Protective effects of irisin on hypoxia-reoxygenation injury in hyperglycemia-treated cardiomyocytes: Role of AMPK pathway and mitochondrial protection

Recent evidence has verified the cardioprotective actions of irisin in different diseases models. However, the beneficial action of irisin on hypoxia-reoxygenation (HR) injury under high glucose stress has not been described. Herein our research investigated the influence of irisin on HR-triggered cardiomyocyte death under high glucose stress. HR model was established in vitro under high glucose treatment. The results illuminated that HR injury augmented apoptotic ratio of cardiomyocyte under high glucose stress; this effect could be abolished by irisin via modulating mitochondrial function. Irisin treatment attenuated cellular redox stress, improved cellular ATP biogenetics, sustained mitochondria potential, and impaired mitochondrion-related cell death. At the molecular levels, irisin treatment activated the 5′-adenosine monophosphate-activated protein kinase (AMPK) pathway and the latter protected cardiomyocyte and mitochondria against HR injury under high glucose stress. Altogether, our results indicated a novel role of irisin in HR-treated cardiomyocyte under high glucose stress. Irisin-activated AMPK pathway and the latter sustained cardiomyocyte viability and mitochondrial function.     

Autophagy in plants: Physiological roles and post‐translational regulation

In eukaryotes, autophagy helps maintain cellular homeostasis by degrading and recycling cytoplasmic materials via a tightly regulated pathway.Over the past few decades, significant progress has been made towards understanding the physiological functions and molecular regulation of autophagy in plant cells. Increasing evidence indicates that autophagy is essential for plant responses to several developmental and environmental cues, functioning in diverse processes such as senescence, male fertility, root meristem maintenance, responses to nutrient starvation,and biotic and abiotic stress. Recent studies have demonstrated that, similar to nonplant systems,the modulation of core proteins in the plant autophagy machinery by posttranslational modifications such as phosphorylation, ubiquitination,lipidation, S-sulfhydration, S-nitrosylation, and acetylation is widely involved in the initiation and progression of autophagy. Here, we provide an overview of the physiological roles and posttranslational regulation of autophagy in plants.     

Macrophage migration inhibitory factor regulates joint capsule fibrosis by promoting TGF-β1 production in fibroblasts

Joint capsule fibrosis caused by excessive inflammation results in post-traumatic joint contracture (PTJC). Transforming growth factor (TGF)-β1 plays a key role in PTJC by regulating fibroblast functions, however, cytokine-induced TGF-β1 expression in specific cell types remains poorly characterized. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in inflammation- and fibrosis-associated pathophysiology. In this study, we investigated whether MIF can facilitate TGF-β1 production from fibroblasts and regulate joint capsule fibrosis following PTJC. Our data demonstrated that MIF and TGF-β1 significantly increased in fibroblasts of injured rat posterior joint capsules. Treatment the lesion sites with MIF inhibitor 4-Iodo-6-phenylpyrimidine (4-IPP) reduced TGF-β1 production and relieved joint capsule inflammation and fibrosis. In vitro, MIF facilitated TGF-β1 expression in primary joint capsule fibroblasts by activating mitogen-activated protein kinase (MAPK) (P38, ERK) signaling through coupling with membrane surface receptor CD74, which in turn affected fibroblast functions and promoted MIF production. Our results reveal a novel function of trauma-induced MIF in the occurrence and development of joint capsule fibrosis. Further investigation of the underlying mechanism may provide potential therapeutic targets for PTJC.     

Gualou Xiebai Banxia decoction ameliorates Poloxamer 407-induced hyperlipidemia

Ethnopharmacological relevance: Gualou Xiebai Banxia (GLXBBX) decoction is a well-known traditional Chinese herbal formula that was first discussed in the Synopsis of the Golden Chamber by Zhang Zhongjing in the Eastern Han Dynasty. In traditional Chinese medicine, GLXBBX is commonly prescribed to treat cardiovascular diseases, such as coronary heart disease and atherosclerosis.Objective: The present study aimed to examine GLXBBX’s preventative capacity and elucidate the potential molecular mechanism of Poloxamer 407 (P407)-induced hyperlipidemia in rats.Materials and methods: Both the control and model groups received pure water, and the test group also received a GLXBBX decoction. For each administration, 3 ml of the solution was administered orally. To establish hyperlipidemia, a solution mixed with 0.25 g/kg P407 dissolved in 0.9% normal saline was injected slowly into the abdominal cavity. At the end of the study, the rats’ plasma lipid levels were calculated using an automatic biochemical analyzer to evaluate the preventative capability of the GLXBBX decoction, and the serum and liver of the rats were collected.Results: The GLXBBX decoction significantly improved P407-induced hyperlipidemia, including increased plasma triglycerides (TGs), aspartate aminotransferase (AST) elevation, and lipid accumulation. Moreover, GLXBBX decoction treatment increased lipoprotein lipase (LPL) activity and mRNA expression of LPL. Furthermore, GLXBBX significantly suppressed the mRNA expression of stearoyl-CoA desaturase (SCD1).Conclusion: GLXBBX significantly improved P407-induced hyperlipidemia, which may have been related to enhanced LPL activity, increased LPL mRNA expression, and decreased mRNA expression of SCD1.     

