Cellular differentiation into hyphae and spores in halophilic archaea.

Several groups of bacteria have complex life cycles involving cellular differentiation and multicellular structures. For example, actinobacteria of the genus Streptomyces form multicellular vegetative hyphae, aerial hyphae, and spores. However, similar life cycles have not yet been described for archaea. Here, we show that several haloarchaea of the family Halobacteriaceae display a life cycle resembling that of Streptomyces bacteria. Strain YIM 93972 (isolated from a salt marsh) undergoes cellular differentiation into mycelia and spores. Other closely related strains are also able to form mycelia, and comparative genomic analyses point to gene signatures (apparent gain or loss of certain genes) that are shared by members of this clade within the Halobacteriaceae. Genomic, transcriptomic and proteomic analyses of non-differentiating mutants suggest that a Cdc48-family ATPase might be involved in cellular differentiation in strain YIM 93972. Additionally, a gene encoding a putative oligopeptide transporter from YIM 93972 can restore the ability to form hyphae in a Streptomyces coelicolor mutant that carries a deletion in a homologous gene cluster (bldKA-bldKE), suggesting functional equivalence. We propose strain YIM 93972 as representative of a new species in a new genus within the family Halobacteriaceae, for which the name Actinoarchaeum halophilum gen. nov., sp. nov. is herewith proposed. Our demonstration of a complex life cycle in a group of haloarchaea adds a new dimension to our understanding of the biological diversity and environmental adaptation of archaea.

Age-related hearing loss accelerates the decline in fast speech comprehension and the decompensation of cortical network connections.

Patients with age-related hearing loss face hearing difficulties in daily life. The causes of age-related hearing loss are complex and include changes in peripheral hearing, central processing, and cognitive-related abilities. Furthermore, the factors by which aging relates to hearing loss via changes in auditory processing ability are still unclear. In this cross-sectional study, we evaluated 27 older adults (over 60 years old) with age-related hearing loss, 21 older adults (over 60 years old) with normal hearing, and 30 younger subjects (18-30 years old) with normal hearing. We used the outcome of the upper-threshold test, including the time-compressed threshold and the speech recognition threshold in noisy conditions, as a behavioral indicator of auditory processing ability. We also used electroencephalography to identify presbycusis-related abnormalities in the brain while the participants were in a spontaneous resting state. The time-compressed threshold and speech recognition threshold data indicated significant differences among the groups. In patients with age-related hearing loss, information masking (babble noise) had a greater effect than energy masking (speech-shaped noise) on processing difficulties. In terms of resting-state electroencephalography signals, we observed enhanced frontal lobe (Brodmann's area, BA11) activation in the older adults with normal hearing compared with the younger participants with normal hearing, and greater activation in the parietal (BA7) and occipital (BA19) lobes in the individuals with age-related hearing loss compared with the younger adults. Our functional connection analysis suggested that compared with younger people, the older adults with normal hearing exhibited enhanced connections among networks, including the default mode network, sensorimotor network, cingulo-opercular network, occipital network, and frontoparietal network. These results suggest that both normal aging and the development of age-related hearing loss have a negative effect on advanced auditory processing capabilities and that hearing loss accelerates the decline in speech comprehension, especially in speech competition situations. Older adults with normal hearing may have increased compensatory attentional resource recruitment represented by the top-down active listening mechanism, while those with age-related hearing loss exhibit decompensation of network connections involving multisensory integration.

LIGHT deficiency attenuates acute kidney disease development in an in vivo experimental renal ischemia and reperfusion injury model.

