scholarly journals Effects of Electrical Stimulation on Peripheral Nerve Regeneration in a Silicone Rubber Conduit in Taxol-Treated Rats

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1063
Author(s):  
Chien-Fu Liao ◽  
Shih-Tien Hsu ◽  
Chung-Chia Chen ◽  
Chun-Hsu Yao ◽  
Jia-Horng Lin ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Peripheral Nerve ◽  
Silicone Rubber ◽  
Motor Coordination ◽  
Neuronal Connectivity ◽  
Medium Frequency ◽  
Antimitotic Agent ◽  
Inflammatory Conditions ◽  
Macrophage Density

Taxol, a type of antimitotic agent, could modulate local inflammatory conditions in peripheral nerves, which may impair their regeneration and recovery when injured. This study provided in vivo trials of silicone rubber chambers to bridge a long 10 mm sciatic nerve defect in taxol-treated rats. It was aimed to determine the effects of electrical stimulation at various frequencies on regeneration of the sciatic nerves in the bridging conduits. Taxol-treated rats were divided into four groups (n = 10/group): sham control (no current delivered from the stimulator); and electrical stimulation (3 times/week for 3 weeks at 2, 20, and 200 Hz with 1 mA current intensity). Neuronal electrophysiology, animal behavior, neuronal connectivity, macrophage infiltration, calcitonin gene-related peptide (CGRP) expression levels, and morphological observations were evaluated. At the end of 4 weeks, animals in the low- (2 Hz) and medium-frequency (20 Hz) groups had dramatic higher rates of successful regeneration (90% and 80%) across the wide gap as compared to the groups of sham and high-frequency (200 Hz) (60% and 50%). In addition, the 2 Hz group had significantly larger amplitudes and evoked muscle action potentials compared to the sham and the 200 Hz group, respectively (P < 0.05). Heat, cold plate licking latencies, motor coordination, and neuronal connectivity were unaffected by the electrical stimulation. Macrophage density, CGRP expression level, and axon number were all significantly increased in the 20 Hz group compared to the sham group (P < 0.05). This study suggested that low- (2 Hz) to medium-frequency (20 Hz) electrical stimulation could ameliorate local inflammatory conditions to augment recovery of regenerating nerves by accelerating their regrowth and improving electrophysiological function in taxol-treated peripheral nerve injury repaired with the silicone rubber conduit.

EFFECTS OF LIGUSTICUM CHUANXIONG ON INJURED PERIPHERAL NERVE IN RATS

2010 ◽  
Vol 22 (04) ◽  
pp. 315-320 ◽  
Author(s):  
Chao-Tsung Chen ◽  
Jaung-Geng Lin ◽  
Tung-Wu Lu ◽  
Chih-Yang Huang ◽  
Chin-Chuan Tsai ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Silicone Rubber ◽  
Critical Factor ◽  
The Other ◽  
High Dose ◽  
Negative Effects ◽  
Ligusticum Chuanxiong

The present study provides in vivo trials of silicone rubber chambers filled with different concentrations (0, 1.25, 12.5, and 125 mg/ml) of Ligusticum Chuanxiong (LC) to bridge a 10 mm sciatic nerve defect in rats. Histological and electrophysiological techniques were used to evaluate the functional recovery of the nerve. At the end of eight weeks, regenerated nerves from all of the groups treated with the LC had similar microstructures compared to the controls. However, the high dose LC group at 125 mg/ml could inhibit the nerve regeneration with a significantly fewer myelinated axons compared to the other three groups. These results indicated that LC could be involved in both positive and negative effects on regenerating nerves. Therefore, whether a proper dosage of an LC is used or not plays a critical factor in deciding if it can sustain nerve regeneration over long gaps.

scholarly journals Noninvasive Stimulation of Peripheral Nerves using Temporally-Interfering Electrical Fields

2021 ◽  
Author(s):  
Boris Botzanowski ◽  
Mary J Donahue ◽  
Malin Silvera Ejneby ◽  
Alessandro L. Gallina ◽  
Ibrahima Ngom ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Peripheral Nerve ◽  
Nerve Stimulation ◽  
Peripheral Nerves ◽  
Sine Wave ◽  
Multielectrode Arrays ◽  
Bioelectronic Medicine ◽  
Nerve Model ◽  
Stimulation Of

Electrical stimulation of peripheral nerves is a cornerstone of bioelectronic medicine. Effective ways to accomplish peripheral nerve stimulation noninvasively without surgically implanted devices is enabling for fundamental research and clinical translation. Here we demonstrate how relatively high frequency sine-wave carriers (3 kHz) emitted by two pairs of cutaneous electrodes can temporally interfere at deep peripheral nerve targets. The effective stimulation frequency is equal to the offset frequency (0.5 - 4 Hz) between the two carriers. We validate this principle of temporal interference nerve stimulation (TINS) in vivo using the murine sciatic nerve model. Effective actuation is delivered at significantly lower current amplitudes than standard transcutaneous electrical stimulation. Further, we demonstrate how flexible and conformable on-skin multielectrode arrays can facilitate precise alignment of TINS onto a nerve. Our method is simple, relying on repurposing of existing clinically-approved hardware. TINS opens the possibility of precise noninvasive stimulation with depth and efficiency previously impossible with transcutaneous techniques.

