ABSTRACT
BACKGROUND: Uterine Carcinosarcomas (UCS) are a rare type of cancer composed of an admixture of high-grade carcinomatous and sarcomatous elements. Clinicopathological prognostic factors in UCS are well established, but studies that approach the impact of biomarkers in this unusual disease are scarce. The study objective was to evaluate the prevalence and prognostic impact of a panel of prominent biomarkers in uterine carcinosarcoma (UCS) using an immunohistochemical characterization with four biomarkers. METHODS AND FINDINGS: The internal database of a single Brazilian institution was carefully explored to select women diagnosed with UCS who were submitted to surgery and postoperative chemotherapy with carboplatin and paclitaxel between January 2012 and December 2017. Tissue microarrays containing UCS samples were evaluated by immunohistochemistry for L1CAM, CDX2, p53 and microsatellite instability markers. A total of 57 cases were included. The mean age was 65.3 years (standard deviation, SD 7.0). L1CAM was negative (score 0, no staining) in 27 (47.4%) patients. Of L1CAM-positive, 10 (17.5%) showed weak (score 1, <10%), 6 (10.5%) showed moderate (score 2, between 10-50%), and 14 (24.6%) showed strong L1CAM staining (score 3, â§50%). dMMR occurred in 3 (5.3%) cases. The p53 was aberrantly expressed in 15 (26.3%) tumors. CDX2 was positive in 3 (5.3%) patients. The three-year progression-free survival (PFS) rate in the general population of the study was 21.2% (95% CI: 11.7-38.1) and the three-year overall survival (OS) rate was 29.4% (95% CI: 18.1-47.6). By multivariate analysis, the presence of metastases and CDX2-positive were significantly associated with poorer PFS (p < 0.001 and p = 0.002, respectively) and OS (p < 0.001 and p = 0.009, respectively). CONCLUSION: The strong influence of CDX2 on prognosis requires further investigation. Biological or molecular variability may have impaired the assessment of the impact of the other markers on survival.
Subject(s)
Carcinosarcoma , Neural Cell Adhesion Molecule L1 , Uterine Neoplasms , Humans , Female , Aged , Prognosis , Tumor Suppressor Protein p53/genetics , Retrospective Studies , Uterine Neoplasms/genetics , Biomarkers, Tumor/genetics , Biomarkers, Tumor/analysis , CDX2 Transcription Factor/geneticsABSTRACT
OBJECTIVES: Accurate prognosis assessment across the heterogeneous population of brain metastases is very important, which may facilitate clinical decision-making and appropriate stratification of future clinical trials. Previous studies have shown the L1 Cell Adhesion Molecule (L1CAM) is potentially involved in human malignancies of multiple different samples and unfavorable survival. However, no data of L1CAM are available for the brain metastases from lung adenocarcinoma, especially for the one with neurosurgical resection. METHOD: The authors investigated the L1CAM expression in cranial metastatic lesions for patients with brain metastases from lung adenocarcinoma after neurosurgical resection using tissue microarrays that were obtained from the Department of Neurosurgery at the Cancer Hospital of the Chinese Academy of Medical Sciences. Furthermore, the relationship between L1CAM expression and clinic-pathological parameters, including overall survival time, was analyzed to assess the prognostic value of L1CAM. RESULTS: L1CAM high expression was found in 62.30% of brain metastases from lung adenocarcinoma and significantly correlated with brain metastasis number (p = 0.028) and Lung-molGPA score (p = 0.042). Moreover, L1CAM expression was an independent predictor of survival for brain metastases after neurosurgical resection in a multivariate analysis. Patients with L1CAM high expression had unfavorable overall survival time (p = 0.016). In addition, the multivariate analysis also showed age and extracranial transfer were also the independent prognostic factors for this type of patient with brain metastases. CONCLUSIONS: A subset of brain metastases from lung adenocarcinoma aberrantly expresses L1CAM. L1CAM is a novel independent prognostic factor for brain metastasis from lung adenocarcinoma after neurosurgical resection.
