Progression of liver fibrosis requires sustained inflammation leading to hepatocytes apoptosis through ER stress, whereas associated with activation of hepatic stellate cells (HSCs) into a fibrogenic and proliferative cell type. Faced with persistent and massive ER stress, HSCs adaptation starts to fail and apoptosis occurs in reversal of liver fibrosis, possibly mediated through calcium perturbations, unfolded protein response, and the pro-apoptotic transcription factor CHOP. Although limited in scope, current studies underscored that ER stress is tightly linked to adaptation, inflammation and apoptosis, and recent evidences suggested that these processes are related to the pathogenesis of liver fibrosis and its recovery.
Recent reports considered that it was the disturbance of calcium homeostasis and the accumulation of misfolded proteins in the endoplasmic reticulum (ER) that activated hepatic stellate cells (HSCs) apoptosis and promoted fibrosis resolution. However, the signal-transducing events that are activated by ER stress after HSCs activation were incompletely understood. In this study, we induced ER stress with thapsigargin (TG), and determined the activation of calpain and the cleavage of caspase by analyzing the protein levels and the correspondingly increased intracellular calcium levels and the induction of the proapoptotic transcription factor CHOP. Moreover, the phosphorylation of JNK and p38 MAPK were followed by the activation of the executioner caspases, caspase-3. As expected, preventing an increase in intracellular calcium levels using intracellular calcium chelators, EGTA, and BAPTA/AM, could substantially inhibit the phosphorylation of JNK and p38 MAPK, abolish the activation of calpains, namely caspase-12, caspase-9, and caspase-3, and provide significant protection for TG-treated activated HSCs. Interestingly, pretreatment with p38 MAPK inhibitor SB202190, JNK inhibitor SP600125, the pan-caspase inhibitor z-VAD-FMK, or calpain inhibitors calpeptin, significantly reduced the cell apoptosis and the cleavage of caspase-12 and caspase-3. However, pretreatment with z-VAD-FMK failed to reduce the activation of calpain. Additionally, pretreatment with SB202190 and SP600125 also decreased the expression of CHOP. Importantly, PDGF-induced collagen Col1α1 and α-smooth muscle actin (α-SMA), markers for the perpetuation phase of HSCs activation, were inhibited in TG-treated activated HSCs. These findings showed that the Calpain/Caspase-12 activation induced by ER stress and the JNK/p38 MAPK phosphorylation induced by the increase of intracellular calcium concentration releasing from ER are the novel signaling pathway underlying the molecular mechanism of fibrosis recovery.
SUMMARYPhospholipase C (PLC) is an enzyme that plays crucial roles in various signal transduction pathways in mammalian cells. However, the role of PLC in plant development is poorly understood. Here we report involvement of PLC2 in auxin-mediated reproductive development in Arabidopsis. Disruption of PLC2 led to sterility, indicating a significant role for PLC2 in reproductive development. Development of both male and female gametophytes was severely perturbed in plc2 mutants. Moreover, elevated auxin levels were observed in plc2 floral tissues, suggesting that the infertility of plc2 plants may be associated with increased auxin concentrations in the reproductive organs. We show that expression levels of the auxin reporters DR5:GUS and DR5:GFP were elevated in plc2 anthers and ovules. In addition, we found that expression of the auxin biosynthetic YUCCA genes was increased in plc2 plants. We conclude that PLC2 is involved in auxin biosynthesis and signaling, thus modulating development of both male and female gametophytes in Arabidopsis.
Aims To synthesize evidences on smartphone application–based intervention and determine its effectiveness on glycaemic control, self‐management behaviours, psychological well‐being, quality of life and cardiometabolic risk factors. Design A systematic review and meta‐analysis of randomized controlled trials (RCTs). Data sources Major English and Chinese electronic databases were searched from January 2008 to January 2021, including PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials, Google Scholar, China National Knowledge Infrastructure (CNKI), Wanfang and Sinomed. Review methods RCTs were screened and selected if they used smartphone applications to support patients in the self‐management of diabetes. Data extraction and methodological assessment were performed by two reviewers independently. Meta‐analysis was performed to pool the intervention effect on outcomes of interest using RevMan 5.3. Results Across 19 included trials involving 2585 participants, smartphone application–based interventions were associated with a clinically and statistically significant reduction of glycated haemoglobin (HbA1c). Beneficial effects were also observed in participants’ behavioural performance, especially in medication adherence. Intervention effects on psychological status, quality of life and cardiometabolic risk factors were nonsignificant. Subgroup analysis showed interactive approach with medium frequency or flexible facilitator–patient interaction induced a larger effect on HbA1c reduction. Besides, patients with baseline HbA1c ≥9% benefited more than those with HbA1c <9% from the use of smartphone applications. Conclusions Smartphone application–based diabetes self‐management intervention could optimize patients’ glycaemic control and enhance participants’ self‐management performance. Further endeavour is required to examine the long‐term effects and cost‐effectiveness of smartphone application–based intervention before promoting the adoption and dissemination of such intervention. Impact This review supports the potential of smartphone application–based intervention as effective approach to optimize glycaemic control and promote self‐management engagement among patients with type 2 diabetes. Suggestions for future research and practice are provided and discussed.
Transient receptor potential melastatin 7 (TRPM7) is involved in both normal physiological processes and pathology of various diseases. The purpose of this study was to explore the function and underlying mechanisms of TRPM7 channels in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLSs) apoptosis induced by thapsigargin in vitro. In this study, using a combination of Western blotting, RT-PCR, and nuclear morphology analysis, we investigated the influence and potential function of TRPM7 channels on the apoptosis induced by thapsigargin in RA FLSs. Chemical inhibitors (Gd(3+) and 2-APB) and specific siRNA for TRPM7 were used to study the role of TRPM7 in RA FLSs apoptosis. The expression of TRPM7 was significantly potentiated in RA FLSs. Co-incubation of RA FLSs with Gd(3+), 2-APB, or TRPM7-siRNA increased cell apoptosis. Furthermore, we found that suppression of TRPM7 channels also increased the expression CHOP and calpain and decreased the expression caspase-3. We conclude that suppression of TRPM7 channels may increase RA FLSs apoptosis in vitro, and this is associated with endoplasmic reticulum (ER) stress. Therefore, inhibition of TRPM7 could activate ER stress and induce RA FLSs apoptosis.
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