ABSTRACT
BACKGROUND: Acute Coronary Syndrome (ACS) stands as a significant contributor to cardiovascular mortality, necessitating improved diagnostic tools for early detection and tailored therapeutic interventions. Current diagnostic modalities, exhibit limitations in sensitivity and specificity, urging the quest for novel biomarkers to enhance discrimination of the different stages of ACS including unstable angina, Non-ST-segment Elevation Myocardial Infarction (NSTEMI), and ST-segment Elevation Myocardial Infarction (STEMI). METHODS: This study investigated the potential of a plasma-circulating multi-noncoding RNA (ncRNA) panel, comprising four miRNAs (miR-182-5p, miR-23a-3p, miR-146a-5p, and miR-183-5p) and three lncRNAs (SNHG15, SNHG5, and RMRP), selected based on their intricate involvement in ACS pathogenesis and signaling pathways regulating post-myocardial infarction (MI) processes. The differential expression of these ncRNAs was validated in sera of ACS patients and healthy controls via real-time polymerase chain reaction (RT-PCR). RESULTS: Analysis revealed a marked upregulation of the multi-ncRNAs panel in ACS patients. Notably, miRNA-182-5p and lncRNA-RMRP exhibited exceptional discriminatory power, indicated by the high area under the curve (AUC) values (0.990 and 0.980, respectively). Importantly, this panel displayed superior efficacy in discriminating between STEMI and NSTEMI, outperforming conventional biomarkers like creatine kinase-MB and cardiac troponins. Additionally, the four miRNAs and lncRNA RMRP showcased remarkable proficiency in distinguishing between STEMI and unstable angina. CONCLUSION: The findings underscore the promising potential of the multi-ncRNA panel as a robust tool for early ACS detection, and precise differentiation among ACS subtypes, and as a potential therapeutic target.
Subject(s)
Acute Coronary Syndrome , MicroRNAs , Myocardial Infarction , Non-ST Elevated Myocardial Infarction , RNA, Long Noncoding , ST Elevation Myocardial Infarction , Humans , Acute Coronary Syndrome/diagnosis , Acute Coronary Syndrome/genetics , ST Elevation Myocardial Infarction/diagnosis , ST Elevation Myocardial Infarction/therapy , Non-ST Elevated Myocardial Infarction/diagnosis , Non-ST Elevated Myocardial Infarction/pathology , RNA, Long Noncoding/genetics , MicroRNAs/genetics , Myocardial Infarction/diagnosis , Myocardial Infarction/genetics , Biomarkers , Angina, Unstable/diagnosis , Angina, Unstable/geneticsABSTRACT
Myocardial ischemiareperfusion injury (MI/R) is considered a main risk factor for global cardiac mortality and morbidity, for which no effective treatment exists. Both inflammation and epigenetic regulation play a pivotal role in the early stage of MI/R. The present study aimed at investigating the prospective anti-inflammatory role of trans-anethole (TNA) in targeting MI/R and its related mechanism in upregulating the expression of the inflammatory and cardiac-related gene (VAV3), and its epigenetic regulators (lncRNA-JRKL-AS1 and miR-1298) that were retrieved from in-silico data analysis in an ischemia/reperfusion (I/R) rat model. MATERIALS & METHODS: TNA was administered in 3 doses (50, 100, and 200 mg/kg), 15 min prior to coronary ligation in male Wistar rats. The left ventricular end-diastolic pressure and dP/dtmax were assessed. Histopathological, biochemical, and molecular analyses were performed to assess the effects of TNA pre-treatment on the I/R rats model. RESULTS: TNA alleviated the I/R-induced cardiac injury pathologically and improved the cardiac function tests and enzymes. At the molecular level, TNA upregulated the expression level of the retrieved RNA-based panel (VAV3 mRNA/miR-1298/lncRNA JRKL-AS1). At the protein level, TNA decreased the cardiac content of the pro-inflammatory cytokine TNF-α. CONCLUSION: TNA has demonstrated a potential ability to alleviate the cardiac injury and attenuate the inflammatory response following ischemia-reperfusion in the rat model through modulation of the expression of RNA panel (VAV3 mRNA/miR-1298/lncRNA JRKL-AS1) and TNF- α protein.
