MEF2C Alleviates Postoperative Cognitive Dysfunction by Repressing Ferroptosis.

BACKGROUND: Ferroptosis, a form of programmed cell death featured by lipid peroxidation, has been proposed as a potential etiology for postoperative cognitive dysfunction (POCD). Myocyte-specific enhancer factor 2C (MEF2C), a transcription factor expressed in various brain cell types, has been implicated in cognitive disorders. This study sought to ascertain whether MEF2C governs postoperative cognitive capacity by affecting ferroptosis. METHODS: Transcriptomic analysis of public data was used to identify MEF2C as a candidate differentially expressed gene in the hippocampus of POCD mice. The POCD mouse model was established via aseptic laparotomy under isoflurane anesthesia after treatment with recombinant adeno-associated virus 9 (AAV9)-mediated overexpression of MEF2C and/or the glutathione peroxidase 4 (GPX4) inhibitor RSL3. Cognitive performance, Nissl staining, and ferroptosis-related parameters were assessed. Dual-luciferase reporter gene assays and chromatin immunoprecipitation assays were implemented to elucidate the mechanism by which MEF2C transcriptionally activates GPX4. RESULTS: MEF2C mRNA and protein levels decreased in the mouse hippocampus following anesthesia and surgery. MEF2C overexpression ameliorated postoperative memory decline, hindered lipid peroxidation and iron accumulation, and enhanced antioxidant capacity, which were reversed by RSL3. Additionally, MEF2C was found to directly bind to the Gpx4 promoter and activate its transcription. CONCLUSIONS: Our findings suggest that MEF2C may be a promising therapeutic target for POCD through its negative modulation of ferroptosis.

Pharmacological inhibition of cGAS ameliorates postoperative cognitive dysfunction by suppressing caspase-3/GSDME-dependent pyroptosis.

Neuroinflammation is a major driver of postoperative cognitive dysfunction (POCD). The cyclic GMP-AMP synthase-stimulator of interferon gene (cGAS-STING) signaling is a prominent alarming device for aberrant double-stranded DNA (dsDNA) that has emerged as a key mediator of neuroinflammation in cognitive-related diseases. However, the role of the cGAS-STING pathway in the pathogenesis of POCD remains unclear. A POCD model was developed in male C57BL/6J mice by laparotomy under isoflurane (Iso) anesthesia. The cGAS inhibitor RU.521 and caspase-3 agonist Raptinal were delivered by intraperitoneal administration. BV2 cells were exposed to Iso and lipopolysaccharide (LPS) in the absence or presence of RU.521, and then cocultured with HT22 cells in the absence or presence of Raptinal. Cognitive function was assessed using the Morris water maze test and novel object recognition test. Immunofluorescence assays were used to observe the colocalization of dsDNA and cGAS. The downstream proteins and pro-inflammatory cytokines were detected using the Western blot and enzyme-linked immunosorbent assay (ELISA). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was used to assess the degree of cell death in the hippocampus following anesthesia/surgery treatment. Isoflurane/laparotomy and Iso + LPS significantly augmented the levels of cGAS in the hippocampus and BV2 cells, accompanied by mislocalized dsDNA accumulation in the cytoplasm. RU.521 alleviated cognitive impairment, diminished the levels of 2'3'-cGAMP, cGAS, STING, phosphorylated NF-κB p65 and NF-κB-pertinent pro-inflammatory cytokines (TNFα and IL-6), and repressed pyroptosis-associated elements containing cleaved caspase-3, N-GSDME, IL-1ß and IL-18. These phenotypes could be rescued by Raptinal in vivo and in vitro. These findings suggest that pharmacological inhibition of cGAS mitigates neuroinflammatory burden of POCD by dampening caspase-3/GSDME-dependent pyroptosis, providing a potential therapeutic strategy for POCD.

Regulating NCOA4-Mediated Ferritinophagy for Therapeutic Intervention in Cerebral Ischemia-Reperfusion Injury.

