Nestin expression in vascular malformations: a novel marker for proliferative endothelium

The effect of a single dose of Mk-801 use on adult brain tissue after an experimental head trauma model applied in immature rats

OBJECTIVE

Within the scope of this research, the long-term effects of experimental blunt head trauma on immature rats and MK-801 administered acutely after trauma on the brain tissue will be examined. In addition, the impact of trauma and MK-801 on Nestin and CD133, which are essential stem cells, will be evaluated by immunohistochemical and ELISA methods.

METHODS

In this study, the contusion trauma model was used. Sprague Dawley rats 30 7-day-old were divided into three groups: Group 1 (n = 10) control group, Group 2 (n = 10) trauma Group (head trauma applied), and Group 3 (n = 10) MK-801 + trauma Group. In the third group, immediately after head trauma, MK-801 (Sigma M107) dissolved in physiological saline was administered as a single dose of 1 mg/kg ip.

RESULTS

The concentration of nestin was significantly higher in the control group compared to both the trauma and trauma+drug groups (p < 0.001). CD133 was statistically significantly higher in the control group compared to the other two groups (p = 0.002). It was determined that the differences in Nestin CA1 and DG measurements resulted from the trauma and control and trauma and trauma+drug groups, and the differences in CD133 CA1 and DG measurements resulted from the trauma and control group.

CONCLUSION

The positive effect of MK-801 on neuroprotective and neuronal proliferation was elaborated. Administration of MK-801 significantly induced nestin and CD133 concentrations in the injured tissue.

CRISPR/CasRx suppresses KRAS-induced brain arteriovenous malformation developed in postnatal brain endothelial cells in mice

Brain arteriovenous malformations (bAVMs) are anomalies forming vascular tangles connecting the arteries and veins, which cause hemorrhagic stroke in young adults. Current surgical approaches are highly invasive, and alternative therapeutic methods are warranted. Recent genetic studies identified KRAS mutations in endothelial cells of bAVMs; however, the underlying process leading to malformation in the postnatal stage remains unknown. Here we established a mouse model of bAVM developing during the early postnatal stage. Among 4 methods tested, mutant KRAS specifically introduced in brain endothelial cells by brain endothelial cell-directed adeno-associated virus (AAV) and endothelial cell-specific Cdh5-CreERT2 mice successfully induced bAVMs in the postnatal period. Mutant KRAS led to the development of multiple vascular tangles and hemorrhage in the brain with increased MAPK/ERK signaling and growth in endothelial cells. Three-dimensional analyses in cleared tissue revealed dilated vascular networks connecting arteries and veins, similar to human bAVMs. Single-cell RNA-Seq revealed dysregulated gene expressions in endothelial cells and multiple cell types involved in the pathological process. Finally, we employed CRISPR/CasRx to knock down mutant KRAS expression, which efficiently suppressed bAVM development. The present model reveals pathological processes that lead to postnatal bAVMs and demonstrates the efficacy of therapeutic strategies with CRISPR/CasRx.

IL-10 regulates the malignancy of hemangioma-derived endothelial cells via regulation of PCNA

Hemangioma (HA) is the most common benign tumor and formed by the proliferating endothelial cells of blood vessels. Interleukins (ILs) have been reported to be critical for HA progression. Our present study found that the expression of IL-10 was decreased in HA cells and tissues as compared to their corresponding controls. Treatment with recombinant IL-10 (rIL-10) can suppress the proliferation of HA cells via suppression of proliferating cell nuclear antigen (PCNA), while over expression of PCNA can attenuate rIL-10-inhibited cell proliferation. Further, rIL-10 can decrease the promoter activity and mRNA stability of PCNA in HA cells. Mechanistically, rIL-10 can increase expression of miR-27b-3p to decrease mRNA stability of PCNA, while down regulation of YY1 is involved in rIL-10 suppressed transcription of PCNA. Collectively, IL-10 can suppress the expression of PCNA via miR-27b-3p mediated suppression of mRNA stability and YY1 mediated down regulation of transcription. It suggested that rIL-10 might be a potential therapeutic approach for HA development and progression.