Subject(s)
MicroRNAs , Myocardial Reperfusion Injury , RNA, Long Noncoding , Allylbenzene Derivatives , Animals , Anisoles , Apoptosis , Disease Models, Animal , Epigenesis, Genetic , Male , MicroRNAs/metabolism , Myocardial Reperfusion Injury/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , RNA, Messenger/therapeutic use , Rats , Rats, WistarABSTRACT
BACKGROUND: Acute coronary syndrome (ACS) is a major cause of death all over the world. STEMI represents a type of myocardial infarction with acute ST elevation. We aimed to assess the predictive power of potential RNA panel expression in acute coronary syndrome. METHOD: We used in silico data analysis to retrieve RNAs related to glycerophospholipid metabolism dysregulation and specific to ACS that results in the selection of Alpha/Beta hydrolase fold domain4 (ABHD4) mRNA and its epigenetic regulators (Foxf1 adjacent noncoding developmental regulatory RNA (FENDRR) lncRNA, miRNA-221, and miRNA-197). We assessed the expression of the serum RNA panel in 68 patients with ACS, 21 patients with chest pain due to non-cardiac causes, and 21 healthy volunteers by quantitative real-time polymerase chain reaction. RESULTS: The study data showed significant down regulation in the expression of the serum levels of FENDRR lncRNA and miRNA-221-3p by 120-fold and 22-fold in Unstable angina (UA) in comparison with healthy volunteers, and by 8.6-fold and 2-fold in ST segment elevation myocardial infarction (STEMI) patients versus UA; concomitant upregulation in the expression of ABHD4 mRNA and miRNA-197-5p by 444-fold and 10-fold in UA compared with healthy volunteers, and by 1.54-fold and 4.5-fold in STEMI versus unstable angina. Performance characteristics analysis showed that the ABHD4-regulating RNA panel were potential biomarkers for prediction of ACS. Moreover, there was a significant association between the 2 miRNAs and ABHD4 mRNA and the regulating FENDRR lncRNA. CONCLUSION: Collectively, ABHD4 mRNA regulating RNA panel based on putative interactions seems to be novel non-invasive biomarkers that could detect ACS early and stratify severity of the condition that could improve health outcome.
Subject(s)
Acute Coronary Syndrome/diagnosis , Biomarkers/blood , Gene Expression Regulation , Lysophospholipase , Acute Coronary Syndrome/blood , Humans , MicroRNAs/blood , RNA, Long Noncoding/blood , RNA, Messenger/bloodABSTRACT
Overexpression of human epidermal growth factor receptor 2 protein (Her-2) in Barrett neoplasia is significant for targeted therapy with trastuzumab. Here, we studied the frequency of Her-2 overexpression in Barrett adenocarcinoma and precursor lesions. Retrospective formalin-fixed paraffin-embedded tissue samples of 25 normal (NM) esophageal mucosa, 50 Barrett esophagus (BE) without dysplasia, 49 BE with low-grade dysplasia (LGD), 50 BE with high-grade dysplasia (HGD), and 50 invasive adenocarcinoma (ICA) were used. A BE tissue microarray was built and analyzed by Her-2 immunohistochemistry (IHC) and Her-2 dual in situ hybridization (DISH). Her-2 IHC expression was negative in NM and low in 26% of BE (IHC score: 1+) and in 24.5% of LGD (IHC score: 1 to 2+). Her-2 overexpression was seen in 28% of HGD and in 24% of ICA (IHC score: 2 to 3+). Her-2 DISH was negative in NM and BE but positive in 6% of LGD, 20% of HGD, and 18% of ICA. Differences in Her-2 DISH positivity between NM and HGD or ICA were statistically significant (P=0.02), but those between NM and LGD or HGD and ICA were not (P=0.2). Although Her-2 overexpression results in ICA were similar to previous reports, the finding of 28% in HGD was unexpected and may have clinical implications. Positive Her-2 DISH in 6% of LGD is novel, suggesting a role of Her-2 during BE progression.
