Ozone Prevents Cochlear Damage From Ischemia-Reperfusion Injury in Guinea Pigs

A novel cell-free therapy using exosomes in the inner ear regeneration

Cellular and molecular alterations associated with hearing loss are now better understood with advances in molecular biology. These changes indicate the participation of distinct damage and stress pathways that are unlikely to be fully addressed by conventional pharmaceutical treatment. Sensorineural hearing loss is a common and debilitating condition for which comprehensive pharmacologic intervention is not available. The complex and diverse molecular pathology that underlies hearing loss currently limits our ability to intervene with small molecules. The present review focuses on the potential for the use of extracellular vesicles in otology. It examines a variety of inner ear diseases and hearing loss that may be treatable using exosomes (EXOs). The role of EXOs as carriers for the treatment of diseases related to the inner ear as well as EXOs as biomarkers for the recognition of diseases related to the ear is discussed.

L-shaped association of triglyceride glucose index and sensorineural hearing loss: results from a cross-sectional study and Mendelian randomization analysis

Background

The association between the sensorineural hearing loss (SNHL) and triglyceride-glucose (TyG) index remains inadequately understood. This investigation seeks to elucidate the connection between the TyG index and SNHL.

Methods

In this cross-sectional study, we utilized datasets sourced from the National Health and Nutrition Examination Survey (NHANES). A comprehensive analysis was conducted on 1,851 participants aged 20 to 69, utilizing complete audiometry data from the NHANES database spanning from 2007 to 2018. All enrolled participants had accessible hearing data, and the average thresholds were measured and calculated as both low-frequency pure-tone average and high-frequency pure-tone average. Sensorineural hearing loss (SNHL) was defined as an average pure tone of 20 dB or higher in at least one better ear. Our analysis involved the application of multivariate linear regression models to examine the linear relationship between the TyG index and SNHL. To delineate any non-linear associations, we utilized fitted smoothing curves and conducted threshold effect analysis. Furthermore, we conducted a two-sample Mendelian randomization (MR) study, leveraging genetic data from genome-wide association studies (GWAS) on circulating lipids, blood glucose, and SNHL. The primary analytical method for the MR study was the application of the inverse-variance-weighted (IVW) approach.

Results

In our multivariate linear regression analysis, a substantial positive correlation emerged between the TyG index and SNHL [2.10 (1.80-2.44), p < 0.0001]. Furthermore, using a two-segment linear regression model, we found an L-shaped relationship between TyG index, fasting blood glucose and SNHL with an inflection point of 9.07 and 94 mg/dL, respectively. Specifically, TyG index [3.60, (1.42-9.14)] and blood glucose [1.01, (1.00-1.01)] concentration higher than the threshold values was positively associated with SNHL risk. Genetically determined triglyceride levels demonstrated a causal impact on SNHL (OR = 1.092, p = 8.006 × 10-4). In addition, blood glucose was found to have a protective effect on SNHL (OR = 0.886, p = 1.012 × 10-2).

Conclusions

An L-shaped association was identified among the TyG index, fasting blood glucose, and SNHL in the American population. TyG index of more than 9.07 and blood glucose of more than 94 mg/dL were significantly and positively associated with SNHL risk, respectively.

Differentially expressed miRNA profiles of serum-derived exosomes in patients with sudden sensorineural hearing loss

Objectives

This study aimed to compare the expressed microRNA (miRNA) profiles of serum-derived exosomes of patients with sudden sensorineural hearing loss (SSNHL) and normal hearing controls to identify exosomal miRNAs that may be associated with SSNHL or serve as biomarkers for SSNHL.

Methods

Peripheral venous blood of patients with SSNHL and healthy controls was collected to isolate exosomes. Nanoparticle tracking analysis, transmission electron microscopy, and Western blotting were used to identify the isolated exosomes, after which total RNA was extracted and used for miRNA transcriptome sequencing. Differentially expressed miRNAs (DE-miRNAs) were identified based on the thresholds of P < 0.05 and |log₂fold change| > 1 and subjected to functional analyses. Finally, four exosomal DE-miRNAs, including PC-5p-38556_39, PC-5p-29163_54, PC-5p-31742_49, and hsa-miR-93-3p_R+1, were chosen for validation using quantitative real-time polymerase chain reaction (RT-qPCR).

