Proline, a multifaceted signalling molecule in plant responses to abiotic stress: understanding the physiological mechanisms

Abiotic stresses have a detrimental impact on plant growth and productivity and are a major threat to sustainable crop production in rapidly changing environments. Proline, an important amino acid, plays an important role in maintaining the metabolism and growth of plants under abiotic stress conditions. Many insights indicate a positive relationship between proline accumulation and tolerance of plants to various abiotic stresses. Because of its metal chelator properties, it acts as a molecular chaperone, an antioxidative defence molecule that scavenges reactive oxygen species (ROS), as well as having signalling behaviour to activate specific gene functions that are crucial for plant recovery from stresses. It also acts as an osmoprotectant, a potential source to acquire nitrogen as well as carbon, and plays a significant role in the flowering and development of plants. Overproduction of proline in plant cells contributes to maintaining cellular homeostasis, water uptake, osmotic adjustment and redox balance to restore the cell structures and mitigate oxidative damage. Many reports reveal that transgenic plants, particularly those overexpressing genes tailored for proline accumulation, exhibit better adaptation to abiotic stresses. Therefore, this review aims to provide a comprehensive update on proline biosynthesis and accumulation in plants and its putative regulatory roles in mediating plant defence against abiotic stresses. Additionally, the current and future directions in research concerning manipulation of proline to induce gene functions that appear promising in genetics and genomics approaches to improve plant adaptive responses under changing climate conditions are also highlighted.

[Comprehensive treatment options and influencing factors in elderly patients with breast cancer]

Objective: To investigate the treatment options for breast cancer patients aged 65 and over, and analyze the influencing factors. Methods: The clinical data of 521 elderly patients aged 65 years or older,who underwent surgery in Peking Union Medical College Hospital from January 2009 to December 2015, were collected. They were all female and 65-98 years old. The patients were divided into 65-74 years old group (n=353) and ≥ 75 years old group (n=168). The differences of variables including age, functional status, treatment methods, pathological characteristics, comorbidities and survival time between the two groups were compared, and the differences of comprehensive treatment methods and their impact on clinical efficacy were analyzed. Results: The main operation methods of the two groups were modified radical mastectomy [39.1% (138/353) and 33.9% (57/168), respectively], breast conserving surgery [56.9% (201/353) and 61.3% (103/353), respectively]. Among the patients choosing adjuvant therapy, there was no significant difference between the two groups except chemotherapy (all P>0.05). Univariate analysis showed that the choice of chemotherapy was related to age, surgical methods, pathological types, tumor burden, molecular typing, functional status and comorbidities (all P<0.05). The Eastern Cooperative Oncology Group (ECOG) score and the number of comorbidities were independent factors affecting the choice of chemotherapy for breast cancer in the elderly: [ECOG score: adjusted OR=0.45 (95CI: 0.26-0.75), number of comorbidities: adjusted OR = 0.63 (95CI:0.41-0.98); all P<0.05]. The 5-year disease-free survival rate of 521 elderly patients with breast cancer was 86.3%, 5-year overall survival rate was 88.8%, and the breast cancer specific survival rate was 94.3%. Conclusions: The comprehensive treatment of breast cancer patients aged 65 and above is not affected by age, but is associated with tumor burden, pathological type, molecular typing, comorbidities and ECOG score. Among them, ECOG score and the number of comorbidities are the independent factors influencing the choice of adjuvant chemotherapy.

[Attenuated Herpes simplex virus 1 vector expressing oncomodulin effectively allieviates mechanical optic nerve injury in rats]

OBJECTIVE

To evaluate the efficacy and safety of attenuated Herpes simplex virus 1 (HSV-1) vector expressing oncomodulin (OCM) for treatment of mechanical optic nerve injury in rats.