Ischemia-reperfusion (I/R), a leading risk factor of acute kidney injury (AKI), is associated with high mortality and risk of progression to chronic kidney disease. However, the molecular mechanism of I/R-AKI remains not fully understood, which hinders its efficient clinical treatment. In this study, we observed that LIGHT deficiency remarkably attenuated I/R-AKI, as evidenced by rescued renal function, ameliorated tubular cell apoptosis, and alleviated inflammatory responses. Consistently, blocking LIGHT signaling with its soluble receptor fusion proteins (HVEM-IgG-Fc or LTßR-IgG-Fc) improved I/R renal dysfunction. RNA-sequencing and corresponding results indicated that LIGHT promoted oxidative stress and inflammation triggered by ischemic injury. Moreover, LIGHT signaling augmented ischemic stress-induced mitochondrial dysfunction characterized by an imbalance in mitochondrial fission and fusion, decreased mtDNA copies, impaired mitophagy, and increased mitochondrial membrane potential (ΔΨm). Mechanistically, LIGHT promoted mitochondrial fission by enhancing Drp1 phosphorylation (Ser616) and its translocation to the mitochondria. In conclusion, these results suggest that LIGHT-HVEM/LTßR signaling is critical for the I/R-AKI pathogenesis and it is further confirmed to be related to the increase in I/R-induced oxidative stress and mitochondria dysfunction, which may be the underlying mechanism of LIGHT signaling-mediated I/R-AKI.

Knockdown of lncRNA TTTY15 alleviates myocardial ischemia-reperfusion injury through the miR-374a-5p/FOXO1 axis.

Myocardial ischemia/reperfusion (I/R) injury greatly contributes to myocardial tissue damage in patients with coronary disease, which eventually leads to heart failure. Long noncoding RNAs (lncRNAs) have an emerging role in the process of myocardial I/R injury. Our previous work revealed the protective role of miR-374a-5p against myocardial I/R injury. In this study, we explored the role of lncRNA TTTY15 and its potential interaction mechanisms with miR-374a-5p in myocardial I/R injury. The expression of TTTY15 was increased both in vitro and in vivo after myocardial I/R injury models according to quantitative real-time polymerase chain reaction. Various assays were conducted to evaluate the regulatory relationship among TTTY15, miR-374a-5p, FOXO1, and autophagy in H9c2 and HL-1 cells. The results showed that TTTY15 suppresses autophagy and myocardial I/R injury by targeting miR-374a-5p. We found that TTTY15 regulates miR-374a-5p, thus affecting FOXO1 expression and autophagy in myocytes during I/R. Furthermore, in an in vivo mouse model of myocardial I/R injury, suppression of TTTY15 successfully alleviated myocardial I/R injury. Our results reveal a novel feedback mechanism in which TTTY15 regulates miRNA processing and a potential target in myocardial I/R injury. TTTY15 is a promising therapeutic target for treating myocardial I/R injury.

Effect of puerarin on action potential and sodium channel activation in human hypertrophic cardiomyocytes.

OBJECTIVE: To study the effect of puerarin on electrophysiology using a hypertrophic cardiomyocyte (HC) model. MATERIALS AND METHODS: Human urine epithelial cells were used to generate the HC model (hiPSC-CM). Cardiomyocyte hypertrophy was induced by applying 10 nM endothelin-1 (ET-1). Effects of puerarin pre-treatment (PPr) and post-treatment (PPo) on action potential, sodium current (INa) activation and inactivation, and recovery following INa inactivation were tested using patch clamp electrophysiology. RESULTS: Depolarization to repolarization 50% time (APD50) and repolarization 30% time (APD30) were significantly prolonged in the PPo and PPr groups compared with the controls. However, there were no significant differences in the action potential depolarization amplitude (APA) or the maximum depolarization velocity (Vmax) in phase 0. The PPr group had a slightly shortened APD90, and an extended APD50 and APD30, but did not exhibit any significant changes in stage A of APA and Vmax. The PPo group did not exhibit any significant changes in INa, while 12 h of PPr improved INa. However, puerarin did not significantly affect the activation, inactivation, or recovery of the sodium channel. CONCLUSIONS: Cardiomyocyte hypertrophy significantly decreased the Vmax of the action potential and the peak density of INa. PPr inhibited the decrease in Vmax and increased the peak density of INa. Thus, puerarin could be used to stabilize the electrophysiological properties of hypertrophic cardiomyocytes and reduce arrhythmias.