Results

Exosomes were isolated from serum and identified based on particle size, morphological examination, and expression of exosome-marker proteins. A total of 18 exosomal DE-miRNAs, including three upregulated and 15 downregulated miRNAs, were found in SSNHL cases. Gene ontology (GO) functional annotation analysis revealed that target genes in the top 20 terms were mainly related to "protein binding," "metal ion binding," "ATP binding," and "intracellular signal transduction." Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that these target genes were functionally enriched in the "Ras," "Hippo," "cGMP-PKG," and "AMPK signaling pathways." The expression levels of PC-5p-38556_39 and PC-5p-29163_54 were significantly downregulated and that of miR-93-3p_R+1 was highly upregulated in SSNHL. Consequently, the consistency rate between sequencing and RT-qPCR was 75% and sequencing results were highly reliable.

Conclusion

This study identified 18 exosomal DE-miRNAs, including PC-5p-38556_39, PC-5p-29163_54, and miR-93-3p, which may be closely related to SSNHL pathogenesis or serve as biomarkers for SSNHL.

Early assessment of extremity compartment syndrome by biochemical markers in a rat model

BACKGROUND

This experimental study aimed to define a biochemical marker that will enable early diagnosis of acute compartment syndrome (ACS) of extremities, a mortal condition that occurs due to trauma.

METHODS

A total of 15 Wistar rats were included in the study in which saline infusion technique, a clinically compatible ACS model, was applied. After the rats were anesthetized with ketamine-xylazine, the in-compartment pressure of the hind limb was slowly increased with saline delivered through the angiocatheter, and after reaching the target compartment pressure, the pressure level was kept with a rubber tourniquet. The in-compartment pressure level was continuously monitored with a pressure transducer. The rats were divided into three groups. No intervention was applied to the control group (CG) (n = 3). In study group 1 (SG1) (n = 6), ACS was created using the saline infusion technique, keeping the in-compartment pressure between 30 and 40 mmHg for 45 min. In study group 2 (SG2) (n = 6), ACS was created using the saline infusion technique, keeping the in-compartment pressure between 30 and 40 mmHg for 90 min. Fasciotomy was performed on all rats. Tissue samples were obtained for histopathological examination and blood samples for biochemical analysis.

RESULTS

Total oxidant status (TOS) (p = 0.004), ischemia-modified albumin (IMA) (p = 0.030), aspartate transferase (AST) (p = 0.003) and neopterin (p = 0.012) levels differed significantly between groups in the early period of muscle ischemia. In fact, TOS levels differed significantly between the groups even in the cellular phase where signs of ischemia were not observed (p = 0.048, p = 0.024). According to histopathological evaluation, there was no significant difference between the groups.

DISCUSSION

TOS can be detected in the early reversible stage of ischemia, when the histopathological findings of ACS do not occur.

Exosomes Derived from microRNA-21 Overexpressing Neural Progenitor Cells Prevent Hearing Loss from Ischemia-Reperfusion Injury in Mice via Inhibiting the Inflammatory Process in the Cochlea

Both exosomes derived from neural progenitor cells (NPCs) can suppress inflammation. Whether exosomes derived from miR-21-transfected NPCs (miR-21-Exo) could be utilized to alleviate hearing loss is investigated. NPCs were transfected with lentiviral vectors overexpressing miR-21, and miR-21-Exo was purified. Morphology and exosome membrane markers were examined with nanoparticle tracking analysis, transmission electron microscopy, and Western blot. After incubation with different concentrations of miR-21-Exo, the viability of RAW 264.7 cells and the relative expressions of miR-21 and IL-10 were determined. The ischemia and reperfusion (I/R) model of C57BL/6 J mice was constructed, and the treatment benefit of miR-21-Exo was revealed by the auditory brainstem response (ABR) test. Immunofluorescence staining of caspase-3 and parvalbumin was used to detect apoptosis hair cells in the cochlea, and Western blot was utilized to detect the relative expressions of P53 and inflammatory cytokines in the cochlea. Isolated exosomes were confirmed by the size of 96 ± 25 nm, single membrane, and positive expression of CD9 and Tsg101. Upregulated miR-21 expression was detected in miR-21-transfected NPCs and miR-21-Exo. miR-21-Exo incubation demonstrated no cytotoxicity but upregulated miR-21 and IL-10 expressions in RAW 264.7 cells. The administration of miR-21-Exo inhibited the increased ABR threshold under 8, 16, and 32 kHz frequencies in cochlea-I/R injury mice and diminished the mean fluorescent intensity of caspase-3/parvalbumin. Moreover, miR-21-Exo treatment increased the IL-10 expression and prevented the increased TNF-α and IL-1β expressions in the cochlea of I/R mice both in mRNA and protein levels. Inner ear administration of miR-21-Exo effectively improved hearing damage caused by I/R.

