Bereaved parents' perceptions of memory making: a qualitative meta-synthesis.

OBJECTIVE: This study aims to investigate the experiences of parents who have experienced bereavement in their efforts to preserve memories of their deceased child. METHODS: Employing a qualitative meta-synthesis approach, this study systematically sought relevant qualitative literature by conducting searches across various electronic databases, including PubMed, Embase, CINAHL, PsycINFO, Web of Science, Cochrane Library, and Wiley, up until July 2023. RESULTS: Nine studies are eligible for inclusion and included in the meta-synthesis. Three overarching categories are identified: (1) Affirming the Significance of Memory Making. (2) Best Practices in Memory Making. (3) Barriers to Effective Memory Making. CONCLUSION: Bereaved parents highly value the act of creating lasting memories, emphasizing its profound significance. While forming these memories, it is imperative to offer family-centered care and honor diverse preferences and needs. It is essential to offer effective support to parents, offering them a range of choices. Furthermore, a more comprehensive examination of memory-making practices is required to better understand their influence on parents' recollections of their deceased child.

Integrated virtual simulation and face-to-face simulation for clinical judgment training among undergraduate nursing students: a mixed-methods study.

BACKGROUND: Virtual simulation and face-to-face simulation are effective for clinical judgment training. Rare studies have tried to improve clinical judgment ability by applying virtual simulation and face-to-face simulation together. This study aimed to evaluate the effect of an integrated non-immersive virtual simulation and high-fidelity face-to-face simulation program on enhancing nursing students' clinical judgment ability and understanding of nursing students' experiences of the combined simulation. METHODS: A sequential exploratory mixed-methods study was conducted in a nursing simulation center of a university in Central China. Third-year nursing students (n = 122) taking clinical training in ICUs were subsequentially assigned to the integrated non-immersive virtual simulation and high-fidelity face-to-face simulation program arm (n = 61) or the face-to-face simulation-only arm (n = 61) according to the order in which they entered in ICU training. Clinical judgment ability was measured by the Lasater Clinical Judgment Rubric (LCJR). Focus group interviews were conducted to gather qualitative data. RESULTS: Students in both arms demonstrated significant improvement in clinical judgment ability scores after simulation, and students in the integrated arm reported more improvement than students in the face-to-face simulation-only arm. The qualitative quotes provided a context for the quantitative improvement measured by the LJCR in the integrated arm. Most of the quantitative findings were confirmed by qualitative findings, including the domains and items in the LJCR. The findings verified and favored the effect of the combination of non-immersive virtual simulation and high-fidelity face-to-face simulation integrated program on enhancing nursing students' clinical judgment ability. CONCLUSIONS: The integrated virtual simulation and face-to-face simulation program was feasible and enhanced nursing students' self-reported clinical judgment ability. This integrated non-immersive virtual simulation and high-fidelity face-to-face simulation program may benefit nursing students and newly graduated nurses in the ICU more than face-to-face simulation only.

Analysis of the factors influencing of sleep quality in intensive care unit awake patients based on a structural equation model: A cross-sectional study.

OBJECTIVE: The objective of this study was to construct and validate a structural equation model (SEM) to identify factors associated with sleep quality in awake patients in the intensive care unit (ICU) and to assist in the development of clinical intervention strategies. RESEARCH METHODS/SETTING: In this cross-sectional study, 200 awake patients who were cared for in the ICU of a tertiary hospital in China were surveyed via several self-report questionnaires and wearable actigraphy sleep monitoring devices. Based on the collected data, structural equation modelling analysis was performed using SPSS and AMOS statistical analysis software. The study is reported using the STROBE checklist. RESULTS: The fit indices of the SEM were acceptable: χ2/df = 1.676 (p < .001) and RMSEA = .058 (p < 0.080). Anxiety/depression had a direct negative effect on the sleep quality of awake patients cared for in the ICU (ß = -.440, p < .001). In addition, disease-freeness progress had an indirect negative effect on the sleep quality of awake patients cared for in the ICU (ß = -.142, p < .001). Analgesics had an indirect negative effect on the sleep quality of awake patients cared for in the ICU through pain and sedatives (ß = -.082, p < .001). Sedation had a direct positive effect on the sleep quality of conscious patients cared for in the ICU (ß = .493; p < .001). CONCLUSION: The results of the SEM showed that the sleep quality of awake patients cared for in the ICU is mainly affected by psychological and disease-related factors, especially anxiety, depression and pain, so we can improve the sleep quality of patients through psychological intervention and drug intervention.