Subject(s)
Adenocarcinoma/metabolism , Barrett Esophagus/metabolism , Receptor, ErbB-2/metabolism , Stomach Neoplasms/metabolism , Adenocarcinoma/pathology , Adult , Aged , Aged, 80 and over , Barrett Esophagus/pathology , Disease Progression , Female , Humans , Immunohistochemistry , In Situ Hybridization , Male , Metaplasia , Middle Aged , Stomach Neoplasms/pathologyABSTRACT
BACKGROUND: DOG1 is a novel gene on gastrointestinal stromal tumors (GISTs) that encodes the chloride channel protein anoctamin 1, also known as discovered on GIST-1 (DOG1) protein. DOG1 antibodies are a sensitive and specific marker against GIST positive for CD117 and CD34 and negative for CD117 and CD34. DOG1 is also independent of KIT or PDGFRA mutation status and considered specific for GIST when it was first discovered in 2004. METHODS: The previous 10 years of literature was searched for articles relating to DOG1. We critically reviewed 12 studies that showed DOG1 was positive in 250 cases of 2,360 tested non-GIST neoplasms (10.6%) at different anatomical sites using monoclonal, polyclonal, or nonspecified antibodies. Criteria for positivity varied between the studies. RESULTS: Monoclonal and polyclonal DOG1 antibodies were reactive in various different non-GIST tumor types spanning 9 organ systems in addition to normal salivary and pancreatic tissues. The tumors included were renal oncocytoma (100%), renal cell carcinoma chromophobe type (86%), solid pseudopapillary neoplasm of the pancreas (51%), neoplastic salivary tissue (17%), synovial sarcoma (15%), leiomyoma (10%), pancreatic adenocarcinoma (7%), and leiomyosarcoma (4%). CONCLUSIONS: By contrast to the original concept that DOG1 antibodies are specific to GIST neoplasms, the studies reviewed showed that the data suggest DOG1 positivity in select non-GIST tumors. Only in the appropriate clinical and pathological context is DOG1 positivity specific and helpful in the diagnosis of GIST.
Subject(s)
Chloride Channels/genetics , Chloride Channels/immunology , Gastrointestinal Neoplasms/diagnosis , Gastrointestinal Neoplasms/genetics , Gastrointestinal Stromal Tumors/diagnosis , Gastrointestinal Stromal Tumors/genetics , Neoplasm Proteins/genetics , Neoplasm Proteins/immunology , Anoctamin-1 , Antibodies, Monoclonal/immunology , Biomarkers, Tumor/genetics , HumansABSTRACT
Human papillomavirus (HPV) related squamous cell carcinoma (SCC) involving the anal canal is a well-known carcinoma associated with high-risk types of HPV. HPV-related SCC with papillary morphology (papillary SCC) has been described in the oropharynx. We describe, for the first time, a case of anal HPV-related squamous carcinoma with papillary morphology. The tumor arose from the anal mucosa. The biopsies revealed a superficially invasive SCC with prominent papillary features and associated in situ carcinoma. The tumor cells were positive for p16 and were also positive for high-risk types of HPV using chromogenic in situ hybridization. The findings are consistent with a HPV-related SCC of the anal canal with papillary features. This tumor shows histologic features similar to a papillary HPV-related SCC of the oropharynx. Additional studies are needed to characterize these lesions.
Subject(s)
Anus Neoplasms/pathology , Carcinoma, Papillary/pathology , Carcinoma, Squamous Cell/pathology , Papillomaviridae/isolation & purification , Papillomavirus Infections/virology , Aged, 80 and over , Anus Neoplasms/chemistry , Anus Neoplasms/therapy , Anus Neoplasms/virology , Biomarkers, Tumor/analysis , Biopsy , Carcinoma, Papillary/chemistry , Carcinoma, Papillary/therapy , Carcinoma, Papillary/virology , Carcinoma, Squamous Cell/chemistry , Carcinoma, Squamous Cell/therapy , Carcinoma, Squamous Cell/virology , Chemoradiotherapy , DNA, Viral/genetics , Female , Human Papillomavirus DNA Tests , Humans , Immunohistochemistry , In Situ Hybridization , Neoplasm Invasiveness , Papillomaviridae/genetics , Papillomavirus Infections/complications , Treatment OutcomeABSTRACT
Please cite this paper as: Tigno, Hansen, Nawang, Shamekh, and Albano (2011). Vasomotion Becomes Less Random as Diabetes Progresses in Monkeys. Microcirculation 18(6), 429-439. OBJECTIVE: Changes in vasomotion may precede other global indices of autonomic dysfunction that track the onset and progression of diabetes. Recently, we showed that baseline spectral properties of vasomotion can discriminate among N, PreDM, and T2DM nonhuman primates. In this study, our aims were to: (i) determine the time dependence and complexity of the spectral properties of vasomotion in three metabolic groups of monkeys; (ii) examine the effects of heat-provoked vasodilatation on the power spectrum; and (iii) compare the effects of exogenous insulin on the vasomotion. MATERIALS AND METHODS: Laser Doppler flow rates were measured from the foot in 9 N, 11 