Ischemic Conditioning Prevents Retinopathy

What is Ischemic Conditioning?
I must confess that I had little knowledge of Ischemic Conditioning and its therapeutic potential before accessing this publication by my friend +Laura A. Pasquini and her team at University of Buenos Aires (users of Neuromics' Neuronal-Glial Markers and Neurotrophins Antibodies.

In the conditioning or pre-conditioning process, blood supply to an organ or a tissue is impaired for a short time (usually less than five minutes) then restored so that blood flow is resumed, and the process repeated two or more times, the cells downstream of the tissue or organ are robustly protected from a final ischemic insult when the blood supply is cut off entirely and permanently.

Here the authors used pressure pulses to induce retinal ischemia. Their results suggest that early vision loss in diabetes could be abated by ischemic conditioning which preserved axonal function and structure: Diego C. Fernandez, Laura A. Pasquini, Damián Dorfman, Hernán J. Aldana Marcos, Ruth E. Rosenstein. Ischemic Conditioning Protects from Axoglial Alterations of the Optic Pathway Induced by Experimental Diabetes in Rats. Research Article | published 20 Dec 2012 | PLOS ONE.

They used our PDGFR-α and an O1 marker to compare conditioned, diabetic with unconditioned, diabetic and controls rats to determine protection on ONs of the eye.

Immature OL (O1+ cells) and OL precursor (PDGFR-α+ cells) were evaluated by immunostaining in transverse ON sections. In the diabetic ON from eyes that received a sham treatment, a significant increase in O1(+) and PDGFR-α (+) area was observed, with the presence of disorganized and hypertrophic cells. In the right panel, the area occupied by glial cells (measured as total optical density (OD)) is shown. Ischemic conditioning significantly prevented these alterations and a clear decrease in O1- and PDGFR-α-immunoreactivity, with cells aligned parallel to axon bundles were found. Data are mean ± SEM (n = 6 nerves/group).

Results suggest that early vision loss in diabetes could be abated by ischemic conditioning which preserved distal axonal function and structure before the neuronal soma loss. Moreover, the present results add new potentialities to the therapeutic effects of ischemic tolerance, which is axon protection. Thus, ischemic tolerance could have promise for application in other neurodegenerative axonal diseases. I will keep you updated on progress.

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.

Early Diagnosis of Diabetic Retinopathy

The earlier the diagnosis the better the outcome. This is especially true with autoimmune diseases like Diabetic Retinopathy (DR). DR is the leading cause of blindness among persons of working age in the industrialized world. Here I feature a publication that shows axoglial alterations at the distal portion of the optic nerve could be the first structural change in the diabetic visual pathway. This could prove good news for discovering better therapies thus preventing blindness: 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

Oligodendrocytes are responsible for insulating axons. Disruptions in the formation of oligodendrocytes could initiate the domino effect that leads to decreasing and eventual total loss of vision. The authors, for example, discovered that in diabetic rats, oligodendrocyte lineage (OL) cells showed hypertrophic somas and a high number of processes.

Images/Data: OL linage evaluation. Immature OL (O1+ cells) and OL precursor (PDGFR-α+ cells) were evaluated by immunostaining and measured as optical density (OD) per section. In the distal ON from animals that were diabetic for 6 weeks, significantly increased O1 and PDGFR-α immunostaining was observed, with the presence of disorganized and hypertrophic cells. Data are mean ± SEM (n = 5 animals per group); *P < 0.01 versus age-matched controls, by Student′s t-test. Scale bar = 50 μm.

At the ultrastructural level, alterations and loss of larger axons were observed in the distal ON from animals that were diabetic for 6 weeks. In these fibers, myelin was highly disorganized, and frequent lamellar membranous bodies were observed.

I will track new develops in this research and post relevant results here.

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.

PDGFs in Non-small Cell Lung Cancer Tumor and Stromal Cells

Serving Cancer and Tumorigenesis Researhers is a central component to our business strategy. This means constantly building our catalog of Cancer Antibodies and Cancer Proteins.

I personally follow up with every customer that purchases our Cancer Research Reagents. This ensures they work as expected. In most cases, this is validate. If not, we fix the expressed issues.

We are now seeing more confirmation by the reagents being referenced in publications. In this publication, our PDGF-C antibody was used as a marker for Non-small Cell Lung Cancer Tumors.

"In univariate analyses, high tumor cell expression of PDGF-B (p
0.001), PDGF-C (p
0.01), and PDGFR-
(p
0.026) were negative prognostic indicators for disease-specific survival."

Donnem, Tom MD, Al-Saad, Samer MD, Al-Shibli, Khalid MD, Andersen, Sigve MD, Busund, Lill-Tove MD, PhD, Bremnes, Roy M. MD, PhD. Prognostic Impact of Platelet-Derived Growth Factors in Non-small Cell Lung Cancer Tumor and Stromal Cells. Journal of Thoracic Oncology. 3(9):963-970, September 2008.

Featured Reagent:
PDGF-C

Related Reagents to Consider:
PDGF R Alpha
PDGF R Beta
VEGF/Flt-1
EGF
Cancer Antibodies
All Neurotrophin and Growth Factor Antibodies
Platelet Derived Growth Factor Proteins
Cancer Research Proteins
Neurotrophin and Growth Factor Proteins