MicroRNA-374a protects against myocardial ischemia-reperfusion injury in mice by targeting the MAPK6 pathway.

AIMS: Clinical treatment strategies for patients with myocardial ischemia typically include coronary artery recanalization to restore myocardial blood supply. However, myocardial reperfusion insult often induces oxidative stress and inflammation, which further leads to apoptosis and necrosis of myocardial cells. Increasing evidence suggests that microRNAs (miRNAs) participate in the pathological and physiological processes associated with myocardial ischemia reperfusion. MAIN METHODS: In this study, we established a myocardial H/R H9C2 cell model and a mouse I/R model to detect molecules implicated in myocardial I/R regulation and to determine the underlying signal transduction pathways. KEY FINDINGS: Herein, we showed that the expression of miR-374a-5p decreased in a myocardial cell model (H9C2 cells) of hypoxia/reoxygenation (H/R) and mouse model of ischemia/reperfusion (I/R). Alternatively, overexpression of miR-374a-5p was found to ameliorate myocardial cell damage within both in vivo and in vitro models of ischemia. Further, mitogen-activated protein kinase 6 (MAPK6) was identified as a direct target of miR-374a-5p. Thus, by targeting MAPK6, miR-374a-5p was found to negatively regulate MAPK6 expression. However, up-regulation of MAPK6 functioned to inhibit the previously observed protective effect of miR-374a-5p in the H9C2 H/R model. SIGNIFICANCE: Taken together, our study suggests that miR-374a-5p may have protective effects against cardiac I/R injury in vivo, and H/R injury in vitro, thereby providing novel insights into the molecular mechanisms associated with ischemia/reperfusion injury and a potential novel therapeutic target.

Effects of combination of balloon Eustachian tuboplasty with methylprednisolone irrigation on treatment of chronic otitis media with effusion in adults.

PURPOSE: Adult chronic otitis media with effusion (COME) is characterized by Eustachian tube dysfunction and mucosal inflammation, which management has long been a challenge because of high recurrence. This study was to investigate the pathological changes of Eustachian tube mucosa and optimized treatment. MATERIALS AND METHODS: Retrospective study of four groups: I: tympanic paracentesis, II: balloon Eustachian tuboplasty (BET), III: BET plus tympanic paracentesis, IV: BET and tympanic paracentesis with methylprednisolone irrigation. Biopsy of Eustachian tube mucosa was obtained preoperative and 1 month post. Recurrence ratio and Eustachian tube scores (ETS) were used to evaluate the effect of treatments. RESULTS: All patients showed narrowed with edematous and thickened Eustachian tube mucosa. At 1 month post-treatment, BET with methylprednisolone irrigation significantly decreased intraepithelial inflammation and restored the quality of epithelium and cilia. For group II to IV, The recurrence rate was significantly lower in group IV compared with the other two, but only significantly lower in group IV VS group II at 3 months and 6 months, no significant difference at 12 months. The recurrence rate was significantly higher in group I during follow-up. The ETS were improved in group II, III and IV after treatment. At 1 month and 3 months posttreatment, group IV had significant higher ETS compared with other groups (P < 0.05). There was no serious complications occurred. CONCLUSION: Methylprednisolone irrigation could help to recover mucosal function. BET and tympanic paracentesis with methylprednisolone irrigation could be regarded as a good choice for COME in adults, which has less recurrence rate and prompt recovery of ET function.

Round Window Niche Drilling with Intratympanic Steroid Is a Salvage Therapy of Sudden Hearing Loss.

