Obesity-associated deterioration of the hippocampus is partially restored after weight loss.

OBJECTIVE: Obesity is a multidimensional condition that is treatable by the restoration of a lean phenotype; however, some obesity-related outcomes may persist after weight normalization. Among the organs of the human body, the brain possesses a relatively low regenerative capacity and could retain perturbations established as a result of developmental obesity. Calorie restriction (CR) or a restricted ketogenic diet (KD) are successfully used as weight loss approaches, but their impact on obesity-related effects in the brain have not been previously evaluated. METHODS: We performed a series of experiments in a rat model of developmental obesity induced by a 12-week cafeteria diet, followed by CR to implement weight loss. First, we assessed the impact of obesity on neurogenesis (BrdU incorporation into the hippocampus), cognitive function (water maze), and concomitant changes in hippocampal protein expression (GC/MS-MS, western blot). Next, we repeated these experiments in a rat model of weight loss induced by CR. We also measured mitochondrial enzyme activity in rats after weight loss during the fed or fasting state. This study was extended by additional experiments with restricted KD used as a weight loss approach in order to compare the efficacy of two different nutritional interventions used in the treatment of obesity on hippocampal functions. By using a modified version of the water maze we evaluated cognitive abilities in rats subjected to weight loss by CR or a restricted KD. RESULTS: In this study, obesity affected metabolic processes, upregulated hippocampal NF-κB, and induced proteomic differences which were associated with impaired cognition and neurogenesis. Weight loss improved neurogenesis and enhanced cognition. While the expression pattern of some proteins persisted after weight loss, most of the changes appeared de novo revealing metabolic adjustment by overactivation of citrate synthase and downregulation of ATP synthase. As a consequence of fasting, the activity of these enzymes indicated hippocampal adaptation to negative energy balance during the weight loss phase of CR. Moreover, the effects on cognitive abilities measured after weight loss were negatively correlated with the animal weight measured at the final stage of weight gain. This was alleviated by KD, which improved cognition when used as a weight loss approach. CONCLUSIONS: The study shows that cognition and mitochondrial metabolism in the hippocampus are affected by CR- or KD-induced weight loss.

Methamphetamine-associated cognitive decline is attenuated by neutralizing IL-1 signaling.

Methamphetamine (METH) abusers are prone to develop a variety of comorbidities, including cognitive disabilities, and the immunological responses have been recognized as an important component involved in the toxicity of this drug. Cytokines are among the key mediators between systemic inflammatory status and tissue responses. One of these, interleukin 1 (IL-1), has been hypothesized to be involved in cognitive functions and also appears to play a pivotal role among inflammatory molecules. In the present study, we demonstrate that exposure of mice to METH markedly increased the protein level of IL-1ß in hippocampal tissue. Additionally, METH administration induced a decline in spatial learning as determined by the Morris water maze test. We next evaluated the hypothesis that blocking IL-1ß signaling can protect against METH-induced loss of cognitive functioning. The results indicated that METH-induced impaired spatial learning abilities were attenuated by co-administration of mouse IL-1 Trap, a dimeric fusion protein that incorporates the extracellular domains of both of the IL-1 receptor components required for IL-1 signaling (IL-1 receptor type 1 and IL-1 receptor accessory protein), linked to the Fc portion of murine IgG2a. This effect was associated with a decrease in hippocampal IL-1ß level. The current study indicates for the first time that the loss of METH-related cognitive decline can be attenuated by neutralizing IL-1 signaling. Our findings suggest a potential new therapeutic pathway for treatment of altered cognitive abilities that occur in METH abusing individuals.

Increased intraocular pressure alters the cellular distribution of HuR protein in retinal ganglion cells - A possible sign of endogenous neuroprotection failure.

