The Description and Analysis of the Complete Genome of Dermacoccus barathri FBCC-B549 Strain.

Dermacoccus barathri is the first reported pathogen within the Dermacoccus genus to cause a catheter-related bloodstream infection, which occurred in 2015. In this study, the complete genome assembly of Dermacoccus barathri was constructed, and the complete genome of Dermacoccus barathri FBCC-B549 consists of a single chromosome (3,137,745 bp) without plasmids. The constructed genome of D. barathri was compared with those of two closely related species within the Dermacoccus genus. D. barathri exhibited a pattern similar to Dermacoccus abyssi in terms of gene clusters and synteny analysis. Contrary to previous studies, biosynthetic gene cluster (BGC) analysis for predicting secondary metabolites revealed the presence of the LAP biosynthesis pathway in the complete genome of D. barathri, predicting the potential synthesis of the secondary metabolite plantazolicin. Furthermore, an analysis to investigate the potential pathogenicity of D. barathri did not reveal any antibiotic resistance genes; however, nine virulence factors were identified in the Virulence Factor Database (VFDB). According to these matching results in the VFDB, despite identifying a few factors involved in biofilm formation, further research is required to determine the actual impact of D. barathri on pathogenicity. The complete genome of D. barathri is expected to serve as a valuable resource for future studies on D. barathri, which currently lack sufficient genomic sequence information.

Effects of Fermented Polygonum cuspidatum on the Skeletal Muscle Functions.

Plant extract fermentation is widely employed to enhance the nutritional and pharmaceutical value of functional foods. Polygonum cuspidatum (Pc) contains flavonoids, anthraquinones, and stilbenes, imparting protective effects against inflammatory diseases, cancer, diabetes, and cardiovascular diseases. However, the effects of fermented Pc on skeletal muscle strength remain unexplored. In this study, we generated fermented Pc using a complex of microorganisms containing Lactobacillus spp. (McPc) and assessed its effects on muscle strength and motor function in mice. Compared to unfermented Pc water extract, elevated levels of emodin and resveratrol were noted in McPc. This was identified and quantified using UPLC-QTOF/MS and HPLC techniques. Gene expression profiling through RNA-seq and quantitative RT-PCR revealed that McPc administration upregulated the expression of genes associated with antioxidants, glycolysis, oxidative phosphorylation, fatty acid oxidation, and mitochondrial biogenesis in cultured C2C12 myotubes and the gastrocnemius muscle in mice. McPc significantly improved skeletal muscle strength, motor coordination, and traction force in mice subjected to sciatic neurectomy and high-fat diet (HFD). McPc administration exhibited more pronounced improvement of obesity, hyperglycemia, fatty liver, and hyperlipidemia in HFD mice compared to control group. These findings support the notion that emodin and resveratrol-enriched McPc may offer health benefits for addressing skeletal muscle weakness.

The effect of noise on the cortical activity patterns of speech processing in adults with single-sided deafness.

The most common complaint in people with single-sided deafness (SSD) is difficulty in understanding speech in a noisy environment. Moreover, the neural mechanism of speech-in-noise (SiN) perception in SSD individuals is still poorly understood. In this study, we measured the cortical activity in SSD participants during a SiN task to compare with a speech-in-quiet (SiQ) task. Dipole source analysis revealed left hemispheric dominance in both left- and right-sided SSD group. Contrary to SiN listening, this hemispheric difference was not found during SiQ listening in either group. In addition, cortical activation in the right-sided SSD individuals was independent of the location of sound whereas activation sites in the left-sided SSD group were altered by the sound location. Examining the neural-behavioral relationship revealed that N1 activation is associated with the duration of deafness and the SiN perception ability of individuals with SSD. Our findings indicate that SiN listening is processed differently in the brains of left and right SSD individuals.

Identification of a novel PARP4 gene promoter CpG locus associated with cisplatin chemoresistance.

