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.

Development and Validation of a New Simple Functional Score in the Older Chinese Population

Background

Existing aging metrics incorporating cognitive and physical function are often not feasible for application in research and clinical practice. Therefore, this study aimed to develop and validate a new simple functional score based on self-reported cognitive and physical function in the older Chinese population.

Methods

The development sample included 3,929 older adults aged 60–95 years from the China Health and Retirement Longitudinal Study (CHARLS). The validation sample included 1,345 older adults aged 60–87 years from the Rugao Longitudinal Aging study (RLAS). Logistic regression models and receiver operating characteristic curves were used to examine the associations of the new functional score with all-cause mortality risk.

Results

Six items were selected to construct the new functional score in CHARLS. This functional score was associated with all-cause mortality risk, with an adjusted odds ratio of 1.10 (95% confidence interval = 1.07, 1.13). This functional score presented additional predictive utility beyond age and sex, as demonstrated by the significantly increased C-statistic, integrated discrimination improvement (IDI), and continuous net reclassification improvement (NRI) (all P < 0.001). Furthermore, this functional score was further validated in RLAS, such that adding the new functional score to a model of age and sex improved all-cause mortality risk discrimination (IDI = 0.036, P < 0.001; NRI = 0.485, P < 0.001). To facilitate the quick screening of the older population with deteriorations in cognitive and physical function, we introduced a publicly available online tool designed for this new functional score.

Conclusions

A new functional score based on six self-reported items was developed and validated in the older Chinese population, and was demonstrated to be a simple and practical tool to assess functional deterioration, showing good feasibility, and performance.

Associations of Serum Albumin With Disability in Activities of Daily Living, Mobility and Objective Physical Functioning Regardless of Vitamin D: Cross-Sectional Findings From the Chinese Longitudinal Healthy Longevity Survey

Objective

To examine the associations of serum albumin, a nutrition indicator, with disability in activities of daily living (ADL), mobility, and objective physical functioning among Chinese older adults.

Materials and Methods

Cross-sectional data of 2233 older adults (≥65 years) who participated in the 2011/2012 main survey of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and the 2012 biomarker sub-study was used. Serum albumin was measured by immunoturbidimetric assay. Physical functioning included subjectively (ADL and mobility) and objectively measured disability (standing up from a chair, picking up a book from the floor, and turning around 360°). Multivariable logistic regression models were performed.

Results

After adjusting for age and sex, compared with participants in the lowest quartile group of serum albumin, those in the highest quartile group had 45% lower odds of disability in ADL (odds ratio [OR]: 0.55; 95% confidence interval [CI]: 0.38, 0.80); 48% lower odds of disability in mobility (OR: 0.52; 95% CI: 0.38, 0.71); 46% lower odds of disability in standing up from a chair (OR: 0.54; 95% CI: 0.34, 0.85); and 37% lower odds of disability in picking up a book from the floor (OR: 0.63; 95% CI: 0.40, 0.97). We did not observe a statistically significant interaction effect between serum albumin and vitamin D on disability in physical functioning.

Conclusion

Serum albumin level was associated with physical functioning among Chinese older adults, regardless of vitamin D level. The findings indicate that appropriate management of poor nutritional status, in particular low serum albumin levels, may contribute to maintaining physical functioning in older adults.

[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.

A Machine Learning-Based Aging Measure Among Middle-Aged and Older Chinese Adults: The China Health and Retirement Longitudinal Study

Objective: Biological age (BA) has been accepted as a more accurate proxy of aging than chronological age (CA). This study aimed to use machine learning (ML) algorithms to estimate BA in the Chinese population. Materials and methods: We used data from 9,771 middle-aged and older Chinese adults (≥45 years) in the 2011/2012 wave of the China Health and Retirement Longitudinal Study and followed until 2018. We used several ML algorithms (e.g., Gradient Boosting Regressor, Random Forest, CatBoost Regressor, and Support Vector Machine) to develop new measures of biological aging (ML-BAs) based on physiological biomarkers. R-squared value and mean absolute error (MAE) were used to determine the optimal performance of these ML-BAs. We used logistic regression models to examine the associations of the best ML-BA and a conventional aging measure-Klemera and Doubal method-BA (KDM-BA) we previously developed-with physical disability and mortality, respectively. Results: The Gradient Boosting Regression model performed the best, resulting in an ML-BA with an R-squared value of 0.270 and an MAE of 6.519. This ML-BA was significantly associated with disability in basic activities of daily living, instrumental activities of daily living, lower extremity mobility, and upper extremity mobility, and mortality, with odds ratios ranging from 1 to 7% (per 1-year increment in ML-BA, all P < 0.001), independent of CA. These associations were generally comparable to that of KDM-BA. Conclusion: This study provides a valid ML-based measure of biological aging for middle-aged and older Chinese adults. These findings support the application of ML in geroscience research and may help facilitate preventive and geroprotector intervention studies.

