Carnosic Acid Prevents Beta-Amyloid-Induced Injury in Human Neuroblastoma SH-SY5Y Cells via the Induction of Autophagy

Beta-amyloid (Aβ), the hallmark protein in Alzheimer’s disease (AD), induces neurotoxicity that involves oxidative stress and mitochondrial dysfunction, leading to cell death. Carnosic acid (CA), a polyphenolic diterpene isolated from the herb rosemary (Rosemarinus officinalis), was investigated in our study to assess its neuroprotective effect and underlying mechanism against Aβ-induced injury in human neuroblastoma SH-SY5Y cells. We found that CA pretreatment alleviated the Aβ_25–35-induced loss of cell viability, inhibited both Aβ_1–42 accumulation and tau hyperphosphorylation, reduced reactive oxygen species generation, and maintained the mitochondrial membrane potential. Moreover, CA increased the microtubule-associated protein light chain 3 (LC3)-II/I ratio and decreased SQSTM1(p62), indicating that CA could induce autophagy. Autophagy inhibitor 3-methyladenine (3-MA) attenuated the neuroprotective effect of CA, suggesting that autophagy was involved in the neuroprotection of CA. It was also observed that CA activated AMP-activated protein kinase (AMPK) but inhibited mammalian target of rapamycin (mTOR). Furthermore, blocking AMPK with si-AMPKα successfully inhibited the upregulation of LC3-II/I, prevented the downregulation of phosphorylation of mTOR and SQSTM1(p62), indicating that CA induced autophagy in SH-SY5Y cells via the activation of AMPK. These results suggested that CA might be a potential agent for preventing AD.     

Silencing of Prrx1b suppresses cellular proliferation,migration, invasion and epithelial–mesenchymal transition in triple‐negative breast cancer

Triple‐negative breast cancer (TNBC) is a highly aggressive tumour subtype associated with poor prognosis. The mechanisms involved in TNBC progression remains largely unknown. To date, there are no effective therapeutic targets for this tumour subtype. Paired‐related homeobox 1b (Prrx1b), one of major isoforms of Prrx1, has been identified as a new epithelial–mesenchymal transition (EMT) inducer. However, the function of Prrx1b in TNBC has not been elucidated. In this study, we found that Prrx1b was significantly up‐regulated in TNBC and associated with tumour size and vascular invasion of breast cancer. Silencing of Prrx1b suppressed the proliferation, migration and invasion of basal‐like cancer cells. Moreover, silencing of Prrx1b prevented Wnt/β‐catenin signaling pathway and induced the mesenchymal‐epithelial transition (MET). Taken together, our data indicated that Prrx1b may be an important regulator of EMT in TNBC cells and a new therapeutic target for interventions against TNBC invasion and metastasis.     

ZEB1 Mediates Acquired Resistance to the Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer

Epithelial-mesenchymal transition (EMT) is one mechanism of acquired resistance to inhibitors of the epidermal growth factor receptor-tyrosine kinases (EGFR-TKIs) in non-small cell lung cancer (NSCLC). The precise mechanisms of EMT-related acquired resistance to EGFR-TKIs in NSCLC remain unclear. We generated erlotinib-resistant HCC4006 cells (HCC4006ER) by chronic exposure of EGFR-mutant HCC4006 cells to increasing concentrations of erlotinib. HCC4006ER cells acquired an EMT phenotype and activation of the TGF-β/SMAD pathway, while lacking both T790M secondary EGFR mutation and MET gene amplification. We employed gene expression microarrays in HCC4006 and HCC4006ER cells to better understand the mechanism of acquired EGFR-TKI resistance with EMT. At the mRNA level, ZEB1 (TCF8), a known regulator of EMT, was >20-fold higher in HCC4006ER cells than in HCC4006 cells, and increased ZEB1 protein level was also detected. Furthermore, numerous ZEB1 responsive genes, such as CDH1 (E-cadherin), ST14, and vimentin, were coordinately regulated along with increased ZEB1 in HCC4006ER cells. We also identified ZEB1 overexpression and an EMT phenotype in several NSCLC cells and human NSCLC samples with acquired EGFR-TKI resistance. Short-interfering RNA against ZEB1 reversed the EMT phenotype and, importantly, restored erlotinib sensitivity in HCC4006ER cells. The level of micro-RNA-200c, which can negatively regulate ZEB1, was significantly reduced in HCC4006ER cells. Our results suggest that increased ZEB1 can drive EMT-related acquired resistance to EGFR-TKIs in NSCLC. Attempts should be made to explore targeting ZEB1 to resensitize TKI-resistant tumors.     