Calcium-binding motif-mediated binding of redundant calcium offers a chimeolysin enhanced bactericidal activity and extended host range under physiological conditions.

OBJECTIVES: Calcium-binding motifs are shared by multiple bacteriophage lysins; however, the influence of calcium on the enzymatic activity and host range of these enzymes is still not understood. To address this, ClyF, a chimeric lysin with a putative calcium-binding motif, was used as a model for in vitro and in vivo investigations. METHODS: The concentration of calcium bound to ClyF was determined by atomic absorption spectrometry. The influence of calcium on the structure, activity and host range of ClyF was assessed by circular dichroism and time-kill assays. The bactericidal activity of ClyF was evaluated in various sera and a mouse model of Streptococcus agalactiae bacteraemia. RESULTS: ClyF has a highly negatively charged surface around the calcium-binding motif that can bind extra calcium, thereby increasing the avidity of ClyF for the negatively charged bacterial cell wall. In line with this, ClyF exhibited significantly enhanced staphylolytic and streptolytic activity in various sera containing physiological calcium, including human serum, heat-inactivated human serum, mouse serum and rabbit serum. In a mouse model of S. agalactiae bacteraemia, intraperitoneal administration of a single dose of 25 µg/mouse ClyF fully protected the mice from lethal infection. CONCLUSIONS: The present data collectively showed that physiological calcium improves the bactericidal activity and host range of ClyF, making it a promising candidate for the treatment of infections caused by multiple staphylococci and streptococci.

Sub-chronic ammonia exposure induces hepatopancreatic damage, oxidative stress, and immune dysfunction in red swamp crayfish (Procambarus clarkii).

Ammonia, as one of the primary water pollutants in aquaculture, has been shown to induce a wide range of ecotoxicological effects on aquatic animals. In order to investigate the antioxidant and innate immune responses in crustaceans disrupted by ammonia, red swamp crayfish (Procambarus clarkii) were exposed to 0, 15, 30, and 50 mg/L total ammonia nitrogen for 30 d, the alterations of antioxidant responses as well as innate immunity were studied. The results showed that the severity of hepatopancreatic injury were aggravated by the increasing ammonia levels, which were mainly characterized by tubule lumen dilatation and vacuolization. The swollen mitochondria and disappeared mitochondria ridges suggested that oxidative stress induced by ammonia targets the mitochondria. Concurrently, enhanced MDA levels, and decreased GSH levels as well as the decreased transcription and activity of antioxidant enzymes, including SOD, CAT, and GPx were noticed, which suggested that high concentrations of ammonia exposure induce oxidative stress in P. clarkii. Furthermore, a significant decrease of the hemolymph ACP, AKP, and PO along with the significant downregulation of immune-related genes (ppo, hsp70, hsp90, alf1, ctl) jointly indicated that ammonia stress inhibited the innate immune function. Our findings demonstrated that sub-chronic ammonia stress induced hepatopancreatic injury and exert suppressive effects on the antioxidant capacity as well as innate immunity of P. clarkii. Our results provide a fundamental basis for the deleterious effects of ammonia stress on aquatic crustaceans.

Lutein inhibits tumor progression through the ATR/Chk1/p53 signaling pathway in non-small cell lung cancer.

Lung cancer is the leading cause of cancer-related death. In particular, non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer cases. Due to tumor resistance and the toxicity of chemotherapeutic agents, it is increasingly critical to discover novel, potent antitumorigenic drugs for treating NSCLC. Lutein, a carotenoid, has been reported to exert toxic effects on cells in several tumor types. However, the detailed functions and underlying mechanisms of lutein in NSCLC remain elusive. The present study showed that lutein significantly and dose-dependently inhibited cell proliferation, arrested the cell cycle at the G0/G1 phase, and induced apoptosis in NSCLC cells. RNA-sequencing analysis revealed that the p53 signaling pathway was the most significantly upregulated in lutein-treated A549 cells. Mechanistically, lutein exerted antitumorigenic effects by inducing DNA damage and subsequently activating the ATR/Chk1/p53 signaling pathway in A549 cells. In vivo, lutein impeded tumor growth in mice and prolonged their survival. In conclusion, our findings demonstrate the antitumorigenic potential of lutein and reveal its molecular mechanism of action, suggesting that lutein is a promising candidate for clinical NSCLC treatment.