Exosomes derived from cochlear spiral ganglion progenitor cells prevent cochlea damage from ischemia-reperfusion injury via inhibiting the inflammatory process

Ischemia-reperfusion injury (I/R)-induced inflammatory process can mediate cochlea damage-related hearing loss; whether cochlear spiral ganglion progenitor cell-derived exosomes (CSGPC-exos) play a protective role by carrying functional microRNAs into recipient cells is unknown. Different doses of CSGPC-exos (0.1 μg/μl, 0.2 μg/μl, 0.5 μg/μl, 1.0 μg/μl) were administrated into the cochleae of the I/R group induced with 30-min occlusion of the bilateral vertebral arteries and sham surgery group. The speech-evoked auditory brainstem response (ABR) test was utilized to estimate the auditory threshold shift. The relative expression of proinflammatory cytokines was detected with RT-PCR and Western blot, while parvalbumin and caspase-3 expression were detected by immunofluorescence staining in the cochleae. The relative expression of microRNAs (miR-21-5p, miR-26a-5p, and miR-181a-5p) was detected in the cochleae. I/R significantly up-regulated ABR threshold shift and promoted hair cell apoptosis indicated by parvalbumin and caspase-3 staining, while CSGPC-exos (0.5 μg/μl, 1.0 μg/μl) could diminish such damages with downregulated proinflammatory factors (IL-6, IL-1β, TNF-α, and Cox-2) and upregulated anti-inflammatory miRNAs (miR-21-5p, miR-26a-5p, and miR-181a-5p) expression in the cochleae. CSGPC-exos could protect cochleae damage from I/R, probably via inhibiting the inflammatory process.

Identification of dyslipidemia as a risk factor for sudden sensorineural hearing loss: A multicenter case-control study

Background

Recently, several studies have reported an association between lipid profiles and sudden sensorineural hearing loss (SSNHL), yet there is considerable variability between the individual studies in defining the precise association between serum lipids levels and SSNHL. This study sought to identify a possible relationship between dyslipidemia and the prevalence and prognosis of SSNHL.

Methods

A case‐control study was carried out at two independent medical centers, including 2,288 SSNHL patients and 2,288 healthy controls. Clinical characteristics and serum lipid parameters were assessed, including total cholesterol (CHOL), high‐density lipoprotein (HDL), low‐density lipoprotein (LDL), triglycerides (Trig), apolipoprotein AI (ApoAI), apolipoprotein B (ApoB), and lipoprotein a (Lpa). Multivariate logistic regression analysis was performed to assess the relationship between lipid profiles and SSNHL in the 4,576 subjects.

Results

Significant differences were identified in several conventional serum lipid markers including CHOL, Trig, HDL, LDL, ApoAI, ApoB, and Lpa, between SSNHL patients and healthy controls. Serum ApoAI levels were significantly lower in patients with bilateral SSNHL compared to unilateral SSNHL. Binary logistic regression analysis revealed that higher levels of ApoB, LDL, Trig, and lower levels of ApoAI and HDL were all associated with an increased risk of SSNHL. After clinical characterization, multivariate analysis showed that only low levels of ApoB predicted likelihood of a recovery of more than 30 dB among patients with SSNHL.

Conclusions

Serum lipids are associated with the incidence and prognosis of SSNHL. Identification of dyslipidemia may improve early evaluation and management of SSNHL risks.

