Evaluation of the regeneration process of the sciatic nerve of a mouse animal model after application of freezing, crushing or electrocoagulation damage / Ocena procesu regeneracji nerwu kulszowego mysiego modelu zwierzecego po zastosowaniu uszkodzenia metoda mrozenia, zmiazdzenia i elektrokoagulacji.

The problem of regeneration of damaged peripheral nerves is an ongoing topic and has long been the subject of intensive research worldwide. This study examined the morphological and functional evaluation of the regeneration process within the damaged sciatic nerve, a mouse animal model. The effect of impaired expression of the TSC-1 gene on the process of nerve regeneration was evaluated, depending on the mode of damage. The research object consisted of 48, 2-month-old male TSC lines. The test group consisted of animals that underwent damage to the sciatic nerve by crushing, freezing and electrocoagulation, while the control group includes mice whose sciatic nerve was not damaged. Behavioral tests were conducted to evaluate the functional return of the limb, after 3,5,7 and 14 days. The first changes in the regeneration process of the damaged neurite are observed as early as day 3 after the injury, while on day 14 after the injury the functional return of the damaged limb was noted.

Neuroprotective effect of curcumin and its potential use in the treatment of neurodegenerative diseases / Neuroprotekcyjne dzialanie kurkuminy i jej potencjalne zastosowanie w leczeniu chorób neurodegeneracyjnych.

The development of methods used in molecular biology has allowed a milestone in medical and pharmaceutical sciences. Progress has also been made in the field of pharmacognosy, which places substances of natural origin contained in plant raw materials at the center of attention. The beneficial effects of some of them have been known for years, while scientific evidence of their health-promoting properties was lacking for a long time. This was also the case with curcumin and the long road from its isolation in pure form in 1842 to the knowledge of its chemical structure in 1910. Due to the chemical properties of the molecule, curcumin is attributed with many health-promoting properties. These affect many organ systems including the skin, visual pathway, respiratory system, circulatory system, digestive system and nervous system. One of the complications that follow nerve damage is the loss of locomotor function in the animal and the development of inflammation within it. Curcumin has anti-inflammatory properties. This is confirmed by its inhibition of nuclear factor κB, a mediator in inflammatory processes. In addition, a very important field associated with neuronal dysfunction is the aging process. This is caused, among other things, by the presence of reactive oxygen species. The neuroprotective effect of curcumin allows to reduce their concentration caused by the accumulation of mutations within the mitochondrial DNA. The beneficial effect on the nervous system is due to the penetration of curcumin across the blood-brain barrier. However, its poor solubility significantly limits the therapeutic properties resulting from curcumin supplementation. Methods are currently being developed to increase its bioavailability using nanoparticles.

Assessment of metabolomics in patients with multiple sclerosis as an indicator of disease development, including relapsing-remitting, primary progressive and secondary progressive stage / Ocena profilu metabolomicznego u pacjentów ze stwardnieniem rozsianym jako wskaznik rozwoju choroby z uwzglednieniem postaci rzutowo - remisyjnej, pierwotnie postepujacej i wtórnie postepujacej.

Metabolomics is a scientific field whose topics include qualitative and quantitative analysis of metabolites, defined as the total set of low-molecular-weight chemical compounds not exceeding 1500 Da. Along with genomics, transcriptomics, and proteomics, it is categorized as a field of science, currently using state-of-the-art diagnostic tools that, in the face of modern medicine, allow a holistic approach to the patient. The presence of metabolites in the analyzed biological material, in contrast to the information contained directly in the genetic material, reflects the current physiological state of the cell, and represents an integral relationship between genotype and phenotype, which can directly contribute in the future to the knowledge of the molecular basis in specific disease entities. An additional aspect that is in favor of metabolic analysis is their decidedly smaller number compared to at least genes, transcriptomes, and proteins. Despite the development of many "omics" technologies, there is a lack of integrative and linking studies to see the full picture of cellular pathways in the future. Such linkage would improve our insight into human pathologies, leading to a revolution in preclinical and clinical research in disease diagnosis, prognosis, drug response and drug development.

The mTOR pathway and transgenic animals with deletion of the TSC gene in the regeneration of the nervous system and selected models of sciatic nerve damage / Szlak mTOR i zwierzeta transgeniczne z delecja genu TSC w procesie regeneracji ukladu nerwowego i wybranych modelach uszkodzen nerwu kulszowego.