Subject(s)
Adenocarcinoma of Lung , Brain Neoplasms , Lung Neoplasms , Neural Cell Adhesion Molecule L1 , Adenocarcinoma of Lung/metabolism , Adenocarcinoma of Lung/pathology , Adenocarcinoma of Lung/surgery , Biomarkers, Tumor , Brain Neoplasms/metabolism , Brain Neoplasms/secondary , Brain Neoplasms/surgery , Humans , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Lung Neoplasms/surgery , Neural Cell Adhesion Molecule L1/biosynthesis , PrognosisABSTRACT
AIMS: L1 cell adhesion molecule (L1CAM) has been shown to be correlated with tumour progression, attributed to its possible association with epithelial-mesenchymal transition (EMT), characterised by the expression of vimentin and loss of e-cadherin. Herein, we investigate the associations between L1CAM and clinicopathological parameters, as well as the expression of vimentin and e-cadherin, in carcinomas restricted to the cervix. METHODS: The study was retrospective observational and included 45 squamous cell carcinomas (63.4%) and 26 adenocarcinomas (36.6%) submitted to primary surgical treatment. Patient age, FIGO (International Federation of Gynecology and Obstetrics) stage, tumour size and follow-up were obtained from the medical records. All the slides were revised to evaluate histological differentiation, lymphovascular space invasion, depth of infiltration, disease-free cervical wall thickness, pattern of invasion front, Silva pattern (for adenocarcinomas) and the percentage of tumour-infiltrating lymphocytes. Tissue microarrays were constructed for immunohistochemical staining for L1CAM, e-cadherin and vimentin. RESULTS: Adenocarcinomas were associated with lower disease-free and overall survival. L1CAM and vimentin expressions were more frequent among adenocarcinomas, although loss of e-cadherin expression was more common among squamous carcinomas. L1CAM expression was associated with larger tumours, vimentin expression and lower disease-free survival. No association was observed between the expression of either L1CAM or vimentin and loss of e-cadherin. High levels of tumour-infiltrating lymphocytes were more frequent in squamous cell carcinoma, high-grade tumours, destructive pattern at front of invasion and loss of e-cadherin expression. CONCLUSIONS: Our results confirm the prognostic role of L1CAM in cervical carcinomas, but suggest a role for mechanisms other than EMT.
Subject(s)
Adenocarcinoma/diagnosis , Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/diagnosis , Neural Cell Adhesion Molecule L1/metabolism , Uterine Cervical Neoplasms/diagnosis , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Antigens, CD/metabolism , Cadherins/metabolism , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Cervix Uteri/metabolism , Cervix Uteri/pathology , Cohort Studies , Epithelial-Mesenchymal Transition , Female , Humans , Immunohistochemistry , Neural Cell Adhesion Molecule L1/genetics , Prognosis , Uterine Cervical Neoplasms/metabolism , Uterine Cervical Neoplasms/pathology , Vimentin/genetics , Vimentin/metabolismABSTRACT
BACKGROUND: Risk stratification of endometrial carcinomas is primarily based on surgical staging that requires extensive retroperitoneal lymph node dissection. One of the most powerful predictor of lymph node involvement is the lymph vascular space invasion (LVSI). The objective of this study was to determine the potential of L1 Cell Adhesion Molecule (L1CAM) to predict LVSI and its association with other risk factors in endometrioid endometrial carcinomas. MATERIALS AND METHODS: We studied 47 consecutive patients aged 37-88 (61.34±10.52). Twenty-three patients (48.9%) were submitted to complete surgical