The mRNA–miRNA–lncRNA Regulatory Network and Factors Associated with Prognosis Prediction of Hepatocellular Carcinoma

The aim of this study was to identify novel prognostic mRNA and microRNA (miRNA) biomarkers for hepatocellular carcinoma (HCC) using methods in systems biology. Differentially expressed mRNAs, miRNAs, and long non-coding RNAs (lncRNAs) were compared between HCC tumor tissues and normal liver tissues in The Cancer Genome Atlas (TCGA) database. Subsequently, a prognosis-associated mRNA co-expression network, an mRNA–miRNA regulatory network, and an mRNA–miRNA–lncRNA regulatory network were constructed to identify prognostic biomarkers for HCC through Cox survival analysis. Seven prognosis-associated mRNA co-expression modules were obtained by analyzing these differentially expressed mRNAs. An expression module including 120 mRNAs was significantly correlated with HCC patient survival. Combined with patient survival data, several mRNAs and miRNAs, including CHST4, SLC22A8, STC2, hsa-miR-326, and hsa-miR-21 were identified from the network to predict HCC patient prognosis. Clinical significance was investigated using tissue microarray analysis of samples from 258 patients with HCC. Functional annotation of hsa-miR-326 and hsa-miR-21-5p indicated specific associations with several cancer-related pathways. The present study provides a bioinformatics method for biomarker screening, leading to the identification of an integrated mRNA–miRNA–lncRNA regulatory network and their co-expression patterns in relation to predicting HCC patient survival.     

植物LEAFY 同源基因的研究进展

本文就近10年来LEAFY(简写为LFY)同源基因的研究进展做了综合分析。通过对19种植物中已分离到的LFY同源基因的序列比较分析发现: LFY同源基因编码区核苷酸和氨基酸序列同源性都较高;在双子叶植物基因组中, 拷贝数却有所不同。该基因的表达特性显示其在不同植物中表达的时间和空间有所差异。根据已知序列推导的氨基酸序列构建的系统进化树表明, 单子叶植物与裸子植物的亲缘关系近于双子叶与裸子植物的亲缘关系。上述研究资料为植物成花机理研究提供了重要参考, 且在研究植物系统进化方面也具有重要的意义。     

Culture and fusion of pollen protoplasts of Brassica oleracea L. var. italica with haploid mesophyll protoplasts of B. rapa L. ssp. pekinensis

Hybrid callus was formed from the successful protoplast fusion between pollen protoplasts of Brassica oleracea var. italica and haploid mesophyll protoplasts of Brassica rapa. The pollen protoplast isolation frequency in broccoli was highly related to the ratio of trinucleate pollens in the male gametophyte population. Large quantities of pollen protoplasts with high vigor could be isolated, and the isolation frequency reached up to 90% in 6.0-7.0 mm long flower buds with about 94.7% trinucleate-stage pollens. Pollen protoplasts could be collected and purified by discontinuous gradient centrifugation. In 1% Na-alginate embedding culture, cell divisions were observed but no further development was found. The haploid mesophyll protoplasts were isolated from in vitro haploid plants of B. rapa. Results strongly showed the variability in culturability of mesophyll protoplasts from different haploid lines. Both pollen protoplasts and haploid mesophyll protoplasts retained a stable round shape in the designed prefusion solution with an osmotic pressure of 0.74 osmol/kg. Polyethylene glycol was used for the protoplast fusion, and 40% polyethylene glycol 4000 enabled the highest fusion frequency of about 20%. Some postfusion protoplasts showed cell divisions up to callus proliferation. Calli were screened by random amplified polymorphic DNA analysis for their hybrid character. Results revealed the existence of the hybrid calli. Some of the hybrid calli grew well with green color and shoot primordia. According to our knowledge, this is the first report about a hybrid formation between two haploid protoplasts. Potential comprehensive applications, as well as problems of this technique, are discussed.     

Overexpression of BLCAP induces S phase arrest and apoptosis independent of p53 and NF-κB in human tongue carcinoma

Bladder cancer-associated protein gene (BLCAP) is a novel candidate tumor suppressor gene identified from the human bladder carcinoma. Our previous studies have shown that BLCAP overexpression could inhibit cell growth by inducing apoptosis in HeLa cells [Zuo Z, Zhao M, Liu J, Gao G, Wu X: Tumor Biol 27: 221–226, 2006]. Such evidence suggests the alterations in BLCAP may play an important role in tumorigenesis. To further study the biological function of the BLCAP gene, we constructed a recombinant retroviral vector encoding BLCAP cDNA. Overexpressed BLCAP, via stable infection of exogenous BLCAP, resulted in growth inhibition of the human tongue cancer cell line Tca8113 in vitro, accompanied by S phase cell cycle arrest and apoptosis. The growth inhibition was correlated with up-regulation of p21^WAF1/CIP1 expression and down-regulation of Bcl-XL and Bcl-2 expressions. However, p53 expression and NF-κB activity remained unchanged post infection. Furthermore, no changes in p53 phosphorylation at Ser46 and nuclear localization, which are critical to p53 function, were observed in BLCAP-overexpressed cells. Taken together, BLCAP may play a role not only in regulating cell proliferation but also in coordinating apoptosis and cell cycle via a novel way independent of p53 and NF-κB. Jun Yao and Li Duan contributed equally to this work.     

一种适合小花蝽实验观察的微养虫笼

介绍了一种适合小花蝽实验观察的新型微养虫笼.该微养虫笼利用透明的塑料培养皿(直径9 cm,高1.5 cm)、离心管(直径1.5 cm,高5 cm)和尼龙纱网(120目)制成.用封口膜和皮筋将微养虫笼封严,微养虫笼的离心管上锥一个小孔,便于加水.可用于小花蝽的基本生物学特性、群体饲养密度的确定、交配行为以及捕食行为、捕食量等试验研究.