METHODS

The proliferation characteristics and OCM expression of the recombinant HSV-1 vector (1716-OCM) was assessed in cultured Vero cells. Twelve-week-old SD rats were randomly divided into control group, 1716-OCM injection group and wild-type virus corneal infection group, and at 7, 14, 30 and 60 days post-infection (3 rats in each group at each time point), the expressions of OCM and HSV-1 structural protein gB in the retina and the hypothalamus of the rats were detected using immunofluorescence assay. Another 20 rats were randomized into sham operation group, PBS treatment group, 1716-OCM infection group and 1716-OCM infection with cAMP sensitization group (n=5), and in the latter 3 groups, rat models of optic nerve injury models were established followed by intravitreal injection of PBS, 1716-OCM or cAMP as indicated. At 45 days after the treatments, the rats were examined for visual electrophysiological function using FVEP method, and the number of retinal ganglion cells (RGCs) and the expression of myelin basic protein in the optic nerve were detected using immunofluorescence assay.

RESULTS

The recombinant 1716-OCM vector was capable of mediating effective expression of OCM in Vero cells in vitro, but its proliferation rate was much lower than that of the wild-type virus. In SD rats, the recombinant virus could mediate the expression of OCM in the RGC layer and choroid layer of the eyes without inducing significant structural damage of the eyes as compared with the wild-type virus. In rat models of optic nerve injury, 1716-OCM combined with cAMP significantly promoted the survival of retinal RGCs (P= 0.007) and inhibited demyelination of the optic nerve (P=0.03) as compared with the mock treatment. FVEP analysis showed that 1716-OCM combined with cAMP significantly promoted the recovery of the peak amplitude of ΔN1-P1 in the rats (P < 0.0001).

CONCLUSION

Attenuated recombinant 1716-OCM vector can mediate OCM expression in the retina of rats, and in rat models of mechanical optic nerve injury, intravitreal injection of 1716-OCM combined with cAMP can effectively alleviate optic nerve injuries.

Nitrate increases cisplatin chemosensitivity of oral squamous cell carcinoma via REDD1/AKT signaling pathway

Although cisplatin is one of the chemotherapeutics most frequently used in oral squamous cell carcinoma (OSCC) treatment, it exerts multiple side effects and poor chemosensitivity. Nitrate reportedly demonstrates several beneficial biological functions, and synthesized nitrates enhance the therapeutic efficacy of chemotherapy. However, the role of inorganic nitrate in cisplatin chemotherapy remains unclear. We therefore investigated the effect of inorganic nitrate exerted on cisplatin sensitivity in OSCC. We found that nitrate did not affect OSCC cell growth and apoptosis in OSCC cells and OSCC xenograft tumor animal studies. Cisplatin induced REDD1 expression and AKT activation in OSCC. However, nitrate could increase cisplatin chemosensitivity, reduce its REDD1 expression, and attenuate AKT signaling activation in OSCC cells. Dysregulation of high levels of REDD1, which could enhance AKT activation, was positively associated with poor prognosis in OSCC patients. Thus, reduced REDD1 expression and retarded AKT activation induced by inorganic nitrate might be a new potential approach to the sensitization of oral cancer to cisplatin treatment in the future.

Establishment and verification of a nomogram for predicting severe acute pancreatitis

OBJECTIVE

The purpose of this study was to establish a nomogram for predicting the severity of acute pancreatitis (AP) and verify its predictive value.

PATIENTS AND METHODS

A total of 571 AP patients received by Ordos Central Hospital from January 2015 to December 2018 were included in this study. According to the 2012 Revised Atlanta classification, the included subjects were classified into severe AP (SAP) group and non-severe AP (NSAP) group [including patient with mild AP (MAP) and moderately SAP (MSAP)]. The baseline characteristics, imageological data and pathological data within 24 h after the disease onset between the two groups were analyzed using One-way analysis of variance (one-way ANOVA). R language was used for establishing a predictive nomogram, whose performance was verified by clinical data of 150 AP cases collected from December 2018 to December 2019.