staging. Nine patients (19.1%) underwent surgical staging without para-aortic dissection. Seven (14.9%) were submitted to hysterectomy with no lymph node dissection. Eight patients (17.0%) only had the biopsy material for analysis. The 32 patients submitted to lymphadenectomy were staged according to the FIGO system and classified among the risk categories of the ESMO-ESGO-ESTRO guidelines. The following histological characteristics were analyzed: tumor size (mm), depth of myometrial infiltration, presence of microcystic, elongated, and fragmented (MELF) pattern of myoinvasion, and lymph vascular space invasion (LVSI). Immunohistochemical analyses of mismatch repair (MMR) proteins MLH1, MSH2, MSH6, and PMS2, p53, and L1CAM were performed in formalin-fixed paraffin embedded whole tumor tissue sections. RESULTS: LVSI was identified in 26/41 (63,4%) of the cases. L1CAM was positive in 8/47 (17%) cases, all of them positive for LVSI and within the high-risk category of ESMO-ESGO-ESTRO. L1CAM-positive cases were associated with high histological grade and p53 aberrant immunohistochemical profile. Besides, it showed a trend to larger tumors, greater depth of myometrial infiltration, and with a higher frequency of the MELF pattern of myoinvasion. LVSI was also associated with FIGO stage, tumor size, depth of myometrial infiltration, and tumor grade. CONCLUSIONS: L1CAM is highly associated with LVSI and could be used as a pre-operative predictor of lymph node involvement in endometrioid endometrial carcinomas.
Subject(s)
Carcinoma, Endometrioid/metabolism , Endometrial Neoplasms/metabolism , Lymphatic Metastasis/diagnosis , Neoplasm Invasiveness/diagnosis , Neural Cell Adhesion Molecule L1/metabolism , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/metabolism , Carcinoma, Endometrioid/pathology , Carcinoma, Endometrioid/surgery , Cohort Studies , Endometrial Neoplasms/pathology , Endometrial Neoplasms/surgery , Female , Humans , Middle Aged , Neoplasm Staging , Preliminary Data , Preoperative PeriodABSTRACT
BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a common malignant disease worldwide, especially in China. We aimed to determine the level of autoantibodies against L1CAM in patients with ESCC. METHODS: Levels of circulating autoantibodies against L1CAM antigens were determined by an enzyme-linked immunosorbent assay in cohort 1 (191 patients with ESCC and 94 normal controls) and validated in cohort 2 (47 patients with ESCC and 47 normal controls). Receiver-operating characteristics were employed to calculate diagnostic accuracy. Cumulative survival time was calculated by the Kaplan-Meier method and analyzed by the log-rank test. RESULTS: In cohorts 1 and 2, levels of autoantibodies against L1CAM were all significantly higher in sera of patients with ESCC compared to normal controls (P < 0.05). Detection of autoantibodies against L1CAM provided a sensitivity of 26.2%, a specificity of 90.4%, and an area under the curve (AUC) of 0.603 (95% CI 0.535-0.672) in diagnosing ESCC in cohort 1, and a sensitivity of 27.7%, a specificity of 91.5%, and an AUC of 0.628 (95% CI 0.516-0.741). Similar results were observed in the diagnosis of early stage ESCC (25.2% sensitivity, 90.4% specificity, and an AUC of 0.611 (95% CI 0.533-0.689) in cohort 1, and 33.3% sensitivity, 91.5% specificity, and an AUC of 0.636 (95% CI 0.439-0.832) in cohort 2). Moreover, positive rates of autoantibodies against L1CAM had no statistical correlation with clinical outcome of ESCC (P > 0.05). CONCLUSIONS: Our results suggest that circulating autoantibodies against L1CAM is a potential biomarker for the early detection of ESCC.