The RNA-binding protein, HuR, modulates mRNA processing and gene expression of several stress response proteins i.e. Hsp70 and p53 that have been postulated to be involved in the pathogenesis of glaucoma, a chronic optic neuropathy leading to irreversible blindness. We evaluated HuR protein expression in retinas and optic nerves of glaucomatous rats and human primary open angle glaucoma patients and its possible impact on stress response mechanisms. We found that the cytoplasmic content of HuR was reduced more extensively in glaucomatous retinas than in optic nerves and this was linked with a declined cytoplasmic Hsp70 level and p53 nuclear translocation. In the optic nerve, the p53 content was decreased as a feature of reactive gliosis. Based on our findings, we conclude that the alteration in the HuR content, observed both in rat glaucoma model and human glaucoma samples, affects post-transcriptionally the expression of genes crucial for maintaining cell homeostasis; therefore, we postulate that HuR may be involved in the pathogenesis of glaucoma.

Application of peripheral nerve conduits in clinical practice: A literature review.

Understanding the pathomechanisms behind peripheral nerve damage and learning the course of regeneration seem to be crucial for selecting the appropriate methods of treatment. Autografts are currently the gold standard procedure in nerve reconstruction. However, due to the frequency of complications resulting from autografting and a desire to create a better environment for the regeneration of the damaged nerve, artificial conduits have become an approved alternative treatment method. The aim of this mini-review is to present the nerve scaffolds that have been applied in clinical practice to date, and the potential directions of developments in nerve conduit bioengineering. Articles regarding construction and characterization of nerve conduits were used as the theoretical background. All papers, available in PubMed database since 2000, presenting results of application of artificial nerve conduits in clinical trials were included into this mini-review. Fourteen studies including ≤10 patients and 10 trials conducted on >10 patients were analyzed as well as 24 papers focused on artificial nerve conduits per se. Taking into consideration the experiences of the authors investigating nerve conduits in clinical trials, it is essential to point out the emergence of bioresorbable scaffolds, which in the future may significantly change the treatment of peripheral nerve injuries. Also worth mentioning among the advanced conduits are hybrid conduits, which combine several modifications of a synthetic material to provide the optimal regeneration of a damaged nerve.

Cognitive impairment and BDNF serum levels.

BACKGROUND/AIMS: To investigate the alterations of brain-derived neurotrophic factor (BNDF) serum levels in subjects with different intensity of cognitive impairment and different neurodegenerative processes. MATERIAL AND METHODS: Serum BDNF levels were analyzed by ELISA kit in 378 subjects: 134 Alzheimer's disease (AD) patients, 115 amnestic mild cognitive impairment (MCI) patients, and 129 controls divided into two groups: neurodegenerative control group (ND), consisting of 49 Parkinson's disease patients without any cognitive complaints, and cognitively normal control group (CN), consisting of 80 subjects without any neurological disorders. RESULTS: AD patients had significantly lower (p<0.001) BDNF serum levels compared to MCI, CN and ND controls. Age and education had significant influence on BDNF serum levels regardless the diagnosis or group assignment. We have found no influence of depression on BDNF serum levels either in our group as a whole, or in each group assessed separately. We found significant correlation between BDNF serum levels and cognitive impairments. After multiple comparisons between the groups, we found that, after adjustment for confounding factors (age, gender, education, depression, cognitive impairment), BDNF serum levels were the lowest in AD group (p=0.05). CONCLUSIONS: Advanced age and low educational level are associated with decreased BDNF serum levels. Decreased BDNF serum levels correspond to the severity of cognitive impairment. There is no correlation between BDNF serum levels and depressive symptoms.

Sciatic nerve regeneration in rats subjected to ketogenic diet.