The protein family of poly (ADP-ribose) polymerases (PARPs) is comprised of multifunctional nuclear enzymes. Several PARP inhibitors have been developed as new anticancer drugs to combat resistance to chemotherapy. Herein, we characterized PARP4 mRNA expression profiles in cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines. PARP4 mRNA expression was significantly upregulated in cisplatin-resistant ovarian cancer cell lines, and this upregulation was associated with the hypomethylation of specific cytosine-phosphate-guanine (CpG) sites (cg18582260 and cg17117459) on its promoter. Reduced PARP4 expression was restored by treating cisplatin-sensitive cell lines with a demethylation agent, implicating the epigenetic regulation of PARP4 expression by promoter methylation. Depletion of PARP4 expression in cisplatin-resistant cell lines reduced cisplatin chemoresistance and promoted cisplatin-induced DNA fragmentation. The differential mRNA expression and DNA methylation status at specific PARP4 promoter CpG sites (cg18582260 and cg17117459) according to cisplatin responses, was further validated in primary ovarian tumor tissues. The results showed significantly increased PARP4 mRNA expressions and decreased DNA methylation levels at specific PARP4 promoter CpG sites (cg18582260 and cg17117459) in cisplatin-resistant patients. Additionally, the DNA methylation status at cg18582260 CpG sites in ovarian tumor tissues showed fairly clear discrimination between cisplatin-resistant patients and cisplatin-sensitive patients, with high accuracy (area under the curve = 0.86, P = 0.003845). Our findings suggest that the DNA methylation status of PARP4 at the specific promoter site (cg18582260) may be a useful diagnostic biomarker for predicting the response to cisplatin in ovarian cancer patients. [BMB Reports 2023; 56(6): 347-352].

Feasibility of Virtual Reality-Based Auditory Localization Training With Binaurally Recorded Auditory Stimuli for Patients With Single-Sided Deafness.

OBJECTIVES: To train participants to localize sound using virtual reality (VR) technology, appropriate auditory stimuli that contain accurate spatial cues are essential. The generic head-related transfer function that grounds the programmed spatial audio in VR does not reflect individual variation in monaural spatial cues, which is critical for auditory spatial perception in patients with single-sided deafness (SSD). As binaural difference cues are unavailable, auditory spatial perception is a typical problem in the SSD population and warrants intervention. This study assessed the applicability of binaurally recorded auditory stimuli in VR-based training for sound localization in SSD patients. METHODS: Sixteen subjects with SSD and 38 normal-hearing (NH) controls underwent VR-based training for sound localization and were assessed 3 weeks after completing training. The VR program incorporated prerecorded auditory stimuli created individually in the SSD group and over an anthropometric model in the NH group. RESULTS: Sound localization performance revealed significant improvements in both groups after training, with retained benefits lasting for an additional 3 weeks. Subjective improvements in spatial hearing were confirmed in the SSD group. CONCLUSION: By examining individuals with SSD and NH, VR-based training for sound localization that used binaurally recorded stimuli, measured individually, was found to be effective and beneficial. Furthermore, VR-based training does not require sophisticated instruments or setups. These. RESULTS: suggest that this technique represents a new therapeutic treatment for impaired sound localization.

Flavobacterium humidisoli sp. nov., isolated from riverside soil.

