Slowing Hearing Loss in Diabetics and Hyperglycemics

Our Neuronal-Glial Markers are used in a variety of applications. Here our P0 or P-Zero antibody is used to show myelination levels in the cochlear ganglion. Demyelination is caused by hyperglycemia and type 2 diabetes and results in hearing loss and eventually deafness. Here's the related publication and highlights: Silvia Murillo-Cuesta, Guadalupe Camarero, Águeda González-Rodríguez, Lourdes Rodríguez-de la Rosa, Deborah J Burks, Carlos Avendaño,Ángela M Valverde and Isabel Varela-Nieto1. Insulin Receptor Substrate 2 (IRS2)-Deficient Mice Show Sensorineural Hearing Loss That Is Delayed by Concomitant Protein Tyrosine Phosphatase 1B (PTP1B) Loss of Function. Online address: http://www.molmed.org. doi: 10.2119/molmed.2011.00328
Highlights: The authors objective was to study the hearing function and cochlear morphology of Irs2-null mice and the impact of PTP1B deficiency. They have studied the auditory brainstem responses and the cochlear morphology of systemic Irs2–/–Ptpn1+/+, Irs2+/+Ptpn1–/– and Irs2–/–Ptpn1–/– mice at different postnatal ages. The results indicated that Irs2–/–Ptpn1+/+ mice present a profound congenital sensorineural deafness before the onset of diabetes and altered cochlear morphology with hypoinnervation of the cochlear ganglion and aberrant stria vascularis, compared with wild-type mice. Simultaneous PTP1B deficiency in Irs2–/–Ptpn1–/– mice delays the onset of deafness.

Images:  Cochlear ganglion and nerve fibers. (A–C) Cresyl violet staining of midmodiolar methacrylate sections of the cochlear ganglion at the cochlear basal turn in Irs2+/+Ptpn1+/+ (A), Irs2–/–Ptpn1+/+ (B) and Irs2–/–Ptpn1–/–mice (C) at postnatal wk 11. A slight reduction in the cellular density was more evident in both mutants (B, C) compared with wild-type (A). (D–F) Myelin P0 immunostaining of the cochlear ganglion shows less intense labeling in Irs2–/–Ptpn1+/+ (E) and Irs2–/–Ptpn1–/– (F) mice than in control mice (D). (G–I) Accordingly, myelin P0 immunostaining of nerve fibers projecting from the cochlear ganglion to the sensory cells is less intense in Irs2–/–Ptpn1+/+ and Irs2–/–Ptpn1–/– (arrows in H and I) than in wild-type mice (G). (J–L) Similarly, a weaker neurofilament 200-kDa immunostaining is observed in Irs2+/+Ptpn1–/– (K, white arrow) and Irs2–/–Ptpn1–/– (L, white arrow) mice compared with wild-type mice (J). Scale bars: A–I, 50 μm; J–L, 75 μm.

The results presented in this study demonstrate for the first time a unique tissue-specific role of IRS2 in cochlear development and hearing function; therefore, the Irs2–/– mouse could be a novel model for the in vivo study of hearing loss associated with altered glucose metabolism. The data also suggest that modulation of PTP1B activity could be a pharmacological target of interest for the sensory syndromes associated with diabetes.

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.

Neuron/Neuron Glial Markers

We have a comprehensive and growing catalog of Neuron/Glial Marker Antibodies and Proteins.

These reagents must work everytime in our customers' applications. Quality is confirmed by pro-active customers follow up and publication referencing the reagents.

Here we have several recent publications.

We are pleased to first feature Dr. Dr. Juana Maria Pasquini, University of and colleagues from University of Buenos Aires. She and her team use our Olig1,2,3 as a marker to study de-myelinating disease.

P.G. Franco, L. Silvestroff, E.F. Soto and J.M. Pasquini. Thyroid hormones promote differentiation of oligodendrocyte progenitor cells and improve remyelination after cuprizone-induced demyelination. doi:10.1016/j.expneurol.2008.04.039
...Olig 1-2-3 antibodies were from Neuromics Antibodies (Edina, MN); ...

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The second references one of our GFAP antibodies.

Sun Jin-qiao, Sha Bin, Zhou Wen-hao and Yang Yi. Basic fibroblast growth factor stimulates the proliferation and differentiation of neural stem cells in neonatal rats after ischemic brain injury. doi:10.1016/j.braindev.2008.06.005.
For the immunofluorescence assays, sections from the SVZ were washed (0.1 M Tris, pH 7.6, 15 min), denatured (2 N HCl, 37oC, 30 min), rinsed (0.1 M P10 min), incubated with 1% H2O2 in 0.1 M Tris for 30 min, rinsed, blocked (10% normal goat serum, 37oC, 30 min).
...GFAP (1:100, Neuromics)...