MiR-223 promotes cardiomyocyte apoptosis by inhibiting Foxo3a expression

OBJECTIVE

MicroRNAs (miRs) are proven to possess diversified functions in the pathogenesis of cardiac diseases. The current study is designed aiming at determining the effect of miR-223 on oxidative stress induced apoptosis in cardiomyocytes.

MATERIALS AND METHODS

Mouse model of myocardial infarction (MI) was constructed, and endogenous level of miR-223 in the border zone of infarcted heart tissues was determined. Primarily cultured cardiomyocytes were exposed to H2O2 treatment to mimic the oxidative stress stimulation. Multiple approaches including quantitative reverse transcription polymerase chain reaction (qRT-PCR), cell viability assay, luciferase assay, Western blot assay and flow cytometry assay were employed to determine its expression, function and mechanism in apoptosis.

RESULTS

MiR-223 expression was significantly upregulated in the border zone of infarcted heart ventricular tissues and in cardiomyocytes treated with H2O2. Overexpression of miR-223 in cardiomyocytes promoted apoptosis, whereas inhibition of endogenous miR-223 protected cardiomyocytes from oxidative stress induced apoptosis. MiR-223 directly targets the 3'untranslated region (UTR) of Foxo3a mRNA. Overexpression of miR-223 inhibited Foxo3a protein expression, however, inhibition of miR-223 suppressed its expression. Silencing Foxo3a using small interfering RNA (siRNA) mimicked the effect of miR-223, indicating its functional significance.

CONCLUSIONS

MiR-223 is an important regulator of cardiomyocyte apoptosis under oxidative stress. Inhibition of the miR-223/Foxo3a signaling axis may be a potential therapeutic strategy for cardiac injuries.

Effect of LSR polymorphism on blood lipid levels and age-specific epistatic interaction with the APOE common polymorphism

The lipolysis stimulated lipoprotein receptor (LSR) is an apolipoprotein (Apo) B and ApoE receptor that participates in the removal of triglyceride-rich lipoproteins during the postprandial phase. LSR gene is located upstream of APOE, an important risk factor for cardiovascular disease (CVD). Since the APOE common polymorphism significantly affects the variability of lipid metabolism, this study aimed to determine the potential impact of a functional SNP rs916147 in LSR gene on lipid traits in healthy subjects and to investigate potential epistatic interaction between LSR and APOE. Unrelated healthy adults (N = 432) and children (N = 328, <18 years old) from the STANISLAS Family Study were used. Age-specific epistasis was observed between APOE and LSR, reversing the protective effect of APOE ε2 allele on cholesterol, ApoE and low-density lipoprotein levels (β: .114, P: .777 × 10^-8 , β: .125, P: .639 × 10^-3 , β: .059, P: .531 × 10^-3 , respectively). This interaction was verified in an independent adult population (n = 1744). These results highlight the importance of the LSR polymorphism and reveal the existence of complex molecular links between LSR and ApoE for the regulation of lipid levels, revealing potential new pathways of interest in type III hyperlipidemia and its involvement in CVD pathology.

[Study on the relationship between uncertainty in illness and caregiving burden in family members of patients with chronic wounds]

