic ectomesenchyme in the odontogenic mixed tumours demonstrated nestin immunolocalisation, particularly in the region adjacent to the odontogenic epithelium. Odontoblasts and their processes, pulp cells near the positive odontoblasts, and flat cells adhering to the dentine showed immunoreaction with nestin in the odontomas and odontoma-like component in the ameloblastic fibro-odontomas. Neoplastic cells in almost half cases of jaw myxoma and one case of odontogenic fibroma expressed nestin.

CONCLUSIONS

The distribution of nestin in the odontogenic mixed tumours suggests that nestin expression in the odontogenic ectomesenchyme is upregulated by stimulation from odontogenic epithelium. In addition, nestin may also be involved in the differentiation from pulp cells to odontoblasts in odontogenic tumours. Therefore, nestin is a useful marker for the odontogenic ectomesenchyme and odontoblasts in odontogenic tumours. Nestin, one of the intermediate filaments constituting the cytoskeleton, is a marker of neural stem cells or progenitor cells. Its expression is also related to tooth development and repair of dentine.

Intermediate filament protein nestin is expressed in developing kidney and heart and might be regulated by the Wilms' tumor suppressor Wt1

Nestin is an intermediate filament protein originally described in neural stem cells and a variety of progenitor cells. More recently, nestin was detected in rat kidney podocytes. We show here that nestin is expressed in a developmentally regulated pattern in the kidney. Nestin was detected by immunohistochemistry in the condensing mesenchyme surrounding the ureter, in developing glomeruli, in podocytes of the adult kidney, and in a podocyte cell line. Nestin shared a striking overlap in expression with the Wilms' tumor suppressor Wt1. Nestin was significantly upregulated in a cell line with inducible Wt1 expression upon induction of Wt1. Cotransfection experiments in human embryonic kidney cells (HEK293) revealed stimulation of a nestin intron 2 enhancer element up to six-fold by the Wt1(-KTS) splice variant. Nestin expression was significantly reduced in an inducible mouse model of glomerular disease. This model is based on podocyte-specific overexpression of Pax2 and associated with a loss of Wt1 expression. Furthermore, also in the developing heart, nestin was found in an overlapping pattern with Wt1 in the epicardium and the forming coronary vessels. Strikingly, in the hearts of Wt1 knockout mice, nestin was barely detectable compared with the hearts of wild-type embryos. Our results show that nestin is expressed at different stages of kidney and cardiac development and suggest that its expression in these organs might be regulated by the Wilms' tumor suppressor Wt1.

Following the Differentiation of Human Pluripotent Stem Cells by Proteomic Identification of Biomarkers

Following the differentiation of cultured stem cells is often reliant on the expression of genes and proteins that provide information on the developmental status of the cell or culture system. There are few molecules, however, that show definitive expression exclusively in a specific cell type. Moreover, the reliance on a small number of molecules that are not entirely accurate biomarkers of particular tissues can lead to misinterpretation in the characterization of the direction of cell differentiation. Here we describe the use of technology that examines the mass spectrum of proteins expressed in cultured cells as a means to identify the developmental status of stem cells and their derivatives in vitro. This approach is rapid and reproducible and it examines the expression of several different biomarkers simultaneously, providing a profile of protein expression that more accurately corresponds to a particular type of cell differentiation.

Differentiation of human embryonic stem cells after transplantation in immune-deficient mice

Our current knowledge of how human tissues grow and develop is limited. We need to increase our understanding of tissue formation if we are to fully realize the potential of stem cells as a source of material for research into health and disease and possible therapeutic applications. Transplanted pluripotent human embryonic stem cells (hESCs) provide a potential system to model and investigate cell differentiation in humans. hESCs transplanted into immune-deficient mice form complex teratomas consisting of a range of differentiated somatic tissues, some of which appear highly organized and resemble structures normally identified in the embryo and adult. Analysis of such tumors may provide a unique opportunity to study organogenesis and lead to novel approaches in bioengineering and the growth of functioning structures composed of a range of alternative cell types. However, little has been done to characterize the developmental potential of hESCs after transplantation. This concise review presents evidence for the ability of hESCs to differentiate in vivo and highlights some of the prominent questions that need to be addressed if transplantation is to be used as a research tool to study hESC differentiation.