Nurses' perceptions of barriers and supportive behaviors in end-of-life care in the intensive care unit: a cross-sectional study.

BACKGROUND AND AIM: Patient deaths are common in the intensive care unit, and a nurse's perception of barriers to and supportive behaviors in end-of-life care varies widely depending upon their cultural background. The aim of this study was to describe the perceptions of intensive care nurses regarding barriers to and supportive behaviors in providing end-of-life care in a Chinese cultural context. METHODS: A cross-sectional survey was conducted among intensive care nurses in 20 intensive care units in 11 general hospitals in central and eastern China. Instruments used in this study were general survey and Beckstrand's questionnaire. Data were collected via online survey platform. Descriptive analysis was used to describe general characteristics of participants and mean and standard deviations of the barriers and supportive behaviors. The mean and standard deviation were used to describe the intensity and frequency of each barrier or supportive behavior following Beckstrand's method to calculate the score of barriers and supportive behaviors. Content analysis was used to analyze the responses to open-ended questions. RESULTS: The response rate was 53% (n = 368/700). Five of the top six barriers related to families and the other was the nurse's lack of time. Supportive behaviors included three related to families and three related to healthcare providers. Nurses in the intensive care unit felt that families should be present at the bedside of a dying patient, there is a need to provide a quiet, independent environment and psychological support should be provided to the patient and family. Nurses believe that if possible, families can be given flexibility to visit dying patients, such as increasing the number of visits, rather than limiting visiting hours altogether. Families need to be given enough time to perform the final rites on the dying patient. Moreover, it is remarkable that nurses' supportive behaviors almost all concern care after death. CONCLUSIONS: According to ICU-nurses family-related factors, such as accompany of the dying patients and acceptence of patient's imminent death, were found the major factors affecting the quality of end-of-life care. These findings identify the most prominent current barriers and supportive behaviors, which may provide a basis for addressing these issues in the future to improve the quality of end-of-life care.

Intercellular Bridge Mediates Ca2+ Signals between Micropatterned Cells via IP3 and Ca2+ Diffusion.

Intercellular bridges are plasma continuities formed at the end of the cytokinesis process that facilitate intercellular mass transport between the two daughter cells. However, it remains largely unknown how the intercellular bridge mediates Ca2+ communication between postmitotic cells. In this work, we utilize BV-2 microglial cells planted on dumbbell-shaped micropatterned assemblies to resolve spatiotemporal characteristics of Ca2+ signal transfer over the intercellular bridges. With the use of such micropatterns, considerably longer and more regular intercellular bridges can be obtained than in conventional cell cultures. The initial Ca2+ signal is evoked by mechanical stimulation of one of the daughter cells. A considerable time delay is observed between the arrivals of passive Ca2+ diffusion and endogenous Ca2+ response in the intercellular-bridge-connected cell, indicating two different pathways of the Ca2+ communication. Extracellular Ca2+ and the paracrine pathway have practically no effect on the endogenous Ca2+ response, demonstrated by application of Ca2+-free medium, exogenous ATP, and P2Y13 receptor antagonist. In contrast, the endoplasmic reticulum Ca2+-ATPase inhibitor thapsigargin and inositol trisphosphate (IP3) receptor blocker 2-aminoethyl diphenylborate significantly inhibit the endogenous Ca2+ increase, which signifies involvement of IP3-sensitive calcium store release. Notably, passive Ca2+ diffusion into the connected cell can clearly be detected when IP3-sensitive calcium store release is abolished by 2-aminoethyl diphenylborate. Those observations prove that both passive Ca2+ diffusion and IP3-mediated endogenous Ca2+ response contribute to the Ca2+ increase in intercellular-bridge-connected cells. Moreover, a simulation model agreed well with the experimental observations.

Structural and biochemical characterization of inorganic pyrophosphatase from Homo sapiens.