The Diversity of Intermediate Filaments in Astrocytes

Despite the remarkable complexity of the individual neuron and of neuronal circuits, it has been clear for quite a while that, in order to understand the functioning of the brain, the contribution of other cell types in the brain have to be accounted for. Among glial cells, astrocytes have multiple roles in orchestrating neuronal functions. Their communication with neurons by exchanging signaling molecules and removing molecules from extracellular space takes place at several levels and is governed by different cellular processes, supported by multiple cellular structures, including the cytoskeleton. Intermediate filaments in astrocytes are emerging as important integrators of cellular processes. Astrocytes express five types of intermediate filaments: glial fibrillary acidic protein (GFAP); vimentin; nestin; synemin; lamins. Variability, interactions with different cellular structures and the particular roles of individual intermediate filaments in astrocytes have been studied extensively in the case of GFAP and vimentin, but far less attention has been given to nestin, synemin and lamins. Similarly, the interplay between different types of cytoskeleton and the interaction between the cytoskeleton and membranous structures, which is mediated by cytolinker proteins, are understudied in astrocytes. The present review summarizes the basic properties of astrocytic intermediate filaments and of other cytoskeletal macromolecules, such as cytolinker proteins, and describes the current knowledge of their roles in normal physiological and pathological conditions.

Evidence for endothelial-to-mesenchymal transition in human brain arteriovenous malformations

BACKGROUND

Brain arteriovenous malformations (AVMs) are rare, potentially devastating cerebrovascular lesions that can occur in both children and adults. AVMs are largely sporadic and the basic disease biology remains unclear, limiting advances in both detection and treatment. This study aimed to investigate human brain AVMs for endothelial-to-mesenchymal transition (EndMT), a process recently implicated in cerebral cavernous malformations (CCMs).

METHODS

We used 29 paraffin-embedded and 13 fresh/frozen human brain AVM samples to profile expression of panels of EndMT-associated proteins and RNAs. CCMs, a cerebrovascular disease also characterized by abnormal vasculature, were used as a primary comparison, given that EndMT specifically contributes to CCM disease biology. AVM-derived cell lines were isolated from three fresh, surgical AVM samples and characterized by protein expression.

RESULTS

We observed high collagen deposition, high PAI-1 expression, and expression of EndMT-associated transcription factors such as KLF4, SNAI1, and SNAI2 and mesenchymal-associated markers such as VIM, ACTA2, and S100A4. SMAD-dependent TGF-β signaling was not strongly activated in AVMs and this pathway may be only partially involved in mediating EndMT. Using serum-free culture conditions, we isolated myofibroblast-like cell populations from AVMs that expressed a unique range of proteins associated with mature cell types and with EndMT. Conditioned medium from these cells led to increased proliferation of HUVECs and SMCs.

CONCLUSIONS

Collectively, our results suggest a role for EndMT in AVM disease. This may lead to new avenues for disease models to further our understanding of disease mechanisms, and to the development of improved diagnostics and therapeutics.

A bigenic mouse model of FSGS reveals perturbed pathways in podocytes, mesangial cells and endothelial cells

Focal segmental glomerulosclerosis is a major cause of end stage renal disease. Many patients prove unresponsive to available therapies. An improved understanding of the molecular basis of the disease process could provide insights leading to novel therapeutic approaches. In this study we carried out an RNA-seq analysis of the altered gene expression patterns of podocytes, mesangial cells and glomerular endothelial cells of the bigenic Cd2ap+/-, Fyn-/- mutant mouse model of FSGS. In the podocytes we observed upregulation of many genes related to the Tgfβ family/pathway, including Gdnf, Tgfβ1, Tgfβ2, Snai2, Vegfb, Bmp4, and Tnc. The mutant podocytes also showed upregulation of Acta2, a marker of smooth muscle and associated with myofibroblasts, which are implicated in driving fibrosis. GO analysis of the podocyte upregulated genes identified elevated protein kinase activity, increased expression of growth factors, and negative regulation of cell adhesion, perhaps related to the observed podocyte loss. Both podocytes and mesangial cells showed strong upregulation of aldehyde dehydrogenase genes involved in the synthesis of retinoic acid. Similarly, the Cd2ap+/-, Fyn-/- mesangial cells, as well as podocytes in other genetic models, and the glomeruli of human FSGS patients, all show upregulation of the serine protease Prss23, with the common thread suggesting important functionality. Another gene with strong upregulation in the Cd2ap+/-, Fyn-/- mutant mesangial cells as well as multiple other mutant mouse models of FSGS was thrombospondin, which activates the secreted inactive form of Tgfβ. The Cd2ap+/-, Fyn-/- mutant endothelial cells showed elevated expression of genes involved in cell proliferation, angioblast migration, angiogenesis, and neovasculature, all consistent with the formation of new blood vessels in the diseased glomerulus. The resulting global definition of the perturbed molecular pathways in the three major cell types of the mutant glomerulus provide deeper understanding of the molecular pathogenic pathways.

