Monday, June 20, 2011

Transfection/Infection of Primary Neurons

Gene Expression Analysis of Neurons is an important tools in basic research and the study of neuropathologies. At the Neuromics' blog: "siRNA, DsiRNA and Plasmid Transfection Efficiency", I have posted many examples of successful tarnsfection of primary neurons and related cells using both our Transfection Kits/Reagents and others.

The other puzzle piece for these studies is having a fresh, pure and easy to use source of cells. Here, Neuromics has many options. These primary neurons and neural progenitors are widely referenced in key publications. Applications referenced include: transfection, pharmacology, electrophysiology, immunocytochemistry, and neuronal development studies.

This posting features infection of our e18 Primary Rat Combined Hippocampus, Cortex, and Ventricular Neurons using Nipah virus related components and HeV pseudotyped virions

Aparna Talekar, Antonello Pessi, and Matteo Porotto. Infection of primary neurons mediated by Nipah virus envelope proteins: Role of host target cells in antiviral action. J. Virol. doi:10.1128/JVI.00452-11.

Abstract: We have previously described heterotypic peptides from parainfluenza virus that potently inhibit Nipah virus in vitro, but are not efficacious in vivo. By contrast, our second-generation inhibitors, featuring a cholesterol moiety, are also efficacious in vivo. The difference between in vitro and in vivo results led us to investigate the basis for this discrepancy. Here we compare the activity of the compounds in standard laboratory cells and in cells relevant to the natural tropism of Nipah virus, i.e. primary neurons, and show that while our first generation inhibitors are poorly active in primary neurons, the cholesterol-conjugated compounds are highly potent. These results highlight the advantage of evaluating antiviral potency in cells relevant to natural host target tissue.

Customer Data: Transfection of functional HeV glycoproteins and infection with HeV pseudotyped virions.In order to establish the feasibility of carrying out the proposed experiments in primary neurons, we show (figure ) that our assays are amenable to use in primary neurons. In the experiment, Combined Hippocampus, Cortex, and Ventricular -E18 (Neuromics) were plated, and at 3 days were transfected with plasmids encoding HeV G/F as well as YFP. On the following day, these cells were infected with HeV or VSV pseudotyped viruses bearing RFP. In the figure, (A) the phase contrast photos show the differentiated neurons; (B) upon excitation for RFP, the red fluorescence indicates neurons infected by HeV pseudotyped virions; (C) upon excitation for YFP, and the green fluorescence shows the efficiency of transfection in neurons. This experiment indicates that the proposed experiments can be carried out in primary neurons, which are transfectable and infectable in our systems, and thus supports all the proposed aims. Data Courtesy of Dr. Matteo Porotto, Weill Cornell Medical College. Larger Image

We will continue to keep you updated.

Friday, June 17, 2011

Chronic Type II Diabetes Mellitus and Cardiovascular Disease

Our Neuropeptide and Neuropeptide Receptors and Leptin and Leptin Receptor Antibdodies are frequently used to study pathologies and biology specific to Obesity and Diabetes.

Here's a new publication studying the relationship between diabetic neuropathy and altered neuropeptide Y and its receptor expression levels in myocardium and plasma.

Robina Matyal, Feroze Mahmood, Michael Robich, Hiliary Glazera, Kamal Khabbaza, Philip Hessa, Cesario Bianchia, Robert Hagberga, Shu-Xu Hua, and Frank W. Sellkea. Chronic type II diabetes mellitus leads to changes in neuropeptide Y receptor expression and distribution in human myocardial tissue. European Journal of Pharmacology. Volume 665, Issues 1-3, 31 August 2011, Pages 19-28.

Abstract: Neuropeptide Y is one of the most abundant neurotransmitters in the myocardium, and is known to influence cardiovascular remodeling. We hypothesized that diabetic neuropathy could possibly be associated with altered neuropeptide Y and its receptor expression levels in myocardium and plasma. Plasma neuropeptide Y levels in diabetic (n = 24, HgbA1c 7.9 ± 1.1%) and non-diabetic (n = 27, HgbA1c 5.8 ± 0.5%) patients undergoing cardiac surgery utilizing cardiopulmonary bypass were analyzed. Right atrial tissue of these patients was used to determine the expression of neuropeptide Y, the receptors 1–5, and leptin by immunoblotting, real-time PCR and immunofluorescence. Apoptosis signaling and endostatin and angiostatin were measured to determine the effects of leptin.

