mGluRs Protect OPCs

Valuable for Remyelination of Damaged Neurons

We add a new publication to our mGluR Markers Category: Arthur M. Butt, Ilaria Vanzulli, Maria Papanikolaou, Irene Chacon De La Rocha, Virginia E. Hawkins. Metabotropic Glutamate Receptors Protect Oligodendrocytes from Acute Ischemia in the Mouse Optic Nerve. Neurochem Res (2017). doi:10.1007/s11064-017-2220-1. Its focus is the protective characteristics of mGluRs.

Images: Expression of mGluR in optic nerve oligodendrocytes. a RT-qPCR of mGluR subtypes in the postnatal (P8–12) and young adult (P30–35) optic nerve, compared to cortex at the same ages (inset); data are expressed as mean ± SEM ΔΔCT relative to GAPDH, ***p < 0.001 determined by ANOVA and post hoc Bonferroni’s test. b, c Oligodendrocytes in optic nerve explant cultures from P8 PLP-DsRed reporter mice after 10 DIV were immunolabelled for mGluR2/3 (d) and mGluR5 (e), illustrating single channels (Di, Dii, Ei, Eii) and the merged channel in which mGluR colocalization with PLP appears white (Diii, Eiii); scale bars 10 µm

Leptin and Remyelination

Leptin Promotes Proliferation of OPCs

Demyelination occurs in many diseases of the Central Nervous System (CNS) including Multiple Sclerosis and Parkinson's Disease. Here researchers show that Leptin plays a role in the proliferation of Oligodendrocyte Precursor Cells (OPCs): These cells are critical for keeping the myelin sheath on Neurons of the CNS healthy and happy.  Ken Matoba, Rieko Muramatsu & Toshihide Yamashita. Leptin sustains spontaneous remyelination in the adult central nervous system. Scientific Reports 7, Article number: 40397 (2017) doi:10.1038/srep40397.

Our LepRB Antibody is used in this study to stain OPCs.

Figures: (a) Representative image of cultured OPCs stained with antibodies against LepRb (green) and PDGFRα (red). Scale bar: 25 μm. (b) Relative BrdU incorporation into the OPC obtained from the brain (left graph) and spinal cord (right graph). Cells were treated with recombinant leptin for 48 h (n = 4). (Left graph) P = 0.005993 (control vs 10 ng/mL), 0.045616 (control vs 100 ng/mL), (Right graph) P = 0.004456 (control vs 10 ng/mL), 0.017859 (control vs 100 ng/mL). (c) Relative BrdU incorporation into the OPC after leptin stimulation (10 ng/ml) with U0126 (20 μM), a MEK inhibitor (n = 4 for brain OPCs, n = 3 for spinal cord OPCs). (Left graph) P = 0.019753 (control vs leptin), 0.039433 (leptin vs leptin + U0126), (Right graph) P = 0.045545 (control vs leptin), 0.04486 (leptin vs leptin + U0126). (d) Representative images of western blotting (upper panels) and quantitative analysis of ERK phosphorylation (lower graph) are shown. OPCs were treated with leptin (10 ng/ml) under indicated periods (n = 3). P = 0.006352 (2 min), 0.016571 (5 min), 0.017675 (10 min), 0.024100 (15 min), 0.081342 (30 min).

We are in the process of looking for Labs to sponsor Neuromics' to isolate and purify adult human OPCs in return for receiving 2,000,000 cells. Stay tuned.

ApoTransferrin and the fate of Neural Stem Cell/Progenitors

Implications for De-Myelinating Diseases Like MS and ALS

Dr. Juana María Pasquini and her team at the University of Buenos Aires are ongoing users of our Neural Stem Cell-Progenitor (NSC-NP) Markers. In this study, they use these markers to determine the states and fates of NSCs and NPs as they proliferate and differentiate and the related role of ApoTransferrin (aTF). Here we learn aTf exposure during differentiating conditions favours OL maturation from OPCs by promoting OL morphological development. This evidence supports a key role of Tf on the generation of OL from NSC/NPCs and highlights its potential in demyelinating disorder treatment: Silvestroff L , Franco PG , Pasquini JM (2012) ApoTransferrin: Dual Role on Adult Subventricular Zone-Derived Neurospheres. PLoS ONE 7(3): e33937. doi:10.1371/journal.pone.0033937.

