Inhibition of ATP-Induced Ca<Superscript>2+</Superscript> Influx by Corticosterone in Dorsal Root Ganglion Neurons

In addition to the classic genomic effects, it is well known that glucocorticoids also have rapid, nongenomic effects on neurons. In the present study, the effect of corticosterone (CORT) on ATP-induced Ca²⁺ mobilization in cultured dorsal root ganglion (DRG) neurons were detected with confocal laser scanning microscopy using fluo-4/AM as a calcium fluorescent indicator that could monitor real-time alterations of intracellular calcium concentration ([Ca²⁺]i). ATP, an algesic agent, caused [Ca²⁺]i increase in DRG neurons by activation of P2X receptor. Pretreatment with CORT (1 nM–1 μM for 5 min) inhibited ATP-induced [Ca²⁺]i increase in DRG neurons. The rapid inhibition of ATP-induced Ca²⁺ response by CORT was concentration-dependent, reversible and could be blocked by glucocorticoid receptor antagonist RU38486 (10 μM). Furthermore, the inhibitory effect of CORT was abolished by protein kinase A inhibitor H89 (10 μM), but was not influenced by protein kinase C inhibitor Chelerythrine chloride (10 μM). On the other hand, membrane-impermeable bovine serum albumin-conjugated corticosterone had no effect on ATP-induced [Ca²⁺]i transients. These observations suggest that a nongenomic pathways may be involved in the effect of CORT on ATP-induced [Ca²⁺]i transients in cultured DRG neurons.     

Disruption of myofibroblastic Notch signaling attenuates liver fibrosis by modulating fibrosis progression and regression

The phenotypic transformation of hepatic myofibroblasts (MFs) is involved in the whole process of the progression and regression of liver fibrosis. Notch signaling has been demonstrated to modulate the fibrosis. In this study, we found that Notch signaling in MFs was overactivated and suppressed with the progression and regression of hepatic fibrosis respectively, by detecting Notch signaling readouts in MFs. Moreover, we inactivated Notch signaling specifically in MFs with Sm22α^CreER-RBPj^flox/flox mice (RBPj^MF-KO), and identified that MFs-specific down-regulation of Notch signaling significantly alleviated CCl₄-induced liver fibrosis during the progression and regression. During the progression of liver fibrosis, MFs-specific blockade of Notch signaling inhibited the activation of HSCs to MFs and increases the expression of MMPs to reduce the deposition of ECM. During the regression of fibrosis, blocking Notch signaling in MFs increased the expression of HGF to promote proliferation in hepatocytes and up-regulated the expression of pro-apoptotic factors, Ngfr and Septin4, to induce apoptosis of MFs, thereby accelerating the reversal of fibrosis. Collectively, the MFs-specific disruption of Notch signaling attenuates liver fibrosis by modulating fibrosis progression and regression, which suggests a promising therapeutic strategy for liver fibrosis.     

Exploration of RNA 3' terminal locations in rat ribosome.

The locations of the 3' ends of RNAs in rat ribosome were studied by a fluorescence-labeling method combined with high hydrostatic pressure and agarose electrophoresis. Under physiological conditions, only the 3' ends of 28 S and 5.8 S RNA in 80 S ribosome could be labeled with a high sensitive fluorescent probe - fluorescein 5-thiosemicarbazide (FTSC), indicating that the 3' termini of 28 S and 5.8 S RNA were located on or near the surface of 80 S ribosome. The 3' terminus of 5 S RNA could be attacked by FTSC only in the case of the dissociation of the 80 S ribosome into two subunits induced by high salt concentration (1 M KCl) or at high hydrostatic pressure, showing that the 3' end of 5 S RNA was located on the interface of two subunits. However, no fluorescence-labeled 18 S RNA could be detected under all the conditions studied, suggesting that the 3' end of 18 S RNA was either located deeply inside ribosome or on the surface but protected by proteins. It was interesting to note that modifications of the 3' ends of ribosomal RNAs including oxidation with NaIO4, reduction with KBH4 and labeling with fluorescent probe did not destroy the translation activity of ribosome, indicating that the 3' ends of RNAs were not involved in the translation activity of ribosome.     

Interaction of MAGED1 with nuclear receptors affects circadian clock function

The circadian clock has a central role in physiological adaption and anticipation of day/night changes. In a genetic screen for novel regulators of circadian rhythms, we found that mice lacking MAGED1 (Melanoma Antigen Family D1) exhibit a shortened period and altered rest–activity bouts. These circadian phenotypes are proposed to be caused by a direct effect on the core molecular clock network that reduces the robustness of the circadian clock. We provide in vitro and in vivo evidence indicating that MAGED1 binds to RORα to bring about positive and negative effects on core clock genes of Bmal1, Rev‐erbα and E4bp4 expression through the Rev‐Erbα/ROR responsive elements (RORE). Maged1 is a non‐rhythmic gene that, by binding RORα in non‐circadian way, enhances rhythmic input and buffers the circadian system from irrelevant, perturbing stimuli or noise. We have thus identified and defined a novel circadian regulator, Maged1, which is indispensable for the robustness of the circadian clock to better serve the organism.     