A novel Gram-stain-negative, yellow-pigmented, non-motile and rod-shaped bacterial strain designated MMS21-Er5T was isolated and subjected to polyphasic taxonomic characterization. MMS21- Er5T could grow at 4-34 °C (optimum, 30 °C), at pH 6-8 (optimum, pH 7) and in the presence of 0-2% NaCl (optimum, 1 %). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that MMS21- Er5T showed low levels of sequence similarities with other species, as the highest similarity of 97.83 % was observed with Flavobacterium tyrosinilyticum THG DN8.8T, then 97.68 % with 'Flavobacterium ginsengiterrae' DCY 55 and 97.63 % with Flavobacterium banpakuense 15F3T, which were well below the suggested cutoff for species distinction. The whole genome sequence of MMS21-Er5T consisted of a single contig of 5.63 Mbp, and the DNA G+C content was 34.06 mol%. The in-silico DNA-DNA hybridization and orthologous average nucleotide identity values were highest with Flavobacterium tyrosinilyticum KCTC 42726T (45.7 and 91.92% respectively). The predominant respiratory quinone for the strain was menaquinone-6 (MK-6), the major cellular fatty acid was iso-C15 : 0, and the diagnostic polar lipids were phosphatidylethanolamine and phosphatidyldiethanolamine. The combination of physiological and biochemical tests clearly distinguished the strain from related species of the genus Flavobacterium. On the basis of these results, strain MMS21-Er5T evidently represents a novel species of the genus Flavobacterium, for which the name Flavobacterium humidisoli sp. nov. is proposed (type strain=MMS21-Er5T=KCTC 92256T =LMG 32524T).

Solitalea lacus sp. nov., isolated from pond sediment.

A Gram-stain-negative, strictly aerobic, oxidase-positive, catalase-negative, motile by gliding, creamy white-pigmented bacterium, designated strain S2-8T, isolated from a sediment sample from a Wiyang pond in the Republic of Korea, was subjected to polyphasic taxonomic analysis. Growth was observed at 10-40 °C (optimum: 30 °C), pH 7-8 and 0-0.5% NaCl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain S2-8T belonged to the family Sphingobacteriaceae in the phylum Bacteroidota and was closely related to Solitalea longa HR-AVT, Solitalea canadensis DSM 3403T and Solitalea koreensis R2A36-4T with 97.2, 96.7 and 93.7 % 16S rRNA gene sequence similarities, respectively. Average nucleotide identity and digital DNA-DNA hybridization values for these type strains were 72.0-75.2% and 21.2-21.9 %, respectively. The major respiratory quinone is menaquinone-7. The major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c). The major polar lipids were phosphatidylethanolamine, two unidentified amino acids and four unidentified lipids. The G+C content of genomic DNA was 37.9 mol%. Based on polyphasic taxonomic analysis, it was observed that strain S2-8T is a novel species belonging to the genus Solitalea, for which the name Solitalea lacus sp. nov. is proposed. The type strain is S2-8T (= KACC 22266T= JCM 34533T).

Development of Novel Musical Stimuli to Investigate the Perception of Musical Emotions in Individuals With Hearing Loss.

BACKGROUND: Many studies have examined the perception of musical emotion using excerpts from familiar music that includes highly expressed emotions to classify emotional choices. However, using familiar music to study musical emotions in people with acquired hearing loss could produce ambiguous results as to whether the emotional perception is due to previous experiences or listening to the current musical stimuli. To overcome this limitation, we developed new musical stimuli to study emotional perception without the effects of episodic memory. METHODS: A musician was instructed to compose five melodies with evenly distributed pitches around 1 kHz. The melodies were created to express the emotions of happy, sad, angry, tender, and neutral. To evaluate whether these melodies expressed the intended emotions, two methods were applied. First, we classified the expressed emotions of melodies with selected musical features from 60 features using genetic algorithm-based k-nearest neighbors. Second, forty-four people with normal hearing participated in an online survey regarding the emotional perception of music based on dimensional and discrete approaches to evaluate the musical stimuli set. RESULTS: Twenty-four selected musical features produced classification for intended emotions with an accuracy of 76%. The results of the online survey in the normal hearing (NH) group showed that the intended emotions were selected significantly more often than the others. K-means clustering analysis revealed that melodies with arousal and valence ratings corresponded to representative quadrants of interest. Additionally, the applicability of the stimuli was tested in 4 individuals with high-frequency hearing loss. CONCLUSION: By applying the individuals with NH, the musical stimuli were shown to classify emotions with high accuracy, as expressed. These results confirm that the set of musical stimuli can be used to study the perceived emotion in music, demonstrating the validity of the musical stimuli, independent of innate musical bias such as due to episodic memory. Furthermore, musical stimuli could be helpful for further studying perceived musical emotion in people with hearing loss because of the controlled pitch for each emotion.