Evaluation of Oxidative-Stress Pathway and Recovery of Sudden Sensorineural Hearing Loss

Introduction  Although the pathogenesis of sudden sensorineural hearing loss (SSNHL) has been discussed in the literature, many unclear points remain. Several authors have hypothesized that oxidative stress plays a role in the pathogenesis of noise-related hearing loss, as well as in drug- and aging-related hearing loss. Reactive oxygen species (ROS) may contribute to the pathogenesis of SSNHL in a similar way as in cases of ototoxicity, noise-induced hearing loss and presbyacusis. Objective  The aim of the present study was to find potential peripheral biomarkers to show the levels of oxidative stress in samples of peripheral blood collected from SSNHL patients with and withouth metabolic disease. Methods  In total, 80 consecutive patients with SSNHL were evaluated in the otolaryngology emergency room and outpatient clinic of a tertiary hospital between May 2017 and May 2019. All patients underwent detailed anamnesis, physical examination, audiometry, magnetic resonance imaging (MRI) of the inner ears, and blood tests for serum lipids and plasma activity of thiobarbituric acid reactive species (TBARS). Results  No significant effect of malondialdehyde (MDA) activity was observed regarding the hearing recovery of patients who developed SSNHL. Conclusion  We did not observe a significant correlation between the concentration of TBARs in the peripheral blood or the presence of arterial hypertension and the severity of the initial hearing loss or the prognosis of hearing recovery in patients with SSNHL. The concentration of TBARs in the peripheral blood may not adequately represent the abnormalities that occur in the intracoclear environment.

Ozone: a natural bioactive molecule with antioxidant property as potential new strategy in aging and in neurodegenerative disorders

Systems medicine is founded on a mechanism-based approach and identifies in this way specific therapeutic targets. This approach has been applied for the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Nrf2 plays a central role in different pathologies including neurodegenerative disorders (NDs), which are characterized by common pathogenetic features. We here present wide scientific background indicating how a natural bioactive molecule with antioxidant/anti-apoptotic and pro-autophagy properties such as the ozone (O₃) can represent a potential new strategy to delay neurodegeneration. Our hypothesis is based on different evidence demonstrating the interaction between O₃ and Nrf2 system. Through a meta-analytic approach, we found a significant modulation of O₃ on endogenous antioxidant-Nrf2 (p < 0.00001, Odd Ratio (OR) = 1.71 95%CI:1.17-2.25) and vitagene-Nrf2 systems (p < 0.00001, OR = 1.80 95%CI:1.05-2.55). O₃ activates also immune, anti-inflammatory signalling, proteasome, releases growth factors, improves blood circulation, and has antimicrobial activity, with potential effects on gut microbiota. Thus, we provide a consistent rationale to implement future clinical studies to apply the oxygen-ozone (O₂-O₃) therapy in an early phase of aging decline, when it is still possible to intervene before to potentially develop a more severe neurodegenerative pathology. We suggest that O₃ along with other antioxidants (polyphenols, mushrooms) implicated in the same Nrf2-mechanisms, can show neurogenic potential, providing evidence as new preventive strategies in aging and in NDs.

Is it possible that direct rigid laryngoscope-related ischemia-reperfusion injury occurs in the tongue during suspension laryngoscopy as detected by ultrasonography: a prospective controlled study

Background: Tongue-related complications can be seen in suspension laryngoscopy (SL) procedures.Aims/objectives: This study aimed to detect tongue edema associated with the pressure exerted by a rigid direct laryngoscope by measuring the tongue area using ultrasonography (USG) in patients undergoing SL procedures.Material and methods: The study group included 31 patients and the control group consisted of 33 patients. Submental USG examinations of the tongue in the coronal plane were performed. In the study and control groups, the first examination (TA¹) was done immediately after intubation and the second examination (TA²) was done after the surgery procedure but before extubation. The USG results regarding tongue area for both the groups were compared.Results: The study and control groups significantly differed in terms of the postoperative tongue area measurements (TA²), as well as tongue edema (based on the TA² - TA¹) values.Conclusions and significance: Direct rigid laryngoscopes may cause tongue edema in SL procedures which was demonstrated by the USG. This tongue edema can be a result of ischemia-reperfusion injury in the tongue due to the pressure exerted by a direct rigid laryngoscope. This study is the first to demonstrate the possible role of USG examination in determining the side effects of SL procedures on the tongue. Trial Registration ClinicalTrials.gov Identifier: NCT04205253.

