Exosomes derived from human placental mesenchymal stem cells in combination with hyperbaric oxygen synergically alleviates spinal cord ischemia-reperfusion injury

Spinal cord ischemia-reperfusion injury (IR) is a terrible non-traumatic injury that occurs after abdominal aortic occlusion and causes serious damage to neurological function. Several treatment strategies have been suggested for IR, but they were not unable to effectively improve these conditions. Herein we investigated whether exosomes derived from human placental mesenchymal stem cells (hpMSCs-Exos) in combination with hyperbaric oxygen (HBO) could alleviate injury and promote recovery in IR rats. Eighty male Sprague-Dawley rats were randomly allocated into five equal groups. In addition to the control group that only underwent laparotomy, IR animals were planned into four groups as follows: IR group; IR-Exos group; IR-HBO group; and IR-Exos + HBO group. Neurological function evaluated before, 6 h, 12 h, 24 h, and 48 h after injury. After the last neurological evaluation, tissue samples were obtained for stereological, biochemical, and molecular assessments. Our results indicated that the neurological function scores (MDI), the numerical density of neurons, the levels of antioxidative factors (GSH, SOD, and CAT), and anti-inflammatory cytokine (IL-10) were considerably greater in treatment groups than in the IR group, and these changes were more obvious in the IR-Exos + HBO ones. This is while the numerical density of glial cells, the levels of an oxidative factor (MDA) and inflammatory cytokines (IL-1β, TNF-α, and IL-18), as well as the expression of an apoptotic protein (caspase-3) were meaningfully decreased in treatment groups, especially IR-Exos + HBO group, compared to the IR group. Generally, it was found that co-administration of hpMSCs-Exos and HBO has synergistic neuroprotective effects in the rats undergoing IR.

Protective Effect of Hyperbaric Oxygen Treatment on Axon Degeneration after Acute Motor Axonal Neuropathy

OBJECTIVES

Acute motor axonal neuropathy (AMAN) is a disease that leads to acute flaccid paralysis and may result from the binding of antibody and antigen to the spinal cord. The objective of this study is to evaluate the protective effect of hyperbaric oxygen treatment (HBOT) on axon degeneration of the spinal cord and sciatic nerve of the AMAN model rabbit. Axonal degeneration was assessed by evaluating glutathione (GSH) activity, interleukin-1β (IL-1β) expression, and clinical and histopathological features.

METHODS

Twenty-one New Zealand rabbits were divided into three groups. The treatment group was exposed to 100% oxygen at 2.4 ATA 90 minutes for 10 days at a decompression rate of 2.9 pounds per square inch/minute. GSH level was evaluated using an enzyme-linked immune-sorbent assay. An expression of IL-1β in the spinal cord was determined by immunohistochemistry. Clinical appearances were done by motor scale and body weight. Histological features observed neuronal swelling and inflammatory infiltration in the sagittal lumbar region and the undulation of the longitudinal sciatic nerve.

RESULTS

Rabbits exposed to HBO had high GSH activity levels (p < 0.05) but unexpectedly had high IL1β expression (p > 0.05). In addition, the HBO-exposed rabbits had a better degree of undulation, the size of neuronal swelling was smaller, the number of macrophages was higher, and motor function was better than the AMAN model rabbits (p < 0.05).

CONCLUSIONS

These findings indicate that HBO therapy can decrease axon degeneration by triggering GSH activity, increasing IL-1β level, and restoring tissues and motor status. In conclusion, HBO has a protective effect on axon degeneration of the spinal cord and sciatic nerve of the AMAN model rabbit.