Attentional modulation of auditory cortical activity in individuals with single-sided deafness.

Persons with single-sided deafness (SSD) typically complain about the impaired ability to locate sounds and to understand speech within background noise. However, the findings from previous studies suggest that paying attention to sounds could mitigate the degraded spatial and speech-in-noise perception. In the present study, we characterize the pattern of cortical activation depending on the side of deafness, and attentional modulation of neural responses to determine if it can assist better sound processing in people with SSD. For the active listening condition, adult subjects with SSD performed sound localization tasks. On the other hand, they watched movies without attending to speech stimuli during passive listening. The sensor-level global field power of N1 and source-level N1 activation were computed to compare the active- and passive-listening conditions and left- and right-sided deafness. The results show that attentional modulation differs depending on the side of deafness: active listening increased the cortical activity in individuals with left-sided deafness but not in those with right-sided deafness. At the source level, the attentional gain was more apparent in left-sided deafness in that paying attention enhanced brain activation in both hemispheres. In addition, SSD participants with larger cortical activities in the right primary auditory cortex had shorter durations of deafness. Our results indicate that the side of deafness can change top-down attentional processing in the auditory cortical pathway in SSD patients.

Rapid production method with increased yield of high-purity extracellular vesicles obtained using extended mitochondrial targeting domain peptide.

Extracellular vesicles (EVs) are nano-sized membranous structures involved in intercellular communication and various physiological and pathological processes. Here, we present a novel method for rapid (within 15 min), large-scale production of high-purity EVs using eMTDΔ4, a peptide derived from Noxa. The treatment of mesenchymal stem cells derived from human Wharton's jelly after trypsinization and subsequent eMTDΔ4 stimulation in a chemically defined sucrose buffer with orbital shaking led to a substantial increase (approximately 30-fold) in EV production with markedly high purity (approximately 45-fold). These EVs (TS-eEVs) showed higher regenerative and immunomodulatory potential than natural EVs obtained from the culture media after 48 h. The calcium chelator BAPTA-AM and calpain inhibitor ALLM, but not the natural EV biogenesis inhibitor GW4869, blocked the TS-eEV production induced by eMTDΔ4, indicating that the eMTDΔ4-mediated regulation of intracellular calcium levels and calpain activity are closely associated with the rapid, mass production of TS-eEVs. The present study may lead to considerable advances in EV-based drug development and production of stem cell-derived EVs for cell therapy.

Hypoxia induces adrenomedullin from lung epithelia, stimulating ILC2 inflammation and immunity.

Hypoxia contributes to airway inflammation and remodeling in several lung diseases; however, exactly how hypoxic pulmonary epithelium regulates allergic inflammation remains to be fully characterized. Here, we report that conditional deletion of the E3 ubiquitin ligase VHL in lung epithelial cells resulted in exacerbated type 2 responses accompanied by selective increase of group 2 innate lymphoid cells (ILC2s) at steady state and following inflammation or helminth infection. Ablation of expression of the hypoxia-inducible factor 2α (HIF2α) significantly reversed VHL-mediated ILC2 activation. VHL deficiency in lung epithelial cells caused increased expression of the peptide hormone adrenomedullin (ADM), and our data suggest that HIF2α controls Adm expression. ADM directly promoted ILC2 activation both in vitro and in vivo. Our findings indicate that the hypoxic response mediated by the VHL-HIF2α axis is critical for control of pulmonary type 2 responses by increasing ADM expression in lung epithelia, causing ILC2 activation.

Association of impedance ratio with corrected Geriatric Nutritional Risk Index in older patients with nondialysis chronic kidney disease stage 5.