Objective: To investigate the current status of uncertainty in illness and caregiving burden in family members of patients with chronic wounds, and to analyze the relationship between them. Methods: A total of 180 patients with chronic wounds admitted to the Department of Emergency of our hospital from October 2017 to March 2018, conforming to the study criteria, were selected by adopting the convenience sampling method. Then one family member who took care of the patients for the longest time and conformed to the study criteria were included in this cross-sectional survey. General Information Questionnaire made by the authors was conducted to investigate the demographic data and wounds of patients, and demographic data of family members. Chinese version of Parent Perception of Uncertainty Scale-Family Member (PPUS-FM) and Caregiver Burden Inventory (CBI) were used to investigate the uncertainty in illness and caregiving burden. Data were processed with multiple linear regression analysis and partial correlation analysis. Results: The effective recovery rate of questionnaire was 91.7% (165/180). (1) The ages of patients were (71±17) years. Among them, there were 89 males and 76 females. The course of chronic wounds was 0.5 to 120.0 months. The wounds were mainly primary occurrence (86.1%, 142 patients), and the main type of wound was pressure ulcer (43.6%, 72 patients). Fifty-seven patients (34.5%) had wound infection. The ages of family members were (56±13) years, and 61.8% (102 people) of them were female. Their daily time of taking care of patients was (10±8) h. (2) The total scores of PPUS-FM of family members were 33 to 125 (88±17) points, mainly in medium level, in which the item score of unpredictability dimension was the highest. (3) The total scores of CBI of family members were 7 to 79 (43±14) points, in which the item score of time-dependence burden dimension was the highest. (4) Uncertainty in PPUS-FM could independently influence 10% of the total variation of caregiving burden in family members of patients (t=3.18, P<0.01). (5) The total scores of PPUS-FM of family members were in significantly positive correlation with the total scores of CBI and scores of physical burden, emotional burden, and social burden, respectively (r=0.33, 0.32, 0.25, 0.36, P<0.05 or P<0.01), while there was no obvious correlation between total scores of PPUS-FM of family members and time-dependence burden/developmental burden (r=0.14, 0.16, P>0.05). Conclusion: There is positive correlation between uncertainty in illness and caregiving burden.

Prostaglandin E2/EP2 receptor signalling pathway promotes diabetic retinopathy in a rat model of diabetes

AIMS/HYPOTHESIS

Diabetic retinopathy is a common microvascular complication of diabetes mellitus and is initiated by inflammation and apoptosis-associated retinal endothelial cell damage. Prostaglandin E₂ (PGE₂) has emerged as a critical regulator of these biological processes. We hypothesised that modulating PGE₂ and its E-prostanoid receptor (EP₂R) would prevent diabetes mellitus-induced inflammation and microvascular dysfunction.

METHODS

In a streptozotocin (STZ)-induced rat model of diabetes, rats received intravitreal injection of PGE₂, butaprost (a PGE₂/EP₂R agonist) or AH6809 (an EP₂R antagonist). Retinal histology, optical coherence tomography, ultrastructure of the retinal vascular and biochemical markers were assessed.

RESULTS

Intravitreal injection of PGE₂ and butaprost significantly accelerated retinal vascular leakage, leucostasis and endothelial cell apoptosis in STZ-induced diabetic rats. This response was ameliorated in diabetic rats pre-treated with AH6809. In addition, pre-treatment of human retinal microvascular endothelial cells with AH6809 attenuated PGE₂- and butaprost-induced activation of caspase 1, activation of the complex containing nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3) and apoptosis-associated speck-like protein containing a C-terminal caspase-activation and recruitment domain (ASC), and activation of the EP₂R-coupled cAMP/protein kinase A/cAMP response element-binding protein signalling pathway.

CONCLUSIONS/INTERPRETATION

The PGE₂/EP₂R signalling pathway is involved in STZ-induced diabetic retinopathy and could be considered as a potential target for diabetic retinopathy prevention and treatment.

The development of CotA mediator cocktail system for dyes decolorization

AIMS

The increasing use of dyes leads to serious environmental concerns, it is significant to explore eco-friendly and economic approaches for dye decolorization. This study aimed to develop mediator cocktail (AS and ABTS) for enhancing the capability of laccase-mediator system in the removal of dyes.

METHODS AND RESULTS

By mediator screening, the mediators of ABTS and AS (ABTS, 2, 2'-azino-bis-(3-ethylbenzothiazo-thiazoline-6-sulphonic acid); AS, acetosyringone) were combined for dyes decolorization. The Box-Behnken Design and response surface analysis was performed to optimize experiment conditions. Comparing the CotA-ABTS-AS cocktail system with CotA-single mediator system showed that the coupling of ABTS and AS could increase the decolorization rate 15 times higher, save a third of the cost and shorten the reaction time by 50%. In addition, our studies revealed that sequential oxidation may occur in CotA-ABTS-AS system.