PreDM, and 7 T2DM monkeys. Baseline flow was measured at 34°C, and under heat stimulation at 44°C. Euglycemic-hyperinsulinemic clamps were performed to produce acute hyperinsulinemia. The Lempel-Ziv complexity, prediction error, and covariance complexity of five-dimensional embeddings were calculated as measures of randomness. RESULTS AND CONCLUSIONS: With progression of diabetes, measures of randomness of the vasomotion progressively decreased, suggesting a progressive loss of the homeostatic capacity of the peripheral circulation to respond to environmental changes. Power spectral density among T2DM animals resided mostly in the 0- to 1.45-Hz range, which excluded the cardiac component, suggesting that with progression of the disease, regulation of flow shifts toward local rather than central (autonomic) mechanisms. Heating increased all components of the spectral power in all groups. In N, insulin increased the vasomotion contributed by endothelial, neurogenic, vascular myogenic, and respiratory processes, but diminished that due to heart rate. In contrast, in T2DM, insulin failed to stimulate the vascular myogenic and respiratory activities, but increased the neural/endothelial and heart rate components. Interestingly, acute hyperinsulinemia resulted in no significant vasomotion changes in the chronically hyperinsulinemic PreDM, suggesting yet another form of "insulin resistance" during this stage of the disease.
Subject(s)
Diabetes Mellitus, Type 2/physiopathology , Hyperinsulinism/physiopathology , Vasoconstriction , Vasodilation , Animals , Blood Flow Velocity , Diabetes Mellitus, Type 2/metabolism , Female , Hyperinsulinism/metabolism , Insulin/metabolism , Macaca mulatta , MaleABSTRACT
Nonhuman primates (NHPs) share with humans many features of lipid metabolism and often develop all features of the metabolic syndrome, including hypertriglyceridemia and low high-density lipoprotein cholesterol, and have been used in many studies of potential therapeutics during the preclinical phase. Here we identify for the first time in middle-aged and older rhesus the natural occurrence of hypercholesterolemia, and this hypercholesterolemia develops despite maintenance on a low-cholesterol diet. The aims of this study were to (a) define normal and hypercholesterolemia in rhesus monkeys, (b) determine the factors associated with the development of hypercholesterolemia, (c) compare the lipoprotein profiles in adult rhesus monkeys fed a low-fat/low-cholesterol diet (LFLC) with the profiles of human subjects, and (d) determine the effect of a 16-week high-fat/high-cholesterol (HFHC) diet feeding on total cholesterol and lipoprotein profiles in middle-aged and older monkeys. In our colony, maintained on a constant diet with negligible cholesterol, the mean total cholesterol level in healthy nondiabetic monkeys was 3.7 ± 0.02 mmol/L, with hypercholesterolemia identified as the 95th percentile of the normal cholesterol distribution (≥5.2 mmol/L). Severe hypercholesterolemia developed in the HFHC-fed group; however, despite the high-fat diet composition, unexpectedly, no weight gain occurred in these NHPs. The diet-induced hypercholesterolemia differed significantly in lipoprotein pattern from that of the spontaneous hypercholesterolemia. In summary, despite ingesting only a LFLC, NHPs frequently develop hypercholesterolemia, reflecting lipoprotein patterns similar to human subjects; and this lipid profile of spontaneous hypercholesterolemia differs significantly from the hypercholesterolemia induced by an HFHC diet.
Subject(s)
Adiposity/physiology , Aging/blood , Diabetes Mellitus, Type 2/blood , Hypercholesterolemia/blood , Animals , Body Weight/physiology , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Diet , Dietary Fats , Female , Macaca mulatta , MaleABSTRACT
The 796RMB cell line is a multipotent stem cell line isolated from human fetal midbrain tissues, a region from which dopamine neurons of the substantia nigra develop. It would be useful to increase the dopaminergic characteristics of this cell line to enhance its usefulness as a cell therapy for Parkinson's disease utilizing transplantation protocols. Sertoli cells and its conditioned media isolated from the testis have been previously shown to enhance tyrosine hydroxylase expression in ventral mesencephalon neurons both in vitro and in vivo. Therefore, the present preliminary study investigated the ability of Sertoli cell pre-conditioned medium to enhance differentiation of the 796MB cell line toward the domaminergic phenotype. Results showed that secretory products derived from Sertoli cell conditioned medium increased cell proliferation and enhanced dopaminergic neuronal differentiation of the 796RMB cell line. These findings may lead to alternative therapeutic cell transplantation protocols for the treatment of Parkinson's disease.