Traumatic damage to the nervous system has been a common occurrence for years, reducing patients' quality of life. The mammalian target of rapamycin (mTOR) pathway plays a key role in nervous system physiology, including by controlling nerve cell survival and differentiation. Excessive activation of the mTOR pathway leads to an increase in cell cycle protein activity and apoptosis of nerve cells. Moreover, current findings suggest the involvement of the mTOR pathway in neuroplasticity. The use of transgenic animals with deletion of the TSC gene as well as various models of sciatic nerve damage, allows activation of the mTOR pathway. Currently, the results confirm that inactivation of point mutations in TSC-1 or TSC-2 genes, activates the canonical signaling pathway of the mTORC-1 complex, in turn, reactivation of the mTORC-1 pathway through the absence of the TSC-1 gene in mature neurons induces axonal regeneration. Dysfunction of the mTORC-1 pathway in Schwann cells (SC) inhibits myelination of nerve fibers. The aim of the present study is to understand the physiology and role of the mTOR pathway as well as to demonstrate the impact of TSC gene deletion in the regeneration of the nervous system. Current research on the activity of the mTOR pathway may provide new strategies to intensify peripheral nerve regeneration.

Bcl-2-proteins and neurotrophins as important factors for the survival of peripheral neurons in transgenic animals / Bialka z rodziny Bcl-2 oraz neurotrofiny jako istotny czynnik decydujacy o przezywalnosci neuronów obwodowych u zwierzat transgenicznych.

Apoptosis is an orderly, active process with the activation of certain genes that allows the cell to follow the path of programmed death. During embryogenesis, programmed cell death templates are essential for the proper formation of organs and the functioning of the nervous system in the regression of primary or abnormal structures. Increased cell mortality in the mature nervous system can lead to various neurodegenerative diseases. For these reasons, the Bcl-2 protein family is being studied intensively in connection with the function of the nervous system. Programmed cell death (PCD) makes it possible to eliminate superfluous cells and thus contribute to the maintenance of homeostasis in the body. Malregulation of apoptosis is characteristic of tumour processes, degenerative changes and autoimmune diseases. Research into gene expression of pro- and anti-apoptotic proteins using knock-out technology is currently raising great hopes for the treatment of patients affected by neurodegenerative changes.

Cerebral metabolism of glucose and selected glucose transporters in neurodegenerative diseases / Mózgowy metabolizm glukozy i wybranych jej transporterów w chorobach neurodegeneracyjnych.

Cerebral glucose metabolism is an issue of researchers' interest for a long time. Disturbed transport and metabolism of glucose in the brain lead to development of numerous neurological pathologies. Recently, a significant correlation between perturbed cerebral glucose metabolism and development of neurodegenerative diseases has been shown. Glucose, a monosaccharide, is the main source of energy for brain cells. Brain is the organ which is the most sensitive to changes in blood glucose level. Perturbed glucose transport leads to disorders of the central glucose metabolism. Neurodegenerative diseases are defined in the literature as progressive and irreversible degeneration of nerve tissue, causing cell death as a result of degenerative processes. The aim of this article is to discuss the physiology and the role of selected glucose transporters in the development of neurodegenerative diseases: expression of selected GLUT1 and GLUT3 transporters in Alzheimer's and Huntington's diseases. Understanding of the cerebral glucose metabolism may be a crucial factor in fight with central nervous system diseases.

The changes in neurotrophic properties of the peripheral nerves extracts following blocking of BDNF activity.

OBJECTIVES: Retinal ganglion cells (RGCs) of adult rats are unable to regenerate their axons after optic nerve injury and soon after they enter the pathway of apoptosis. They may, however, survive and regenerate new axons in response to application of specific peripheral nerve extracts that presumably contain a range of neurotrophic substances. One of the recognized substances of proven neurotrophic activity is brain-derived neurotrophic factor (BDNF). We have investigated whether blocking the BDNF activity in post-microsomal fractions obtained from 7 day pre-degenerated peripheral nerves would affect its neurotrophic properties towards RGCs after optic nerve transection in adult rats. METHODS: Autologous connective tissue chambers sutured to the distal end of transected optic nerve served as active substances containers. Surviving RGCs were visualized using Dil. The number of myelinated outgrowing fibers within the chambers was evaluated in histologic sections. RESULTS: BDNF and 7 day pre-degenerated nerve extracts, and also extracts with blocked BDNF activity, enhanced RGC fibers outgrowth. The regeneration was significantly weaker in the control group. Blocking the BDNF activity in the 7 day pre-degenerated peripheral nerve extract reduced its neurotrophic effects but the differences were insignificant in comparison with non-blocked extracts. DISCUSSION: The regeneration intensities in groups receiving 7 day pre-degenerated peripheral nerve extracts (PD7) and BDNF were comparable. The number of surviving cells was higher in the PD7 group and there were more regenerating fibers in the BDNF group, which may be explained by the strong BDNF effect on axonal collateralization and sprouting.

