Hypochlorite (ClO–) and singlet oxygen (1O2) commonly coexist in living systems and exert important interplaying roles in many diseases. To dissect their complex inter-relationship, it is urgently required to construct a fluorescent probe that can discriminate ClO– and 1O2 in living organisms. Herein, by taking the 3-(aliphaticthio)-propan-1-one group as the unique recognition unit for both ClO– and 1O2, we proposed the first fluorescent probe, Hy-2, to simultaneously discriminate ClO– and 1O2 with high sensitivity and selectivity. Probe Hy-2 itself showed fluorescence in blue channel. After treatment with ClO– and 1O2, respectively, pronounced fluorescence enhancements were observed in the green channel and red channel correspondingly. Moreover, upon development of the probe with aggregation-induced emission (AIE) characteristics, the probe could work well in a solution with high water volume fraction. Probe Hy-2 was also able to accumulate into mitochondria and was utilized as an effective tool to image exogenous and endogenous ClO– and 1O2 in mitochondria. Significantly, as the first trial, probe Hy-2 was employed to simultaneously monitor the variation of ClO– and 1O2 level in cecal tissues of rat in the cecal ligation and puncture (CLP)-induced polymicrobial sepsis model. The results demonstrated that the expressed ClO– and 1O2 levels were tightly correlated with the severity of sepsis, inferring that the overproduction of ClO– and 1O2 is an important factor in the pathogenesis of sepsis. The probe illustrated herein may provide a guide for further exploring the functions of ClO– and 1O2 in various diseases.

Tetramethylpyrazine (TMP) with significant protective effects on cardiovascular is the active ingredient of traditional Chinese medicine Rhizoma Chuanxiong (RC). However, many studies have reported the low content of TMP in RC. The endophytes of medicinal plants have the biosynthetic potential to produce the same or similar active metabolites as the host, while few reports were conducted to explore the endophytic bacteria of Ligusticum chuanxiong Hort. and its productive capacity for the important ingredient TMP. The present paper focuses on the isolation and identification of TMP producing endophytic bacteria from RC. In this study, the endophytic bacteria were isolated from the rhizome of Ligusticum chuanxiong Hort. (Umbelliferae). Yeast extract peptone glucose medium (YP) was used for fermentation medium (37 °C, 220 rpm agitation, 144 h). GC and GC/MS were performed to determine and verify the product, the fermentation characteristics were investigated. Morphological observation, physiological and biochemical indexes combining with 16S rRNA sequence analysis were carried out to identify the endophytic bacteria. As a result, five strains of endophytic Bacillus subtilis were firstly isolated and identified from RC, named as LB3, LB3-2-1, LB6-2, LB4, LB5 respectively. All five strains of endophytic B. subtilis produced TMP, while LB5 had the highest production of 10.69 g/L at the 144 h fermentation. This work demonstrates the fact that the endophytic B. subtilis of RC can produce a high level of TMP, indicating the endophytic B. subtilis might play a role in the accumulation of TMP during the growth period of RC.

Background: Several studies have shown that excessive protein degradation is a major cause of skeletal muscle atrophy induced by sepsis, and autophagy is the main pathway participating in protein degradation. However, the role of autophagy in sepsis is still controversial. Previously, we found that neuregulin-1b (NRG-1b) alleviated sepsis-induced diaphragm atrophy through the phosphatidylinositol-3 kinase signaling pathway. Akt/mechanistic target of rapamycin (mTOR) is a classic signaling pathway to regulate autophagy, which maintains intracellular homeostasis. This study aimed to investigate whether NRG-1b could alleviate sepsis-induced skeletal muscle atrophy by regulating autophagy. Methods: L6 rat myoblast cells were differentiated using 2% fetal bovine serum into myotubes, which were divided into four groups: Con group treated with normal serum; Sep group treated with septic serum to form a sepsis cell model; septic serum þ NRG-1b (SN) group treated with septic serum for 24 h followed by injection with NRG-1b and incubation for another 48 h; and serumþNRG-1bþLY294002 group, in which the PI3K inhibitor LY294002 was added 30 min before NRG-1b, and other treatments were similar to those in SN group. Effects of NRG-1b were also evaluated in vivo using Sprague-Dawley (SD) rats, in which sepsis was induced by cecal ligation and puncture (CLP). Results: In L6 myotubes treated with septic serum, the expression of autophagy-related proteins UNC-51 like kinase 1, p-Beclin-1, and Beclin-1, and the ratio of LC3B II/ I were highly increased, while protein p62 expression was decreased, indicating that autophagy was excessively activated. Moreover, NRG-1 expression was decreased, as detected by confocal immunofluorescence and western blotting. Upon exogenous addition of NRG-1b, autophagy was inhibited by the activation of Akt/mTOR signaling pathway, and cell viability was also increased. These effects disappeared in the presence of LY294002. In SD rats, sepsis was induced by CLP. NRG-1b was shown to inhibit autophagy in these rats via the Akt/mTOR pathway, leading to increased body weight of the septic SD rats and alleviation of atrophy of the tibialis anterior muscle. Conclusion: NRG-1b could alleviate sepsis-induced skeletal muscle atrophy by inhibiting autophagy via the AKT/mTOR signaling pathway.

The present study described a rapid method for readily detecting the total numbers of viable bacteria cells in various samples (including surface water, solid inoculants and soil samples) using an...

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