Ischemic stroke presents a global health challenge, necessitating an in-depth comprehension of its pathophysiology and therapeutic strategies. While reperfusion therapy salvages brain tissue, it also triggers detrimental cerebral ischemia-reperfusion injury (CIRI). In our investigation, we observed the activation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy in an oxygen-glucose deprivation/reoxygenation (OGD/R) model using HT22 cells (P < 0.05). This activation contributed to oxidative stress (P < 0.05), enhanced autophagy (P < 0.05) and cell death (P < 0.05) during CIRI. Silencing NCOA4 effectively mitigated OGD/R-induced damage (P < 0.05). These findings suggested that targeting NCOA4-mediated ferritinophagy held promise for preventing and treating CIRI. Subsequently, we substantiated the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway effectively regulated the NCOA4-mediated ferritinophagy, by applying the cGAS inhibitor RU.521 and performing NCOA4 overexpression (P < 0.05). Suppressing the cGAS-STING pathway efficiently curtailed ferritinophagy (P < 0.05), oxidative stress (P < 0.05), and cell damage (P < 0.05) of CIRI, while NCOA4 overexpression could alleviate this effect (P < 0.05). Finally, we elucidated the specific molecular mechanism underlying the protective effect of the iron chelator deferoxamine (DFO) on CIRI. Our findings revealed that DFO alleviated hypoxia-reoxygenation injury in HT22 cells through inhibiting NCOA4-mediated ferritinophagy and reducing ferrous ion levels (P < 0.05). However, the protective effects of DFO were counteracted by cGAS overexpression (P < 0.05). In summary, our results indicated that the activation of the cGAS-STING pathway intensified cerebral damage during CIRI by inducing NCOA4-mediated ferritinophagy. Administering the iron chelator DFO effectively attenuated NCOA4-induced ferritinophagy, thereby alleviating CIRI. Nevertheless, the role of the cGAS-STING pathway in CIRI regulation likely involves intricate mechanisms, necessitating further validation in subsequent investigations.

Overexpression of AtMYB2 Promotes Tolerance to Salt Stress and Accumulations of Tanshinones and Phenolic Acid in Salvia miltiorrhiza.

Salvia miltiorrhiza is a prized traditional Chinese medicinal plant species. Its red storage roots are primarily used for the treatment of cardiovascular and cerebrovascular diseases. In this study, a transcription factor gene AtMYB2 was cloned and introduced into Salvia miltiorrhiza for ectopic expression. Overexpression of AtMYB2 enhanced salt stress resistance in S. miltiorrhiza, leading to a more resilient phenotype in transgenic plants exposed to high-salinity conditions. Physiological experiments have revealed that overexpression of AtMYB2 can decrease the accumulation of reactive oxygen species (ROS) during salt stress, boost the activity of antioxidant enzymes, and mitigate oxidative damage to cell membranes. In addition, overexpression of AtMYB2 promotes the synthesis of tanshinones and phenolic acids by upregulating the expression of biosynthetic pathway genes, resulting in increased levels of these secondary metabolites. In summary, our findings demonstrate that AtMYB2 not only enhances plant tolerance to salt stress, but also increases the accumulation of secondary metabolites in S. miltiorrhiza. Our study lays a solid foundation for uncovering the molecular mechanisms governed by AtMYB2 and holds significant implications for the molecular breeding of high-quality S. miltiorrhiza varieties.

Biomimetic nano-chelate diethyldithiocarbamate Cu/Fe for enhanced metalloimmunity and ferroptosis activation in glioma therapy.