Quantitative and qualitative analysis of proteins in rat peripheral nerves predegenerated for 7 days.

OBJECTIVES: In contrast to peripheral nerves, central neurons do not regrow spontaneously after injury. Our previous studies showed that transplantation of degenerating peripheral nerves or their extracts can induce regeneration in the injured central nervous system. Non-predegenerated nerves show much weaker neurotrophic activity. The aim of the present work was to examine quantitatively and qualitatively the protein composition of rat sciatic nerve extracts. MATERIAL AND METHODS: The experiments were carried out on male Wistar C rats. Distal fragments were collected immediately after transection or after 7 day-long predegeneration. The nerves were homogenized, centrifuged and ultracetrifuged. Extracts were analyzed by means of two-dimensional electrophoresis. RESULTS: The two-dimensional electrophoresis showed 69 protein subfractions with isoelectric points ranging from 4.2 to 7.0 pH and molecular weight ranging from 13.5 kDa to 335.4 kDa in extracts obtained from nonpredegenerated nerves. In predegenerated nerve extracts 114 subfractions with isoelectric points ranging from 4.2 to 7.4 pH and molecular weight from 21.1 kDa to 335.4 kDa were found. Fractions: 25.5 kDa, 31.6 kDa, 36 kDa, 38.4 kDa, 42.4 kDa, 46.6 kDa, and 50.5 kDa showed significant increase and two fractions: 68.5 kDa and 335.4 kDa demonstrated significant decrease in the number of subfractions in predegenerated nerves. Fractions 160.8 kDa, 236.1 kDa, and 5 fractions below 21.1 kDa were present only in extracts from non-predegenerated nerves. CONCLUSIONS: In conclusion, the results of our study demonstrate that the most intense changes in protein composition in degenerating nerves take place in low molecular weight fractions.

[Neutrophins in biology and medicine]. / Neurotrofiny w biologii i medycynie.

Nerve growth factor NGF was the first neurotrophic substance to be identified, isolated, and characterized. NGF is member of a class of substances which has been termed the neurotrophins familly. This family of NGF-related trophic factors includes also brain-derived neurotrophic factor--BDNF, neurotrophin-3, neurotrophin-4/5 and neurotrophin-6 and 7. Each neurotrophin is able to bind to the p75NTR and a specyfic Trk tyrosine kinase receptor. Traditional view is that trophic factors are relesed from target cells, retrogradely transported along their axons, and rapidly degraded upon arrival in cell bodies. But several trophic factors can move anterogradely along axons. NGF-responsive cells are known to belong to the hemopoetic-immune system and to populations in the brain involved in neuroendocrine function. The concentration of NGF is elevated in a number of inflammatory and autoimmune states in conjuction with increased accumulation of mast cells. Neurotrophins can also regulate adult nervous system plasticity by promoting neuronal survival and stimulating nerve regrowth following injury. The potential exists for these neurotrophic factors to be used as therapeutic agents for the treatment neurodegenerative disorders.

[Metalloproteinases activity (MMP-2, MMP-9) in distal stumps of rat sciatic nerves]. / Aktywnosc metaloproteinaz (MMP-2, MMP-9) w odcinkach dystalnych przecietych nerwów kulszowych doroslych szczurów.

In case of nerve transection we observed biochemical and morphological changes in axons. The aim of present study was to examine neurotrophic activity of two important metalloproteinases: MMP-2 and MMP-9. To examine their activity in nerve supernatants, gelatin zymography was used. We concluded that the levels of MMP-2 and MMP-9 expression are increased in 4th, 5th and 6th day after nerve transection. The identification of the molecular mechanism underlying this activity could be the main key for the elaborating of further strategies for repair of the damaged nervous system.