Ozone alleviates ischemia/reperfusion injury by inhibiting mitochondrion-mediated apoptosis pathway in SH-SY5Y cells

Cerebral ischemia/reperfusion (I/R) injuries are common and often cause severe complications. Ozone has been applied for protecting I/R injury in animal models of several organs including cerebra, but the detailed mechanism remains unclear. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase measurement were used to determine the influence of ozone on cell activity and damage of SH-SY5Y cells. Some redox items such as catalase (CAT), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were measured by enzyme-linked immunosorbent assay. The mitochondrial membrane potential (ΔΨ_m ) was determined by JC-1 assay. Cytochrome-c (cyt-c) level in the cytoplasm and mitochondrion was measured by western blotting. Apoptosis was determined by flow cytometry, and some apoptosis-related molecules were detected by quantitative real-time polymerase chain reaction and western blotting. Ozone alleviated oxidative damage by increasing GSH-Px, SOD, CAT, and decreasing MDA. Ozone decreased mitochondrial damage caused by I/R injury and inhibited the release of cyt-c from mitochondrion to cytoplasm in SH-SY5Y cells. The cell apoptosis caused by I/R was inhibited by ozone, and ozone could decrease apoptosis by increasing the ratio of Bcl-2/Bax and inhibiting caspase signaling pathway in SH-SY5Y cells. Ozone has the ability of maintaining redox homeostasis, decreasing mitochondrion damage, and inhibiting neurocytes apoptosis induced by I/R. Therefore, ozone may be a promising protective strategy against cerebral I/R injury.

Use of Gases to Treat Cochlear Conditions

Although the cochlear vascular supply (stria vascularis) is designed to block to certain compounds and molecules, it must enable gas exchange to survive. The inner ear capillaries must deliver oxygen and remove carbon dioxide for the cochlea to function. These gases diffuse through tissues across a concentration gradient to reach the desired target. Tight junctions or the endothelial basement membrane do not impede them. Therefore, gases that can diffuse into the inner ear are attractive as therapeutic agents. The two gases most often used in this way are oxygen and hydrogen, although carbon dioxide, ozone, and argon have also been investigated. Typically, oxygen is delivered as hyperbaric oxygen (HBO) (oxygen at pressure higher than atmospheric) to provide increased oxygen levels to the inner ear. This not only relieves hypoxia, but also has anti-inflammatory and other biochemical effects. HBO is used clinically to treat idiopathic sudden sensorineural hearing loss, and both animal and human studies suggest it may also assist recovery after acute acoustic trauma. Laboratory studies suggest hydrogen works as a free radical scavenger and reduces the strong oxidants hydroxyl radicals and peroxynitrite. It also has anti-apoptotic effects. Because of its anti-oxidant and anti-inflammatory effects, it has been studied as a treatment for ototoxicity and shows benefit in an animal model of cisplatinum toxicity. Gas diffusion offers an effective way to provide therapy to the inner ear, particularly since some gases (oxygen, hydrogen, carbon dioxide, ozone, argon) have important therapeutic effects for minimizing cochlear damage.

The atherogenic index (ATH index) as a potential predictive marker of idiopathic sudden sensorineural hearing loss: a case control study

BACKGROUND

The importance of blood lipids in the pathogenesis of sudden sensorineural hearing loss (SSNHL) is widely discussed in the literature. However, the published results that hyperlipidaemia causes hearing problems are contradictory. The objective of this study was to establish whether increased lipid levels affect the risk of idiopathic SSNHL.

METHODS

A case-controlled study was conducted of 27 patients with idiopathic SSNHL and 24 healthy control subjects. All of the subjects underwent complete audiological examination. The plasma levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo) A-I, apoB and apoE were measured with commercially available kits (Chronolab Systems, Spain). Several clinical ratios and indices of lipid metabolism were calculated.