Type D Personality Predicts Poor Medication Adherence in Chinese Patients with Type 2 Diabetes Mellitus: A Six-Month Follow-Up Study

Background

Type D personality and medication nonadherence have been shown to be associated with poor health outcomes. Type D personality is associated with poor medication adherence in patients with coronary artery disease, myocardial infarction, and heart failure. However, the relationship between type D personality and medication adherence in patients with Type 2 Diabetes Mellitus (T2DM) remains unknown. This study aims to examine whether type D personality was associated with medication adherence in patients with T2DM.

Design and Settings

A follow-up study was conducted in general hospital of the People''s Liberation Army in Beijing.

Methods

412 T2DM patients (205 females), who were recruited by circular systematic random sampling, provided demographic and baseline data about medical information and completed measures of Type D personality. Then, 330 patients went on to complete a self-report measure of medication adherence at the sixth month after baseline data collection. Chi-square test, t tests, and hierarchical multiple regression analyses were conducted, as needed.

Results

Patients with type D personality were significantly more likely to have poor medication adherence (p<0.001). Type D personality predicts poor medication adherence before and after controlling for covariates when it was analyzed as a categorical variable. However, the dimensional construct of type D personality was not associated with medication adherence when analyzed as a continuous variable.

Conclusion

Although, as a dimensional construct, type D personality may not reflect the components of the personality associated with poor medication adherence in patients with T2DM, screening for type D personality may help to identify those who are at higher risk of poor medication adherence. Interventions, aiming to improve medication adherence, should be launched for these high-risk patients.     

Native Magnetic Resonance T1-Mapping Identifies Diffuse Myocardial Injury in Hypothyroidism

Background and Aim

Hypothyroidism (HT) is characterized by thyroid hormone deficiencies, which can lead to diffuse myocardial interstitium lesions in patients with HT. Myocardial longitudinal relaxation time (T1) mapping is a potential diagnostic tool for quantifying diffuse myocardial injury. This study aimed to assess the usefulness of T1 mapping in identifying myocardial involvement in HT, and determine the relationship between T1 values and myocardial function.

Methods

A cross-sectional study was conducted with 30 untreated HT patients alongside 23 age- and sex-matched healthy controls. All subjects underwent cardiac magnetic resonance (CMR) with non-contrast (native) T1 mapping using a modified Look-Locker inversion-recovery (MOLLI) sequence to assess the native T1 values of myocardium and cardiac function.

Results

Native myocardial T1 values were significantly increased in HT patients, especially those with pericardial effusion (p < 0.05), compared with healthy controls. In addition, significantly reduced peak filling rate (PFR) and prolonged peak filling time (PFT) were obtained (p < 0.05) in HT patients compared with controls. Furthermore, stroke volume (SV) and cardiac index (CI) were significantly lower in HT patients than controls (all p < 0.05). Interestingly, native T1 values were negatively correlated with free triiodothyronine (FT3), PFR, SV and CI (all p < 0.05).

Conclusion

Diffuse myocardial injuries are common in HT patients, and increased T1 values are correlated with FT3 and cardiac function impairment. These findings indicate that T1 mapping might be useful in evaluating myocardial injuries in HT patients.     

Unbiased Deep Sequencing of RNA Viruses from Clinical Samples

Here we outline a next-generation RNA sequencing protocol that enables de novo assemblies and intra-host variant calls of viral genomes collected from clinical and biological sources. The method is unbiased and universal; it uses random primers for cDNA synthesis and requires no prior knowledge of the viral sequence content. Before library construction, selective RNase H-based digestion is used to deplete unwanted RNA — including poly(rA) carrier and ribosomal RNA — from the viral RNA sample. Selective depletion improves both the data quality and the number of unique reads in viral RNA sequencing libraries. Moreover, a transposase-based ''tagmentation'' step is used in the protocol as it reduces overall library construction time. The protocol has enabled rapid deep sequencing of over 600 Lassa and Ebola virus samples-including collections from both blood and tissue isolates-and is broadly applicable to other microbial genomics studies.     