RESULTS

One-way ANOVA shows that SAP and NSAP patients show significant differences in sex, calcium ions, creatinine, neutrophils ratio, lymphocytes ratio and eosinophils ratio (p<0.05). A predictive nomogram was accordingly established using the six indicators. Validation on this predictive nomogram showed high internal validation concordance index (C-index) of 0.69 (95% CI, 0.64-0.74), and high external validation C-index of 0.71 (95% CI, 0.67-0.76).

CONCLUSIONS

This nomogram can be used as a clinical tool to predict the severity of SAP.

Reduced MAGI3 level by HPV18E6 contributes to Wnt/β-catenin signaling activation and cervical cancer progression

Human papillomavirus type 18 (HPV18) has high carcinogenic power in invasive cervical cancer (ICC) development. However, the underlying mechanism remains elusive. The carcinogenic properties of HPV18 require the PDZ‐binding motif of its E6 oncoprotein (HPV18 E6) to degrade its target PSD95/Dlg/ZO‐1 (PDZ) proteins. In this study, we demonstrated that the PDZ protein membrane‐associated guanylate kinase, WW and PDZ domain containing 3 (MAGI3) inhibited the Wnt/β‐catenin pathway, and subsequently cervical cancer (CC) cell migration and invasion, via decreasing β‐catenin levels. By reducing MAGI3 protein levels, HPV18 E6 promoted CC cell migration and invasion through activation of Wnt/β‐catenin signaling. Furthermore, HPV18 rather than HPV16 was preferentially associated with the downregulation of MAGI3 and activation of the Wnt/β‐catenin pathway in CC. These findings shed light on the mechanism that gives HPV18 its high carcinogenic potential in CC progression.

Psychological stress and its correlates in Chinese patients with acute coronary syndrome

Funding Acknowledgements

None.

Background

Psychological stress is associated with high incidence of coronary heart disease and increases the risk of mortality and poor health status. Although a few studies have investigated psychological stress in this population, this problem is usually unrecognized and untreated in most Chinese patients with acute coronary syndrome. There is insufficient information regarding the features of psychological stress and associated factors among this population.

Purpose

This study aimed to assess the level of psychological stress and to identify its correlates in Chinese patients with acute coronary syndrome.

Methods

Patients aged over 18 years and with acute coronary syndrome were invited to participate in a cross-sectional survey in two tertiary public hospitals in China, from June to July 2019. A total of 332 patients completed measures of sociodemographic and clinical characteristics, psychological stress (10-item Perceived Stress Scale), and illness perception (Brief Illness Perceptions Questionnaire). Independent sample t-tests, bivariate correlations, and multivariable linear regression were performed to analyze potential correlates, including age, gender, education level, employment status, income, episode of illness, revascularization procedure, comorbidities, body mass index, blood pressure, blood glucose, blood lipids, and illness perception.

Results

The average patient age was 62.2 years, 67.5% were male, and 54.2% had less than high school education. The mean score for psychological stress was 21.30 ± 3.99 and 66.9% of patients had high psychological stress (score ≥ 20). Multivariable regression analysis showed that being overweight/obesity versus normal weight (body mass index:  ≥ 24 kg/m2 versus &lt; 24 kg/m2) was associated with lower psychological stress (β =  -0.134, p = 0.007). Having a high level of fasting blood glucose (≥ 6.1 mmol/L) versus normal fasting blood glucose (&lt; 6.1 mmol/L) was associated with high psychological stress (β = 0.123, p = 0.017). Additionally, negative cognitive illness perception (β = 0.190, p = 0.01), negative emotional illness perception (β = 0.290, p &lt; 0.001), and poor illness understanding (β = 0.118, p = 0.032) were associated with high psychological stress.

Conclusions

Patients with acute coronary syndrome experience high psychological stress that is significantly correlated with body mass index, fasting blood glucose, and illness perception. Health professionals should recognize this issue and interventions looking to relive psychological stress may benefit from targeting these correlates.