CONCLUSIONS

Compared with CotA laccase-single mediator system, the CotA-ABTS-AS cocktail system showed advantages including higher efficiency, lower cost and shorter reaction time.

SIGNIFICANCE AND IMPACT OF THE STUDY

This was the first report on the dyes decolorization by laccase mediator cocktail system. These results paved the curb for the application of laccase mediator system in various industrial processes.

[Experimental studies on correlation between nucleolus spindle-related protein 1 and the malignant progression and prognosis of human glioblastoma multiforme]

Objective: To investigate the correlation between nucleolus spindle-related protein 1 (NUSAP1) and malignant progression and prognosis of human glioblastoma multiforme (GBM). Methods: RT-PCR and immunohistochemical technique were applied to analyze NUSAP1 expression level in GBM surgical specimens. Correlations between NUSAP1 expression and molecular classification and survival of patients with GBM were also investigated in TCGA database. The gene silencing technique was used to silence NUSAP1 expression in U87 cells, CCK-8 assay was used to detect cell proliferation, flow cytometry was used to detect cell cycle changes, and in vivo tumorigenicity was evaluated after NUSAP1 silencing in tumor-bearing mice. Results: NUSAP1 expression level in GBM was higher than that in non-tumor brain tissue. Survival curve analysis showed that the survival time of GBM patients with high NUSAP1 expression decreased significantly (P<0.01). NUSAP1 expression was relatively lower in mesenchymal and neural molecular subtypes of GBM, when compared with the other two molecular subtypes. And it was closely related with specific genetic aberrations (such as PTEN loss and IDH1 mutation). Silencing NUSAP1 inhibited G2/M cell cycle progression of GBM cells, and inhibited cell proliferation both in vitro and in vivo. Conclusion: Expression of NUSAP1 is closely related to progress and prognosis of GBM, and can be a biomarker reflecting GBM prognosis and act as a therapeutic target with potential clinical application value.

[Experimental study of glioma stem cell-mediated immune tolerance in tumor microenvironment]

Objective: To investigate the tumor microenvironment of immune tolerance induced by glioma stem cells (GSC). Methods: Human GSC SU3 cells transfected with red fluorescent protein (SU3-RFP) gene were implanted into the brain, subcutis (armpit and foot), liver and abdominal cavity of transgenic green fluorescence protein (GFP) nude mice to establish RFP(+) /GFP(+) dual fluorescence solid tumor model. The re-cultured cells derived from implanted tumor tissues, SU3-RFP cells co-cultured with peritoneal fluid of transgenic GFP nude mice and malignant ascites of tumor-bearing mice were observed by fluorescence microscopy and real-time video image tracing to analyze the microenvironment of immune tolerance mediated by RFP(+) /GFP(+) implanted tumor. Results: Dual fluorescence labeled frozen section showed that all of cells in the tumor microenvironment were GFP(+) , while the pressed tissue-patch showed that the tumor blood vessels exhibited a RFP(+) /GFP(+) double-positioning yellow. In the GFP single fluorescence labeled tumor tissue, all of cells in the microenvironment were green, including tumor edge, necrotic foci and blood vessel. Among them, CD68(+) , F4/80(+) , CD11c(+) , CD11b(+) and CD80(+) cells were observed. In the dual fluorescence labeled co-cultured cells, the phagocytosis and fusion between green host cells and red tumor cells were also observed, and these fusion cells might transfer to the malignant dendritic cells and macrophages. Conclusions: The tumor microenvironment of immune tolerance induced by GSC is not affected by the tissue types of tumor-inoculated sites, and the immune tolerance mediated by inflammatory cells is associated with the inducible malignant transformation, which may be driven by cell fusion.

Immunotolerant indoleamine-2,3-dioxygenase is increased in condyloma acuminata

BACKGROUND

The tryptophan-depleting enzyme indoleamine-2,3-dioxygenase (IDO) is critical for the regulation of immunotolerance and plays an important role in immune-associated skin diseases.