Ferroptosis has emerged as a promising therapeutic approach for glioma. However, its efficacy is often compromised by the activated GPX4-reduced glutathione (GSH) system and the poor brain delivery efficiency of ferroptosis inducers. Therefore, suppression of the GPX4-GSH axis to induce the accumulation of lipid peroxides becomes an essential strategy to augment ferroptosis. In this study, we present a metalloimmunological strategy to target the GPX4-GSH axis by inhibiting the cystine/glutamate antiporter system (system Xc-) and glutathione synthesis. To achieve this, we developed a complex of diethyldithiocarbamate (DDC) chelated with copper and ferrous ions (DDC/Cu-Fe) to trigger T-cell immune responses in the tumor microenvironment, as well as to inhibit tumor-associated macrophages, thereby alleviating immunosuppression. To enhance brain delivery, the DDC/Cu-Fe complex was encapsulated into a hybrid albumin and lactoferrin nanoparticle (Alb/LF NP), targeting the nutrient transporters (e.g., LRP-1 and SPARC) overexpressed in the blood-brain barrier (BBB) and glioma cells. The Alb/LF NP effectively promoted the brain accumulation of DDC/Cu-Fe, synergistically induced ferroptosis in glioma cells and activated anticancer immunity, thereby prolonging the survival of glioma-bearing mice. The nanoformulation of DDC/Cu-Fe provides a promising strategy that combines ferroptosis and metalloimmunology for glioma treatment.

Neuronal-specific TNFAIP1 ablation attenuates postoperative cognitive dysfunction via targeting SNAP25 for K48-linked ubiquitination.

BACKGROUND: Synaptosomal-associated protein 25 (SNAP25) exerts protective effects against postoperative cognitive dysfunction (POCD) by promoting PTEN-induced kinase 1 (PINK1)/Parkin-mediated mitophagy and repressing caspase-3/gasdermin E (GSDME)-mediated pyroptosis. However, the regulatory mechanisms of SNAP25 protein remain unclear. METHODS: We employed recombinant adeno-associated virus 9 (AAV9)-hSyn to knockdown tumor necrosis factor α-induced protein 1 (TNFAIP1) or SNAP25 and investigate the role of TNFAIP1 in POCD. Cognitive performance, hippocampal injury, mitophagy, and pyroptosis were assessed. Co-immunoprecipitation (co-IP) and ubiquitination assays were conducted to elucidate the mechanisms by which TNFAIP1 stabilizes SNAP25. RESULTS: Our results demonstrated that the ubiquitin ligase TNFAIP1 was upregulated in the hippocampus of mice following isoflurane (Iso) anesthesia and laparotomy. The N-terminal region (residues 1-96) of TNFAIP1 formed a conjugate with SNAP25, leading to lysine (K) 48-linked polyubiquitination of SNAP25 at K69. Silencing TNFAIP1 enhanced SH-SY5Y cell viability and conferred antioxidant, pro-mitophagy, and anti-pyroptosis properties in response to Iso and lipopolysaccharide (LPS) challenges. Conversely, TNFAIP1 overexpression reduced HT22 cell viability, increased reactive oxygen species (ROS) accumulation, impaired PINK1/Parkin-dependent mitophagy, and induced caspase-3/GSDME-dependent pyroptosis by suppressing SNAP25 expression. Neuron-specific knockdown of TNFAIP1 ameliorated POCD, restored mitophagy, and reduced pyroptosis, which was reversed by SNAP25 depletion. CONCLUSIONS: In summary, our findings demonstrated that inhibiting TNFAIP1-mediated degradation of SNAP25 might be a promising therapeutic approach for mitigating postoperative cognitive decline. Video Abstract.

Simultaneous Promotion of Salt Tolerance and Phenolic Acid Biosynthesis in Salvia miltiorrhiza via Overexpression of Arabidopsis MYB12.