OBJECTIVES: Ketogenic diet (KD) is a high-fat-content diet with insufficiency of carbohydrates that induces ketogenesis. Besides its anticonvulsant properties, many studies have shown its neuroprotective effect in central nervous system, but its influence on peripheral nervous system has not been studied yet. We examined the influence of KD on regeneration of peripheral nerves in adult rats. METHODS: Fifty one rats were divided into three experimental (n = 15) and one control (n = 6) groups. Right sciatic nerve was crushed and animals were kept on standard (ST group) or ketogenic diet, the latter was introduced 3 weeks before (KDB group) or on the day of surgery (KDA group). Functional (CatWalk) tests were performed once a week, and morphometric (fiber density, axon diameter, and myelin thickness) analysis of the nerves was made after 6 weeks. Body weight and blood ketone bodies level were estimated at the beginning and the end of experiment. RESULTS: Functional analysis showed no differences between groups. Morphometric evaluation showed most similarities to the healthy (uncrushed) nerves in KDB group. Nerves in ST group differed mostly from all other groups. Ketone bodies were elevated in both KD groups, while post-surgery animals' body weight was lower as compared to ST group. DISCUSSION: Regeneration of sciatic nerves was improved in KD - preconditioned rats. These results suggest a neuroprotective effect of KD on peripheral nerves.

Poly(D,L-Lactide-Co-Glycolide) Tubes With Multifilament Chitosan Yarn or Chitosan Sponge Core in Nerve Regeneration.

PURPOSE: The influence of different kinds of nerve guidance conduits on regeneration of totally transected rat sciatic nerves through a 7-mm gap was examined. MATERIALS AND METHODS: Five different types of conduits made of chitosan and poly(D,L-lactide-co-glycolide) (PLGA) were constructed and tested in vivo. We divided 50 animals into equal groups of 10, with a different type of conduit implanted in each group: chitosan sponge core with an average molecular mass of polymer (Mv) of 287 kDa with 7 channels in a PLGA sleeve, chitosan sponge core with an Mv of 423 kDa with 7 channels in a PLGA sleeve, chitosan sponge core (Mv, 423 kDa) with 13 channels in a PLGA sleeve, chitosan multifilament yarn in a PLGA sleeve, and a PLGA sleeve only. Seven weeks after the operation, we examined the distance covered by regenerating nerve fibers, growing of nerves into the conduit's core, and intensity and type of inflammatory reaction in the conduit, as well as autotomy behavior (reflecting neuropathic pain intensity) in the animals. RESULTS: Two types of conduits were allowing nerve outgrowth through the gap with minor autotomy and minor inflammatory reactions. These were the conduits with chitosan multifilament yarn in a PLGA sleeve and the conduits with 13-channel microcrystalline chitosan sponge in a PLGA sleeve. CONCLUSIONS: The type of chitosan used to build the nerve guidance conduit influences the intensity and character of inflammatory reaction present during nerve regeneration, which in turn affects the distance crossed by regenerating nerve fibers, growing of the nerve fibers into the conduit's core, and the intensity of autotomy in the animals.

Low Concentration of BDNF in the Acute Phase of Ischemic Stroke as a Factor in Poor Prognosis in Terms of Functional Status of Patients.

BACKGROUND According to recent studies, brain-derived neurotrophic factor (BDNF) probably plays a role in development of cerebral ischemia and can be significant for the prognosis of improved mobility after stroke. The aim of this prospective study was to evaluate the blood concentration of BDNF during the 1st day of first-ever ischemic stroke and find a potential association between BDNF concentration and the neurological status in the acute period, as well as between BDNF and the functional status in the sub-acute phase of stroke. MATERIAL AND METHODS The prospective study involved 87 patients aged 39-99 years (42 women, 45 men) with first-in-life complete ischemic stroke. All study subjects underwent analysis as follows: BDNF blood concentration and neurological status according to NIHSS on the 1st day of stroke, comorbidities, etiological type of ischemic stroke by ASCOD, and functional status on the 14th and 90th day after the onset according to mRankin scale. RESULTS Mean concentration of BDNF in the study group was 9.96 ng/mL±5.21, median 10.39 ng/mL. Patients aged ≤65 years (25 individuals) had a significantly higher mean concentration of BDNF (11.94 ng/mL±4.46; median 12.34 ng/mL) than the older subjects (62 individuals) with a mean concentration of 9.17 ng/mL±5.32 (median 8.66 ng/mL). The mean score by mRankin scale on the 90th day was significantly higher among patients with lower concentrations of BDNF on the 1st day of stroke, which reflects their poorer functional status. The functional status on the 90th day was significantly worse (3-6 points by Rankin scale) in patients who had BDNF below the mean value in the acute phase of stroke. The independent factors for poor functional status of patients on the 90th day after stroke were a score >4 points by NIHSS (RR 1.14; 95% CI: 1.00-1.31; p=0.027) and the concentration of BDNF below the mean value (assessed on the 1st day of stroke) (RR 14.49; CI 4.60-45.45; p=0.000). CONCLUSIONS The neurological status and concentration of BDNF on the 1st day of ischemic stroke are independent prognostic factors in medium-term observation. Reduction in the concentration of BDNF in the acute phase of stroke is a factor for poor prognosis in terms of the functional status of patients on the 90th day after onset.