BACKGROUND: The usual calculation of body mass index (BMI) can be misleading in patients with advanced chronic kidney disease (CKD) because their altered fluid balances may not be reflected. We obtained corrected BMI (cBMI) and corrected Geriatric Nutritional Risk Index (cGNRI) values and investigated whether the impedance ratio (IR) of 200/5 kHz, measured using bioimpedance spectroscopy, was associated with cGNRI in older patients with nondialysis CKD stage 5 (CKD5-ND). METHODS: Patients over 65 years old (n = 118) were divided into groups by cGNRI tertiles. The differences between the correlations were tested using Steiger's z-test. The IR and cBMI were used as both continuous and categorical variables in the regression analyses to determine the factors that were independently associated with the cGNRI. RESULTS: Patients in the third cGNRI tertile had a significantly lower mean IR than those in the other 2 tertiles (P < .001). Across the 3 cGNRI tertile groups, the IR was incrementally lower in the higher cGNRI tertiles (P for trend < .001). The Steiger's z-test showed that the IR had a significantly stronger correlation with cGNRI than cBMI had with cGNRI. In the multivariable linear regression analyses, the IR was independently associated with the cGNRI, after adjusting for various confounders. CONCLUSION: The current results revealed that the IR was a more sensitive indicator of nutrition risk than BMI and was independently associated with cGNRI in older patients with CKD5-ND. Our study suggests that the IR is an appropriate tool for nutrition risk screening.

Implementation of Vancomycin Therapeutic Monitoring Guidelines: Focus on Bayesian Estimation Tools in Neonatal and Pediatric Patients.

BACKGROUND: The 2020 consensus guidelines for vancomycin therapeutic monitoring recommend using Bayesian estimation targeting the ratio of the area under the curve over 24 hours to minimum inhibitory concentration as an optimal approach to individualize therapy in pediatric patients. To support institutional guideline implementation in children, the objective of this study was to comprehensively assess and compare published population-based pharmacokinetic (PK) vancomycin models and available Bayesian estimation tools, specific to neonatal and pediatric patients. METHODS: PubMed and Embase databases were searched from January 1994 to December 2020 for studies in which a vancomycin population PK model was developed to determine clearance and volume of distribution in neonatal and pediatric populations. Available Bayesian software programs were identified and assessed from published articles, software program websites, and direct communication with the software company. In the present review, 14 neonatal and 20 pediatric models were included. Six programs (Adult and Pediatric Kinetics, BestDose, DoseMeRx, InsightRx, MwPharm++, and PrecisePK) were evaluated. RESULTS: Among neonatal models, Frymoyer et al and Capparelli et al used the largest PK samples to generate their models, which were externally validated. Among the pediatric models, Le et al used the largest sample size, with multiple external validations. Of the Bayesian programs, DoseMeRx, InsightRx, and PrecisePK used clinically validated neonatal and pediatric models. CONCLUSIONS: To optimize vancomycin use in neonatal and pediatric patients, clinicians should focus on selecting a model that best fits their patient population and use Bayesian estimation tools for therapeutic area under the -curve-targeted dosing and monitoring.

25-Hydroxycholesterol suppress IFN-γ-induced inflammation in microglia by disrupting lipid raft formation and caveolin-mediated signaling endosomes.