Biochar-Induced Priming Effects in Young and Old Poplar Plantation Soils

The priming effect (PE) induced by biochar provides a basis for evaluating its carbon (C) sequestration potential in soils. A 60 days’ laboratory incubation was conducted, which involved the amendment of biochar (1% of soil mass) produced from rice straw at 300ºC (B300) and 500ºC (B500) to young (Y) and old (O) poplar plantation soils, with the aim of studying the responses of biochar-induced PEs to poplar plantation ages. This incubation included six treatments: Y + CK (control), Y + B300, Y + B500, O + CK, O + B300, and O + B500. Carbon dioxide (CO₂) emissions were significantly increased (p < 0.05) in the B300 amended soils, while it was decreased in the B500 amended soils compared to the CK. The primed CO₂ emissions were 2.35 times higher in the Y + B300 than the O + B300 treatments, which was measured to be 18.6 and 5.56 mg C·kg^-1 with relative PEs of 12.4% and 3.35%, respectively. However, there was little difference between the primed CO2 emissions in Y + B500 and O + B500 treatments, which were measured to be -24.9 and -29.6 mg·C·kg^-1 with relative PEs of -16.6% and -17.8%, respectively. Dissolved organic carbon (DOC) was significantly lower in the young poplar plantation soil than that in the old poplar plantation soil regardless of biochar amendment throughout the incubation, indicating greater C-limit of soil microorganisms in the young poplar plantation soil. Using ¹³C isotope tracing, neither B300 nor B500 decreased native soil-derived DOC, which indicated that the negative B500-induced PEs were not due to a reduction in the availability of native soil-derived C. In conclusion, the response of biochar-induced PEs to poplar plantation age depends on biochar types while soil available C indirectly affects biocharinduced PEs. Further studies should focus on how the interactive effects between soil C availability and microbial community impacts biochar-induced PEs.     

Circadian rhythm disorder: a potential inducer of vascular calcification?

Journal of Physiology and Biochemistry - Over the past decades, circadian rhythm has drawn a great attention in cardiovascular diseases. The expressions of rhythm genes fluctuate in accordance with...     

Exogenous hydrogen sulfide protects fatty liver against ischemia–reperfusion injury by regulating endoplasmic reticulum stress‐induced autophagy in macrophage through mediating the class A scavenger receptor pathway in rats

Fatty liver disease is a disease manifested with excessive alcohol intake and obese. Importantly, hydrogen sulfide (H₂S) has been revealed to participate in the progression of fatty liver; however, the underlying mechanism has not been clearly elucidated yet. In this study, we aimed to investigate the effects of exogenous H₂S on fatty liver ischemia–reperfusion injury (IRI) through mediating class A scavenger receptor (SRA) pathway in rats. By determining endoplasmic reticulum stress (ERS)‐related factors, autophagy markers and apoptosis‐related factors in liver tissue and liver function, levels of oxidative stress, inflammatory factors, and hepatocyte apoptosis, the effects of H₂S on IRI‐induced autophagy, oxidative stress, and inflammation were all examined in rat model of fatty liver IRI. Results from obtained data showed that H₂S decreased the expression of SRA, Grp78, PERK, CHOP, and Caspase‐3, and increased that of LC3‐II/LC3‐I, in addition to alleviating the pathological changes of liver and reducing the levels of ALT, AST, LDH TBARS, and MDA. Moreover, H₂S decreased the levels of oxidative stress, the expression of pro‐inflammatory factors including tumor necrosis factor α, interleukin 1, and interleukin 6, and the apoptosis of hepatocytes. Our findings suggested exogenous H₂S could reduce ERS by mediating the SRA pathway and protect liver function by inducing autophagy, and protect against IRI by reducing oxidative stress and inflammation.     

Pioglitazone attenuates advanced glycation end products‐induced apoptosis and calcification by modulating autophagy in tendon‐derived stem cells

Diabetes mellitus (DM) is one of the prominent risk factors for pathological development and progression of tendinopathy. One feature of DM‐related changes in tendinopathy is accumulation of advanced glycation end products (AGEs) in affected tendons. Pioglitazone (Pio), a peroxisome proliferator‐activated receptor γ agonist, performs a protective effect against AGEs. The present study aimed to investigate the pathogenetic role of AGEs on tendon‐derived stem cells (TDSCs) and to determine the effect of Pio on AGEs‐induced TDSC dysfunctions. Results indicated that AGEs induced TDSC apoptosis as well as compensatory activation of autophagy. Pharmacologic activation/inhibition of autophagy leaded to alleviate/exacerbate apoptosis induced by AGEs. We further confirmed the effect of Pio on autophagy, which ameliorated apoptosis and abnormal calcification caused by AGEs both in vitro and in vivo. Thus, we suggest that Pio ameliorates the dysfunctions of TDSCs against AGEs by promoting autophagy, and we also reveal that Pio is a potential pharmacological choice for tendinopathy.     

Data‐Independent Acquisition Mass Spectrometry‐Based Proteomics and Software Tools: A Glimpse in 2020

This review provides a brief overview of the development of data‐independent acquisition (DIA) mass spectrometry‐based proteomics and selected DIA data analysis tools. Various DIA acquisition schemes for proteomics are summarized first including Shotgun‐CID, DIA, MS^E, PAcIFIC, AIF, SWATH, MSX, SONAR, WiSIM, BoxCar, Scanning SWATH, diaPASEF, and PulseDIA, as well as the mass spectrometers enabling these methods. Next, the software tools for DIA data analysis are classified into three groups: library‐based tools, library‐free tools, and statistical validation tools. The approaches are reviewed for generating spectral libraries for six selected library‐based DIA data analysis software tools which are tested by the authors, including OpenSWATH, Spectronaut, Skyline, PeakView, DIA‐NN, and EncyclopeDIA. An increasing number of library‐free DIA data analysis tools are developed including DIA‐Umpire, Group‐DIA, PECAN, PEAKS, which facilitate identification of novel proteoforms. The authors share their user experience of when to use DIA‐MS, and several selected DIA data analysis software tools. Finally, the state of the art DIA mass spectrometry and software tools, and the authors’ views of future directions are summarized.