Plasma neuropeptide Y levels were significantly increased in patients with Type II diabetes mellitus as compared to non-diabetic patients (P = 0.026). Atrial tissue neuropeptide Y mRNA levels were lower in diabetic patients (P = 0.036). There was a significant up-regulation of myocardial Y2 and Y5 receptors (P = 0.009, P = 0.01 respectively) in the diabetic patients. Leptin, involved with apoptosis and angiogenesis, was down regulated in diabetic patients (P = 0.05). The levels of caspase-3, endostatin and angiostatin were significantly elevated in diabetic patients (P = 0.003, P = 0.008, P = 0.01 respectively). Y1 receptors were more likely to be localized within the nuclei of cardiomyocytes and vascular smooth muscle cells.

Neuropeptide expression is altered differentially in the serum and myocardium by diabetes. Altered regulation of this system in diabetics may be in part responsible for the decreased angiogenesis, increased apoptosis, and increased vascular smooth muscle proliferation leading to coronary artery disease and heart failure in this patient population.

Wednesday, June 15, 2011

SOX2 as a Marker for Melanoma

I would like to post a new application for our SOX2 neural progenitor marker.

Alvaro C. Laga, Qian Zhan,Carsten Weishaupt, Jie Ma, Markus H. Frank, George F. Murphy. SOX2 and nestin expression in human melanoma: an immunohistochemical and experimental study. Experimental Dermatology. Volume 20, Issue 4, pages 339–345, April 2011. DOI: 10.1111/j.1600-0625.2011.01247.x.

SOX2 is an embryonic neural crest stem-cell transcription factor recently shown to be expressed in human melanoma and to correlate with experimental tumor growth. SOX2 binds to an enhancer region of the gene that encodes for nestin, also a neural progenitor cell biomarker. To define further the potential relationship between SOX2 and nestin, we examined co-expression patterns in 135 melanomas and 37 melanocytic nevi. Immunohistochemical staining in 27 melanoma tissue sections showed an association between SOX2 positivity, spindle cell shape and a peripheral nestin distribution pattern. In contrast, SOX2-negative cells were predominantly epithelioid, and exhibited a cytoplasmic pattern for nestin. In tissue microarrays, co-expression correlated with tumor progression, with only 11% of nevi co-expressing SOX2 and nestin in contrast to 65% of metastatic melanomas, and preliminarily, with clinical outcome. Human melanoma lines that differentially expressed constitutive SOX2 revealed a positive correlation between SOX2 and nestin expression. Experimental melanomas grown from these respective cell lines in murine subcutis and dermis of xenografted human skin maintained the association between SOX2-positivity, spindle cell shape, and peripheral nestin distribution. Moreover, the cytoplasmic pattern of nestin distribution was observed in xenografts generated from SOX2-knockdown A2058 melanoma cells, in contrast to the periperhal nestin pattern seen in tumors grown from A2058 control cells transfected with non-target shRNA. In aggregate, these data further support a biologically significant linkage between SOX2 and nestin expression in human melanoma.

Sunday, June 12, 2011

Assembly and Maintenance of GABAergic Synapses

Understanding the mechanisms underlying Axon Growth and Guidance is key to finding the root cause of neurological diseases and discovering potential therapies.

In this important study, researchers TrkB is required for the localization of an Ig superfamily cell adhesion molecule, Contactin-1, in Golgi and granule cells and the absence of Contactin-1 also results in deficits in inhibitory synaptic development. This demonstrates that TrkB controls the assembly and maintenance of GABAergic synapses and suggest that TrkB functions, in part, through promoting synaptic adhesion: TrkB (Tropomyosin-Related Kinase B) Controls the Assembly and Maintenance of GABAergic Synapses in the Cerebellar Cortex. The Journal of Neuroscience, February 23, 2011 • 31(8):2769 –2780 • 276

Contactin-1 IHC and WB
Images: Inactivation of TrkB kinase activity disrupts the localization of GABAergic synaptic proteins. A–I, Homozygous mice carrying TrkB F616A allele were treated with water or 1NMPP1 from P0 to P28 and analyzed at P28. The localization of GAD65 (green; B), GAD67 (green; E) and gephyrin (red; H ) in the IGL is reduced in TrkB F616A mice treated with 1NMPP1 compared with TrkB F616A mice treated with water (A, D, G). C, F, I, Quantification of the area ratio of GAD65:vGluT1 (C), GAD67:vGluT1 (F ) and gephyrin:vGluT1 expression (I) in control and 1NMPP1-treated mice. J–R, Homozygousmice carrying TrkB F616A allele were treated with water or 1NMPP1 from P30 to P50 and analyzed at P50. The localization of GAD65 (green; K ), GAD67 (green; N ) and gephyrin (red; Q) is reduced in TrkB F616A mice treated with 1NMPP1 compared with control (J, M, P). L, O, R, Quantification of the area ratio of GAD65:vGluT1 (L), GAD67:vGluT1 (O) and gephyrin:vGluT1 expression (R) in control and 1NMPP1-treated mice. Scale bar, 10 um.