Acute microglial activation plays an important role in neuroprotection. However, dysregulated, prolonged microgliosis exacerbates neurodegeneration through excessive release of pro-inflammatory cytokines and cytotoxic factors. Interferon-gamma (IFN-γ), an inflammatory cytokine, exacerbates the detrimental microglial response. Although various anti-inflammatory drugs have been evaluated as interventions for microglia-mediated neuroinflammation, no anti-inflammatories are in clinical use for microgliosis. The present study evaluated the anti-inflammatory mechanisms of oxysterols, blood brain barrier (BBB) penetrable bioactive lipids, revealing that this intervention suppresses neuroinflammation by disrupting membrane lipid raft formation and caveolae-mediated endosomal IFN-γ signaling. We find that 25-hydroxycholesterol (25-HC) rapidly repressed IFN-γ receptor trafficking to lipid rafts in microglia by disrupting raft formation, thereby suppressing microglial inflammatory response. IFN-γ treatment upregulated expression of Cav-1, a major component of caveolae, and IFN-γ signaling was sustained through Cav-1+ signaling endosomes. 25-HC repressed IFN-γ induction of Cav-1 expression in microglia, and subsequently suppressed the chronic inflammatory response. Taken together, these findings demonstrated that 25-HC effectively regulate the inflammatory status of microglia by mediating the formation of rafts and caveolae-dependent signaling endosomes. Given the important roles of IFN-γ and microglia in the pathology of neurodegenerative brain diseases, a novel anti-inflammatory mechanism of 25-HC that is not receptor-dependent, but rather is related to the regulation of membrane rafts and caveolae, suggests a new therapeutic target for inflammatory neurodegenerations.

Corrigendum: Ear-Specific Hemispheric Asymmetry in Unilateral Deafness Revealed by Auditory Cortical Activity.

[This corrects the article DOI: 10.3389/fnins.2021.698718.].

Ear-Specific Hemispheric Asymmetry in Unilateral Deafness Revealed by Auditory Cortical Activity.

Profound unilateral deafness reduces the ability to localize sounds achieved via binaural hearing. Furthermore, unilateral deafness promotes a substantial change in cortical processing to binaural stimulation, thereby leading to reorganization over the whole brain. Although distinct patterns in the hemispheric laterality depending on the side and duration of deafness have been suggested, the neurological mechanisms underlying the difference in relation to behavioral performance when detecting spatially varied cues remain unknown. To elucidate the mechanism, we compared N1/P2 auditory cortical activities and the pattern of hemispheric asymmetry of normal hearing, unilaterally deaf (UD), and simulated acute unilateral hearing loss groups while passively listening to speech sounds delivered from different locations under open free field condition. The behavioral performances of the participants concerning sound localization were measured by detecting sound sources in the azimuth plane. The results reveal a delayed reaction time in the right-sided UD (RUD) group for the sound localization task and prolonged P2 latency compared to the left-sided UD (LUD) group. Moreover, the RUD group showed adaptive cortical reorganization evidenced by increased responses in the hemisphere ipsilateral to the intact ear for individuals with better sound localization whereas left-sided unilateral deafness caused contralateral dominance in activity from the hearing ear. The brain dynamics of right-sided unilateral deafness indicate greater capability of adaptive change to compensate for impairment in spatial hearing. In addition, cortical N1 responses to spatially varied speech sounds in unilateral deaf people were inversely related to the duration of deafness in the area encompassing the right auditory cortex, indicating that early intervention would be needed to protect from maladaptation of the central auditory system following unilateral deafness.

Small heterodimer partner (SHP) aggravates ER stress in Parkinson's disease-linked LRRK2 mutant astrocyte by regulating XBP1 SUMOylation.