OBJECTIVE: To explore the effectiveness and safety of round window niche drilling combined with intratympanic methylprednisolone injection for the salvage treatment of sudden sensorineural hearing loss (SSNHL) and its associated tinnitus after failed primary treatment. METHOD: SSNHL patients who showed a less than 10-dB improvement of pure-tone average after receiving standard systemic treatment and intratympanic steroid injection were enrolled. All included patients were randomly divided into two groups (control and study). Patients in the study group received round window niche drilling combined with daily intratympanic methylprednisolone for 7 times; the control group received only daily intratympanic methylprednisolone for 7 times. One month after treatment, the improvements of PTA, speech discrimination score (SDS), tinnitus and the incidence of adverse events were analyzed. RESULTS: 20 patients (10 for each group) were included in this study. The baseline between two groups showed no statistical significance. Patients in the study group experienced an average hearing improvement of 20.38 dB, SDS 19.3 compared with 2.1 dB and SDS 2.0 in the control group. None (0%) in the control group and 4 patients (40%) showed marked recovery, 5 patients (50%) showed slight improvement of hearing in the study group after 1 month. All patients in the study group showed significant recovery of tinnitus. Both tinnitus handicap inventory and a symptom visual analogue scale between two groups revealed statistical differences (p < 0.001, p = 0.002, respectively). None in the control and study groups experienced vertigo, infection and facial paralysis. CONCLUSION: Round window niche drilling increases the contact area and time of methylprednisolone. It is an effective and safe salvage therapy of idiopathic SSNHL and its induced tinnitus.

High-dose PMA with RANKL and MCSF induces THP­1 cell differentiation into human functional osteoclasts in vitro.

Osteoclasts are large multinuclear cells, which serve role in erosive bone disease. However, it is not possible to separate osteoclasts from cortical bone in order to culture the cells for further experiments. Therefore, a human osteoclast model is required to investigate the underlying mechanism of bone destruction. The most commonly­used osteoclast model is the RAW264.7 cell line, a murine mononuclear macrophage cell line; however, there exists no reliable osteoclast model using a human cell line. The aim of the present study was to establish a functional osteoclast model using the THP­1 cell line. Suspended THP­1 cells were stimulated for 2 days with 5 or 100 ng/ml phorbol­12 myristate­13 acetate (PMA) in order to induce the cells to differentiate into adherent macrophages. A 10­day stimulation with 50 ng/ml receptor activator of nuclear factor κ­B ligand (RANKL) and macrophage colony­stimulating factor (MCSF) was performed in order to induce macrophage differentiation into osteoclasts. Treatment with high­dose PMA with RANKL and MCSF enabled the THP­1 cells to form tartrate­resistant acid phosphatase­positive osteoclasts, which were able absorb bone in a bone resorption test. Treatment with low­dose PMA with RANKL and MCSF failed to induce THP­1 cell differentiation into osteoclasts. PMA alone, or a combination of RANKL and MCSF alone, is insufficient to stimulate THP­1 cell differentiation into osteoclasts. In the present study, a reliable human osteoclast model was established using the THP­1 cell line. This osteoclast model may provide a useful tool for further studies.

[Placental Foxp3 expression in patients with preeclampsia and correlation of Foxp3 gene locus 924 (rs2232365) polymorphism with preeclampsia].

OBJECTIVE: To detect changes of Foxp3 expression in the decidua in patients with preeclampsia and investigate the correlation of Foxp3-924 (rs2232365) polymorphisms with preeclampsia. METHODS: From October 2011 to December 2012, 252 normal pregnant women and 156 preeclampsia patients of Han nationality from the same geographic region were tested for Foxp3-924 genotypes by polymerase chain reaction with sequence-specific primer (PCR-SSP). Sixty-eight of the patients with preeclampsia (33 with mild and 35 with severe preeclampsia) and 30 of the normal pregnant women were also examined for Foxp3 expression in the decidua using immunohistochemical method. RESULTS: Foxp3 positive expression rates in the decidua was 51.52% in mild preeclampsia and 28.57% in severe preeclampsia cases, significantly lower than that in the control group (86.67%, P<0.05). In preeclampsia patients, the frequencies of Foxp3-924G/G, G/A, and A/A genotypes were 0.1346, 0.4615 and 0.4038, respectively, and the frequencies of Foxp3-924A and Foxp3-924 G were 0.6346 and 0.3654, respectively. The genotype frequencies of Foxp3-924G/G, G/A and A/A in the control group were 0.1508, 0.4087 and 0.4405, respectively, and the frequencies of Foxp3-924 A and Foxp3-924 G were 0.6448 and 0.3552, respectively. No significant differences were found in the gene frequencies of Foxp3-924G/A between preeclampsia patients and the control group (P>0.05). CONCLUSION: The expression level of Foxp3 in the placental tissue of preeclampsia patients is significantly lower than that in normal pregnant women, suggesting that lowered Foxp3 expression decreases the immunosuppressive function and causes imbalance of immune tolerance between maternal-fetal to induce preeclampsia. Foxp3-924 polymorphisms is not significantly correlated with the occurrence of preeclampsia.