OBJECTIVES

To analyse the level of IDO in condyloma acuminata (CA) and its role in this condition.

METHODS

IDO expression was assessed in the skin and peripheral blood of healthy controls and patients with CA. To assess the role of skin IDO in immunity, the ability of isolated epidermal cells to metabolize tryptophan and the influence on polyclonal T-cell mitogen (PHA)-stimulated T-cell proliferation were explored.

RESULTS

IDO median fluorescence intensities in peripheral blood mononuclear cells from patients with CA were similar to those from healthy controls. Immunohistochemistry showed that IDO⁺ cells were rare in normal skin and the control skin of patients with CA, but were greatly accumulated in wart tissue. Most fluorescence signals of IDO⁺ cells did not overlap with those of CD1a⁺ Langerhans cells. Human papillomavirus (HPV) DNA probe in situ hybridization showed a large number of IDO⁺ cells in the HPV^- site. Keratinocytes in the skin of healthy controls and the circumcised skin of patients with CA could minimally transform tryptophan into kynurenine, but IDO-competent epidermal cells from warts could transform tryptophan. In addition, these IDO-competent epidermal cells could inhibit PHA-stimulated T-cell proliferation. The addition of an IDO inhibitor, 1-methyl-d-tryptophan, restored the inhibited T-cell proliferation.

CONCLUSIONS

Abnormally localized high IDO expression might be involved in the formation of a local immunotolerant microenvironment.

MicroRNA-155 is a biomarker of T-cell activation and immune dysfunction in HIV-1-infected patients

OBJECTIVES

MicroRNA-155 (miR-155) regulates T-cell differentiation and activation. It has also been associated with HIV infection. However, it remains unclear whether miR-155 is related to the T-cell response in HIV-infected individuals (e.g. T-cell activation and exhaustion).

METHODS

We performed a cross-sectional study involving 121 HIV-1-infected patients on highly active antiretroviral therapy (HAART) and 43 HAART-naïve patients. MiR-155 levels in the peripheral blood were determined by quantitative reverse transcription-polymerase chain reaction (PCR). T-cell immune activation, exhaustion, and homeostasis were measured by determining the expression of CD38, programmed death 1 (PD-1) and CD127 via flow cytometry.

RESULTS

The levels of miR-155 in total peripheral blood mononuclear cells, CD4 T cells and CD8 T cells from HIV-1-infected patients were increased (P < 0.01). Nonresponders and HAART-naïve patients also exhibited a higher percentage of CD8⁺ CD38⁺ T cells and a lower percentage of CD4⁺ CD127⁺ and CD8⁺ CD127⁺ T cells (P < 0.05). We also found higher levels of PD-1 expression on the CD4⁺ and CD8⁺ T cells of HIV-1-infected patients (P < 0.05).

CONCLUSIONS

Our findings suggest that miR-155 levels in the peripheral blood of HIV-1-infected patients are increased and associated with T-cell activation. Therefore, miR-155 is a potential biomarker of the immune response following HIV-1 infection.

Inhibition of BDNF-AS Provides Neuroprotection for Retinal Ganglion Cells against Ischemic Injury

Background: Brain-derived neurotrophic factor (BDNF) protects retinal ganglion cells against ischemia in ocular degenerative diseases. We aimed to determine the effect of BDNF-AS on the ischemic injury of retinal ganglion cells. Methods: The levels of BDNF and BDNF-AS were measured in retinal ganglion cells subjected to oxygen and glucose deprivation. The lentiviral vectors were constructed to either overexpress or knock out BDNF-AS. The luciferase reporter gene assay was used to determine whether BDNF-AS could target its seed sequence on BDNF mRNA. The methyl thiazolyl tetrazolium assay was used to determine cell viability, and TUNEL staining was used for cell apoptosis. Results: The levels of BDNF-AS were negatively correlated with BDNF in ischemic retinal ganglion cells. BDNF-AS directly targeted its complementary sequences on BDNF mRNA. BDNF-AS regulated the expression of BDNF and its related genes in retinal ganglion cells. Down-regulation of BDNF-AS increased cell viability and decreased the number of TUNEL-positive retinal ganglion cells under oxygen and glucose deprivation conditions. Conclusion: Inhibition of BDNF-AS protected retinal ganglion cells against ischemia by increasing the levels of BDNF.

