ROCKs are expressed in brain tumors and are required for glioma-cell migration on myelinated axons

The interactions between migrating glioma cells and myelinated fiber tracts are poorly understood. We identified that C6 glioma cells can migrate along myelinated chicken retinal axons in a novel coculture, thereby expressing small GTPases of the Rho family and serine/threonine Rho-associated kinases (ROCKs). We found that the ROCK1 isoform is also highly expressed in native human high-grade gliomas. Glioma cells migrated faster in vitro along myelinated axons than on laminin-1, with the former but not the latter being specifically and reversibly blocked by the ROCK inhibitor Y27632. These data suggest that the mechanisms underlying the migration of glioma cells on myelinated axons differ from those underlying the migration on extracellular matrix molecules such as laminin-1.

Translin-associated factor-X (Trax) is a molecular switch of growth-associated protein (GAP)-43 that controls axonal regeneration

The ability of neurons to form axons requires the choreographed assembly of growth cones. We show that there is a time window from postnatal day 14 (P14) until P21/22 when axons of rat retinal ganglion cells will regenerate under serum-free culture conditions. In contrast, no outgrowth occurred before P13, and growth declined from P22 and ceased after P30. Using proteomics, we have identified translin-associated factor X (Trax), a DNA-binding factor that is expressed during this period of postnatal development. Trax is shown to coexpress with growth-associated protein GAP-43. Small interfering RNA-mediated inhibition of Trax expression resulted in downregulation of both Trax and GAP-43 transcripts and protein both before and during the period of regeneration (P8) and (P16). In contrast, silencing of Trax at P30 resulted in significant upregulation of the GAP-43 transcript and protein and induced outgrowth of axons. These data suggest that Trax regulates GAP-43 transcription and regeneration-promoting effects during the postnatal maturation period. Trax may represent a new potent therapeutic target gene for optic nerve and spinal cord injuries.

[Efficacy of a combination therapy with vitamins B6, B12 and folic acid for general feeling of ill-health. Results of a non-interventional post-marketing surveillance study]

OBJECTIVE

In the present non-interventional postmarketing surveillance study, patients with symptoms of an inadequate supply of vitamins were tested for how a treatment with a combination vitamin injection consisting of vitamins B6, B12 and folic acid affects mood and fitness. The evaluation of the efficacy and tolerability as well as the documentation of adverse drug reactions were carried out by the physician.

METHODS

The patient collective included 1430 patients (70.8% women, average age 67.1 years, average BMI 25.5 kg/m2). The average duration of treatment was 4.5 weeks with an average of 8.3 intramuscular injections. The principal method for determining the efficacy was the self-assessment scale of well-being (Bf-S) according to Zerssen (sum score with a value range between 0 and 56 points).

RESULTS

The sum score of the Bf-S decreased from 37.5 (+/-10.1) points at admission to 15.6 (+/- 9.4) points after four weeks of treatment. The subjective impression improved correspondingly in 96.3% of the patients. The improvement of the Bf-S was equally good in women and men. The number of injections correlated with the improvement in the sum score. The tolerability was mainly rated as very good or good.

CONCLUSIONS

Eight vitamin infections over four weeks led to a clear improvement in the mood and vitality of patients with symptoms of intracellular vitamin B deficiency.

Axonal regeneration in the organotypically cultured monkey retina: biological aspects, dependence on substrates and age-related proteomic profiling

Injury to the mature primate and subprimate optic nerve results in irreversible impairment and loss of vision, because the retinal ganglion cells (RGCs) fail to regenerate their cut axons within the optic nerve interior. This study was performed to examine whether aging monkey RGCs retain the ability to regenerate their axons in organ culture and whether axonal regeneration is associated with specific proteomic profile. Retinal stripes obtained from marmoset eyes (C. jacchus) were cultured between the day of birth and adult stages on different substrates like laminin-1, laminin-2, collagen, matrigel and poly-D-lysine. No neurotrophic factors were added to the medium. Axonal growth was monitored with microscopy and immunohistochemistry. Onset and rate of growth was examined with time-lapse videography. Vigorous regeneration of axons occurred from identifiable morphological types of RGCs throughout all stages of life, although the numbers of axons decreased with age. Axonal growth occurred virtually only on laminin-1. Growth correlated with re-expression of the laminin-1 receptor alpha6-integrin and sustained staining for GAP-43 as shown by immunohistochemistry and immunoblotting. At proteomic level, there is a maturation-dependent change in the protein immunostaining within the retina. When retinal slices of the same age were compared, regeneration-specific protein staining included calmodulin, fatty acid binding protein, alpha-crystallin, IFN-gamma, cyclin-dependent kinase inhibitor (p21), beta-hemoglobin, 60s-ribosomal protein, GAP-DH and ADP-ribosylation factor (ARF). To our knowledge these data are the first from subhuman animals to suggest that axonal regeneration of injured RGCs is correlated to expression of identifiable proteins within the retina.

