Impaired regeneration of bcl-2-lacking peripheral nerves.

OBJECT: The outcome of peripheral nerve damage in still not satisfactory, despite the general capacity of peripheral nervous system to regenerate. The molecular mechanisms underlying nerve regeneration are still not clear, but it is likely that apoptosis regulating genes plays a crucial role in these processes. The aim of the present study was to establish the role of the anti-apoptotic gene bcl-2 in peripheral nerve repair. MATERIAL AND METHODS: Sciatic nerves of bcl-2-deficient and wild type mice were transected, and immediately re-sutured. The regeneration was assessed functionally and morphologically throughout the 4-week follow-up. RESULTS: We found markedly worse sciatic function index outcome, as well as more significant atrophy of denervated muscles in bcl-2 knock-out animals when compared with wild-type ones. The intensity of histological regeneration features, including GAP-43-positive growth cones, Schwann cells and macrophages in the distal stump of the transected nerve, was also decreased. The number of motor and sensory neurons in the relevant cross-sections of spinal cord was similar in both groups of mice. CONCLUSION: We concluded that the bcl-2 gene plays an important role in peripheral nerve regeneration, influencing nerve injury site clearing, fiber regrowth and myelination.

Bcl-2 deficiency deprives peripheral nerves of neurotrophic activity against injured optic nerve.

Optic nerve injury leads to retinal ganglion cell apoptosis, thus preventing fiber regeneration. Peripheral nerve grafts are known to promote survival and regeneration in injured adult mammalian central nervous system, including optic nerve, but the mechanisms of their activity remain unclear. It is likely that they attenuate the apoptotic cascade triggered by axotomy in retinal ganglion cells. The aim of this work was to examine the role of the antiapoptotic gene bcl-2 in the optic nerve regeneration induced by such grafts. Experiments were carried out on bcl-2-deficient and wild-type mice. We have reported previously that predegeneration markedly enhances neurotrophic activity of peripheral nerve grafts, so we applied both predegenerated and non-predegenerated implants to the transected optic nerves. We studied the neurotrophic effects of bcl-2-deficient grafts on wild-type and bcl-2 knock-out optic nerves, as well as wild-type grafts on both strains of mouse optic nerves. After application of fluorescent dye to the end of the graft, we counted the stained retinal ganglion cells. Predegenerated wild-type grafts promoted survival and outgrowth of retinal ganglion cells axons in both types of mice. By contrast, non-predegenerated and predegenerated bcl-2-deficient grafts induced little or no regeneration in the optic nerves. These results indicate that the lack of bcl-2 gene does not deprive retinal ganglion cells of their regenerative potential. At the same time, we found that bcl-2 knock-out dispossesses peripheral nerves of their neurotrophic activity.

[Fusogens in the treatment of nervous system injury]. / Fuzogeny w terapii uszkodzen ukladu nerwowego.

In the paper a new method is presented of injured nerve fibres repair by means of the so-called fusogens. This entirely novel approach to the treatment of injuries of the central nervous system and peripheral nerves in humans may be feasible in a near future. Unquestionable advantages of these substances include their easy applicability and no undesirable side effects. What remains to be established is their mode of operation and precise therapeutic indications.

[Extracellular matrix metalloproteinases--perspectives of their use in medicine]. / Metaloproteinazy macierzy pozakomórkowej--perspektywy ich wykorzystania w medycynie.

Extracellular matrix turnover disturbances are implicated in many human diseases. Matrix Metalloproteinases (MMP) are believed to play a pivotal role in maintaining the intricate balance between extracellular matrix synthesis and degradation. These enzymes are active in the cleavage of many matrix proteins. There is evidence that matrix metalloproteinases activity changes in many pathological conditions, including inflammatory and degenerative disorders as well as tumour progression and metastases. This review focuses on the recent view on physiological and pathological function of MMPs. Authors aimed also to show the putative role of matrix metalloproteinases as a diagnostic tool in future medicine.