Inorganic pyrophosphatase (PPase) plays an essential role in energy conservation and provides energy for many biosynthetic pathways. Here, we present two three-dimensional structures of PPase from Homo sapiens (Hu-PPase) at 2.38 Å and 3.40 Å in different crystallization conditions. One of the Hu-PPase structures complex of two magnesium metal ions was determined to be a monomer (Hu-PPase-mono) here, while the other one to be a dimer-dimer (Hu-PPase-dd). In each asymmetric unit of Hu-PPase-mono, there are four α-helices and ten ß-strands and folds as a barrel structure, and the active site contains two magnesium ions. Like PPases from many species, we found that Hu-PPase was able to undergo self-assembly. To our surprise, disruption of the self-assembly of Hu-PPase did not influence its enzymatic activity or the ability to promote cell growth. Our work uncovered that different structure forms of Hu-PPase and found that the pyrophosphatase activity of Hu-PPase is independent of its self-assembly.

Long non-coding RNA GAS5 accelerates oxidative stress in melanoma cells by rescuing EZH2-mediated CDKN1C downregulation.

BACKGROUND: The significance of long non-coding RNAs (lncRNAs) in mediating oxidative stress of cancers has been implicated recently. This study proposed a potential therapeutic target lncRNA growth arrest-specific transcript 5 (GAS5) for melanoma, due to its crucial role in oxidative stress and apoptosis of melanoma cells by regulating the enhancer of zeste homolog 2 (EZH2)-mediated CDKN1C expression. METHODS: The lncRNA GAS5 expression pattern was examined in melanoma tissues and cells. The correlation of lncRNA GAS5, EZH2, and CDKN1C with survival rate of melanoma patients was analyzed. In melanoma cell lines, lncRNA GAS5 expression was overexpressed or knocked down to clarify its effects on cell viability, apoptosis, and oxidative stress. The interaction between lncRNA GAS5 and EZH2 was examined by RIP and RNA pull-down assays followed by verification of the target relationship between EZH2 and CDKN1C. RESULTS: High expression of EZH2 and poor expression of lncRNA GAS5 and CDKN1C was observed in melanoma tissues and found to be correlated with the reduction in survival expectancy of melanoma patients. Overexpression of lncRNA GAS5 or CDKN1C or EZH2 knockdown could inhibit cell viability but enhance melanoma cell apoptosis and oxidative stress. Importantly, lncRNA GAS5 attenuated EZH2 expression by recruiting E2F4 to the EZH2 promoter region and knockdown of EZH2 upregulated CDKN1C expression by inhibiting the H3K27me3. CONCLUSION: The evidence provided by our study highlighted the involvement of lncRNA GAS5 in the translational suppression of EZH2 as well as the upregulation of CDKN1C, resulting in the promotion of melanoma cell apoptosis and oxidative stress.

Silencing of microRNA-517a induces oxidative stress injury in melanoma cells via inactivation of the JNK signaling pathway by upregulating CDKN1C.

BACKGROUND: Melanoma is notoriously resistant to current treatments, and less than 25% of metastatic melanoma cases respond to existing therapies. Growing evidence has shown that microRNAs (miRNAs) play a vital role in the prognosis of melanoma. MiR-517a has been implicated in many types of cancer; however, its expressional features and potential biological functions in melanoma remain unclear. The present study aimed to investigate the possible effects of miR-517a on oxidative stress (OS) in melanoma cells. METHODS: miR-517a expression in melanoma was determined using RT-qPCR. After treatment with different concentrations of H2O2, cell viability was determined in order to identify the most appropriate H2O2 concentration. Through loss and gain of function experiments, the interactions between miR-517a, the cyclin dependent kinase inhibitor 1C (CDKN1C) and the c-Jun NH2-terminal kinase (JNK) signaling pathway, as well as their roles in OS of melanoma cells were identified. Moreover, the expression of Cleaved Caspase-3, extent of ERK1/2 phosphorylation, Bax/Bcl-2 ratio, levels of T-AOC, ROS and MDA, and SOD activity were also tested. Finally, melanoma cell viability and apoptosis were detected. RESULTS: MiR-517a was upregulated, while CDKN1C was downregulated in melanoma tissues and cells. MiR-517a targets CDKN1C and consequently reduced its expression. Inhibition of miR-517a was shown to increase Cleaved Caspase-3 expression, Bax/Bcl-2 ratio, levels of ROS and MDA, as well as cell apoptosis but decrease extent of ERK1/2 phosphorylation, T-AOC levels, SOD activity, along with cell proliferation and mitochondrial membrane potential. CONCLUSIONS: Overall, silencing miR-517a results in upregulated CDKN1C expression, and inhibited JNK signaling pathway activation, consequently promoting OS in melanoma cells.

miR-429 and miR-424-5p inhibit cell proliferation and Ca2+ influx by downregulating CaSR in pulmonary artery smooth muscle cells.