Subject(s)
Autoantibodies/blood , Biomarkers, Tumor/blood , Carcinoma, Squamous Cell/blood , Esophageal Neoplasms/blood , Neural Cell Adhesion Molecule L1/immunology , Adult , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/immunology , Carcinoma, Squamous Cell/secondary , Carcinoma, Squamous Cell/therapy , Case-Control Studies , Combined Modality Therapy , Esophageal Neoplasms/immunology , Esophageal Neoplasms/pathology , Esophageal Neoplasms/therapy , Female , Follow-Up Studies , Humans , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Invasiveness , Prognosis , ROC Curve , Survival RateABSTRACT
SARA (Smad Anchor for Receptor Activation) plays a crucial role in Rab5-mediated endocytosis in cell lines localizing to early endosomes where it regulates morphology and function. Here, we analyzed the role of SARA during neuronal development and tested whether it functions as a regulator of endocytic trafficking of selected axonal and membrane proteins. Suppression of SARA perturbs the appearance of juxtanuclear endocytic recycling compartments and the neurons show long axons with large growth cones. Furthermore, surface distribution of the cell adhesion molecule L1 in axons and the fusion of vesicles containing transferring receptor (TfR) in dendrites were increased in neurons where SARA was silenced. Conversely, SARA overexpression generated large early endosomes and reduced neurite outgrowth. Taken together, our findings suggest a significant contribution of SARA to key aspects of neuronal development, including neurite formation.
Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Axons/metabolism , Dendrites/metabolism , Neurogenesis , Animals , Cells, Cultured , Endocytosis , Neural Cell Adhesion Molecule L1/metabolism , Rats , Receptors, Transferrin/metabolismABSTRACT
Human adult dental pulp stem cells (DPSCs) are self-renewing stem cells that originate from the neural crest during development and remain within the dental pulp niche through adulthood. Due to their multi-lineage differentiation potential and their relative ease of access they represent an exciting alternative for autologous stem cell-based therapies in neurodegenerative diseases. In animal models, DPSCs transplanted into the brain differentiate into functional neurons or astrocytes in response to local environmental cues that appear to influence the fate of the surviving cells. Here we tested the hypothesis that DPSCs might be able to respond to factors present in the retina enabling the regenerative potential of these cells. We evaluated the response of DPSCs to conditioned media from organotypic explants from control and chemically damaged rat retinas. To evaluate cell differentiation, we analyzed the expression of glial fibrillary acidic protein (GFAP), early neuronal and retinal markers (polysialic acid-neural cell adhesion molecule (PSA-NCAM); Pax6; Ascl1; NeuroD1) and the late photoreceptor marker rhodopsin, by immunofluorescence and reverse transcription polymerase chain reaction (RT-PCR). Exposure of DPSC cultures to conditioned media from control retinas induced a 39% reduction on the number of DPSCs that expressed GFAP; the expression of Pax6, Ascl1, PSA-NCAM or NeuroD1 was undetectable or did not change significantly. Expression of rhodopsin was not detectable in control or after exposure of the cultures with retinal conditioned media. By contrast, 44% of DPSCs exposed to conditioned media from damaged retinas were immunopositive to this protein. This response could not be reproduced when conditioned media from Müller-enriched primary cultures was used. Finally, quantitative RT-PCR was performed to compare the relative expression of glial cell-derived neurotrophic factor (GDNF), nerve growth factor (NGF), ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) in DPSC co-cultured with retinal organotypic explants, where BDNF mRNA expression was significantly upregulated in retinal-exposed cultures. Our data demonstrate that DPSC cultures respond to cues from the rat retina and differentiate to express retinal neuronal markers.