Transcription factors play crucial roles in regulating plant abiotic stress responses and physiological metabolic processes, which can be used for plant molecular breeding. In this study, an R2R3-MYB transcription factor gene, AtMYB12, was isolated from Arabidopsis thaliana and introduced into Salvia miltiorrhiza under the regulation of the CaMV35S promoter. The ectopic expression of AtMYB12 resulted in improved salt tolerance in S. miltiorrhiza; transgenic plants showed a more resistant phenotype under high-salinity conditions. Physiological experiments showed that transgenic plants exhibited higher chlorophyll contents, and decreased electrolyte leakage and O2- and H2O2 accumulation when subjected to salt stress. Moreover, the activity of reactive oxygen species (ROS)-scavenging enzymes was enhanced in S. miltiorrhiza via the overexpression of AtMYB12, and transgenic plants showed higher superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities compared with those of the wild type (WT) under salt stress, coupled with lower malondialdehyde (MDA) levels. In addition, the amount of salvianolic acid B was significantly elevated in all AtMYB12 transgenic hair roots and transgenic plants, and qRT-PCR analysis revealed that most genes in the phenolic acid biosynthetic pathway were up-regulated. In conclusion, these results demonstrated that AtMYB12 can significantly improve the resistance of plants to salt stress and promote the biosynthesis of phenolic acids by regulating genes involved in the biosynthetic pathway.

Inhibition of PINK1-Mediated Mitophagy Contributes to Postoperative Cognitive Dysfunction through Activation of Caspase-3/GSDME-Dependent Pyroptosis.

PTEN-induced kinase 1 (PINK1)-mediated mitophagy and caspase-1/gasdermin D canonical pyroptosis pathways have been implicated in the pathogenesis of postoperative cognitive dysfunction (POCD). However, gasdermin E (GSDME), another recently identified executioner of pyroptosis that can be specifically cleaved by caspase-3, is highly expressed in the brain and neurons. This study aimed to ascertain whether PINK1-dependent mitophagy governs postoperative cognitive capacity through caspase-3/GSDME. Twelve month old male Sprague-Dawley rats underwent exploratory laparotomy under isoflurane anesthesia. Lipopolysaccharide (LPS)-primed SH-SY5Y cells were used to mimic postsurgical neuroinflammation. For the interventional study, rats were administered with adeno-associated virus serotype 9 (AAV9)-mediated silencing of Pink1 and/or caspase-3 inhibitor Ac-DEVD-CHO (Ac-DC). SH-SY5Y cells were treated with siPINK1 and/or Ac-DC. Cognitive performance was assessed using the Morris water maze test. The mitophagy- and pyroptosis-related parameters were determined in the hippocampus and SH-SY5Y cells. Anesthesia/surgery and LPS caused defective PINK1-mediated mitophagy and activation of caspase-3/GSDME-dependent pyroptosis. AAV-9 mediated Pink1 overexpression mitigated cognitive impairment and caspase-3/GSDME-dependent pyroptosis. Conversely, inhibition of PINK1 aggravates POCD and overactivates neuronal pyroptosis. These abnormalities were rescued by Ac-DC treatment. Collectively, PINK1-mediated mitophagy regulates anesthesia and surgery-induced cognitive impairment by negatively affecting the caspase-3/GSDME pyroptosis pathway, which provides a promising therapeutic target for POCD.

Dexmedetomidine infusion for emergence coughing prevention in patients undergoing an endovascular interventional procedure: A randomized dose-finding trial.