Cytosolic free Ca2+ concentration is a key factor in pulmonary vasoconstriction and vascular remodeling of pulmonary artery smooth muscle cells (PASMCs). These processes contribute to pulmonary arterial hypertension and are influenced by expression of calcium-sensing receptor (CaSR). Although regulation of CaSR expression is precisely controlled, the contribution of microRNAs (miR) is incompletely understood. Here, we demonstrate that miR-429, miR-424-5p, miR-200b-3p, and miR-200c-3p regulate CaSR by targeting specific 3'-untranslated region, suggesting that these miRNAs function as CaSR inhibitors in PASMCs. Moreover, miR-429 and miR-424-5p inhibit proliferation of PASMCs by downregulating CaSR, resulting in reduced Ca2+ influx under both normoxia and hypoxia. These findings indicate miR-429 and miR-424-5p target CaSR and may function as Ca2+ influx suppressors in pulmonary arterial hypertension-associated diseases.

Microfluidic assemblies designed for assessment of drug effects on deformability of human erythrocytes.

Extreme deformability of human erythrocytes is a prerequisite for their ability to squeeze through narrow capillaries of the blood microcirculation system. Various drugs can modify this deformability and consequently provoke circulation problems. We demonstrate that microfluidic assemblies are very convenient platforms for in vitro study of the associated processes. Two types of microfluidic channels were designed to quantitatively investigate modifications of erythrocyte deformability induced by hydrogen peroxide, ethanol and pentoxifylline based on transit velocity measurements. With a high sensitivity our microfluidic assemblies show that hydrogen peroxide decreases erythrocyte deformability in a dose-dependent manner. Then, results on ethanol resolve a biphasic nature of this reactant on the deformability of single erythrocyte cells. Results on pentoxifylline provide evidence that, similar to ethanol, also this medical drug has a double-sided effect on the erythrocyte deformability, i.e. increasing the deformability at low concentrations, while decreasing it at higher ones. Taken together, our microfluidic designs propose a potent measurement method for the erythrocyte deformability, as well as providing a perspective to evaluate effects of drugs on it.

Validation of a Chinese version critical-care pain observation tool in nonintubated and intubated critically ill patients: Two cross-sectional studies.

AIMS AND OBJECTIVES: To validate the Chinese version of the Critical-Care Pain Observation Tool (CPOT) in nonintubated and intubated ICU patients. BACKGROUND: While CPOT was found to have the best psychometric properties among objective pain assessment scales, there is no Chinese version CPOT for nonintubated patients. DESIGN: Cross-sectional design was used in these two observational studies. METHODS: Seventy-six nonintubated patients and 53 intubated patients were assessed to examine internal consistency, criterion-related and discriminative validity of CPOT in the first study. Pain assessment during low pain condition as well as increased pain condition was performed by Numeric Rating Scale (NRS) and the Chinese version COPT. Forty nonintubated patients and 43 intubated patients were assessed to examine inter-rater reliability in the second study. A bedside nurse and a researcher independently executed paired pain assessments with CPOT in the same conditions. The STROBE Statement was followed to guide these studies. RESULTS: The Cronbach's α in nonintubated patients and intubated patients was 0.903-0.930 and 0.868-0.870. The intraclass correlation coefficients (ICCs) in nonintubated patients ranged from 0.959-0.982, and the ICC in intubated patients ranged from 0.947-0.959, confirming the inter-rater reliability. The moderately positive Pearson's correlations between CPOT and NRS scores (r = 0.757-0.838 in nonintubated patients, r = 0.574-0.705 in intubated patients) indicated the criterion-related validity. A significant increase in CPOT scores in the increased pain condition compared with those acquired in the low pain condition verified the discriminative validity. CONCLUSIONS: The Chinese version of CPOT was presented to be valid and reliable for both nonintubated and intubated critically ill adults, which could be applicable for pain assessment in patients in ICU. RELEVANCE TO CLINICAL PRACTICE: This study provides an applicable pain assessment tool for both nonintubated patients and intubated patients in ICU.