BACKGROUND: Endoplasmic reticulum (ER) stress is a common feature of Parkinson's disease (PD), and several PD-related genes are responsible for ER dysfunction. Recent studies suggested LRRK2-G2019S, a pathogenic mutation in the PD-associated gene LRRK2, cause ER dysfunction, and could thereby contribute to the development of PD. It remains unclear, however, how mutant LRRK2 influence ER stress to control cellular outcome. In this study, we identified the mechanism by which LRRK2-G2019S accelerates ER stress and cell death in astrocytes. METHODS: To investigate changes in ER stress response genes, we treated LRRK2-wild type and LRRK2-G2019S astrocytes with tunicamycin, an ER stress-inducing agent, and performed gene expression profiling with microarrays. The XBP1 SUMOylation and PIAS1 ubiquitination were performed using immunoprecipitation assay. The effect of astrocyte to neuronal survival were assessed by astrocytes-neuron coculture and slice culture systems. To provide in vivo proof-of-concept of our approach, we measured ER stress response in mouse brain. RESULTS: Microarray gene expression profiling revealed that LRRK2-G2019S decreased signaling through XBP1, a key transcription factor of the ER stress response, while increasing the apoptotic ER stress response typified by PERK signaling. In LRRK2-G2019S astrocytes, the transcriptional activity of XBP1 was decreased by PIAS1-mediated SUMOylation. Intriguingly, LRRK2-GS stabilized PIAS1 by increasing the level of small heterodimer partner (SHP), a negative regulator of PIAS1 degradation, thereby promoting XBP1 SUMOylation. When SHP was depleted, XBP1 SUMOylation and cell death were reduced. In addition, we identified agents that can disrupt SHP-mediated XBP1 SUMOylation and may therefore have therapeutic activity in PD caused by the LRRK2-G2019S mutation. CONCLUSION: Our findings reveal a novel regulatory mechanism involving XBP1 in LRRK2-G2019S mutant astrocytes, and highlight the importance of the SHP/PIAS1/XBP1 axis in PD models. These findings provide important insight into the basis of the correlation between mutant LRRK2 and pathophysiological ER stress in PD, and suggest a plausible model that explains this connection.

Protective role of ABCA1 in ischemic preconditioning is mediated by downregulation of miR-33-5p and miR-135-5p.

Ischemic preconditioning (IPC) significantly reduces ischemia-reperfusion injury in the brain by inducing ischemic tolerance. Although emerging evidence suggests that microRNAs (miRNAs) contribute to the pathogenesis of brain ischemia and IPC-induced neuroprotection, the role of miRNAs and their underlying mechanisms are still unclear. IPC was induced in male C57BL/6 mice by brief bilateral common carotid artery occlusion. After 24 h, mice underwent transient middle cerebral artery occlusion followed by 3 h of reperfusion. Expression levels of messenger RNAs (mRNAs) and proteins were examined in the ipsilateral cortex, and mimics and inhibitors of selective miRNAs were transfected into Neuro-2a cells before oxygen-glucose deprivation (OGD). Post-IPC miRNA expression profiling identified neuroprotection-associated changes in miRNA expression in the ipsilateral cortex after ischemic stroke. Among them, miR-33-5p and miR-135b-5p were significantly downregulated by IPC. Inhibition of miR-33-5p and miR-135b-5p expression protected Neuro-2a cells from OGD-induced apoptosis. Inhibition of these two miRNAs significantly increased mRNA and protein levels of ATP-binding cassette subfamily A member 1 (ABCA1), and a binding assay showed that these two miRNAs showed specificity for Abca1 mRNA. Overexpression of ABCA1 decreased the Bax/Bcl2 mRNA ratio and activation of caspase-9 and caspase-3, whereas knockdown of ABCA1 expression increased the Bax/Bcl2 mRNA ratio and the percentage of Neuro-2a cells with a loss of mitochondrial membrane potential after OGD-treatment. In conclusion, ABCA1 expression is regulated by miR-33-5p and miR-135b-5p. Increased ABCA1 expression following IPC exerts a protective influence against cerebral ischemia via suppression of a mitochondria-dependent apoptosis pathway.

Mitochondrial Targeting Domain Homologs Induce Necrotic Cell Death Via Mitochondrial and Endoplasmic Reticulum Disruption.

The mitochondrial targeting domain (MTD) of Noxa contributes to its mitochondrial localization and to apoptosis induction. As a peptide, MTD fused with octa-arginine (R8), a CPP, induces necrosis related to intracellular calcium influx and destruction of mitochondria and endoplasmic reticulum. We searched for homologs of MTD, and compared their cell killing capability when fused with R8. Three of the seven peptides triggered cell death with similar mechanisms. The comparative analysis of peptide sequences showed that four amino acid sites of MTD are critical in regulating necrosis, suggesting the potential to generate artificial, adjustable cytotoxic peptides, which could be effective medicines for many diseases. Thus, homologs functionality could hint to the functions of their belonging proteins.