scholarly journals Effects of endogenous inflammation signals elicited by nerve growth factor, interferon-γ, and interleukin-4 on peripheral nerve regeneration

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Chien-Fu Liao ◽  
Chung-Chia Chen ◽  
Yu-Wen Lu ◽  
Chun-Hsu Yao ◽  
Jia-Horng Lin ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Peripheral Nerve Regeneration ◽  
Interferon Γ ◽  
Interleukin 4 ◽  
Potential Growth ◽  
Inflammatory Conditions ◽  
Ifn Γ ◽  
Negative Controls

Abstract Background Large gap healing is a difficult issue in the recovery of peripheral nerve injury. The present study provides in vivo trials of silicone rubber chambers filled with collagen containing IFN-γ or IL-4 to bridge a 15 mm sciatic nerve defect in rats. Fillings of NGF and normal saline were used as the positive and negative controls. Neuronal electrophysiology, neuronal connectivity, macrophage infiltration, location and expression levels of calcitonin gene-related peptide and histology of the regenerated nerves were evaluated. Results At the end of 6 weeks, animals from the groups of NGF and IL-4 had dramatic higher rates of successful regeneration (100 and 80%) across the wide gap as compared to the groups of IFN-γ and saline controls (30 and 40%). In addition, the NGF group had significantly higher NCV and shorter latency compared to IFN-γ group (P < 0.05). The IL-4 group recruited significantly more macrophages in the nerves as compared to the saline controls and the NGF-treated animals (P < 0.05). Conclusions The current study demonstrated that NGF and IL-4 show potential growth-promoting capability for peripheral nerve regeneration. These fillings in the bridging conduits may modulate local inflammatory conditions affecting recovery of the nerves.

Facilitated migration of cells from a transected peripheral nerve over collagen fibers: in vivo observations

1989 ◽  
Vol 47 ◽  
pp. 888-889
Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Collagen Gel ◽  
Collagen Fibers ◽  
Control Group ◽  
Guide Tube ◽  
Sprague Dawley ◽  
Silicone Tube ◽  
Thin Sections

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.

Increased Circulatory Extrarenal 1α,25-Dihydroxyvitamin D3 in Bilaterally Nephrectomized Rats

2020 ◽  
Vol 20 (9) ◽  
pp. 1523-1530
Author(s):  
Murat Dabak ◽  
Durrin O. Dabak ◽  
Tuncay Kuloglu ◽  
Ersoy Baydar ◽  
Hakan Bulut ◽  
...  
Keyword(s):  
Immune Cells ◽  
Low Dose ◽  
Systemic Circulation ◽  
Bilateral Nephrectomy ◽  
Dihydroxyvitamin D3 ◽  
Hydroxyvitamin D ◽  
Inflammatory Conditions ◽  
Calcium Phosphorus ◽  
25 Hydroxyvitamin D

Background: Extrarenal 1α,25-dihydroxyvitamin D3 (1,25-D) locally produced by immune cells plays crucial roles in the regulation of the immune system. However, in vivo status of extrarenal 1,25-D and 25-hydroxyvitamin D (25-D) in acute inflammatory conditions are unknown. Objective: The aim of this study was to determine the extrarenal 1,25-D level in circulation in bilaterally nephrectomized rats, induced by low-dose lipopolysaccharide (LPS). Methods: Renal 1,25-D synthesis was terminated through bilateral nephrectomy in rats. The rats received intraperitoneal LPS (50 μg/kg BW) three times and the experiment was ended 24 hours after nephrectomy. Serum 1,25-D, 25-D, calcium, phosphorus, intact parathyroid hormone, and calcitonin levels were measured and immunohistochemistry was applied to detect the sources of extrarenal 1,25- D synthesis. Results: Circulatory 1,25-D concentration remarkably increased in both LPS-treated and non-treated bilaterally nephrectomized rats. Elevated circulatory 1,25-D did not have hypercalcemic endocrinal effects. The increased 1,25-D level also resulted in a concurrent rapid and dramatic depletion of circulatory 25-D. Conclusions: Extrarenal 1,25-D could enter into the systemic circulation and, therefore, might have systemic effects besides its autocrine and paracrine functions.

scholarly journals Effects of Taxol on Regeneration in a Rat Sciatic Nerve Transection Model

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Shih-Tien Hsu ◽  
Chun-Hsu Yao ◽  
Yuan-Man Hsu ◽  
Jia-Horng Lin ◽  
Yung-Hsiang Chen ◽  
...  
Keyword(s):  
Growth Factors ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Nerve Transection ◽  
Cremophor El ◽  
Neuronal Connectivity ◽  
Sciatic Nerve Transection ◽  
Expression Levels ◽  
Nerve Growth Factors