Subject(s)
Adult Stem Cells/physiology , Cell Differentiation/physiology , Dental Pulp/physiology , Retina/metabolism , Rhodopsin/metabolism , Adult , Adult Stem Cells/cytology , Animals , Brain-Derived Neurotrophic Factor/metabolism , Cell Culture Techniques , Coculture Techniques , Culture Media, Conditioned , Dental Pulp/cytology , Ependymoglial Cells/metabolism , Glial Fibrillary Acidic Protein/metabolism , Humans , Nerve Growth Factors/metabolism , Neural Cell Adhesion Molecule L1/metabolism , RNA, Messenger/metabolism , Rats, Long-Evans , Retina/injuries , Sialic Acids/metabolism , Tissue Culture Techniques , Young AdultABSTRACT
The granule cells (GCs) of the dentate gyrus transiently express markers of the GABAergic phenotype early during development. However, GCs are generated throughout life, posing the question of whether the newborn neurons in the adult rodent recapitulate the development of the neurotransmitter phenotype of GCs generated during embryonic and early postnatal development. In this work we asked whether newborn GCs transiently express a GABAergic phenotype during their development in the adult rat. Using retroviral infection, we labeled dividing cells in the dorsal hippocampus with GFP, identified them as granule cells, and determined their expression of GABAergic markers at different developmental stages. We found that GFP-positive cells express Prox-1 and calbindin, identifying them as GCs. GABA or GAD(67) was expressed in 13% of GFP-positive cells at 7 dpi, in 16% at 10 dpi and in 20% at 15 dpi. At 30 dpi, however, no GFP-positive cell somata containing GABAergic markers were detected, but their mossy fiber boutons did contain GAD(67). Interestingly, developing GCs detected with doublecortin and PSA-NCAM in non-injected adult rats, did not express GABAergic markers, suggesting that retroviral injection/infection stimulates their transient expression. However, in non-injected rats, a number of mossy fiber boutons of newborn granule cells detected with PSA-NCAM did express GAD(67). Our findings reveal that developing GCs born in the adult are able to transiently up-regulate the expression of GABAergic markers to be detected in their soma in response to insults, while they constitutively express GAD(67) in their mossy fibers.
Subject(s)
Cytoplasmic Granules/physiology , Gene Expression Regulation/physiology , Hippocampus/cytology , gamma-Aminobutyric Acid/physiology , Animals , Animals, Newborn/genetics , Biomarkers/metabolism , Calbindins , Cell Differentiation/genetics , Cytoplasmic Granules/genetics , Cytoplasmic Granules/virology , Doublecortin Domain Proteins , Doublecortin Protein , Green Fluorescent Proteins/biosynthesis , Green Fluorescent Proteins/genetics , HEK293 Cells , Hippocampus/embryology , Hippocampus/virology , Humans , Male , Microtubule-Associated Proteins/genetics , Moloney murine leukemia virus/genetics , Neural Cell Adhesion Molecule L1/genetics , Neuropeptides/genetics , Phenotype , Rats , Rats, Sprague-Dawley , Retroviridae/genetics , S100 Calcium Binding Protein G/genetics , Sialic Acids/genetics , gamma-Aminobutyric Acid/biosynthesis , gamma-Aminobutyric Acid/geneticsABSTRACT
In rats, iron deficiency produces an alteration in myelin formation. However, there is limited information on the effects of this condition on oligodendroglial cell (OLGc) proliferation and maturation. In the present study, we further analyzed the hypomyelination associated with iron deficiency by studying the dynamics of oligodendrogenesis. Rats were fed control (40 mg Fe/kg) or iron-deficient (4 mg Fe/kg) diets from gestation day 5 until postnatal day 3 (P3) or 11 (P11). OLGc proliferation, migration and differentiation were investigated before and after an intracranial injection of apotransferrin at 3 days of age (P3). The proliferating cell population was evaluated at P3. Iron-deficient (ID) animals showed an increase in the oligodendrocyte precursors cell (OPC) population in comparison with controls. The overall pattern of migration of cells labeled with BrdU was investigated at P11. Iron deficiency increased the amount of BrdU(+) cells in the corpus callosum (CC) and decreased OLGc maturation and myelin formation. Changes in nerve conduction were analyzed by measuring visual evoked potentials. Latency and amplitude were significantly disturbed in ID rats compared with controls. Both parameters were substantially normalized when animals were treated with a single intracranial injection of 350 ng apotransferrin (aTf). The current results give support to the idea that iron deficiency increases the number of proliferating and undifferentiated cells in the CC compared with the control. Treatment with aTf almost completely reverted the effects of iron deficiency, both changing the migration pattern and increasing the number of mature cells in the CC and myelin formation.