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.

Intermediate Filaments and the Regulation of Cell Motility during Regeneration and Wound Healing

SUMMARYIntermediate filaments (IFs) comprise a diverse group of flexible cytoskeletal structures, the assembly, dynamics, and functions of which are regulated by posttranslational modifications. Characteristically, the expression of IF proteins is specific for tissues, differentiation stages, cell types, and functional contexts. Recent research has rapidly expanded the knowledge of IF protein functions. From being regarded as primarily structural proteins, it is now well established that IFs act as powerful modulators of cell motility and migration, playing crucial roles in wound healing and tissue regeneration, as well as inflammatory and immune responses. Although many of these IF-associated functions are essential for tissue repair, the involvement of IF proteins has been established in many additional facets of tissue healing and regeneration. Here, we review the recent progress in understanding the multiple functions of cytoplasmic IFs that relate to cell motility in the context of wound healing, taking examples from studies on keratin, vimentin, and nestin. Wound healing and regeneration include orchestration of a broad range of cellular processes, including regulation of cell attachment and migration, proliferation, differentiation, immune responses, angiogenesis, and remodeling of the extracellular matrix. In this respect, IF proteins now emerge as multifactorial and tissue-specific integrators of tissue regeneration, thereby acting as essential guardian biopolymers at the interface between health and disease, the failing of which contributes to a diverse range of pathologies.

Expression of nestin in embryonic tissues and its effects on clinicopathological characteristics of patients with placenta previa

In this study, we examined expression of nestin in the spinal cord, lung, kidney, stomach, colon, and intestine tissues at different stages of embryos in patients with placenta previa. Fetuses of 75 patients with placenta previa were assigned to case group and 80 fetuses from healthy pregnant women with normal placenta who voluntarily terminated pregnancy to control group. Clinical data of pregnant women were collected at the time of admission. Blood from elbow vein was collected to determine expression of serum nestin. Tissues from spinal cord, lung, kidney, stomach, colon, and intestine in 3-7 months fetuses of the two groups were extracted. Expression of nestin in tissues was detected by immunohistochemistry, Western blotting and RT-qPCR. The mRNA expression of nestin in the case group was increased. Nestin expression was correlated with the gestational age, age of foetus, and type of placenta previa in patients with placenta previa. Positive nestin expression was detected in the spinal cord, lung, kidney, stomach, intestine, and colon tissues in normal and placenta previa embryo at Stage I. The positive cell density and nestin expression decreased at Stage II, and further decreased at Stage III. The case group had higher nestin mRNA and protein levels throughout human fetal development. Findings of this study suggested that, nestin, as a specific marker of neural precursor cells, was expressed in various tissues of the embryo in patients with placenta previa and nestin expression was lower with increased maturation of the embryo.

Association of the intermediate filament nestin with cancer stage: a meta-analysis based on 223 positive/high nestin cases and 460 negative/low case-free controls

Background

Nestin, a member of the intermediate filament protein family, has been reported to be associated with several types of neoplastic transformation. However, questions remain, with studies reporting sometimes inconclusive or conflicting data. Thus, the aim of this study was to evaluate literature reports on the relationship between nestin and cancer stage.

Methods

Relevant articles published as of June 2014 were retrieved from multiple databases. After applying specific inclusion criteria, we chose seven articles relating to nestin expression and cancer stage, which included a total of 223 positive/high nestin cases and 460 negative/low case-free controls.

Results

Overall, positive/high nestin was significantly associated with median or advanced stages of several types of cancer (nestin and cancer stage: OR = 1.90, 95% CI = 1.30–2.78; nestin and lymph node: OR = 2.17, 95% CI = 1.26–3.72). Notably, studies relating to lung cancer (three qualifying articles) showed a significant association between nestin and lung cancer stage (OR = 2.00, 95% CI = 1.16–3.44).

Conclusion

These findings indicate that positive/high nestin may be more strongly linked to median or advanced cancer stage and correlated with malignant characteristics that lead to poor prognosis in different cancers, especially lung cancer.

Human brain arteriovenous malformations express lymphatic-associated genes

Objective

Brain arteriovenous malformations (AVMs) are devastating, hemorrhage-prone, cerebrovascular lesions characterized by well-defined feeding arteries, draining vein(s) and the absence of a capillary bed. The endothelial cells (ECs) that comprise AVMs exhibit a loss of arterial and venous specification. Given the role of the transcription factor COUP-TFII in vascular development, EC specification, and pathological angiogenesis, we examined human AVM tissue to determine if COUP-FTII may have a role in AVM disease biology.

