Wednesday, September 22, 2010

Glutaredoxin 2 prevents aggregation of mutant SOD1

Our PTEN-induced kinase, PINK1 or PARK6 Antibody is an excellent marker for Amyotrophic Lateral Sclerosis (ALS) and Parkinson's Disease (PD) researchers.

Here's  new publication referencing use of this antibody:  Alberto Ferri, Paolo Fiorenzo, Monica Nencini, Mauro Cozzolino, Maria Grazia Pesaresi, Cristiana Valle, Sara Sepe, Sandra Moreno, and Maria Teresa Carrì. Glutaredoxin 2 prevents aggregation of mutant SOD1 in mitochondria and abolishes its toxicity.
Hum. Mol. Genet., first published on Sep 20, 2010 as doi: doi:10.1093/hmg/ddq383

Vulnerability of motoneurons in amyotrophic lateral sclerosis (ALS) arises from a combination of several mechanisms, including protein misfolding and aggregation, mitochondrial dysfunction and oxidative damage. Protein aggregates are found in motoneurons in models for ALS linked to a mutation in the gene coding for Cu,Zn superoxide dismutase (SOD1) and in ALS patients as well. Aggregation of mutant SOD1 in the cytoplasm and/or into mitochondria has been repeatedly proposed as a main culprit for the degeneration of motoneurons. It is, however, still debated whether SOD1 aggregates represent a cause, a correlate or a consequence of processes leading to cell death. We have exploited the ability of glutaredoxins (Grxs) to reduce mixed disulfides to protein thiols either in the cytoplasm and in the IMS (Grx1) or in the mitochondrial matrix (Grx2) as a tool for restoring a correct redox environment and preventing the aggregation of mutant SOD1. Here we show that the overexpression of Grx1 increases the solubility of mutant SOD1 in the cytosol but does not inhibit mitochondrial damage and apoptosis induced by mutant SOD1 in neuronal cells (SH-SY5Y) or in immortalized motoneurons (NSC-34). Conversely, the overexpression of Grx2 increases the solubility of mutant SOD1 in mitochondria, interferes with mitochondrial fragmentation by modifying the expression pattern of proteins involved in mitochondrial dynamics, preserves mitochondrial function and strongly protects neuronal cells from apoptosis. The toxicity of mutant SOD1, therefore, mostly arises from mitochondrial dysfunction and rescue of mitochondrial damage may represent a promising therapeutic strategy.
Related Reagents:
PARK2 Co-regulated (PACRG)
PARK7 (DJ-1)
LRRK2 (PARK8)                        
Neurodegenerative Disease Research Antibodies                          

Neurodegenerative Disease Research Proteins
Neurotransmission -Neurotransmission Research Antibody Categories                         
Neurotrophins and Growth Factor Antibodies
Neuron-Glial Expressed-Includes Neurotrophin Proteins
Apoptosis Research Reagents-Apoptosis Categories-includes: detection kits, antibodies and proteins

Primary Neurons and Astrocytes -Primary human, rat and mouse neurons and astrocytes by Category

Wednesday, September 15, 2010

TRHR1 and LepRb receptors and Thermogenesis

I would like to thank Montina Van Meter, Lab Manager, Autonomic Neuroscience at Pennington Biomedical Research Center, for alerting me to this just published study. Included are excellent images of stained LepRb (OB-Rb) and GAD1 expressing neurons localized in loose clusters of cells in the DMN, NST, and the VLM.

This study focus on identifying loci in the hindbrain where leptin and TRH act synergistically to increase thermogenesis. Since thermogenic processes are at the root of how our bodies regulate energy, understanding the related expression and signaling pathways could be key to finding therapies for obesity.

Maria J. Barnes, Richard C. Rogers, Montina J. Van Meter and Gerlinda E. Hermann. Co-localization of TRHR1 and LepRb receptors on neurons in the hindbrain of the rat. doi:10.1016/j.brainres.2010.07.094