A new protocol for cultivation of predegenerated adult rat Schwann cells.

The purpose of this study was to optimize the methodology of cultivation of predegenerated Schwann cells (SCs). SCs were isolated from 7-day-predegenerated sciatic nerves of adult rats. We applied commercially available culture medium for cultivation of endothelial cells endothelial cell culture medium (EBM-2) instead of Dulbecco's Modified Eagle's Medium commonly used to culture adult Schwann cells. Additionally, cell culture medium was supplemented with factors specifically supporting SCs growth as: bovine pituitary extract (5 µg/ml), heregulin (40 ng/ml) and insulin (2.5 ng/ml). Similarly to the reports of others authors, we did not observe any beneficial effects of Forskolin application, so we didn't supplement our medium with it. Cell culture purity was determined by counting the ratio of GFAP, N-Cadherin and NGFR p75-positive cells to total number of cells. About 94-97 % of cells were confirmed as Schwann cells. As a result, we obtained sufficient number and purity of Schwann cells to be applied in different experimental models in rats. EBM-2 medium coated with fibronectin was the best for cultivation of adult rat Schwann cells.

Variable spatial magnetic field influences peripheral nerves regeneration in rats.

Generator of spatial magnetic field is one of most recent achievements among the magnetostimulators. This apparatus allows to obtain the rotating magnetic field. This new method may be more effective than other widely used techniques of magnetostimulation and magnetotherapy. We investigated the influence of alternating, spatial magnetic field on the regeneration of the crushed rat sciatic nerves. Functional and morphological evaluations were used. After crush injury of the right sciatic nerve, Wistar C rats (n = 80) were randomly divided into four groups (control and three experimental). The experimental groups (A, B, C) were exposed (20 min/day, 5 d/week, 4 weeks) to alternating spatial magnetic field of three different intensities. Sciatic Functional Index (SFI) and tensometric assessments were performed every week after nerve crush. Forty-eight hours before the sacrificing of animals, DiI (1,1'-di-octadecyl-3,3,3',3'-tetramethyloindocarbocyanine perchlorate) was applied 5 mm distally to the crush site. Collected nerves and dorsal root ganglia (DRG) were subjected to histological and immunohistochemical staining. The survival rate of DRG neurons was estimated. Regrowth and myelination of the nerves was examined. The results of SFI and tensometric assessment showed improvement in all experimental groups as compared to control, with best outcome observed in group C, exposed to the strongest magnetic field. In addition, DRG survival rate and nerve regeneration intensity were significantly higher in the C group. Above results indicate that strong spatial alternating magnetic field exerts positive effect on peripheral nerve regeneration and its application could be taken under consideration in the therapy of injured peripheral nerves.

The influence of spatial pulsed magnetic field application on neuropathic pain after tibial nerve transection in rat.