Do peripheral nerve extracts protect retinal ganglion cells from axotomy-induced death?

PURPOSE: Study the effect of peripheral nerve extracts and BDNF on retinal ganglion cell (RGC) regeneration in adult rats. METHODS: Postmicrosomal fractions were obtained from 7-day, predegenerated, as well as non-predegenerated peripheral adult rats nerves. Autologous connective tissue chambers filled with fibrin were implanted into a gap-injury site in the optic nerve. Chambers contained either fibrin, the fractions, or BDNF. RGCs retrogradely labeled with DiI were counted, the distance covered by regrowing fibers traced with rhodamine B was measured, and number of myelinated fibers in the middle part of the chambers was estimated. RESULTS: BDNF and predegenerated nerve extracts enhanced RGC fiber outgrowth. The regeneration was significantly weaker in the groups with non-predegenerated nerve extracts, as well as fibrin, and was absent in the control group. CONCLUSION: Predegenerated nerve extracts, as well as BDNF, applied to injured optic nerves by means of connective tissue chambers, are able to induce retinal ganglion cell regeneration.

[Protein composition and structure of the myelin sheath. Part I]. / Struktura powlok mielinowych. Czesc I.

During the past few years, significant advances have been made in meeting structure of myelin sheaths and the mechanisms participating in myelination and demyelination. Myelin is formed by Schwann cells in the peripheral nervous system (PNS) and oligodendrocytes in the central nervous system (CNS). Myelin is composed of several layers of membranes wrapped around axons. In contrast majority of biological membranes both CNS and PNS myelin is characterized by a high ratio between lipids and proteins. Myelin in CNS and PNS don't differ in respect to lipids, but their protein components are different. Better understanding of myelin structure and function and as well as processes of myelination and demyelination will help to clarify some aspects of demyelinating diseases and injures in the nervous system.

[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.

Regeneration of sciatic nerves of adult rats induced by extracts from distal stumps of pre-degenerated peripheral nerves.

Despite numerous experimental and clinical attempts to reconstruct injuries of peripheral nerves, the methods developed until now have not been sufficiently effective. We examined the influence of extracts (postmicrosomal fractions) obtained from non-pre-degenerated or 7-day-pre-degenerated distal segments of peripheral nerves on the regeneration of injured sciatic nerves of male adult rats. The extracts were introduced to the site of injury with autologous connective tissue chambers filled with fibrin. Reference groups were treated with brain-derived neurotrophic factor (BDNF) or fibrin only. We examined DiI-labeled motoneurons, toluidine blue-labeled myelinated fibers in the mid-part of the chambers, and AChE-positive nerve endings to assess the regeneration intensity. In addition, the length of fibers regrowing within the chambers was measured. We found that extracts obtained from distal stumps of 7-day-pre-degenerated peripheral nerves enhanced nerve regeneration as strongly as BDNF.

Pre-degenerated peripheral nerve extracts applied to the proximal stump of transected sciatic nerve enhance both regeneration and autotomic behavior in rats.

BACKGROUND: Peripheral nerve regeneration after traumatic injury and standard repair with a nerve autograft is often incomplete and results in neuropathic pain. Peripheral nerve extracts applied to the proximal nerve stump by means of autologous, dead-ended connective tissue chambers (deCTC) are known to accelerate the rate of axon regeneration. This study tested if such extracts would influence autotomy, which is a behavioral measure of neuropathic pain in animal models. MATERIAL/METHODS: The study was performed on Wistar rats. DeCTCs, filled with postmicrosomal fraction obtained from 7-day-predegenerated nerves (7D group) or fibrin (F group), were implanted into transected sciatic nerve. In the control group (C), sciatic nerve was transected and its distal part was removed. The self-mutilation behavior in rats was assessed daily for seven weeks after sciatic nerve transection. The onset as well as intensity of autotomy was measured. The progress of regeneration was assessed under light microscopy and histochemistry. RESULTS: The earliest onset and greatest severity of autotomy were found in the 7D group. Regeneration progress was also highest in this group. In the F group, we found weaker regeneration and less autotomy. The control group showed no regeneration, but more autotomy than the F group. CONCLUSIONS: Intensified autotomy may be the price paid for enhanced peripheral nerve regeneration after application of growth-promoting substances.