Subject(s)
Culture Media, Conditioned/pharmacology , Mesencephalon/cytology , Neurons/physiology , Sertoli Cells/chemistry , Stem Cells/drug effects , Animals , Animals, Newborn , Cell Count/methods , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Dopamine/metabolism , Fetus , Humans , Male , Microtubule-Associated Proteins/metabolism , Rats , Tyrosine 3-Monooxygenase/metabolismABSTRACT
Systemic lupus erythematosus (SLE) is a common systemic autoimmune disease that involves several vital organs including the cardiovascular system, joints, and kidneys. The pathology is characterized by accumulation of autoreactive lymphocytes that attack the patients' own tissues, secretion of autoantibodies and deposition of immune complexes in vital organs. Chronic widespread inflammation is the hallmark of SLE and the target of current therapy. According to recent theories, intonating immune circuits of inflammatory cytokines and immune cells constitute highly specialized targets for SLE therapy, which nonetheless consists for the most part of anti-inflammatory medications and cytotoxic drugs. For advanced autoimmune disorders, cell therapy aiming at introducing "healthy" stem cells has been promising, keeping in mind that in its current state, stem cell therapy is reserved for the most advanced diseases refractory to traditional therapy. Ongoing studies in our laboratories examined the role of the bone marrow microenvironment, in particular, mesenchymal stem cells (MSCs) in the etiopathogenesis of SLE. Specifically, we are testing the hypothesis that, in human SLE mouse model, marrow MSCs are defective structurally and functionally. Preliminary data indicate that structural and functional defects in MSC population from an autoimmune mouse model for human SLE may contribute to this pathology and consequently present a target for cell therapy.
Subject(s)
Lupus Erythematosus, Systemic/etiology , Mesenchymal Stem Cells/immunology , Mesenchymal Stem Cells/pathology , Animals , Bone Marrow/immunology , Cell Communication , Cell Differentiation , Cell Proliferation , Cells, Cultured , Colony-Forming Units Assay , Connexin 43/immunology , Connexin 43/metabolism , Disease Models, Animal , Hematopoietic Stem Cells/immunology , Hematopoietic Stem Cells/metabolism , Hematopoietic Stem Cells/pathology , Humans , Immunohistochemistry , Lupus Erythematosus, Systemic/immunology , Lupus Erythematosus, Systemic/pathology , Lupus Erythematosus, Systemic/physiopathology , Male , Mesenchymal Stem Cells/metabolism , Mice , Mice, Inbred C57BL , Osteoblasts/immunology , Osteoblasts/metabolism , Osteoblasts/pathologyABSTRACT
Sertoli cells (SCs) are testis-derived cells that secrete trophic factors important for the development of germ cells. Both porcine and rat SCs have been used as graft facilitators - neonatal porcine SCs to support islets in diabetes and 15-day-old rat SCs to enhance dopaminergic neuron transplants in Parkinson's disease models. However, there has never been a study examining the optimal SCs preparation to enhance tyrosine hydroxylase expression in the ventral mesencephalon (VM) neuron. The aim of this study was to compare the ability of both rat and porcine SCs to enhance tyrosine hydroxylase expression (TH) and neuronal survival at the same postnatal developmental ages. The SCs were isolated from 1-, 9-, or 15-day-old rat, or neonate (2-5 days), 2-month, or 4-month-old pig, and co-cultured with VM tissue from 13.5-day-old embryos. Our results showed that VM neurons co-cultured with SCs dispersed over the culture plate and had extensive neuritic outgrowth, while VM neurons cultured alone tended to cluster together forming a mass of cells with limited neurite outgrowth. TH expression was significantly increased when VM neurons were co-cultured with 15-day rat SCs or 2-month pig SCs but not when the cells were co-cultured with other ages of SCs. This suggests that secretion of trophic factors by SCs varies according to the developmental age, and it is critical for the success of graft facilitation that SCs from the appropriate age and species be used.