Androgen receptor regulates cardiac fibrosis in mice with experimental autoimmune myocarditis by increasing microRNA-125b expression.

Cardiac fibrosis is an important cardiac remodeling event in the development of inflammation dilated cardiomyopathy （iDCM）. We have previously observed that degradation enhancer of androgen receptor (ASC-J9®) could improve cardiac inflammation and fibrosis. Using Primary CFs, we demonstrated that ASC-J9® attenuates the expression of miR-125b, which subsequently inhibits the generation of collagen. In contrast, overexpressed AR in CFs induced collagen production, increases mir-125b.We also found that inhibition of miR-125b attenuates fibrosis which induced by the overexpression of AR. Our results indentify the functional role for AR as a regulator of cardiac fibrosis due to myocarditis and further show that AR exerts its effect by increasing microRNA-125b expression. Treatment with degradation enhancer of AR limits cardiac fibrosis in iDCM, thereby providing potentially a therapeutic approach for patients with iDCM.

Targeting androgen receptor with ASC-J9 attenuates cardiac injury and dysfunction in experimental autoimmune myocarditis by reducing M1-like macrophage.

BACKGROUD: Macrophages are important mediators in inflammatory cardiovascular diseases. Experimental autoimmune myocarditis (EAM) is characterized by pronounced macrophages infiltration, cardiac necrosis and cardiac fibrosis. Androgen receptor (AR) is a regulator of immune system which can control macrophages' infiltration and function in various inflammatory-related diseases. However, the effect of AR on the inflammatory response in EAM is unknown. Our study aims to investigate the potential role of AR on the development of autoimmune myocarditis. METHODS AND RESULTS: In our study, we found that AR was increased in the myocardium and was associated with the time-course of EAM progression, which motivated us to use ASC-J9 (an enhancer of AR degradation). The results revealed that ASC-J9 administration in EAM mice resulted in an attenuation in the severity of disease and cardiac injury, a reduced CD4+T cell response, reduced monocyte/macrophage infiltration, and decreases in the pro-inflammatory cytokines. Furthermore, ASC-J9 was also found to prevent Raw264.7 cells polarization to M1 macrophages in response to LPS by upregulating suppressor of cytokine signaling 1(SOCS1) and downregulating signal transducer and activator of the transcription 5(STAT5) activity. CONCLUSIONS: AR facilitated EAM development, and targeting AR with ASC-J9 attenuated cardiac injury and dysfunction by inhibiting macrophages polarization towards M1 macrophages.

Hypotonic stress promotes ATP release, reactive oxygen species production and cell proliferation via TRPV4 activation in rheumatoid arthritis rat synovial fibroblasts.

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune-disease with complex and unclear etiology. Hypotonicity of synovial fluid is a typical characteristic of RA, which may play pivotal roles in RA pathogenesis. In this work, we studied the responses of RA synovial fibroblasts to hypotonic stress in vitro and further explored the underlying mechanisms. Data showed that hyposmotic solutions significantly triggered increases in cytosolic calcium concentration ([Ca2+]c) of synoviocytes. Subsequently, it caused rapid release of ATP, as well as remarkable production of intracellular reactive oxygen species (ROS). Meanwhile, hypotonic stimulus promoted the proliferation of synovial fibroblasts. These effects were almost abolished by calcium-free buffer and significantly inhibited by gadolinium (III) chloride (a mechanosensitive Ca2+ channel blocker) and ruthenium red (a transient receptor potential vanilloid 4 (TRPV4) blocker). 4α-phorbol 12,13-didecanoate, a specific agonist of TRPV4, also mimicked hypotonic shock-induced responses shown above. In contrast, voltage-gated channel inhibitors verapamil and nifedipine had little influences on these responses. Furthermore, RT-PCR and western blotting evidently detected TRPV4 expression at mRNA and protein level in isolated synoviocytes. Taken together, our results indicated that hypotonic stimulus resulted in ATP release, ROS production, and cell proliferation depending on Ca2+ entry through activation of TRPV4 channel in synoviocytes.