[Effects of prenatal maternal seizure on hippocampal damage and cognitive deficits in offspring rats]

Objective: To observe hippocampal damage and cognitive impairment of offspring exposed to prenatal maternal seizure induced by amygdala kindling, and to explore the underlying mechanism by the detection of pathological changes of placenta. Method: Adult female SD rats were randomly divided into three groups: control group(8 rats), kindling group(12 rats) and sham group(8 rats). All the rats were allowed to mate after one week's fully kindling. The pregnant rats in kindling group received electric stimulation every 48 h. Dams were allowed to deliver naturally. Effects of maternal seizure on the number of offspring, the survival rate and body weight of pups were observed. HE staining was used to visualize histopathological changes of placenta. Morris water maze test was used to assess the cognitive function and Nissal's staining to detect hippocampal morphology of the offspring. One-way ANOVA analysis and χ² test were used. Result: Compared with the sham group (95%(78/82)) and the control group (95%(82/86)), the survival rate of pups in kindling group(81%(66/82))was much lower (χ²=13.817, P=0.001). There were no significant differences in the number of pups per litter and pups birth-weight between kindling group and sham group or control group(F=0.312 and 0.257, P=0.736 and 0.776). HE staining showed that placental tissues from control and sham groups were normal whereas the histologic abnormalities of placentas from kindling group were characterized by thickening of the villus vascular walls, luminal stenosis, trophoblasts hyperplasia, abnormalities of trophoblasts with nuclear pyknosis and karyorrhexis and accumulation of inflammatory lymphocytes in labyrinthine zone. Nissl staining showed that neurons in hippocampus of P₀(0 d after birth) and P₈₄(84 d after birth) offspring from control and sham groups were normal, but neuronal damages were obvious in hippocampus of P₀ and P₈₄ offspring from kindling groups, and the damages in P₀ pups were severe with a marked loss of neuron, shrinkage of cells and nuclear pyknosis and karyorrhexis. In the Morris water maze, compared with the sham group ((29±8), (19±9), (10±4)s) and the control group ((25±6), (17±5), (14±4)s) rats in the kindling group ((36±8), (29±8), (30±11)s) exhibited significantly longer escape latency from the 3^rd, 4^th, and 5^th days (F=6.276, 7.518, 18.422, P=0.030, 0.003, 0.000), significant less time in the target quadrant ((27±8) vs.(58±11)and(68±13)s, F=35.993, P=0.000) and reduced number of crossing the platform ((4.4±1.7) vs. (7.2±1.6) and (8.5±1.3)times, F=18.377, P=0.000). In addition, there was no significant difference between control and sham groups(P all >0.05). Conclusion: The prenatal maternal seizures induced significant pathological damages to hippocampus and cognitive impairment of offspring. Hypoxia-ischemia of placenta might play an important role in this process.

[Discussion on the species and naming of medical bamboo slips unearthed from Han tomb in Laoguanshan]

920 pieces of bamboo slip, including broken bamboo slips, found in Laoguanshan Han tomb, are placed in two locations. In one of the location, 736 pieces, except 20 pieces of " chi jian" , of medical bamboo slips are stored. The Chengdu Municipal Institute of Archaeology and Cultural Relics Protection Center of Jingzhou preliminary sorted out these pieces and tentatively give them the names: Wu se mai zang lun, Bi xi yi lun, Mai si hou, Liu shi bing fang, Bing yuan lun, Zhu bing zheng hou, Jing mai shu, Gui mai shu. Through our comprehensive reading, font comparison, comparison of the contents, and investigation on the texts, it was suggested that the batch of medical slips might be divided into nine kinds of documents, namely, Bi xi zhen fa, Zhen zhi lun, Liu shi bing fang, Zhu bing yi, Zhu bing er, Shi er mai, Bie mai, Ci shu, Ni shun wu se mai zang yan jing shen.