Subject(s)
Mesencephalon/cytology , Mesencephalon/enzymology , Neurons/enzymology , Sertoli Cells/physiology , Tyrosine 3-Monooxygenase/biosynthesis , Tyrosine 3-Monooxygenase/genetics , Animals , Animals, Newborn , Cell Division/physiology , Cell Separation , Cell Survival , Cells, Cultured , Coculture Techniques , Immunohistochemistry , Male , Mesencephalon/embryology , Neurites/physiology , Neurons/ultrastructure , Rats , Sertoli Cells/ultrastructure , SwineABSTRACT
Benign neurofibromas and malignant peripheral nerve sheath tumors are serious complications of neurofibromatosis type 1. The epidermal growth factor receptor is not expressed by normal Schwann cells, yet is overexpressed in subpopulations of Nf1 mutant Schwann cells. We evaluated the role of EGFR in Schwann cell tumorigenesis. Expression of EGFR in transgenic mouse Schwann cells elicited features of neurofibromas: Schwann cell hyperplasia, excess collagen, mast cell accumulation, and progressive dissociation of non-myelin-forming Schwann cells from axons. Mating EGFR transgenic mice to Nf1 hemizygotes did not enhance this phenotype. Genetic reduction of EGFR in Nf1(+/-);p53(+/-) mice that develop sarcomas significantly improved survival. Thus, gain- and loss-of-function experiments support the relevance of EGFR to peripheral nerve tumor formation.
Subject(s)
ErbB Receptors/metabolism , Neurofibroma/metabolism , Neurofibromatosis 1/metabolism , Neurofibromatosis 1/pathology , Peripheral Nerves/metabolism , Peripheral Nerves/pathology , Schwann Cells/physiology , 2',3'-Cyclic-Nucleotide Phosphodiesterases/genetics , 2',3'-Cyclic-Nucleotide Phosphodiesterases/metabolism , Animals , Cells, Cultured , ErbB Receptors/genetics , Fibrosis , Humans , Mast Cells/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neoplasms, Nerve Tissue/genetics , Neoplasms, Nerve Tissue/metabolism , Neoplasms, Nerve Tissue/pathology , Neurofibroma/genetics , Neurofibroma/pathology , Neurofibromatosis 1/genetics , Neurofibromin 1/genetics , Neurofibromin 1/metabolism , Peripheral Nerves/ultrastructure , Schwann Cells/cytology , Signal Transduction/physiology , Survival Rate , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolismABSTRACT
Cell replacement therapy is of great interest as a long-term treatment of neurodegenerative diseases such as Parkinson's disease (PD). We have previously shown that Sertoli cells (SC) provide neurotrophic support to transplants of dopaminergic fetal neurons and NT2N neurons, derived from the human clonal precursors cell line NTera2/D1 (NT2), which differentiate into dopaminergic NT2N neurons when exposed to retinoic acid. We have created SC-NT2 cell tissue constructs cultured in the high aspect ratio vessel (HARV) rotating wall bioreactor. Sertoli cells, NT2, and SC plus NT2 cells combined in starting ratios of 1:1, 1:2, 1:4 and 1:8 were cultured in the HARV in DMEM with 10% fetal bovine serum and 1% growth factor reduced Matrigel for 3 days, without retinoic acid. Conventional, non-HARV, cultures grown in the same culture medium were used as controls. The presence of tyrosine hydroxylase (TH) was assessed in all culture conditions. Sertoli-neuron-aggregated-cell (SNAC) tissue constructs grown at starting ratios of 1:1 to 1:4 contained a significant amount of TH after 3 days of culture in the HARV. No TH was detected in SC HARV cultures, or SC, NT2 or SC-NT2 conventional co-cultures. Quantitative stereology of immunolabled 1:4 SNAC revealed that approximately 9% of NT2 cells differentiate into TH-positive (TH+) NT2N neurons after 3 days of culture in the HARV, without retinoic acid. SNAC tissue constructs also released dopamine (DA) when stimulated with KCl, suggesting that TH-positive NT2N neurons in the SNAC adopted a functional dopaminergic phenotype. SNAC tissue constructs may be an important source of dopaminergic neurons for neuronal transplantation.