The purpose of the study was to examine the influence of the spatial variable magnetic field (induction: 150-300 µT, 80-150 µT, 20-80 µT; frequency 40 Hz) on neuropathic pain after tibial nerve transection. The experiments were carried out on 64 male Wistar C rats. The exposure of animals to magnetic field was performed 1 d/20 min., 5 d/week, for 28 d. Behavioural tests assessing the intensity of allodynia and sensitivity to mechanical and thermal stimuli were conducted 1 d prior to surgery and 3, 7, 14, 21 and 28 d after the surgery. The extent of autotomy was examined. Histological and immunohistochemical analysis was performed. The use of extremely low-frequency magnetic fields of minimal induction values (20-80 µT/40 Hz) decreased pain in rats after nerve transection. The nociceptive sensitivity of healthy rats was not changed following the exposition to the spatial magnetic field of the low frequency. The results of histological and immunohistochemical investigations confirm those findings. Our results indicate that extremely low-frequency magnetic field may be useful in the neuropathic pain therapy.

Automated determination of peripheral nerve stimulation parameters to achieve desired effector response - a procedural routine, preliminary studies and proposal of improvements.

BACKGROUND: The feasibility of selectively stimulating fascicles and fibers within peripheral nerves has been demonstrated by a number of groups. Although various multi-contact electrodes have been developed for this purpose, the lack of procedures for fast determination of stimulation parameters to produce the desired effector activity hampers the clinical application of these techniques.In this paper, we propose an automated search routine that may facilitate the determination of stimulation parameters. To verify the routine's performance, we also developed an another routine that performs systematic stimulus-response mapping (the mapping routine). METHOD: The mapping routine performs systematic mapping of all possible combinations of the allowed stimulation parameters (i.e. combinations of electrode contacts used to provide the stimulus and sets of stimulus parameters values) and the observed displacements. The proposed automated search routine, similarly to the mapping routine, maps stimulation parameters to muscle responses, but it first investigates stimuli of the low charge and during the mapping process it compares the recorded responses with the desired one. Depending on the result of that comparison, it decides whether the use of a particular combination of electrode contacts should be further investigated or skipped.Both approaches were implemented on a custom-made closed-loop FES platform and preliminary experiments were performed on a rat model. The rat's sciatic nerve was stimulated with a 12-contact cuff electrode and the resulting displacement of the rat's paw was determined using a MEMS accelerometer. RESULTS: The automated search routine was faster than the mapping routine; however, it failed to find correct stimulation parameters in one out of three searches. This could be due to unexpectedly high variability in the responses to a constant stimulus. CONCLUSION: Our initial tests have proven that the proposed method determines the desired stimulation parameters much more quickly than systematic stimulus-response mapping. However, the factors influencing the variability of responses to constant stimuli should be identified, and their influence diminished; the remaining essential variability can then be identified. Thereafter, the criteria influencing the search process should be investigated and refined.Further improvements to the search routine are also proposed.

[Schwann cells in therapy of spinal cord injuries]. / Komórki Schwanna w terapii uszkodzen rdzenia kregowego.

Schwann cells (SC) have a special activity in the repair processes after injury of the nervous system because of the capability of differentiation, migration, proliferation and myelinization of axons. They enhance production of numerous neurotrophic factors, thus creating a permissive environment for axonal regeneration. Experimental studies using SC in neuronal transplants showed that these cells with their basal membrane with adhesion molecules are attractive material for neural prostheses facilitating axon growth. Moreover, SC can produce stable myelin, restoring normal function of the neuron. Transplantations of SC in myelin injury have been used in animal models of multiple sclerosis, Parkinson's disease, and brain and spinal cord injuries. Because the transplanted SC have no ability to migrate within the normal nervous system, in many experiments SC derived from rat embryos were applied. Such cells migrated through normal nervous tissue and co-operated with host cells, their survival was longer, and myelin was not destroyed in multiple sclerosis. Also, fast recovery of motor activity in injured axons in rat spinal cord was observed, especially after transplantation of SC derived from skin progenitor cells or progenitor cells which have a phenotype characteristic for SC. Many authors have reported early apoptosis of transplanted SC, so a more complex repair strategy is needed that combines SC transplantation with other methods in order to achieve longer survival and optimal functional recovery following spinal cord injury.