Subject(s)
Apoproteins/therapeutic use , Cell Proliferation/drug effects , Demyelinating Diseases/drug therapy , Demyelinating Diseases/pathology , Iron Deficiencies , Oligodendroglia/drug effects , Prenatal Exposure Delayed Effects , Transferrin/therapeutic use , Age Factors , Analysis of Variance , Animals , Animals, Newborn , Apoproteins/metabolism , Basic Helix-Loop-Helix Transcription Factors/metabolism , Body Weight/physiology , Brain , Bromodeoxyuridine/metabolism , Cell Count , Cell Differentiation/drug effects , Cell Differentiation/physiology , Corpus Callosum/metabolism , Corpus Callosum/pathology , Demyelinating Diseases/etiology , Demyelinating Diseases/physiopathology , Electroencephalography/methods , Evoked Potentials, Visual/drug effects , Evoked Potentials, Visual/physiology , Female , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Developmental/physiology , Hematocrit/methods , Myelin Basic Protein/metabolism , Nerve Tissue Proteins/metabolism , Neural Cell Adhesion Molecule L1/metabolism , Oligodendroglia/physiology , Photic Stimulation/methods , Pregnancy , Proliferating Cell Nuclear Antigen/metabolism , Rats , Sialic Acids/metabolism , Transferrin/metabolismABSTRACT
The region that surrounds the central canal of the spinal cord derives from the neural tube and retains a substantial degree of plasticity. In turtles, this region is a neurogenic niche where newborn neurons coexist with precursors, a fact that may be related with the endogenous repair capabilities of low vertebrates. Immunohistochemical evidence suggests that the ependyma of the mammalian spinal cord may contain cells with similar properties, but their actual nature remains unsolved. Here, we combined immunohistochemistry for cell-specific markers with patch-clamp recordings to test the hypothesis that the ependyma of neonatal rats contains immature neurons similar to those in low vertebrates. We found that a subclass of cells expressed HuC/D neuronal proteins, doublecortin, and PSA-NCAM (polysialylated neural cell adhesion molecule) but did not express NeuN (anti-neuronal nuclei). These immature neurons displayed electrophysiological properties ranging from slow Ca(2+)-mediated responses to fast repetitive Na(+) spikes, suggesting different stages of maturation. These cells originated in the embryo, because we found colocalization of neuronal markers with 5-bromo-2'-deoxyuridine when injected during embryonic day 7-17 but not in postnatal day 0-5. Our findings represent the first evidence that the ependyma of the rat spinal cord contains cells with molecular and functional features similar to immature neurons in adult neurogenic niches. The fact that these cells retain the expression of molecules that participate in migration and neuronal differentiation raises the possibility that the ependyma of the rat spinal cord is a reservoir of immature neurons in "standby mode," which under some circumstances (e.g., injury) may complete their maturation to integrate spinal circuits.