Methods

We examined 40 human brain AVMs by immunohistochemistry (IHC) and qRT-PCR for the expression of COUP-TFII as well as other genes involved in venous and lymphatic development, maintenance, and signaling. We also examined proliferation and EC tube formation with human umbilical ECs (HUVEC) following COUP-TFII overexpression.

Results

We report that AVMs expressed COUP-TFII, SOX18, PROX1, NFATC1, FOXC2, TBX1, LYVE1, Podoplanin, and vascular endothelial growth factor (VEGF)-C, contained Ki67-positive cells and heterogeneously expressed genes involved in Hedgehog, Notch, Wnt, and VEGF signaling pathways. Overexpression of COUP-TFII alone in vitro resulted in increased EC proliferation and dilated tubes in an EC tube formation assay in HUVEC.

Interpretation

This suggests AVM ECs are further losing their arterial/venous specificity and acquiring a partial lymphatic molecular phenotype. There was significant correlation of gene expression with presence of clinical edema and acute hemorrhage. While the precise role of these genes in the formation, stabilization, growth and risk of hemorrhage of AVMs remains unclear, these findings have potentially important implications for patient management and treatment choice, and opens new avenues for future work on AVM disease mechanisms.

Contribution of nestin positive esophageal squamous cancer cells on malignant proliferation, apoptosis, and poor prognosis

Background

The stem cell-associated intermediate filament nestin has recently been linked with neoplastic transformation, but the specific mechanism by which nestin positive tumor cells leads to malignant invasion and metastasis behaviors of esophageal squamous cell carcinoma (ESCC) remains unclear.

Methods

To obtain insight into the biological role of nestin in ESCC, we explored the association of the nestin phenotype with malignant proliferation and apoptosis in esophageal squamous cancer cells. Nestin expression was determined in ESCC specimens and cell lines, and correlated with clinicopathological properties, including clinical prognosis and proliferative markers. The association of the nestin phenotype with apoptotic indicators was also analyzed.

Results

Nestin was expressed in ESCC specimens and cell lines. ESCC patients with nestin-positive tumors had significantly shorter median survival and progression-free survival times than those with nestin-negative tumors. Positive staining for the proliferation markers Ki67 and PCNA (proliferating cell nuclear antigen) was detected in 56.9% and 60.2% of ESCC specimens, respectively, and was strongly correlated with the nestin phenotype. Notably, expression of cyclin dependent kinase-5 (CDK5) and P35 was detected in 53.8% and 48.4% of ESCC specimens, respectively, and was strongly associated with the nestin phenotype.

Conclusion

Our data demonstrated nestin expression in ESCC specimens and cell lines, and revealed a strong association of the nestin phenotype with poor prognosis in ESCC patients. Furthermore, we showed that nestin positive ESCC cells played an important role in the malignant proliferation and apoptosis.

Role of the stem cell-associated intermediate filament nestin in malignant proliferation of non-small cell lung cancer

Background

Nestin is associated with neoplastic transformation, but the mechanisms by which nestin contributes to invasion and malignancy of lung cancer remain unknown. Considering that proliferation is necessary for malignant behavior, we investigated the mechanism of nestin action in association with the proliferative properties of non-small cell lung cancer (NSCLC).

Methods

Nestin expression was examined in NSCLC specimens and cell lines. Associations with clinicopathological features, including prognosis and proliferative markers, were evaluated. Effects of nestin knockdown on proliferation and the signaling pathways involved were further investigated.

Results

Nestin was expressed in most cancer specimens and all the tumor cell lines analyzed. High nestin expression in malignant tissue was associated with high Ki-67 or PCNA levels and poor patient outcomes. Conversely, knockdown of nestin expression led to significant inhibition of tumor cell proliferation, decreased colony forming ability, and cell cycle G1 arrest. Furthermore, nestin knockdown resulted in inhibition of Akt and GSK3β activation.

Conclusions

Our data demonstrate that nestin expression in NSCLC cells is associated with poor prognosis of patients and tumor cell proliferation pathway. Downregulation of nestin efficiently inhibited lung cancer cell proliferation, which might be through affecting cell cycle arrest and Akt-GSK3β-Rb signaling pathway.