Abstract Recent studies describe taxol as a candidate treatment for promoting central nerve regeneration. However, taxol has serious side effects including peripheral neurotoxicity, and little information is known about the effect of taxol on peripheral nerve regeneration. We investigated the effects of taxol on regeneration in a rat sciatic nerve transection model. Rats were divided into four groups (n = 10): normal saline (i.p.) as the control, Cremophor EL vehicle, and 2 or 6 mg/kg of taxol in the Cremophor EL solution (four times in day-2, 4, 6, and 8), respectively. We evaluated neuronal electrophysiology, animal behaviour, neuronal connectivity, macrophage infiltration, location and expression levels of calcitonin gene-related peptide (CGRP), and expression levels of both nerve growth factors and immunoregulatory factors. In the high-dose taxol group (6 mg/kg), neuronal electrophysiological function was significantly impaired. Licking latencies were significantly changed while motor coordination was unaffected. Neuronal connectivity, macrophage density, and expression levels of CGRP was dramatically reduced. Expression levels of nerve growth factors and immunoregulatory factors was also reduced, while it was increased in the low-dose taxol group (2 mg/kg). These results indicate that taxol can modulate local inflammatory conditions, impair nerve regeneration, and impede recovery of a severe peripheral nerve injury.

scholarly journals N-Terminomics Strategies for Protease Substrates Profiling

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4699
Author(s):  
Mubashir Mintoo ◽  
Amritangshu Chakravarty ◽  
Ronak Tilvawala
Keyword(s):  
Mass Spectrometry ◽  
Protease Activity ◽  
Viral Infections ◽  
Mass Spectrometry Analysis ◽  
Post Translational Modification ◽  
Spectrometry Analysis ◽  
Physiological Conditions ◽  
Inflammatory Conditions ◽  
Biological Mixtures

Proteases play a central role in various biochemical pathways catalyzing and regulating key biological events. Proteases catalyze an irreversible post-translational modification called proteolysis by hydrolyzing peptide bonds in proteins. Given the destructive potential of proteolysis, protease activity is tightly regulated. Dysregulation of protease activity has been reported in numerous disease conditions, including cancers, neurodegenerative diseases, inflammatory conditions, cardiovascular diseases, and viral infections. The proteolytic profile of a cell, tissue, or organ is governed by protease activation, activity, and substrate specificity. Thus, identifying protease substrates and proteolytic events under physiological conditions can provide crucial information about how the change in protease regulation can alter the cellular proteolytic landscape. In recent years, mass spectrometry-based techniques called N-terminomics have become instrumental in identifying protease substrates from complex biological mixtures. N-terminomics employs the labeling and enrichment of native and neo-N-termini peptides, generated upon proteolysis followed by mass spectrometry analysis allowing protease substrate profiling directly from biological samples. In this review, we provide a brief overview of N-terminomics techniques, focusing on their strengths, weaknesses, limitations, and providing specific examples where they were successfully employed to identify protease substrates in vivo and under physiological conditions. In addition, we explore the current trends in the protease field and the potential for future developments.

scholarly journals The Ncoa7 locus regulates V-ATPase formation and function, neurodevelopment and behaviour

2020 ◽  
Author(s):  
Enrico Castroflorio ◽  
Joery den Hoed ◽  
Daria Svistunova ◽  
Mattéa J. Finelli ◽  
Alberto Cebrian-Serrano ◽  
...  
Keyword(s):  
Neurodevelopmental Disorders ◽  
Regulatory Protein ◽  
Molecular Function ◽  
Neuronal Connectivity ◽  
Nuclear Receptor Coactivator ◽  
Lysm Domain ◽  
Behavioural Assessment ◽  
And Function ◽  
The Brain

Abstract Members of the Tre2/Bub2/Cdc16 (TBC), lysin motif (LysM), domain catalytic (TLDc) protein family are associated with multiple neurodevelopmental disorders, although their exact roles in disease remain unclear. For example, nuclear receptor coactivator 7 (NCOA7) has been associated with autism, although almost nothing is known regarding the mode-of-action of this TLDc protein in the nervous system. Here we investigated the molecular function of NCOA7 in neurons and generated a novel mouse model to determine the consequences of deleting this locus in vivo. We show that NCOA7 interacts with the cytoplasmic domain of the vacuolar (V)-ATPase in the brain and demonstrate that this protein is required for normal assembly and activity of this critical proton pump. Neurons lacking Ncoa7 exhibit altered development alongside defective lysosomal formation and function; accordingly, Ncoa7 deletion animals exhibited abnormal neuronal patterning defects and a reduced expression of lysosomal markers. Furthermore, behavioural assessment revealed anxiety and social defects in mice lacking Ncoa7. In summary, we demonstrate that NCOA7 is an important V-ATPase regulatory protein in the brain, modulating lysosomal function, neuronal connectivity and behaviour; thus our study reveals a molecular mechanism controlling endolysosomal homeostasis that is essential for neurodevelopment. Graphic abstract

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