OBJECTIVE: Dexmedetomidine has been introduced in emergence coughing, agitation, and shivering prevention. This study aimed to investigate the optimal dose of dexmedetomidine for emergence cough prophylaxis. METHODS: In this randomized, double-blinded, and prospective trial, 356 patients scheduled for an endovascular interventional procedure were randomly assigned to 0.3 (D 0.3), 0.4 (D 0.4), 0.5 (D 0.5), and 0.6 (D 0.6) µg·kg-1·h-1 dexmedetomidine rate, or saline control (C), from anesthesia induction until the end of surgery. The primary outcomes measured were cough grade and frequency. Additionally, groups were compared according to mean arterial pressure (MAP), heart rate, agitation, shivering, postoperative nausea and vomiting (PONV), extubation time, sedation scores, and postoperative first night sleep quality (secondary outcomes). RESULTS: A total of 351 patients were included in the analysis. The respective incidences of D 0.3, D 0.4, and D 0.5 versus C group were: 78.6%, 68.6%, 53.4% and 42.9% vs 89.7% for cough (p = 0.002, p < 0.001, and p < 0.001 between group D 0.4, D 0.5 and D 0.6 vs C, respectively); 30%, 27.1%, 20.5%, 15.7% vs 44.1% for agitation (p = 0.04, p = 0.003, and p < 0.001 between group D 0.4, D 0.5 and D 0.6 vs C, respectively); 8.6%, 7.1%, 6.8%, 5.7% vs 22.1% for shivering (p = 0.027, p = 0.013, p = 0.01, and p = 0.01 between D 0.3, D 0.4, D 0.5 and D 0.6 vs C, respectively); and 52.9%, 57.1%, 42.5%, 44.3% vs 61.8% for poor sleep quality (p = 0.02 and p = 0.04 between group D 0.5 and D 0.6 vs C, respectively). D 0.4, D 0.5 and D 0.6 showed lower MAP during extubation, compared with the C group. Also, D 0.5 and D 0.6 presented a slight delay in extubation (3.1 and 3.3 min longer than C; p = 0.002 and p < 0.001, respectively). Meanwhile, the frequency of atropine, vasopressor administration, PONV and dizziness were similar to the control. CONCLUSIONS: Both 0.5 and 0.6 µg·kg-1·h-1 dexmedetomidine infusion rates effectively mitigated emergence coughing with prolonged extubation time, besides sleep disturbance. D 0.4, D 0.5, and D 0.6 reduced agitation and sustained hemodynamic stability. Finally, the four doses applied were effective in shivering attenuation.

Ultrasound-guided parasternal intercostal nerve block for postoperative analgesia in mediastinal mass resection by median sternotomy: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Ultrasound-guided parasternal intercostal nerve block is rarely used for postoperative analgesia, and its value remains unclear. This study aimed to evaluate the effectiveness of ultrasound-guided parasternal intercostal nerve block for postoperative analgesia in patients undergoing median sternotomy for mediastinal mass resection. METHODS: This randomized, double-blind, placebo-controlled trial performed in Renmin Hospital, Wuhan University, enrolled 41 participants aged 18-65 years. The patients scheduled for mediastinal mass resection by median sternotomy were randomly assigned were randomized into 2 groups, and preoperatively administered 2 injections of ropivacaine (PSI) and saline (control) groups, respectively, in the 3rd and 5th parasternal intercostal spaces with ultrasound-guided (USG) bilateral parasternal intercostal nerve block. Sufentanil via patient-controlled intravenous analgesia (PCIA) was administered to all participants postoperatively. Pain score, total sufentanil consumption, and postoperative adverse events were recorded within the first 24 h. RESULTS: There were 20 and 21 patients in the PSI and control group, respectively. The PSI group required 20% less PCIA-sufentanil compared with the control group (54.05 ± 11.14 µg vs. 67.67 ± 8.92 µg, P < 0.001). In addition, pain numerical rating scale (NRS) scores were significantly lower in the PSI group compared with control patients, both at rest and upon coughing within 24 postoperative hours. Postoperative adverse events were generally reduced in the PSI group compared with controls. CONCLUSIONS: USG bilateral parasternal intercostal nerve block effectively reduces postoperative pain and adjuvant analgesic requirement, with good patient satisfaction, therefore constituting a good option for mediastinal mass resection by median sternotomy.

Sleep Disturbance and Psychological Profiles of Medical Staff and Non-Medical Staff During the Early Outbreak of COVID-19 in Hubei Province, China.