Rho-kinase inhibitor fasudil reduces allergic airway inflammation and mucus hypersecretion by regulating STAT6 and NFκB

BACKGROUND

Airway mucus hypersecretion is a key pathophysiological feature in asthma. Fasudil, a selective Rho-A/Rho kinase inhibitor, has been used in clinical trials to treat pulmonary hypertension. However, its function in modulating airway mucus hypersecretion in asthma remains undefined.

OBJECTIVE

We examined whether fasudil, a selective Rho-A/Rho kinase inhibitor, affects the mucus hypersecretion by suppressing MUC5AC via signal transducer and activator of transcription factor 6 (STAT6) and nuclear factor-kappa B (NFκB) in mice and cells.

METHODS

We measured mucus secretion and the expression of Rho-kinase in the airway tissue of patients with asthma. BALB/c mice were sensitized and challenged with ovalbumin (OVA) followed with fasudil treatment. The lung tissues were assessed for airway inflammation and mucus secretion. Cytokine levels and airway responsiveness were determined. STAT6 and NFκB were quantified by Western blot. 16HBE cells were stimulated with house dust mite (HDM) extracts. MUC5AC and muc5ac promoter activities were measured. Using siRNA to knockdown STAT6 in epithelial cells, we determined the impact of STAT6 on muc5ac promoter activity. NFκB nuclear translocation was observed with immunostaining.

RESULTS

Fasudil administration significantly decreased the number of inflammatory cells, inflammation index in the lung and airway responsiveness. Fasudil also reduced mucous secretion and MUC5AC expression in OVA-challenged mice. Fasudil down-regulated the levels of IL-17, IL-4 and IL-13 in the lung tissue of OVA-challenged mice. Fasudil also decreased the expression and phosphorylation of NFκB and STAT6 as well as the nuclear translocation of NFκB. In addition, human airway epithelial cells (16HBE) were challenged with HDM extracts and then treated with fasudil. Fasudil inhibited HDM extract-induced MUC5AC expression, which is associated with a reduction in STAT6 and NFκB in epithelial cells.

CONCLUSIONS AND CLINICAL RELEVANCE

These findings indicate that the Rho-A/Rho kinase inhibitor, fasudil, plays a negative regulatory role in allergen-induced mucus secretion and MUC5AC expression by regulating STAT6 and NFκB.

Primary cilia are not calcium-responsive mechanosensors

Primary cilia are solitary, generally non-motile, hair-like protrusions that extend from the surface of cells between cell divisions. Their antenna-like structure leads naturally to the assumption that they sense the surrounding environment, the most common hypothesis being sensation of mechanical force through calcium-permeable ion channels within the cilium¹. This Ca²⁺- Responsive MechanoSensor (CaRMS) hypothesis for primary cilia has been invoked to explain a large range of biological responses, from control of left-right axis determination in embryonic development to adult progression of polycystic kidney disease and some cancers^2,3. Here, we report the complete lack of mechanically induced calcium increases in primary cilia, in tissues upon which this hypothesis has been based. First, we developed a transgenic mouse, Arl13b-mCherry-GECO1.2, expressing a ratiometric genetically encoded calcium indicator (GECI) in all primary cilia. We then measured responses to flow in primary cilia of cultured kidney epithelial cells, kidney thick ascending tubules, crown cells of the embryonic node, kinocilia of inner ear hair cells, and several cell lines. Cilia-specific Ca²⁺ influxes were not observed in physiological or even highly supraphysiological levels of fluid flow. We conclude that mechanosensation, if it originates in primary cilia, is not via calcium signaling.