The efficacy of dendritic cell vaccine for newly diagnosed glioblastoma: A meta-analysis of randomized controlled studies

INTRODUCTION

The efficacy of dendritic cell vaccine to treat glioblastoma remained elusive and therefore we conducted a meta-analysis to explore the influence of dendritic cell vaccine on treatment efficacy of glioblastoma.

METHODS

PubMed, EMbase, Web of science, EBSCO and Cochrane library databases have been searched through October 2020, and we included randomized controlled trials (RCTs) assessing the efficacy of dendritic cell vaccine for glioblastoma.

RESULTS

Four RCTs and 267 patients were included in the meta-analysis. Compared to control group for glioblastoma, dendritic cell vaccine demonstrated no obvious impact on overall survival (HR=0.59; 95% CI=0.34 to 1.04; P=0.07), progression-free survival (PFS, HR=0.72; 95% CI=0.52 to 1.00; P=0.05), nervous system disorders (OR=0.61; 95% CI=0.29 to 1.29; P=0.20), or adverse events (OR=1.44; 95% CI=0.82 to 2.50; P=0.20).

CONCLUSIONS

Dendritic cell vaccine may be not effective to treat glioblastoma.

[Chaihu Guizhi decoction produces antidepressant-like effects via sirt1-p53 signaling pathway]

OBJECTIVE

To investigate the mechanism of the antidepressant-like effects of Chaihu Guizhi decoction (CGD).

OBJECTIVE

Chaihu Guizhi decoction at the daily dose of 17 g/kg and solvent vehicle were administered by gavage in 12 and 14 male C57BL/6J mice for 7 consecutive days, respectively. Forced swimming test (FST), elevated plus maze (EPM) test, open field test (OFT) and novelty-suppressed feeding test (NSF) were performed to assess the depression- and anxiety-like behaviors and motor ability of the mice. We further used chronic social defeat stress (CSDS) and social interaction test to evaluate the antidepressant-like effects of CGD in comparison with the solvent vehicle. Western blotting and RT-qPCR were performed to detect the expressions of sirt1, p53, acetylated p53, and the neuron plasticity-related genes including synapsin I (Syn1), Rab4B, SNAP25 and tubulin beta4b in the hippocampus of the mice.

OBJECTIVE

In FST, the immobility time of CGDtreated mice was decreased significantly (P < 0.05); no significant differences were found in the performances in EPM, NSF and OFT tests between the two groups. In social interaction test, the mouse models of CSDS treated with CGD showed significantly increased time in the interaction zone (P < 0.05). Compared with those in the vehicle group, the CGD-treated mouse models exhibited significantly increased protein level of SIRT1 and decreased p53 acetylation (P < 0.05) with up-regulated synapsin I mRNA expression in the hippocampus (P < 0.05); no significant difference were found in Rab (P=0.813), SNAP (P=0.820), or Tubb mRNA expressions (P=0.864) between the two groups.

OBJECTIVE

CGD produces antidepressant-like effects in mice possibly through the sirt1-p53 signaling pathway and synaptic plasticity.

[Application of serum N -glycan profiling diagnostic model in evaluation of liver fibrosis in patients with hepatitis C]