Subject(s)
Ependyma/cytology , Neurons/cytology , Spinal Cord/cytology , Acids/metabolism , Action Potentials , Adenosine Triphosphate/metabolism , Animals , Animals, Newborn , Bromodeoxyuridine , Calcium/metabolism , Doublecortin Domain Proteins , Doublecortin Protein , ELAV Proteins/metabolism , ELAV-Like Protein 3 , ELAV-Like Protein 4 , Ependyma/growth & development , Ependyma/metabolism , Immunohistochemistry , In Vitro Techniques , Membrane Potentials , Microtubule-Associated Proteins/metabolism , Neural Cell Adhesion Molecule L1/metabolism , Neurons/metabolism , Neurons/ultrastructure , Neuropeptides/metabolism , Patch-Clamp Techniques , Rats , Rats, Sprague-Dawley , Sialic Acids/metabolism , Sodium/metabolism , Spinal Cord/growth & development , Spinal Cord/metabolismABSTRACT
Huntington's disease is a neurodegenerative autosomal disorder characterized by selective loss of striatal and cortical neurons. The mammalian brain subventricular zone contains a population of neural precursors involved in postnatal neurogenesis. These newly generated cells migrate from the subventricular zone along the rostral migratory stream and differentiate into mature olfactory bulb neurons throughout adulthood. The establishment of this pathway depends upon a variety of molecules, including polysialylated neural cell adhesion molecule (PSA-NCAM). We used a murine model of Huntington's disease, the R6/2 transgenic mouse, and in vivo bromodeoxyuridine administration to label cells undergoing proliferation and to follow their migration along the rostral migratory stream. Bromodeoxyuridine labeling did not show any significant increase in proliferation of progenitor cells in symptomatic R6/2 mice, but migration of neuroblasts along the rostral migratory stream was significantly diminished. The decrease in neuroblast migration was not due to an alteration in the expression of PSA-NCAM along the rostral migratory stream since immunohistochemical analysis showed no significant differences between R6/2 and wild type mice. In addition, we used Fluoro-Jade C to evaluate apoptosis and demonstrated that the number of apoptotic cells in the rostral migratory stream is similar in affected and wild type animals, suggesting that cell death is not responsible for the differences observed in neuroblast migration. We conclude that in R6/2 mice, progenitor cells have an impaired migration in their route to the olfactory bulb, with accumulation of cells in the caudal rostral migratory stream that does not result from changes in PSA-NCAM expression and/or cell death.
Subject(s)
Brain/physiopathology , Cell Movement/physiology , Huntington Disease/physiopathology , Neural Cell Adhesion Molecule L1/metabolism , Neurons/physiology , Sialic Acids/metabolism , Animals , Apoptosis/physiology , Brain/pathology , Bromodeoxyuridine , Disease Models, Animal , Female , Fluoresceins , Gene Expression , Huntingtin Protein , Huntington Disease/metabolism , Huntington Disease/pathology , Immunohistochemistry , Male , Mice , Mice, Transgenic , Nerve Tissue Proteins/genetics , Neurogenesis/physiology , Nuclear Proteins/geneticsABSTRACT
Adult neural stem cells (NSC) proliferate and differentiate depending on the composition of the cellular and molecular niche in which they are immersed. Until recently, microglial cells have been ignored as part of the neurogenic niche. We studied the dynamics of NSC proliferation and differentiation in the dentate gyrus of the hippocampus (DG) and characterized the changes of the neurogenic niche in adrenalectomized animals (ADX). At the cellular level, we found increased NSC proliferation and neurogenesis in the ADX animals. In addition, a morphologically distinct subpopulation of NSC (Nestin+/GFAP-) with increased proliferating profile was detected. Interestingly, the number of microglial cells at stages 2 and 3 of activation correlated with increased neurogenesis (r2 = 0.999) and the number of Nestin-positive cells (r2 = 0.96). At the molecular level, transforming growth factor beta (TGF-beta) mRNA levels were increased 10-fold in ADX animals. Interestingly, TGF-beta levels correlated with the amount of neurogenesis detected (r2 = 0.99) and the number of stage 2 and 3 microglial cells (r2 = 0.94). Furthermore, blockade of TGF-beta biological activity by administration of an anti-TGF-beta type II receptor antibody diminished the percentage of 5-bromo-2'-deoxyuridine (BrdU)/PSA-NCAM-positive cells in vivo. Moreover, TGF-beta was able to promote neurogenesis in NSC primary cultures. This work supports the idea that activated microglial cells are not pro- or anti-neurogenic per se, but the balance between pro- and anti-inflammatory secreted molecules influences the final effect of this activation. Importantly, we identified an anti-inflammatory cytokine, TGF-beta, with neurogenic potential in the adult brain.