Rodent Models of Diabetic Retinopathy as a Useful Research Tool to Study Neurovascular Cross-Talk.

Diabetes is a group of metabolic diseases leading to dysfunction of various organs, including ocular complications such as diabetic retinopathy (DR). Nowadays, DR treatments involve invasive options and are applied at the sight-threatening stages of DR. It is important to investigate noninvasive or pharmacological methods enabling the disease to be controlled at the early stage or to prevent ocular complications. Animal models are useful in DR laboratory practice, and this review is dedicated to them. The first part describes the characteristics of the most commonly used genetic rodent models in DR research. The second part focuses on the main chemically induced models. The authors pay particular attention to the streptozotocin model. Moreover, this section is enriched with practical aspects and contains the current protocols used in research in the last three years. Both parts include suggestions on which aspect of DR can be tested using a given model and the disadvantages of each model. Although animal models show huge variability, they are still an important and irreplaceable research tool. Note that the choice of a research model should be thoroughly considered and dependent on the aspect of the disease to be analyzed.

Deficiency of the RNA-binding protein ELAVL1/HuR leads to the failure of endogenous and exogenous neuroprotection of retinal ganglion cells.

Introduction: ELAVL1/HuR is a keystone regulator of gene expression at the posttranscriptional level, including stress response and homeostasis maintenance. The aim of this study was to evaluate the impact of hur silencing on the age-related degeneration of retinal ganglion cells (RGC), which potentially describes the efficiency of endogenous neuroprotection mechanisms, as well as to assess the exogenous neuroprotection capacity of hur-silenced RGC in the rat glaucoma model. Methods: The study consisted of in vitro and in vivo approaches. In vitro, we used rat B-35 cells to investigate, whether AAV-shRNA-HuR delivery affects survival and oxidative stress markers under temperature and excitotoxic insults. In vivo approach consisted of two different settings. In first one, 35 eight-week-old rats received intravitreal injection of AAV-shRNA-HuR or AAV-shRNA scramble control. Animals underwent electroretinography tests and were sacrificed 2, 4 or 6 months after injection. Retinas and optic nerves were collected and processed for immunostainings, electron microscopy and stereology. For the second approach, animals received similar gene constructs. To induce chronic glaucoma, 8 weeks after AAV injection, unilateral episcleral vein cauterization was performed. Animals from each group received intravitreal injection of metallothionein II. Animals underwent electroretinography tests and were sacrificed 8 weeks later. Retinas and optic nerves were collected and processed for immunostainings, electron microscopy and stereology. Results: Silencing of hur induced apoptosis and increased oxidative stress markers in B-35 cells. Additionally, shRNA treatment impaired the cellular stress response to temperature and excitotoxic insults. In vivo, RGC count was decreased by 39% in shRNA-HuR group 6 months after injection, when compared to shRNA scramble control group. In neuroprotection study, the average loss of RGCs was 35% in animals with glaucoma treated with metallothionein and shRNA-HuR and 11.4% in animals with glaucoma treated with metallothionein and the scramble control shRNA. An alteration in HuR cellular content resulted in diminished photopic negative responses in the electroretinogram. Conclusions: Based on our findings, we conclude that HuR is essential for the survival and efficient neuroprotection of RGC and that the induced alteration in HuR content accelerates both the age-related and glaucoma-induced decline in RGC number and function, further confirming HuR's key role in maintaining cell homeostasis and its possible involvement in the pathogenesis of glaucoma.

The sitting position during neurosurgical procedures does not influence serum biomarkers of pulmonary parenchymal injury.