Rationale for hyperbaric oxygen therapy in traumatic injury and wound care in small animal veterinary practice

Hyperbaric oxygen therapy is in wide use in human medicine around the world. Although hyperbaric oxygen therapy is available for veterinary use, it is still significantly underutilised. The physical principles, gas laws and physiologic mechanisms by which hyperbaric oxygen therapy is therapeutic, especially in traumatic injuries and complicated wound care, are discussed. Then, considerations are offered for the implementation of hyperbaric oxygen therapy in veterinary practices. Finally, a review of clinical indications for veterinary practices, including a presentation of select literature, is provided. Applying hyperbaric oxygen therapy in an earlier and more consistent manner could improve short- and long-term outcomes in complicated wounds. The authors also hope this information may stimulate interest in the design of future, prospective studies for the various clinical situations described.

Acute spontaneous spinal cord infarction: Utilisation of hyperbaric oxygen treatment, cerebrospinal fluid drainage and pentoxifylline

INTRODUCTION

Spinal cord infarction (SCI) is a potentially devastating disorder presenting with an acute anterior spinal artery syndrome, accounting for an estimated 1% of stroke presentations. Aetiologies include aortic surgical complications, systemic hypotension, fibrocartilaginous embolism and vascular malformations. Diagnosis is clinical combined with restriction on diffusion-weighted magnetic resonance imaging (MRI). There are no treatment guidelines for non-perioperative cases although there is limited literature regarding potential therapies, including hyperbaric oxygen treatment (HBOT) and cerebrospinal fluid (CSF) drainage. We describe 13 cases of acute SCI, five receiving HBOT, and three also receiving pentoxifylline and drainage of lumbar CSF.

METHODS

Data for all patients with MRI-proven SCI at Fiona Stanley Hospital from 2014-2019 were reviewed.

RESULTS

Thirteen patients, median age 57 years (31-74), 54% female, were identified. Aetiologies: two fibrocartilaginous emboli; seven likely atherosclerotic; two thromboembolic; two cryptogenic. All presented with flaccid paraplegia except one with Brown-Sequard syndrome. Levels ranged from C4 to T11. Five patients received HBOT within a median time of 40 hours from symptom onset, with an average 15 treatments (10-20). Three of these received triple therapy (HBOT, pentoxifylline, CSF drainage) and had median Medical Research Council manual muscle testing power of 5, median modified Rankin Score (mRS) of 1 and American Spinal Injury Association (ASIA) score of D on discharge, compared with 2 power, mRS 3.5 and ASIA B in those who did not.

CONCLUSIONS

SCI can be severely disabling. Triple therapy with pentoxifylline, CSF drainage and HBOT may reduce disability and further prospective trials are required.

The effect of hyperbaric oxygen therapy combined with hair transplantation surgery for the treatment of alopecia

BACKGROUND

Transplanted hair follicles suffer from various injuries, which are difficult to prevent. Hyperbaric oxygen therapy (HBOT) was reported to be an excellent procedure to promote capillary regeneration and reduce ischemia-reperfusion injury.

AIM

To evaluate the clinical efficacy of HBOT as an adjuvant therapy for hair transplantation surgery.

METHODS

Thirty-four patients with II-IV alopecia were divided into the control group and HBOT group randomly. The control group was treated with routine FUE procedure, while HBOT group combined with HBOT. Patients were treated with 100% oxygen under 2.0 atmospheres absolute pressure for 60 minutes through a facemask during HBOT and take the therapy daily for 7 days continuously after operation. Satisfaction and clinical improvement were evaluated at the fourth week and the sixth month postoperatively.

RESULTS

Itching and folliculitis were significantly decreased in HBOT group (11.8% vs 35.3%). In addition, HBOT resulted in a lower postoperative shedding rate (27.6 ± 2.6% vs 69.1 ± 2.4%); nevertheless, the survival rate at 9 months showed no significant difference between HBOT (96.9 ± 0.5%) and control (93.8 ± 0.6%). The early postoperative satisfaction in control group was much lower than HBOT group (52.9% vs 88.2%), whereas all patients showed satisfaction with the final result.