Combined blockade of AKT/mTOR pathway inhibits growth of human hemangioma via downregulation of proliferating cell nuclear antigen

Protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway plays a crucial role in the tumorigenesis and progression of multiple tumors, and has been shown to be important therapeutic targets for cancer. The present study aimed to explore the role and molecular mechanisms of AKT/mTOR pathway in human hemangioma (HA). Twenty-five cases of human HA tissues were collected. The expression of AKT, mTOR and proliferating cell nuclear antigen (PCNA) proteins was evaluated using semi-quantitative immunohistochemistry in biopsy samples in different phases of HA. AKT/mTOR pathway was blocked by recombinant small hairpin RNA adenovirus vector rAd5-AKT+mTOR (rAd5-Am), used for infecting proliferating phase HA-derived endothelial cells (HDEC). The expression of AKT, mTOR and PCNA was detected by Real-time PCR and Western blot assays. Cell proliferative activities were determined by MTT assay, and cell cycle distribution and apoptosis were analyzed by flow cytometry. As a consequence, the expression of AKT, mTOR and PCNA was significantly increased in proliferative phase HA, while that was decreased in involutive phase. Combined blockade of AKT/mTOR pathway by rAd5-Am diminished cell proliferative activities, and induced cell apoptosis and cycle arrest with the decreased expression of AKT, mTOR and PCNA in proliferative phase HDEC. In conclusion, the activity of AKT/mTOR pathway was increased in proliferative phase HA, while it was decreased in involutive phase. Combined blockade of AKT/mTOR pathway might suppress cell proliferation via down-regulation of PCNA expression, and induce apoptosis and cycle arrest in proliferative phase HDEC, suggesting that AKT/mTOR pathway might represent the important therapeutic targets for human HA.

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.

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.

Expression of nestin in lymph node metastasis and lymphangiogenesis in non-small cell lung cancer patients

Stem cell marker nestin has been reported to be activated in various neoplasms, and its expression is correlated with poor prognosis. However, nestin expression in non-small cell lung cancer still remains unclear. The present study aimed to investigate nestin expression in 52 tissue samples of non-small cell lung cancer by immunohistochemical staining and explore its correlation with some clinicopathologic characteristics. The associations of nestin with lymphatic vessel density, microvessel density, vascular endothelial growth factor, vascular endothelial growth factor-C, and cyclooxygenase-2 (COX-2) were further observed to determine the linkage between nestin and lymphangiogenesis. The results showed that nestin expressed in tumor cells of 45 samples. High nestin expression correlated significantly with poor differentiation (P = .007), adenocarcinoma (P = .000), N2 lymph node metastasis (P = .006), high microvessel density (P = .033), and lymphatic vessel density (P = .020). Multivariate analysis of N1 and N2 lymph node metastasis revealed a 1.086-fold increase in hazard ratio of N2 lymph node involvement (P = .011) in patients with high nestin expression in primary tumor. More important, multivariate analysis showed a significant correlation of lymphatic vessel density with nestin and vascular endothelial growth factor-C expression (P = .039 and P = .045), independent of vascular endothelial growth factor, COX-2, and other clinicopathologic characteristics. The results demonstrated that nestin expressed in most tumor cells of non-small cell lung cancer tissue and had a direct linkage to lymph node metastasis and tumor-induced lymphangiogenesis, independent of COX-2 signal pathway.

Case of follicular mucinosis: nestin-expression in mucin-producing cells

A 29-year-old Japanese man had an asymptomatic, solitary, indurated, erythematous plaque measuring 30 mm x 30 mm on his jaw that had been present for a month. The skin lesion had follicular hyperkeratosis, and lacked hair. A skin biopsy specimen showed a dense perifollicular infiltration composed of lymphocytes, with an admixture of eosinophils in the full thickness of the dermis. The hair follicles and sebaceous glands had reticular epithelial degeneration by mucoid material of the outer root sheath and sebaceous epithelium. The mucoid material stained with Alcian blue at pH 2.5. The clinical and histological features were consistent with the diagnosis of follicular mucinosis. On immunohistochemistry, the outer root sheath cells with reticular epithelial degeneration were nestin-positive and keratin 15-negative. These results suggest that the outer root sheath cells with reticular epithelial degeneration come from the nestin-positive, multipotent, hair follicle stem cells.