OBJECTIVE: The outbreak of coronavirus disease 2019 (COVID-19) has considerably burdened the healthcare system in the Hubei Province, the most severely affected region in China. The aim of our study was to assess the psychological effects of COVID-19 epidemic on the healthcare workers in Hubei. METHODS: A total of 2737 healthcare workers were sampled using a two-dimensional code shared online between Mar 4 and Mar 9, 2020. The questionnaires consisted of three elements: baseline characteristics, Pittsburgh Sleep Quality Index (PSQI), and Hospital Anxiety and Depression Scale (HADS). The primary outcome variables were PQSI, anxiety and depression scores of non-medical staff, non-frontline medical staff and frontline medical staff. Binary logistical regression analyses were used to compare between respondents with and without sleep disturbance. RESULTS: About 61.6% of the respondents reported sleep problems, 22.6% experienced anxiety, and 35% exhibited depressive symptoms. The prevalence of sleep disorders was higher among the frontline healthcare workers compared to the non-frontline and non-medical staff, while anxiety and depression were prevalent in the entire cohort. Logistic regression analysis identified medical occupation, family burden, bereavement, anxiety, and depression as significantly predictive of poor sleep quality. CONCLUSIONS: Frontline medical staff are more vulnerable to sleep disturbances. Psychosocial interventions are needed to help allied healthcare personnel to better respond to COVID-19 and future outbreaks.

Parasternal Intercostal Block Complementation Contributes to Postoperative Pain Relief in Modified Radical Mastectomy Employing Pectoral Nerve Block I and Serratus-Intercostal Block: A Randomized Trial.

PURPOSE: Pectoral nerve block I (PECS I) and serratus-intercostal plane block (SIPB) can anesthetize the majority mammary region, while parasternal intercostal block (PSI) targets the internal area during breast resection surgery. The aim of this study was to determine whether including PSI with PECS I and SIPB is more effective compared to PECS I and SIPB alone. PATIENTS AND METHODS: Sixty-two adult females undergoing unilateral modified radical mastectomy (MRM) were randomly assigned to receive either PECS I and SIPB (PS group, n=31) or a combination of PECS I, SIPB, and PSI (PSP group, n=31). The outcomes were measured with a numerical rating scale (NRS) score, and in terms of opioid consumption and anesthesia-related complications within 48 h after surgery. RESULTS: Although there were no differences in the NRS scores between the two groups during the inactive periods, the combination of three nerve blocks significantly reduced the NRS scores during movement. In addition, morphine equivalent consumption was lower in the PSP group compared to the PS group. Postoperative adverse events were similar in both groups in terms of regional anesthesia-related complications. CONCLUSION: The combination of PECS I block, SIPB, and PSI block provides superior pain relief and postoperative recovery for patients undergoing MRM.

Knockout of the OsNAC006 Transcription Factor Causes Drought and Heat Sensitivity in Rice.

Rice (Oryza sativa) responds to various abiotic stresses during growth. Plant-specific NAM, ATAF1/2, and CUC2 (NAC) transcription factors (TFs) play an important role in controlling numerous vital growth and developmental processes. To date, 170 NAC TFs have been reported in rice, but their roles remain largely unknown. Herein, we discovered that the TF OsNAC006 is constitutively expressed in rice, and regulated by H2O2, cold, heat, abscisic acid (ABA), indole-3-acetic acid (IAA), gibberellin (GA), NaCl, and polyethylene glycol (PEG) 6000 treatments. Furthermore, knockout of OsNAC006 using the CRISPR-Cas9 system resulted in drought and heat sensitivity. RNA sequencing (RNA-seq) transcriptome analysis revealed that OsNAC006 regulates the expression of genes mainly involved in response to stimuli, oxidoreductase activity, cofactor binding, and membrane-related pathways. Our findings elucidate the important role of OsNAC006 in drought responses, and provide valuable information for genetic manipulation to enhance stress tolerance in future plant breeding programs.

Universal stress protein in Malus sieversii confers enhanced drought tolerance.

Drought is an important environmental factor that can severely affect plant growth and reproduction. Although many genes related to drought tolerance have been studied in economically important crops, very few genes have been functionally identified in Malus sieversii. In this study, we isolated a new gene based on throughput RNA sequencing analysis and constructed genetic expression vectors and transformed in Arabidopsis thaliana for functional verification. The results showed that MsUspA ectopic expression driven by constitutive (CaMV 35S) promoter gave rise to substantial improvements in ability of transgenic A. thaliana plants to survive under extreme drought conditions. Improved drought resistance mainly depends on more compact cellular structure, longer roots, strong resilience and low-level ROS. Molecular expression analysis showed that MsUspA may be involved in hormone and secondary metabolite synthesis regulation to improve drought resistance.