CONCLUSION

Hyperbaric oxygen therapy is able to minimize the postsurgical follicle shedding and lead to less folliculitis and itching, which provides evidence for HBOT to act as an adjuvant therapy for hair transplantation surgery.

Effects of hyperbaric oxygen and iloprost on intestinal ischemia-reperfusion induced acute lung injury

Purpose

To research the effects of iloprost (IL) and hyperbaric oxygen (HBO) combination treatment on lung injury and on tumor necrosis factor alpha (TNF-α), myeloperoxidase (MPO), malondialdehyde (MDA), and soluble intercellular adhesion molecule-1 (sICAM-1) levels after tissue or organ ischemia-reperfusion, and on ischemia-reperfusion induced lung neutrophil sequestration.

Methods

Forty white New Zealand rabbits were assigned randomly into 5 groups: HBO, IL, HBO+IL, control, and sham groups. TNF-α values were checked before ischemia, in the 1st hour of ischemia and in the 1st and 4th hours of reperfusion, also at the end of reperfusion period, plasma and tissue MPO values, MDA values, and sICAM-1 levels were detected. After sacrifice, the degree of lung injury was determined by histopathological examination.

Results

Compared to the control group all therapy groups showed a drastically meaningful reduction in TNF-α increase in 1, 2, and 4 hours. Plasma and lung MDA, MPO, and sICAM-1 levels were significantly lower in IL, HBO, HBO+IL, and sham groups compared with the control group. IL and/or HBO suppressed MDA and MPO increase in the lung tissue and in plasma. Additionally, histopathological score was significantly lower in HBO, IL, HBO+IL, and sham groups than that of the control group.

Conclusion

Both HBO and IL therapy have a beneficial effect by causing a meaningful reduction in TNF-α production, MPO, MDA, sICAM-1 levels and pulmonary neutrophil sequestration; which play a role, especially, in ischemia reperfusion induced lung damage.

[The administration of neurocytoprotectors in a rat model of experimental spinal cord ischemia]

AIM

To study an effect of cortexin on functional recovery and morphology of the spinal cord of rats with spinal cord ischemia.

MATERIAL AND METHODS

Spinal cord ischemia was achieved by ligation of the infrarenal abdominal aorta in 16 rats stratified into two equal groups: the ligation of infrarenal aorta was performed in the control group, aorta ligation was performed also in the experimental group with preliminary intraperitoneally administration of cortexin in a dose of 0.15 mg/kg 30 min before procedure. Evaluation of neurologic deficit was performed by the Tarlov's scale. Morphological evaluation was made by analyzing the histological sections of the lumbar and sacral cord using the Nissl's method of coloring. Statistical analysis was performed as well.

RESULTS AND CONCLUSION

A pronounced and significant effect of cortexin, which was clinically expressed in a decrease in neurological deficit (p=0.0095), morphologically in an increase in the number of normochromic neurons (р=0.01), and a decrease in shrunken neurons (р=0.0001) and shadow cells (р=0.0003), was noted. The results suggest a potential myeloprotective effect of cortexin. The drug can be considered in the context of treatment of vascular myelopathy.

Centrally acting drug moxonidine decreases reactive oxygen species via inactivation of the phosphoinositide-3 kinase signaling in the rostral ventrolateral medulla in hypertensive rats

OBJECTIVE

Centrally acting antihypertensive action of moxonidine is a result of activation of Imidazoline-1 receptor (I1R) in the rostral ventrolateral medulla (RVLM). Hypertension shows an increase in reactive oxygen species (ROS) in the RVLM. The present objective was to determine the phosphoinositide-3 kinase (PI3K) signaling pathway involved in the effect of moxonidine on ROS generation in the RVLM of spontaneously hypertensive rat (SHR).

METHODS

Wistar-Kyoto rats and SHR received intracisternal infusion (2 weeks) of tested agents which were subjected to subsequent experiments. In-situ ROS in the RVLM was evaluated by the oxidative fluorescence dye. Western blot and PCR analysis were performed to detect the expression levels of PI3K signaling pathway. Lentivirus was injected bilaterally into the RVLM for silencing PI3K signaling.