Regulation of expression of trehalose-6-phosphate synthase during cold shock in Arthrobacter strain A3.

Trehalose is a chemical chaperone known to protect a variety of organisms against cold stress. Members of the genus Arthrobacter, which belongs to the Actinomycetales group, exhibit strong resistance to stress conditions, but exactly how trehalose synthesis is regulated in conditions of cold stress is still unknown. Here, we report that Arthrobacter strain A3, which was isolated from the alpine permafrost, has only two trehalose synthesis pathways (OtsA/B and TreS), while other Arthrobacter spp. have three. Mutants and immunoblot analyses indicate that trehalose is mainly synthesized via OtsA at low temperatures in Arthrobacter strain A3. Therefore, we have focused on the regulation of OtsA expression during cold shock. The results indicated that both low temperature and accumulation of trehalose can inhibit OtsA expression. The elongation factor Tu, which binds to OtsA, stabilizes the expression of OtsA in the cold.

The catalytic efficiency of trehalose-6-phosphate synthase is effected by the N-loop at low temperatures.

The enzyme OtsA (trehalose-6-phosphate synthase) is ubiquitous in both prokaryotic and eukaryotic organisms, where it plays a critical role in stress resistance and glucose metabolism. Here, we cloned the otsA gene from Arthrobacter sp. Cjts, and expressed and then purified the recombinant proteins. Enzyme activity analysis indicated that the high catalytic efficiency of OtsA from Arthrobacter sp. Cjts resulted from the high affinity of the enzyme for uridine 5'-diphosphoglucose (UDP-Glc) at low temperatures. We also confirmed that the N-loop sequence of OtsA has a large effect on its affinity for UDP-Glc. Sequence analysis indicated that the flexibility of the N-loop may be directly related to the catalytic efficiency of OtsA at low temperatures.

[Changes of IFN-gamma, IL-2, IL-6 and IL-10 in the patient with cardiac surgery under combined acupuncture anesthesia].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on cytokines in the cardiac surgical patient and to evaluate the application of combined acupuncture anesthesia to cardiac surgery. METHODS: Thirty patients with atrial septal defect were divided into 3 groups, general anesthesia group (A), acupuncture anesthesia group (B) and combined general anesthesia and EA group (C). Peripheral blood samples were collected before anesthesia, before cardiopulmonary bypass (CPB), 30 min after CPB and 24 h after operation to determine the levels of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-6 and IL-10. RESULTS: The levels of IFN-gamma and IL-2 decreased in the 3 groups after CPB and further decreased 24 h after operation, and in the group C were higher than those in the group B. The levels of IL-6 and IL-10 significantly increased 24 h after operation in the 3 groups with no significant difference among the 3 groups. CONCLUSION: The general anesthesia combined with EA can not completely improve the decrease of IFN-gamma and IL-2 induced by CPB, indicating that the good response of the general anesthesia combined with EA to stress can partially improve the immunosupression induced by CPB. Acupuncture does not have significant effect on inflammatory cytokine reaction induced by cardiac surgery.