BACKGROUND: The sitting position during neurosurgical operations predisposes to air penetration through veins and the movement of the air through the pulmonary circulation. Contact of an air bubble with the endothelium can lead to acute lung injury. The presence of specific pulmonary proteins in the plasma such as surfactant protein D (SP-D) and Clara cell protein (CC16) is a biomarker of damaging processes at the air-blood barrier. The aim of our study was to examine the hypothesis that the level of investigated pulmonary biomarkers in plasma is higher in patients operated on in the sitting position. METHODS: The study included patients undergoing planned neurosurgical operations, who were divided into two groups: the sitting group (40 patients, operated on in the sitting position) and the supine group (24 patients, operated in the supine position). After the operation blood samples were drawn, centrifuged, frozen and stored until analyses were conducted. The determination of the SP-D and CC16 levels was performed using an ELISA test. Air embolism (VAE) was defined as a sudden drop in etCO2 of more than 2 mmHg and the presence of air bubbles in the aspirated blood from the central cannula. In all patients, the number of hospitalization days in the postoperative period was calculated. RESULTS: There were no differences in the average levels of SP-D between the groups (the mean in the sitting group was 95.56 ng/mL and the mean in the supine group was 101.21 ng/mL). The average levels of CC16 were similar in both groups as well (6.56 ng/mL in the sitting group and 6.79 ng/mL in the supine group). There was a statistically significant positive correlation between SP-D and CC16 values in both groups. VAE was diagnosed clinically in 12.5% of cases in the sitting group without a significant increase in SP-D and CC16 levels. On average, patients in both groups were discharged from the hospital within 9 days of surgery. CONCLUSION: The sitting position and intraoperative VAE during neurosurgical procedures do not affect the concentration of plasma biomarkers of pulmonary parenchymal injury such as SP-D and CC16.

Air gun impactor--a novel model of graded white matter spinal cord injury in rodents.

Understanding mechanisms of spinal cord injury and repair requires a reliable experimental model. We have developed a new device that produces a partial damage of spinal cord white matter by means of a precisely adjusted stream of air applied under high pressure. This procedure is less invasive than standard contusion or compression models and does not require surgical removal of vertebral bones. We investigated the effects of spinal cord injury made with our device in 29 adult rats, applying different experimental parameters. The rats were divided into three groups in respect to the applied force of the blast wave. Functional outcome and histopathological effects of the injury were analyzed during 12-week follow-up. The lesions were also examined by means of magnetic resonance imaging (MRI) scans. The weakest stimulus produced transient hindlimb paresis with no cyst visible in spinal cord MRI scans, whereas the strongest was associated with permanent neurological deficit accompanied by pathological changes resembling posttraumatic syringomyelia. Obtained data revealed that our apparatus provided a spinal cord injury animal model with structural changes very similar to that present in patients after moderate spinal cord trauma.

TXNIP inhibition in the treatment of diabetes. Verapamil as a novel therapeutic modality in diabetic patients.

Loss of pancreatic ß-cell is a critical factor in the pathogenesis of type 1 diabetes and it also occurs in type 2. TXNIP (thioredoxin - interacting protein), also known as vitamin D3-upregulated protein 1, or thioredoxin-binding-protein-2, regulates this process and modulates cellular redox balance. TXNIP is localized primarily in the nucleus, but under oxidative stress it moves to mitochondria, where it interacts with mitochondrial thioredoxin 2. Overexpression of TXNIP induced by hyperglycaemia is typical for diabetes and insulin resistance and leads to apoptosis of pancreatic ß-cell, cardiomyopathy, metabolic disorders and multiple harmful effects. It activates NLRP3 inflamasomme and IL-1ß, a cytokine involved in type 2 diabetes and insulin resistance. TXNIP influences peroxisome proliferator-activated receptor alpha transcriptional activity, expression of glucose transporter-1, nitric oxide production in endothelium and insulin production in ß-cells. TXNIP overexpression leads to diabetic retinopathy, nephropathy, atherosclerosis, it occurs in cancers and autoimmune diseases, while its deficiency protects ß cells. Reduction of TXNIP is an important target in diabetes treatment. In this mechanism insulin, metformin and inhibitors of dipeptydylopeptydase IV are involved. It has been observed that calcium channel blockers (CCB) used in hypertension also inhibit TXNIP expression in cardiomyocytes. L-type channels identification in pancreatic ß-cells revealed that CCB inhibit TXNIP expression also in ß-cells. For the first time, verapamil was distinguished as an agent that not only inhibits TXNIP expression in pancreatic ß-cells, but also enhances ß cell survival and function, and possibly prevents diabetes.