Objective: To study the changes of serum N-glycan abundance in patients with liver fibrosis at different stages of hepatitis C, and to establish and evaluate the diagnostic model for clinical application value. Methods: Data of 169 hepatitis C virus-infected cases with liver fibrosis were enrolled. Nine kinds of serum N-glycans were detected and analyzed using DNA sequencer-assisted fluorophore-assisted capillary electrophoresis technology. A binary logistics regression method was used to establish a diagnostic model based on the changes in the relative content of N-glycans in each stage of liver fibrosis. Receiver operating characteristic curve was used to evaluate and compare the diagnostic efficacy with other liver fibrosis diagnostic models. Results: N-glycan diagnostic model (B and C) had highest AUROC= 0.776, 0.827 for distinguishing fibrosis S1~S2 to S3~S4 and S1~S3 to S4 than GlycoFibroTest (AUROC = 0.760, 0.807), GlycoCirrhoTest (AUROC = 0.722, 0.787), aspartate aminotransferase to platelet ratio index (AUROC = 0.755, 0.751), FIB-4 index (AUROC = 0.730, 0.774), and S-index (AUROC = 0.707, 0.744). However, the diagnostic efficacy of model A (AUROC = 0.752) for distinguishing fibrosis S1 with S2~S4 had lower diagnostic potency than that of the aspartate aminotransferase to platelet ratio index (AUROC = 0.807). Diagnostic efficiency was improved when the N-glycan profiling and the aspartate aminotransferase to platelet ratio index were combined to diagnose liver fibrosis in each stage, and the area under the receiver operating characteristic curve was 0.839, 0.825, and 0.837, respectively. Conclusion: The serum N-glycan profiling diagnostic model has potential clinical application value in the diagnosis of liver fibrosis in patients with hepatitis C.

The acquisition of Mycobacterium tuberculosis infection in village doctors in China: a prospective study

BACKGROUND: Occupational exposure-related risk of Mycobacterium tuberculosis infection has been reported for village doctors in China. This prospective study aims to estimate the infection acquisition in this key population.METHODS: At baseline, all village doctors registered in Zhongmu County were tested by QuantiFERON^®-TB Gold In-Tube (QFT) and QuantiFERON^®-TB Gold Plus (QFT-Plus) in parallel. Those negatives for either of the tests were retested to identify conversions at the 2-year follow-up investigation.RESULTS: A total of 367 eligible participants completed the 2-year follow-up survey with frequency of conversion of 5.0% (18/361) for QFT and 6.1% (21/343) for QFT-Plus. The agreement of follow-up results between the tests was 93.2% with a κ coefficient of 0.43 (95%CI 0.20-0.65). Among QFT-Plus convertors, the difference between TB1 and TB2 tubes (TB2-TB1) was significantly increased as compared with baseline results (P = 0.039). Participants from the villages with occurrence of microbiologically confirmed pulmonary TB showed higher frequency of QFT conversions (11.0% vs. 3.2%, P = 0.011) and QFT-Plus conversions (12.3% vs. 4.4%, P = 0.027) than those from the villages without occurrence.CONCLUSION: Our results consistently suggest that capability on occupational protection and M. tuberculosis infection control should be improved in village doctors in China.

[Airway parameters and reference value range of high-resolution CT reconstruction in general population]

Objective: To investigate the measurement of small airways by high-resolution CT and image post-processing software. Screen and analyze the reconstructed airway parameters in order to find the best imaging biomarker parameters of small airway changes and calculate the reference value range; meanwhile, explore its influencing factors. Methods: From a water plant and a medical school, 169 cases of the general population aged 20 to 60 were selected as research objects, and questionnaire surveys and CT tests were performed, and CT data were reconstructed with image post-processing software. The reference value range of the general population was evaluated, and a linear mixed effect model was used to adjust the age, gender, height, BMI, and smoking status, and analyze the influencing factors of airway parameters. Results: The ratio of sixth-grade tracheal wall area to total tracheal area in the Left B1+2 to carina was (53.01±13.35) %, Left B9 to carina was (50.44±12.98) %, Right B1 to carina was (52.73±12.22) %, and Right B9 to carina was (52.93±11.85) %. The ratio of nineth-grade tracheal wall area to total tracheal area in the Left B1+2 to carina was (44.08±14.66) %, Left B9 to carina was (42.44±15.89) %, Right B1 to carina was (46.51±14.03) %, and Right B9 to carina is (43.54±15.87) %. BMI affect the area of the tracheal wall, all p value<0.05. Conclusion: High-resolution CT small airway morphology can make a preliminary assessment of the susceptible population of small airway-related diseases based on a range of reference values, and prevent and control it in combination with influencing factors.