Proliferation rates under different conditions are shown in A–C. BrdU incorporation (red) during proliferation (CTLP, A) or differentiation (CTLPCTLD, B). BrdU+ cells are expressed as a percentage of total nuclei for either condition in C. Free floating NS during proliferation express Nestin (D, green) and GFAP (E, green). After dissociation, NS-derived cells continue to express Nestin (F, green). PDGFRα+ (G, green) and NG2+ cells (H, green). Few MBP+ (I, green) cells were found under proliferative conditions. A large proportion of BrdU incorporating cells (J, red) co-expressed with NG2 (J, green). Some BLBP+ cells (K, green) incorporated BrdU (K, red). After differentiation (L–O), MBP+ cells were found with a highly branched and complex morphology (L, green). Cells expressed GFAP (M, green), as well as the neuronal NF200 marker (N, green). BrdU incorporating (O, red) cells were mostly NG2+ (O, green) during differentiation conditions. BrdU+ cells co-expressing NG2, as a proportion of total BrdU+ cells, are shown in P for either culture condition. A representative Western Blot membrane in Q shows how MBP levels increase in whole cell protein extracts as cells differentiate. The densitometric analysis of the MBP isoforms/GAPDH ratio of 5 independent experiments was semi-quantitated in R. All 4 MBP isoforms were pooled and considered as a single value before normalizing to GAPDH values. Blue colour in images indicates Höechst nuclear dye. Scale bar in A represents 250 µm for A and B. Scale bar in D equals 100 µm in D–I and L–N, scale bar in J equals 250 µm in J and O, and scale bar in K represents 50 µm. Bars in P represent mean values of 2 independent experiments. Bars in C and R represent Mean + SD of 4 and 5 individual cultures, respectively. Student's t Test was used to analyze data in C, while a One Way ANOVA with an SNK Post-test was used to analyze data in R. * p<0.05, ** p<0.01, *** p<0.001

Note:  PDGFRα+ is a marker for oligodendrocytes (OLs).

Here's the pathway model that sumarizes authors' findings

I will keep you posted on research that could implications for the discovery of de-myelinating disorder therapies.

Diabetic retinopathy blindness-root causes

Diabetic retinopathy is a leading cause of acquired blindness. This publication from our friends at University of Buenos Aires touches on potential root causes: Diego C. Fernandez, Laura A. Pasquini, Damián Dorfman, Hernán J. Aldana Marcos, Ruth E. Rosenstein. Early Distal Axonopathy of the Visual Pathway in Experimental Diabetes. doi:10.1016/j.ajpath.2011.09.018
" In animals that had been diabetic for 6 weeks, a large increase in astrocyte reactivity occurred in the distal (but not the intraorbital) portion, which coincided with significant axon loss. Moreover, profound myelin alterations and altered morphologic features of oligodendrocyte lineage were observed at the distal (but not the proximal) optic nerve portion. The present results suggest that axoglial alterations at the distal portion of the optic nerve could be the first structural change in the diabetic visual pathway."
The authors used our PDGFR Alpha/CD140A Marker to Study the change in Oligodendrocyte Lineage precursor cells. Expression of the protein was increased in these cells with the presence of disorganized and hypertrophic cells. This could disrupt formation of myelin resulting the pathological alteration at the distal portion.

Mouse epiSCs Into Myelinating Cells

This study published recently in Nature Methods hit my radar scope becaused it referenced use of our widely used and frequently published stem cell marker Tuj 1 (Neuron-specific class III beta-tubulin): Fadi J Najm, Anita Zaremba, Andrew V Caprariello, Shreya Nayak, Eric C Freundt, Peter C Scacheri, Robert H Miller & Paul J Tesar. Rapid and robust generation of functional oligodendrocyte progenitor cells from epiblast stem cells. Nature Methods (2011) doi:10.1038/nmeth.1712.

Dr. Paul Tesar and his team at Case Western University demonstrated the ability to convert pluripotent epiblast stem cells into pure populations of myelinating cells, called oligodendrocyte progenitor cells (OPCs). First, stem cells in a petri dish are treated with molecules to direct them to become the most primitive cells in the nervous system. To produce OPCs, these primitive cells are treated with a defined set of proteins. The cells were cultured on laminin and treated withh apporopriate growth factors. The OPCs were nearly homogenous and could be multiplied to obtain more than a trillion cells.

The OPCs were treated with thyroid hormone, which is key to regulating the transition of the OPCs to oligodendrocytes. The result was the OPCs stopped proliferating and turned into oligodendrocytes within four days.

These methods could used to potentially produce stable and pure populations of human OPCs in a significant enough number to treat patients with demyelinating diseases such as multiple sclerosis and cerebral palsy.