Structural basis for the interaction between the Golgi reassembly-stacking protein GRASP65 and the Golgi matrix protein GM130.

GM130 and GRASP65 are Golgi peripheral membrane proteins that play a key role in Golgi stacking and vesicle tethering. However, the molecular details of their interaction and their structural role as a functional unit remain unclear. Here, we present the crystal structure of the PDZ domains of GRASP65 in complex with the GM130 C-terminal peptide at 1.96-Å resolution. In contrast to previous findings proposing that GM130 interacts with GRASP65 at the PDZ2 domain only, our crystal structure of the complex indicates that GM130 binds to GRASP65 at two distinct sites concurrently and that both the PDZ1 and PDZ2 domains of GRASP65 participate in this molecular interaction. Mutagenesis experiments support these structural observations and demonstrate that they are required for GRASP65-GM130 association.

Effects of 1, 25-Dihydroxyvitamin D3 on Experimental Autoimmune Myocarditis in Mice.

BACKGROUND/AIMS: Myocarditis is an important inflammatory disease of the heart which causes life-threatening conditions. 1, 25(OH)2 D3 has effects on multiple systems and diseases. The present study was aimed to investigate the effect of 1, 25(OH)2 D3 on experimental autoimmune myocarditis (EAM), and explored the underlying mechanisms involved. METHODS: EAM was induced by immunizing BALB/c mice with cardiac α-myosin heavy chain peptides (MyHC-α). 1, 25(OH)2 D3 (1,000 ng/kg once) or vehicle was administered intraperitoneally every other day during the entire experiment. On day 21, transthoracic echocardiography was performed and cardiac inflammatory infiltration was detected by hematoxylin and eosin (HE). The terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, and Western blots for the expression of protein caspase-3 and cleaved-caspase3 were used to evaluate apoptosis. Transmission electron microscopy and Western blots for the expression of protein Beclin-1, LC3B, and P62 were used to evaluate autophagy. RESULTS: The ratio of heart weight/body weight was significantly reduced in 1, 25(OH)2 D3 -treated EAM mice, compared with vehicle -treated ones. 1, 25(OH)2 D3 treatment improved cardiac function, diminished cell infiltration in cardiac, suppressed myocardial apoptosis, decreased the number of autophagosomes, and decreased the protein expression of Beclin-1, LC3-II and p62. CONCLUSIONS: The present results demonstrated that administration of 1, 25(OH)2 D3 decreased EAM severity. 1, 25(OH)2 D3 treatment may be a feasible therapeutic approach for EAM.

MicroRNA-101a inhibits cardiac fibrosis induced by hypoxia via targeting TGFßRI on cardiac fibroblasts.

BACKGROUND/AIMS: Hypoxia is a basic pathological challenge that is associated with numerous cardiovascular disorders including aberrant cardiac remodeling. Transforming growth factor beta (TGF-ß) signaling pathway plays a pivotal role in mediating cardiac fibroblast (CF) function and cardiac fibrosis. Recent data suggested that microRNA-101a (miR-101a) exerted anti-fibrotic effects in post-infarct cardiac remodeling and improved cardiac function. This study aimed to investigate the potential relationship between hypoxia, miR-101a and TGF-ß signaling pathway in CFs. METHODS AND RESULTS: Two weeks following coronary artery occlusion in rats, the expression levels of both TGFß1 and TGFßRI were increased, but the expression of miR-101a was decreased at the site of the infarct and along its border. Cultured rat neonatal CFs treated with hypoxia were characterized by the up-regulation of TGFß1 and TGFßRI and the down-regulation of miR-101a. Delivery of miR-101a mimics significantly suppressed the expression of TGFßRI and p-Smad 3, CF differentiation and collagen content of CFs. These anti-fibrotic effects were abrogated by co-transfection with AMO-miR-101a, an antisense inhibitor of miR-101a. The repression of TGFßRI, a target of miR-101a, was validated by luciferase reporter assays targeting the 3'UTR of TGFßRI. Additionally, we found that overexpression of miR-101a reversed the improved migration ability of CFs and further reduced CF proliferation caused by hypoxia. CONCLUSION: Our study illustrates that miR-101a exerts anti-fibrotic effects by targeting TGFßRI, suggesting that miR-101a plays a multi-faceted role in modulating TGF-ß signaling pathway and cardiac fibrosis.