2个玉米抗矮花叶病分子标记的有效性评价

玉米矮花叶病是玉米重要的病毒病害,培育抗病品种是防治该病最经济有效的方法,将常规育种方法与分子育种技术相结合可以大大提高抗病育种的效率。本研究利用前期研究开发的2个分子标记Indel186-9和SCAR112,检测100份常用玉米自交系的标记基因型,结合100份玉米自交系抗性表型鉴定结果进行2个分子标记辅助选择的有效性分析。结果表明,目前种质资源中高抗病材料较少,亟待进行抗病改良。本试验所用的自交系包括不同血缘,抗源主要来源于PB和四平头种质。Indel186-9标记和SCAR112标记的选择符合率均达到80%,同时使用两者选择符合率达到91.67%,其中抗病选择符合率达到100%。Indel186-9和SCAR112标记分别可以使抗病级别从平均7.26级提高到平均2.4级,平均7.63级提高到平均4.27级。试验证明2个标记均可用于对玉米抗矮花叶病材料的选择,正确组合使用可提高对玉米抗矮花叶病材料的选择效率。     

Scleral Cross-Linking Using Riboflavin UVA Irradiation for the Prevention of Myopia Progression in a Guinea Pig Model: Blocked Axial Extension and Altered Scleral Microstructure

PurposeTo develop methods of collagen cross-linking (CXL) in the sclera for the treatment of progressive myopia and to investigate the biomechanical and histological changes that occur in as a result.MethodsTwenty 14-day-old guinea pigs were divided into 3 groups: the cross-linking group (CL, n = 8), non cross-linking group (NCL, n = 8), and control group (n = 4). The scleras of the right eyes of the guinea pigs in the CL group were surgically exposed and riboflavin was dropped onto the irradiation zone for 20 seconds prior to ultraviolet-A (UVA) irradiation. The same procedure was conducted on the NCL group but without UVA irradiation. No procedure was conducted on the control group. The right eyes of the guinea pigs in the CL and NCL groups were then fitted with -10.00DS optics for six weeks. Retinoscopy and the axial lengths (AXL) were measured at baseline, and at the second, fourth and sixth weeks post-treatment in all three groups. All animal subjects were euthanized after the sixth week and then biomechanical and histopathological examinations of the scleras were conducted.ResultsThe mean AXL of the NCL group was longer than both the control and CL groups at six weeks (P = 0.001). The mean refractive error in the NCL group was statistically significantly more negative than both the control and the CL groups at six weeks (P = 0.001). The scleral collagen fiber arrangements of the CL and control groups were denser and more regularly distributed than the NCL group. Ultimate stress of the sclera was lowest in the NCL group, followed by the CL then the control group (P<0.05). Ultimate strain (%) of the sclera was lowest in the CL group followed by the NCL and then the control group (P<0.05).ConclusionOur study demonstrates that scleral CXL using riboflavin UVA irradiation effectively prevents the progression of myopia by increasing scleral biomechanical strength in a guinea pig model.     

Influence of substance P on carotid sinus nerve baro- and chemoreceptor activity in rabbits.

Substance P (SP) is abundant in the carotid sinus nerve (CSN) and has been implicated in baro- and chemoreceptor reflexes. We examined the effect of SP on blood pressure, heart rate, phrenic nerve activity, hindlimb perfusion pressure, and cardiac contractile strength in urethane-anesthetized rabbits with bilaterally cut cervical sympathetic, vagus, and aortic depressor nerves. Retrograde simultaneous injection of SP (0.5-2.7 micrograms/kg in 0.2-0.3 ml saline) into both carotid sinus areas via the internal carotid arteries decreased blood pressure (by 56%), heart rate (by 13%), cardiac contractility (by 25%) and phrenic nerve activity (by 77%). The effect on hindlimb perfusion pressure was variable. There was both a reflex effect and direct hindlimb vasodilation. In another group of rabbits, the carotid sinus areas were vascularly isolated and perfused with SP (0.19 micrograms/min dissolved in Locke's solution) or Locke's solution alone for 5 min. While carotid sinus perfusion pressure was maintained in the range of 80-120 mmHg, mean arterial blood pressure, heart rate, and unit activity from the CSN were recorded. SP increased the activity of 11 of 18 baroreceptor fibers and inhibited all of 20 chemoreceptor fibers. SP decreased mean arterial blood pressure and heart rate, but the changes were less than those obtained with injection of SP into nonisolated carotid sinus arteries because systemic effects of SP, which in some cases counteracted the reflex effects, were eliminated.