The association between daily yogurt consumption and serum lipid profiles in the general adult population: the TCLSIH cohort study

The purpose of this cross-sectional study is to determine the association between yogurt consumption and lipid profiles in the general Chinese population. In this cross-sectional study, a total of 26,824 participants were included from Tianjin, China. Lipid profiles were determined by automated biochemical analyser. Yogurt consumption frequency was assessed by a validated food frequency questionnaire. Analysis of covariance was used to determine the association between daily yogurt consumption and lipid profiles. In the final multivariate model, daily yogurt consumption was negatively associated with triglyceride (TG) (p for trend <0.001) and positively associated with high density lipoprotein cholesterol (HDL-C) (p for trend = 0.02). There were no significant differences (p for trend >0.05) between daily yogurt consumption and total cholesterol (TC) or low density lipoprotein cholesterol (LDL-C). Results suggested that higher daily yogurt consumption was negatively correlated with TG and positively correlated with HDL-C in the general Chinese population.

High Blood Uric Acid Is Associated With Reduced Risks of Mild Cognitive Impairment Among Older Adults in China: A 9-Year Prospective Cohort Study

Background: It remains unsolved that whether blood uric acid (UA) is a neuroprotective or neurotoxic agent. This study aimed to evaluate the longitudinal association of blood UA with mild cognitive impairment (MCI) among older adults in China.

Methods: A total of 3,103 older adults (aged 65+ years) free of MCI at baseline were included from the Healthy Aging and Biomarkers Cohort Study (HABCS). Blood UA level was determined by the uricase colorimetry assay and analyzed as both continuous and categorical (by quartile) variables. Global cognition was assessed using the Mini-Mental State Examination four times between 2008 and 2017, with a score below 24 being considered as MCI. Cox proportional hazards models were used to examine the associations.

Results: During a 9-year follow-up, 486 (15.7%) participants developed MCI. After adjustment for all covariates, higher UA had a dose-response association with a lower risk of MCI (all P_{for  trend} < 0.05). Participants in the highest UA quartile group had a reduced risk [hazard ratio (HR), 0.73; 95% (CI): 0.55–0.96] of MCI, compared with those in the lowest quartile group. The associations were still robust even when considering death as a competing risk. Subgroup analyses revealed that these associations were statistically significant in younger older adults (65–79 years) and those without hyperuricemia. Similar significant associations were observed when treating UA as a continuous variable.

Conclusions: High blood UA level is associated with reduced risks of MCI among Chinese older adults, highlighting the potential of managing UA in daily life for maintaining late-life cognition.

[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.

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.

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.

Burden of caregivers who care for oldest-old parents with disability: A cross-sectional study

OBJECTIVE

To describe the characteristics of oldest-old Chinese with disability and their adult-child caregivers, and the extent to which these characteristics were associated with caregiver burden.

METHODS

The study was based on 168 pairs of disabled oldest-old adults and their adult-child caregivers, derived from the Chinese Longitudinal Healthy Longevity Survey. Descriptive analyses of care recipients' and caregivers' characteristics were conducted respectively, in reference to caregiver burden. Statistically significant characteristics identified in these bivariate analyses were then jointly evaluated in multiple linear regression models with caregiver burden as the outcome.

RESULTS

Care recipients positive emotion status [(β = -0.227 (-0.412, -0.042)], multiple chronic disease [(β = 0.513 (0.081, 0.945)], and caregivers spent more caregiving time [(β = 0.225 (0.061, 0.389)] were main factors associated with caregiver burden.

CONCLUSION

Adult-children caregivers perceived heavier burden if care recipients had low positive emotions, had multiple chronic diseases, and caregivers spent more time caregiving.

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.

Serum 25-hydroxyvitamin D in relation to disability in activities of daily living, mobility, and objective physical functioning among Chinese older adults

OBJECTIVES

Vitamin D deficiency is common among older adults, but its association with physical function is not fully understood. The aim of this study was to investigate the associations between serum 25-hydroxyvitamin D and disability in activities of daily living (ADL), mobility, and objective physical functioning among Chinese older adults.

METHODS

We used cross-sectional data of 2225 older adults (≥65 years) who participated in the 2011/2012 main survey of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and the 2012 biomarker sub-study. Serum levels of 25-hydroxyvitamin D were measured by enzyme immunoassay. Outcomes included ADL disability, mobility disability, and disability in three objective physical examinations (standing-up from a chair, picking-up a book from the floor, and turning-around 360°).

RESULTS

The multiple regression models suggested that participants in the serum 25-hydroxyvitamin D deficiency group had higher odds of ADL disability (OR: 4.08; 95% confidence interval (CI): 2.81, 5.92), mobility disability (OR: 1.59; 95% CI: 1.05, 2.41), and disability in standing-up from a chair (OR: 2.43; 95% CI: 1.60, 3.69), picking-up a book from the floor (OR: 3.09; 95% CI: 2.07, 4.60), and turning-around 360° (OR: 3.09; 95% CI: 2.07, 4.60). Subgroup analyses revealed that some of the above associations (particularly those with mobility disability and disability in turning-around 360°) were only statistically significant among the oldest-old.

CONCLUSIONS

Among the oldest-old in China, serum 25-hydroxyvitamin D deficiency was associated with disability in ADL, mobility, and objective physical functioning, highlighting the importance of managing the serum 25-hydroxyvitamin D level to promote healthy aging.