Regeneration of retinal ganglion cell axons in organ culture is increased in rats with hereditary buphthalmos

This study used organ cultures to examine whether retinal ganglion cells (RGCs) retain their ability to regenerate axons in buphthalmos. A rat mutant with hereditary buphthalmos was used to (1) determine whether the extent of RGC loss corresponds to the severity and duration of elevated intraocular pressure (IOP), (2) examine whether RGCs exposed to an elevated IOP are able to regenerate their axons in a retina culture model, and (3) analyze the proteome of the regenerating retina in order to identify putative regeneration-associated proteins. Retrograde labeling of RGCs revealed a decrease in their numbers in the retinas of buphthalmic eyes that increased with age. Quantification of axons growing out of retinal explants taken at different stages of the disease demonstrated that buphthalmic RGCs possess a remarkable potential to regrow axons. As expected, immunohistochemistry and immunoblotting revealed that elevated IOP was associated with upregulation of certain known proteins, such as growth-associated protein 43, glial fibrillary acidic protein, and endothelin-1. In addition, two-dimensional polyacrylamide gel electrophoresis and mass spectrometry revealed several spots corresponding to proteins that were specifically regulated when buphthalmic RGCs were permitted to regrow their axons. Out of the proteins identified, heat-shock protein (HSP)-60 was constantly expressed during axonal growth at all stages of the disease. Antibodies against HSP-60 reduced axonal growth, indicating the involvement of this protein in regenerative axonal growth. These data are the first to show that diseased retinal neurons can grow their axons, and that HSP-60 supports neuritogenesis. This model may help to elucidate the fundamental mechanisms of optic neuropathy at stages preceding death caused by chronic injury, and aid in the development of neuroprotective strategies.

Elongation of axons during regeneration involves retinal crystallin beta b2 (crybb2)

Adult retinal ganglion cells (RGCs) can regenerate their axons in vitro. Using proteomics, we discovered that the supernatants of cultured retinas contain isoforms of crystallins with crystallin beta b2 (crybb2) being clearly up-regulated in the regenerating retina. Immunohistochemistry revealed the expression of crybb within the retina, including in filopodial protrusions and axons of RGCs. Cloning and overexpression of crybb2 in RGCs and hippocampal neurons increased axonogenesis, which in turn could be blocked with antibodies against beta-crystallin. Conditioned medium from crybb2-transfected cell cultures also supported the growth of axons. Finally real time imaging of the uptake of green fluorescent protein-tagged crybb2 fusion protein showed that this protein becomes internalized. These data are the first to show that axonal regeneration is related to crybb2 movement. The results suggest that neuronal crystallins constitute a novel class of neurite-promoting factors that likely operate through an autocrine mechanism and that they could be used in neurodegenerative diseases.

[Relevance of infection with equine herpesvirus 1 (EHV-1) in a German thoroughbred stud: vaccination, abortion and diagnosis]

The aim of the present study was to clarify whether an EHV-1 induced abortion can be prognosticated by an increase of antibody titres, virus shedding and/or viraemia and whether the current abortion diagnostic is suitable. In this context the immune response post immunization and a possible reactivation were of great interest. For this purpose blood samples of 32 mares between the ages of 5-21 years were regularly investigated during a period of two years before and after vaccination and pregnancy. Neutralization tests, indirect immunofluorescence tests as well as PCR and virus isolation were used for EHV-1 diagnostics. It could be shown that the horses reacted individually to vaccination. In 14 cases a EHV-1-reactivation was suggested. An abortion prognosis was not possible even using serological, virological and molecular biological parameters. In addition, virus shedding and antibody titres were individual. An acute infection was detectable by a significant rise of antibodies and viraemia as well as virus shedding in the secretions. For the abortion diagnostics the antigen detection in combination with virus isolation and PCR from fetal lungs gave reliable results. In addition, the virological and serological investigation of the mare is recommendable. For prophylaxis we would advise a regular vaccination and strict hygiene.

The plastocyanin binding domain of photosystem I

The molecular recognition between plastocyanin and photosystem I was studied. Photosystem I and plastocyanin can be cross-linked to an active electron transfer complex. Immunoblots and mass spectrometric analysis of proteolytic peptides indicate that the two negative patches conserved in plant plastocyanins are cross-linked with lysine residues of a domain near the N-terminus of the PsaF subunit of photosystem I. Conversion of these negative to uncharged patches of plastocyanin by site-directed mutation D42N/E43Q/D44N/E45Q and E59Q/E60Q/D61N respectively, reveals the first patch to be essential for the electrostatic interaction in the electron transfer complex with photosystem I and the second one to lower the redox potential. The domain in PsaF, not found in cyanobacteria, is predicted to fold into two amphipathic alpha-helices. The interacting N-terminal helix lines up six lysines on one side which may guide a fast one-dimensional diffusion of plastocyanin and provide the electrostatic attraction at the attachment site, in addition to the hydrophobic interaction in the area where the electron is transferred to P700 in the reaction center of photosystem I. This two-step interaction is likely to increase the electron transfer rate by more than two orders of magnitude in plants as compared with cyanobacteria. Our data resolve the controversy about the function of PsaF.

Light-induced charge separation between plastocyanin and the iron-sulfur clusters FA and FB in the complex of plastocyanin and photosystem I

The light-induced electron transfer in a crosslinked complex between plastocyanin and photosystem I from spinach was studied by EPR at low temperature. Electron donation from reduced plastocyanin to P700+ was observed under illumination above a temperature of about 160 K, resulting in a second charge separation and an electron transfer from rereduced P700 to the terminal electron acceptors FA/FB. The charge-separated state Pc oxP700+ [FA/FB](2-) was found to be stable at 15 K. Implications of these results for the kinetic constants of the donation reaction and the backtransfer of electrons from reduced acceptors as well as for the structural models of the terminal acceptors are discussed.