Direct isolation of neural stem cells in the adult hippocampus after traumatic brain injury

Recently, we have manipulated endogenous neural stem/progenitor cells (NSCs) in situ in the adult mouse to undergo neurogenesis and anatomic circuit re-formation de novo in the neocortex, where it does not normally occur, by using a highly targeted brain injury model. However, how the NSCs respond to injury in the adult mouse brain is poorly understood. While studying the molecular mechanisms that regulate NSC fates after brain injury, it is important to develop a strategy to identify NSCs in niches and isolate them directly from fresh tissue after brain injury. Here we report that we directly isolated NSCs from adult brains after traumatic brain injury by genetically labeling NSCs with EGFP combined with fluorescence-activated cell sorting (FACS) technique without an intervening cell culture and with high concentrations of growth factors. The isolated EGFP-positive cells can self-renew and have the potential to differentiate into both neurons and glia in vitro, confirming that the FACS-sorted EGFP-positive cells are NSCs. This unique approach provides a useful tool to isolate large amounts of endogenous NSCs in situ for identifying the critical molecules that regulate fate decision and neurogenesis in the adult brain after injury.

Induction of nestin synthesis in rat brain cells by ischemic damage

Nestin, an intermediate filament protein, is known to be expressed in proliferating and provisional cells in the forming mammalian brain, disappearing on differentiation. The aim of the present work was to identify the morphological types and locations of cells regaining the ability to synthesize nestin after transient total brain ischemia in rats. Transient ischemia was found to be followed by the induction of nestin synthesis in astrocytes in the damaged area; these cells acquired structural features not characteristic of the adult brain, and these persisted in the long term. Nestin synthesis was also induced in proliferation-capable undifferentiated cells in the subventricular zone. The acquisition by astrocytes of some of the phenotypic features of immature glial cells, however, does not provide grounds for the notion that they were transformed into neural stem cells.

Immunohistochemical expression of nestin in adenohypophysial vessels during development of pituitary infarction

OBJECTIVES

The aim of this work was to investigate the immunohistochemical expression of nestin, a member of the intermediate filament family, in adenohypophysial vasculature during development and progression of pituitary infarction.

METHODS

Forty-five nontumorous adenohypophyses and 34 pituitary adenomas of various types, all exhibiting acute or healing infarcts, were examined immunohistochemically using the streptavidin-biotin-peroxidase complex method.

RESULTS

In both adenohypophyses and pituitary adenomas without infarction, nestin was expressed in only a few capillaries and endothelial cells. In acute infarcts without a vascular response, no nestin was demonstrable within necrotic capillaries (50 cases). In organizing infarcts, newly formed vessels spreading into necrotic zones showed nestin expression in all capillaries and practically every endothelial cell (25 cases). In the hypocellular, fibrotic scar phase, only a few vessels (4) were apparent, and immunoreactivity was focal and mild.

CONCLUSIONS

Nestin is strongly expressed in newly formed capillaries and is downregulated when infarcts transform to fibrous tissue. Nestin expression may provide valuable insight into the process of pituitary angiogenesis.

Nestin expression in different tumours and its relevance to malignant grade

BACKGROUND

Nestin, an intermediate filament (IF) protein, is expressed in proliferating progenitor cells of developmental and regenerating tissues, and is identified as a neuroepithelial precursor cell marker. Recently, nestin was detected in some neoplasms such as glioma, ependymoma, melanoma, rhabdomyosarcoma, gastrointestinal stromal tumour (GIST), and testicular stromal tumour. Moreover, the expression intensity of nestin exhibited significant correlation with the malignant grade of glioma.

AIMS

To detect the expression of nestin in different tumours and to analyse the relationship between the expression of nestin and the malignant grade of the tumours.

METHODS

Formalin-fixed and paraffin-embedded surgical samples of neoplastic tissues were obtained from the Department of Pathology of Sun Yat-sen University. Histological analysis and immunohistochemical staining for nestin were performed. Histoscores were analysed by semi-quantitative evaluation.

RESULTS

Nestin was expressed predominantly in the cytoplasm of angiosarcoma, pancreatic adenocarcinoma and GIST samples, and some tumour cells expressed in the nucleus. There was a statistically significant difference between the histoscore of nestin in high malignant GIST (2.2366 (0.6920)) and that in low malignant GIST (1.3783 (0.4268)) (p = 0.003); and also between that in high malignant angiosarcoma (1.9188 (0.2069)) and that in low malignant angiosarcoma (0.6474 (0.3273)) (p = 0.000). Cavernous angioma did not express nestin. The histoscore of nestin in high malignant pancreatic adenocarcinoma (7/14) was 1.1767 (0.4676), and that in low malignant pancreatic adenocarcinoma (3/8) was 0.6577 (0.0056) (no significant difference, p = 0.112).

CONCLUSIONS

Results suggest that the expression of nestin may play an important role in the development of some neoplasms such as GIST and angiosarcoma.