RESULTS

Detailed analysis of lipid metabolism in patients with idiopathic SSNHL has shown that disturbances in auditory function are associated with increased atherogenicity of the lipid profile. However, there were no significant differences in the conventional parameters of lipid metabolism (TC, TG and HDL-C) between patients with idiopathic SSNHL and subjects in the control group. Higher values of the apoB/apoA-I ratio, atherogenic index of plasma (AIP) and atherogenic index (ATH index) in patients with SSNHL indicated increased atherogenicity of the lipid profile. Binary logistic regression analysis showed that of these three indices, only higher values of the ATH index were significantly associated with an increased risk of idiopathic SSNHL.

CONCLUSIONS

The ATH index can be used as a marker indicating the risk of idiopathic SSNHL when the conventional lipid indices are still normal.

Postconditioning Ozone Alleviates Ischemia-Reperfusion Injury and Enhances Flap Endurance in Rats

Introduction: Muscle-flap transferring is a routine approach utilized in reconstructive operations; however, flap morbidity is often a source of post-operative difficulty. Ischemia-Reperfusion Injury (IRI) is an important contributor to the viability of flaps after transferring. The goal of this research was for assess the probable useful impacts of ozone on flap survival in a rat muscle-flap design. Materials and Methods: We examined the effects of postconditioning ozone administration on viability of pedicled composite flaps. Twenty-eight Wistar rats were randomized into four groups: sham-operated (S), ischemia-reperfusion (IR), sham-operated + ozone (O), IR + ozone (IR + O), respectively. The animals were sacrificed on the eighth day. In a general histological evaluation, flap tissues were examined with a light microscope, and apoptotic cells were counted. The Apoptotic Index (AI) was then calculated. Flap-tissue samples were sent for analyses of malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and protein carbonyl (PCO), and blood samples were sent for analyses of Total Oxidant Score (TOS), and Total Antioxidant Capacity (TAC). Data were evaluated statistically using the Kruskal-Wallis test. Results: The histomorphometric score was remarkably greater in O (p = .002). The AI was greater in IR (p = .002). The antioxidant parameters values as regards SOD, GSH-Px, CAT, and TAC were found to be greater in O (p < .005). The oxidant parameters values as regards MDA, PCO, TOS were found to be greater in IR (p < .005). Discussion: The current research indicates that ozone application can attenuate the muscle-flap injury brought about by IR through triggering the increase of the antioxidant capacity.

Primary Cultivation and Identification of Vascular Smooth Muscle Cells from the Spiral Modiolar Artery of Guinea Pigs

Background

This article reports a method to obtain vascular smooth muscle cells (SMCs) from the spiral modiolar artery (SMA) of guinea pigs and provides materials for related experimental studies.

Material/Methods

SMA was separated from the cochlea of guinea pigs, digested with trypsin (1.25 g/L) and allowed to adhere in a 35-mm culture dish. The morphology of the sample was investigated, and the sample was identified by immunofluorescence analysis, flow cytometry, Western blot, and RT-PCR. Cell viability was calculated using trypan blue and flow cytometry. Whole-cell patch clamp was used to record the membrane input resistance (R_input), reciprocal membrane input conductance (G_input), membrane input capacitance (C_input), and resting membrane potential (RP) of the SMCs.

Results

Microscopy results showed that the cells had typical peak–valley growth pattern. The cell growth curve was similar to an S curve, and flow cytometry results showed that the cell apoptosis rate was less than 10%. Moreover, flow cytometry, immunofluorescent staining, Western blot and RT-PCR detected the specific and intensely positive expression of cell type-specific markers α-SM-actin, SM22α, calponin and desmin. Furthermore, following properties of the P3 and P6 cells were obtained: R_input, 2611±356 and 2477±338 MΩ; G_input, 0.454±0.071 and 0.273±0.037 ns; C_input, 17.029±0.917 and 18.042±1.051 pF, and RP −20.602±1.503 and −22.192±1.905 mV.