Ultrasound-Guided Pectoral Nerve Block I and Serratus-Intercostal Plane Block Alleviate Postoperative Pain in Patients Undergoing Modified Radical Mastectomy.

BACKGROUND: Simultaneous application of pectoral nerve block and serratus-intercostal plane block (SPB) is one of the most desirable multimodal analgesic strategies, with wide implementation of the enhanced recovery after surgery pathway for modified radical mastectomy (MRM). OBJECTIVES: The aim of the present study was to investigate the efficacy and safety of ultrasound-guided pectoral nerve block I (PECS I) and SPB for postoperative analgesia following MRM. STUDY DESIGN: A randomized, prospective study. SETTING: An academic medical center. METHODS: A total of 61 women undergoing MRM were randomly divided into 2 groups. The control group (group C, n = 32) received general anesthesia only, whereas the PECS I + SPB treated group (group PS, n = 29) received a combination of pectoral nerve block and SPB in addition to general anesthesia. RESULTS: Pain scores on a visual analog scale, opioid consumption, the duration at the postanesthesia care unit, and the incidence of adverse events were lower in group PS, compared with that of the group C. Moreover, PECS I together with SPB contributed to better sleep quality and higher patient satisfaction of pain relief. LIMITATIONS: This study was limited by its sample size. CONCLUSIONS: These results suggest that the combination of PECS I and SPB provide superior perioperative pain relief in breast cancer surgery. KEY WORDS: Pectoral nerve block, serratus-intercostal plane block, postoperative analgesia, modified radical mastectomy.

Enhancement of tanshinone production in Salvia miltiorrhiza hairy root cultures by metabolic engineering.

BACKGROUND: Tanshinones are diterpenoid compounds that are used to treat cardiovascular diseases. As current extraction methods for tanshinones are inefficient, there is a pressing need to improve the production of these bioactive compounds to meet increasing demand. RESULTS: Overexpression of SmMDS (2-c-methyl-d-erythritol 2,4-cyclodiphosphate synthase, a tanshinone biosynthesis gene) in transgenic Salvia miltiorrhiza hairy roots significantly increased the tanshinone yield compared to the control, and total tanshinone content in SmMDS-overexpressing lines increased after elicitor treatment. Total tanshinones increased to 2.5, 2.3, and 3.2 mg/g DW (dry weight) following treatment with Ag+, YE (yeast extract), and MJ (methyl jasmonate), respectively, compared with the non-induced transgenic line (1.7 mg/g DW). Also, qRT-PCR analysis showed that the expression levels of two pathway genes was positively correlated with increased accumulation of tanshinone. CONCLUSIONS: Our study provides an effective strategy for increasing the content of tanshinones and other natural compounds using a combination of genetic engineering and elicitor treatment.

Identification of Glutathione Peroxidase (GPX) Gene Family in Rhodiola crenulata and Gene Expression Analysis under Stress Conditions.

Glutathione peroxidases (GPXs) are important enzymes in the glutathione-ascorbate cycle for catalyzing the reduction of H2O2 or organic hydroperoxides to water. GPXs play an essential role in plant growth and development by participating in photosynthesis, respiration, and stress tolerance. Rhodiola crenulata is a popular traditional Chinese medicinal plant which displays an extreme energy of tolerance to harsh alpine climate. The GPXs gene family might provide R. crenulata for extensively tolerance to environment stimulus. In this study, five GPX genes were isolated from R. crenulata. The protein amino acid sequences were analyzed by bioinformation softwares with the results that RcGPXs gene sequences contained three conserve cysteine residues, and the subcellular location predication were in the chloroplast, endoplasmic reticulum, or cytoplasm. Five RcGPXs members presented spatial and temporal specific expression with higher levels in young and green organs. And the expression patterns of RcGPXs in response to stresses or plant hormones were investigated by quantitative real-time PCR. In addition, the putative interaction proteins of RcGPXs were obtained by yeast two-hybrid with the results that RcGPXs could physically interact with specific proteins of multiple pathways like transcription factor, calmodulin, thioredoxin, and abscisic acid signal pathway. These results showed the regulation mechanism of RcGPXs were complicated and they were necessary for R. crenulata to adapt to the treacherous weather in highland.