Surgical Menopause Impairs Retinal Conductivity and Worsens Prognosis in an Acute Model of Rat Optic Neuropathy.

Deficiency of estradiol during the menopausal period is an important risk factor for neurodegenerative diseases, including various optic neuropathies. The aim of this study was to evaluate the impact of surgical menopause on the function and survival ratio of RGCs in the rat model of ONC (optic nerve crush). We used eight-week-old female Long Evans rats, divided into two main groups depending on the time between ovariectomy procedure (OVA) and euthanasia (two weeks vs. seven weeks), and subgroups-OVA, OVA + ONC, or ONC. Retinal function was assessed with electroretinography (ERG). RGC loss ratio was evaluated using immunolabelling and counting of RGCs. Seven weeks after OVA, the menopause morphologically affected interneurons but not RGC; however, when the ONC procedure was applied, RGCs appeared to be more susceptible to damage in case of deprivation of estrogens. In our analysis, PhNR (photopic negative responses) were severely diminished in the OVA + ONC group. A deprivation of estrogens in menopause results in accelerated retinal neurodegeneration that firstly involves retinal interneurons. The lack of estrogens increases the susceptibility of RGCs to insults.

SCD1-Fatty Acid Desaturase Inhibitor MF-438 Alleviates Latent Inflammation Induced by Preservative-Free Prostaglandin Analog Eye Drops.

INTRODUCTION: Prostaglandin analogs are the first line of treatment in patients with glaucoma. Recently, many preservative-free prostaglandin analogs have been marketed to increase their tolerance in chronic use. However, potentially safer formulations have been reported to induce inflammation within ocular surface and adnexa, associated with pronounced activation of tissue macrophages. AIM: We aimed to evaluate the effect of a Stearoyl-CoA desaturase-1 (SCD1) inhibitor, MF-438, on the differentiation of monocytes exposed to eye drop detergents, representing saturated fatty acid derivatives. METHODS: A culture of human peripheral blood monocytes was exposed to eye drops containing fatty acid derivatives (eye drop detergents), pf-latanoprost (Monoprost®, hydroxystearate macrogolglycerol - MGHS40) or pf-tafluprost (Taflotan®, polysorbate 80 - PS80), as well as pf-latanoprost+MF-438, MGHS40, and PS80. For the negative control C(-), monocytes were cultured in basal medium, and for the positive controls, monocytes were stimulated with Lipopolysaccharide (LPS) and Interferon γ (IFNγ) (M1 macrophages) or Interleukin-4 (IL-4) (M2 macrophages). The concentration of desaturase in the cell homogenates was determined by ELISA. The number of cells was counted under a microscope at 20x magnification. RESULTS: The following concentrations of SCD1 (ng/mL) were measured: 7.8±0.3 - pf-latanoprost group; 1.5±0.4 - pf-tafluprost group; 6.8±0.7 - MGHS40 group; 0.4±0.002 - PS80 group; 0.9±0.02 - pf-latanoprost+MF-438 group; 5.4±1.6 - C(-) control; 0.5±0.04 - M1 control; 2.2±0.13 - M2 control. The percentages of macrophages in culture were 33.6%, 17.6%, 33%, 0%, 13.5%, 18.6%, 36.3%, and 39.3% for the pf-latanoprost, pf-tafluprost, MGHS40, PS80, pf-latanoprost+MF-438, C(-), M1, and M2 cultures, respectively. There was a strong correlation between SCD1 concentration and macrophage count in the culture (r=0.8, p<0.05). CONCLUSION: Inhibition of SCD1 in monocytes prevents their transformation into macrophages after exposure to saturated fatty acid derivatives contained in eye drops, which may contribute to the limitation of latent inflammation within ocular adnexa and could possibly translate into better tolerability of the topical treatment.