RESULTS

ROS production in the RVLM was dose-dependently reduced in SHRs treated with infusion of moxonidine (20 nmol/day), which was prevented by the I1R antagonist efaroxan but not by the α2-adrenoceptor antagonist yohimbine. Moxonidine pretreatment significantly blunted cardiovascular sensitivity to injection of tempol (5 nmol) or angiotensin II (10 pmol) into the RVLM in SHR. Expression levels of PI3K/Akt, nuclear factor kappa-B (NFκB), NADPHase (NOX4), and angiotensin type I receptor (AT1R) in the RVLM were markedly decreased in SHR treated with moxonidine. Infection of lentivirus containing PI3K shRNA in the RVLM effectively prevented effects of moxonidine on cardiovascular activity and expression levels of Akt, NFκB, NOX4, and AT1R.

CONCLUSION

The centrally antihypertensive drug moxonidine decreases ROS production in the RVLM through inactivation of the PI3K/Akt signaling pathway in hypertension.

Comparison of hyperbaric oxygen versus iloprost treatment in an experimental rat central retinal artery occlusion model

PURPOSE

Central retinal artery occlusion (CRAO) is one of the serious ophthalmological emergencies with poor visual prognosis. Iloprost is a stable prostacyclin analogue and has prominent anti-edema, anti-inflammatory, vasodilatory, and antiagregant effects. The main objective of this work was to investigate iloprost as an alternative agent versus hyperbaric oxygen (HBO) in the treatment of CRAO.

METHODS

Twenty-eight healthy Wistar albino male rats were randomly assigned into control (n = 7, sham operation), HBO (n = 7), iloprost (n = 7), and sham groups (n = 7). CRAO model was created through optic nerve exploration and ligation. Full-thickness retina (FTR), outer nuclear layer (ONL), inner nuclear layer (INL) and ganglion cell layer (GCL) thickness were measured on Hematoxylin/Eosin (H&E) stained retinal sections and immunohistochemical analysis including terminal deoxynucleotidyl transferase-mediated biotindeoxyuridine triphosphate nick-end labeling (TUNEL) assay was performed to determine the apoptotic index (AI).

RESULTS

AI values of HBO (0.204 ± 0.067) and iloprost (0.197 ± 0.052) groups were significantly lower than sham (0.487 ± 0.046) group (p < 0.001). Any significant difference was found between the HBO and iloprost groups in terms of AI (p = 0.514). A statistically significant increase in thickness of FTR, ONL, INL and GCL was detected in HBO, iloprost and sham groups compared to the control group (p = 0.002). FTR, ONL, INL and GCL thickness were significantly thinner in HBO and iloprost groups than in the sham group (p = 0.002). A significant lesser increase was observed in all the retinal layers thickness in iloprost group versus HBO group (p = 0.002) except for INL (p = 0.665).

CONCLUSIONS

The study results demonstrated anti-edema, neuroprotective, and anti-apoptotic effects of iloprost quantitatively; thus, iloprost may be a beneficial alternative agent in the treatment of CRAO.

Current and emerging treatment options for spinal cord ischemia

Spinal cord infarction (SCI) is a rare but disabling disorder caused by a wide spectrum of conditions. Given the lack of randomized-controlled trials, contemporary treatment concepts are adapted from guidelines for cerebral ischemia, atherosclerotic vascular disease, and acute traumatic spinal cord injury. In addition, patients with SCI are at risk for several potentially life-threatening but preventable systemic and neurologic complications. Notably, there is emerging evidence from preclinical studies for the use of neuroprotection in acute ischemic injury of the spinal cord. In this review, we discuss the current state of the art for the therapy and prevention of SCI and highlight potential emerging treatment concepts awaiting translational adoption.