Ectopic Overexpression of bol-miR171b Increases Chlorophyll Content and Results in Sterility in Broccoli ( Brassica oleracea L var. italica).

MiR171 plays pleiotropic roles in the growth and development of several plant species. However, the mechanism underlying the miR171-mediated regulation of organ development in broccoli remains unknown. In this study, bol-miR171b was characterized and found to be differentially expressed in various broccoli organs. The ectopic overexpression of bol-miR171b in Arabidopsis affected the leaf and silique development of transgenic lines. In particular, the chlorophyll content of leaves from overexpressed bol-miR171b transgenic Arabidopsis was higher than that of the vector controls. The fertility and seed yield of Arabidopsis with overexpressed bol-miR171b were markedly lower than those of the vector controls. Similarly, overexpressed bol-miR171b transgenic broccoli exhibited dark green leaves with high chlorophyll content, and nearly all of the flowers were sterile. These results demonstrated that overexpression of bol-miR171b could increase the chlorophyll content of transgenic plants. Degradome sequencing was conducted to identify the targets of bol-miR171b. Two members of the GRAS gene family, BolSCL6 and BolSCL27, were cleaved by bol-miR171b-3p in broccoli. In addition to the genes targeted by bol-miR171b-3p, adenylylsulfate reductase 3 ( APSR3), which played important roles in plant sulfate assimilation and reduction, was speculated to be cleaved by bol-miR171b-5p, suggesting that the star sequence of bol-miR171b may also have functions in broccoli. Comparative transcriptome analysis further revealed that the genes involved in chloroplast development and sulfate homeostasis should participate in the bol-miR171b -mediated regulatory network. Taken together, these findings provided new insights into the function and regulation of bol-miR171b in broccoli and indicated the potential of bol-miR171b as a small RNA molecule that increased leaf chlorophyll in plants by genetic engineering.

Transcriptome and DNA methylome reveal insights into yield heterosis in the curds of broccoli (Brassica oleracea L var. italic).

BACKGROUND: Curds are the main edible organs, which exhibit remarkable yield heterosis in F1 hybrid broccoli. However, the molecular basis underlying heterosis in broccoli remains elusive. RESULTS: In the present study, transcriptome profiles revealed that the hybridization made most genes show additive expression patterns in hybrid broccoli. The differentially expressed genes including the non-additively expressed genes detected in the hybrid broccoli and its parents were mainly involved in light, hormone and hydrogen peroxide-mediated signaling pathways, responses to stresses, and regulation of floral development, which suggested that these biological processes should play crucial roles in the yield heterosis of broccoli. Among them, light and hydrogen peroxide-mediated signaling pathways represent two novel classes of regulatory processes that could function in yield or biomass heterosis of plants. Totally, 53 candidate genes closely involved in curd yield heterosis were identified. Methylome data indicated that the DNA methylation ratio of the hybrids was higher than that of their parents. However, the DNA methylation levels of most sites also displayed additive expression patterns. These sites with differential methylation levels were predominant in the intergenic regions. In most cases, the changes of DNA methylation levels in gene regions did not significantly affect their expression levels. CONCLUSIONS: The differentially expressed genes, the regulatory processes and the possible roles of DNA methylation modification in the formation of curd yield heterotic trait were discovered. These findings provided comprehensive insights into the curd yield heterosis in broccoli, and were significant for breeding high-yield broccoli varieties.