Conclusions

Various highly purified SMCs were obtained from the SMA of guinea pigs. We provide an ideal experimental material for the study of the pathogenesis of diseases related to the circulation disturbances in the inner ear in vitro. The results can be used to evaluate the effects of drugs on vascular smooth muscle.

Ozone protects the rat lung from ischemia-reperfusion injury by attenuating NLRP3-mediated inflammation, enhancing Nrf2 antioxidant activity and inhibiting apoptosis

Ischemia-reperfusion injury (IRI) is a major cause of lung dysfunction during cardiovascular surgery, heart transplantation and cardiopulmonary bypass procedures, and the inflammatory response, oxidative stress, and apoptosis play key and allegedly maladaptive roles in its pathogenesis. The aim of this study was to initially elucidate whether ozone induces oxidative preconditioning by activating nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and secondly to determine whether ozone oxidative preconditioning (OzoneOP) protects the lung from IRI by attenuating nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3)-mediated inflammation, enhancing the antioxidant activity of Nrf2 and inhibiting apoptosis. Rats treated with or without OzoneOP (2 ml containing 100 µg/kg/day) were subjected to 1 h of lung ischemia followed by 2 h of reperfusion for 10 days. Lung damage, antioxidant capacity, inflammation and apoptosis were evaluated and compared among different groups after reperfusion. OzoneOP significantly ameliorated changes in lung morphology and protected the lung from IRI by attenuating oxidative stress, inflammation-induced injury and lung apoptosis. Moreover, OzoneOP increased the expression of Nrf2 and decreased the levels of NLRP3, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), un-cleavable cysteine-requiring aspartate protease-1 (procaspase-1), cysteine-requiring aspartate protease-1 (caspase-1) and interleukin-1β (IL-1β) in the rat lungs. In summary, these results provide new insights into the molecular events modulated by ozone and suggest that ozone therapy may be an integrative support for patients with lung IRI.

MIF protects against oxygen-glucose deprivation-induced ototoxicity in HEI-OC1 cochlear cells by enhancement of Akt-Nrf2-HO-1 pathway

Ischemia and oxidative stress play crucial roles in the pathophysiology of sudden sensorineural hearing loss (SSNHL). Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine and serves an important role in hearing function. The present study was designed to evaluate the effect of MIF on oxygen-glucose deprivation (OGD)-induced ototoxicity and to elucidate its molecular mechanism. In HEI-OC1 auditory cells, OGD reduced cell viability and increased supernatant lactate dehydrogenase (LDH) and MIF in a time-dependent manner. However, the reduced cell viability exerted by OGD was attenuated by antioxidant and MIF. Luciferase reporter assay demonstrated that MIF could activate NF-E2-related factor 2 (Nrf2), and real-time PCR showed increased mRNA expressions of Nrf2 and two Nrf2-responsive genes, including heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). MIF also suppressed oxidative stress induced by OGD, as demonstrated by decreased MDA and increased GSH in cellular supernatant. Inhibition of Nrf2 using siRNA suppressed HO-1 protein expression, the protective effect on OGD-induced injury and decrease in oxidative stress by MIF. Moreover, MIF prevented OGD-induced reduction of Akt1 phosphorylation at Ser473. LY294002, an inhibitor of PI3K/Akt signaling, attenuated the enhancement of Nrf2 protein and protective effect of MIF in OGD-treated cochlear cells. We demonstrate that MIF protects cochlear cells against OGD-induced injury through activation of Akt-Nrf2-HO-1 pathway.

Artificial Organs 2017: A Year in Review

In this Editor's Review, articles published in 2017 are organized by category and summarized. We provide a brief reflection of the research and progress in artificial organs intended to advance and better human life while providing insight for continued application of these technologies and methods. Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. Peer-reviewed Special Issues this year included contributions from the 12th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion edited by Dr. Akif Undar, Artificial Oxygen Carriers edited by Drs. Akira Kawaguchi and Jan Simoni, the 24th Congress of the International Society for Mechanical Circulatory Support edited by Dr. Toru Masuzawa, Challenges in the Field of Biomedical Devices: A Multidisciplinary Perspective edited by Dr. Vincenzo Piemonte and colleagues and Functional Electrical Stimulation edited by Dr. Winfried Mayr and colleagues. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years.