Example images: Distribution of LepRb+ fibers in hindbrain. LepRb-ir (red) fibers and varicosities are seen among TRHR1-ir (green) cells and fibers. These red and green fibers are adjacent and co-mingle but do not show co-localization of receptors. This pattern is seen in (A) fascicles of the solitary tract (ST); (B) raphe pallidus (RP), and (C) raphe obscurrus (RO). (D) Border between the medial solitary nucleus (NST) and the area postrema (AP; white dashed line) showing an abundance of LepRb-ir (red) fibers and
 neurons (white arrows for selected neurons) in the NST but not the AP. (E) LepRb-ir staining is suppressed by pretreatment of tissue with LepRb epitope blocking peptide. (F) TRHR1-ir staining is suppressed by treatment with excess TRHR1. Scale bar A–D=100 microns; E, F=300 microns. cc=central canal.
Abstract: We have reported a highly cooperative interaction between leptin and thyrotropin releasing hormone (TRH) in the hindbrain to generate thermogenic responses (Hermann et al., 2006) (Rogers et al., 2009). Identifying the locus in the hindbrain where leptin and TRH act synergistically to increase thermogenesis will be necessary before we can determine the mechanism(s) by which this interaction occurs. Here, we performed heat-induced epitope recovery techniques and in situ hybridization to determine if neurons or afferent fibers in the hindbrain possess both TRH type 1 receptor and long-form leptin receptor [TRHR1; LepRb, respectively]. LepRb receptors were highly expressed in the solitary nucleus [NST], dorsal motor nucleus of the vagus [DMN] and catecholaminergic neurons of the ventrolateral medulla [VLM]. All neurons that contained LepRb also contained TRHR1. Fibers in the NST and the raphe pallidus [RP] and obscurrus [RO] that possess LepRb receptors were phenotypically identified as glutamatergic type 2 fibers (vglut2). Fibers in the NST and RP that possess TRHR1 receptors were phenotypically identified as serotonergic [i.e., immunopositive for the serotonin transporter; SERT]. Co-localization of LepRb and TRHR1 was not observed on individual fibers in the hindbrain but these two fiber types co-mingle in these nuclei. These anatomical arrangements may provide a basis for the synergy between leptin and TRH to increase thermogenesis.

Related Reagents:
Leptin and Leptin Receptor Antibodies
Leptin Proteins

Tuesday, September 14, 2010

Isolation of Medulloblastoma Stem Cells (Video Protocol)

I am pleased to present this excellent video. It also has excellent images using key stem cell markers as the cells undergo differentiation:

Sep 1, 2010 ... GFAP antibody, Neuromics, CH22102,
Chicken, 1:1000. Tuj1 antibody, Sigma, T5076, Mouse, 1:2000. NeuN
antibody, Millipore, MAB377, Mouse, ...

Thursday, September 09, 2010

Potential Therapeutic Targets for Bone Cancer Pain-P2X Receptors

Cancer pain is difficult to treat as it appears to be driven simultaneously by inflammatory, neuropathic and tumorigenic mechanisms. I have reported on multiple occasions publication referencing use of our Pain and Inflammation Research Antibodies in studying bone cancer pain.

I would like to alert you to the latest reference:

Timothy K. Y. Kaan, Ping K. Yip, Sital Patel, Meirion Davies, Fabien Marchand, Debra A. Cockayne, Philip A. Nunn, Anthony H. Dickenson, Anthony P. D. W. Ford, Yu Zhong, Marzia Malcangio, and Stephen B. McMahon Systemic blockade of P2X3 and P2X2/3 receptors attenuates bone cancer pain behaviour in rats. Brain, September 2010; 133: 2549 - 2564.

......Slides were then incubated with rabbit anti-P2X3 (1:2000, Neuromics) and sheep anti-calcitonin gene-related peptide (1:1000, Biomol...anti-beta-III-tubulin (1:4000, Promega) and guinea pig anti-P2X3 (1:100, Neuromics). The next day, after three washes with phosphate-buffered......

Summary: Pain remains an area of considerable unmet clinical need, and this is particularly true of pain associated with bone metastases, in part because existing analgesic drugs show only limited efficacy in many patients and in part because of the adverse side effects associated with these agents. An important issue is that the nature and roles of the algogens produced in bone that drive pain-signalling systems remain unknown. Here, we tested the hypothesis that adenosine triphosphate is one such key mediator through actions on P2X3 and P2X2/3 receptors, which are expressed selectively on primary afferent nocioceptors, including those innervating the bone. Using a well-established rat model of bone cancer pain, AF-353, a recently described potent and selective P2X3 and P2X2/3 receptor antagonist, was administered orally to rats and found to produce highly significant prevention and reversal of bone cancer pain behaviour. This attenuation occurred without apparent modification of the disease, since bone destruction induced by rat MRMT-1 carcinoma cells was not significantly altered by AF-353. Using in vivo electrophysiology, evidence for a central site of action was provided by dose-dependent reductions in electrical, mechanical and thermal stimuli-evoked dorsal horn neuronal hyperexcitability following direct AF-353 administration onto the spinal cord of bone cancer animals. A peripheral site of action was also suggested by studies on the extracellular release of adenosine triphosphate from MRMT-1 carcinoma cells. Moreover, elevated phosphorylated-extracellular signal-regulated kinase expression in dorsal root ganglion neurons, induced by co-cultured MRMT-1 carcinoma cells, was significantly reduced in the presence of AF-353. These data suggest that blockade of P2X3 and P2X2/3 receptors on both the peripheral and central terminals of nocioceptors contributes to analgesic efficacy in a model of bone cancer pain. Thus, systemic P2X3 and P2X2/3 receptor antagonists with central nervous system penetration may offer a promising therapeutic tool in treating bone cancer pain.

Related Reagents:

All Purinergic Receptors
Neurotransmission Research Antibodies