Genome-Wide Identification and Expression Analysis of MAPK Gene Family in Lettuce (Lactuca sativa L.) and Functional Analysis of LsMAPK4 in High- Temperature-Induced Bolting.

The mitogen-activated protein kinase (MAPK) pathway is a widely distributed signaling cascade in eukaryotes and is involved in regulating plant growth, development, and stress responses. High temperature, a frequently occurring environmental stressor, causes premature bolting in lettuce with quality decline and yield loss. However, whether MAPKs play roles in thermally induced bolting remains poorly understood. In this study, 17 LsMAPK family members were identified from the lettuce genome. The physical and chemical properties, subcellular localization, chromosome localization, phylogeny, gene structure, family evolution, cis-acting elements, and phosphorylation sites of the LsMAPK gene family were evaluated via in silico analysis. According to phylogenetic relationships, LsMAPKs can be divided into four groups, A, B, C, and D, which is supported by analyses of gene structure and conserved domains. The collinearity analysis showed that there were 5 collinearity pairs among LsMAPKs, 8 with AtMAPKs, and 13 with SlMAPKs. The predicted cis-acting elements and potential phosphorylation sites were closely associated with hormones, stress resistance, growth, and development. Expression analysis showed that most LsMAPKs respond to high temperatures, among which LsMAPK4 is significantly and continuously upregulated upon heat treatments. Under heat stress, the stem length of the LsMAPK4-knockdown lines was significantly shorter than that of the control plants, and the microscope observations demonstrated that the differentiation time of flower buds at the stem apex was delayed accordingly. Therefore, silencing of LsMAPK4 significantly inhibited the high- temperature-accelerated bolting in lettuce, indicating that LsMPAK4 might be a potential regulator of lettuce bolting. This study provides a theoretical basis for a better understanding of the molecular mechanisms underlying the MAPK genes in high-temperature-induced bolting.

Molecular insights into inhibiting effects of lignin on cellulase investigated by molecular dynamics simulation.

The hydrolysis of lignocellulose into fermentable monosaccharides using cellulases represents a critical stage in lignocellulosic bioconversion. However, the inactivation of cellulase in the presence of lignin is attributed to the high cost of biofinery. To address this challenge, a comprehensive investigation into the structure-function relationship underlying lignin-driven cellulase inactivation is essential. In this study, molecular docking and molecular dynamics (MD) simulations were employed to explore the impacts of lignin fragments on the catalytic efficiency of cellulase at the atomic level. The findings revealed that soluble lignin fragments and cellulose could spontaneously form stable complexes with cellulase, indicating a competitive binding scenario. The enzyme's structure remained unchanged upon binding to lignin. Furthermore, specific amino acid residues have been identified as involved in interactions with lignin and cellulose. Hydrophobic interactions were found to dominate the binding of lignin to cellulase. Based on the mechanisms underlying the interactions between lignin fragments and cellulase, decreased hydrophobicity and change in the charge of lignin may mitigate the inhibition of cellulase. Furthermore, site mutations and chemical modification are also feasible to improve the efficiency of cellulase. This study may contribute valuable insights into the design of more lignin-resistant enzymes and the optimization of lignocellulosic pretreatment technologies.Communicated by Ramaswamy H. Sarma.

[Atorvastatin use and coronary flow reserve in patients with coronary slow flow].

OBJECTIVE: To investigate the impact of statin use on coronary flow reserve (CFR) in patients with slow coronary flow. METHODS: A total of 91 patients with chest pain and coronary slow flow but normal coronary angiography were included in this study, patients were divided into statin group (atorvastatin 20 mg/d for 8 weeks, n = 51) and non-statin group (n = 40), 26 healthy subjects with normal angiography and negative exercise ECG test served as normal controls. Blood cholesterol was measured. Doppler coronary flow velocity and Doppler reserve measurement of distal left anterior descending were recorded at rest and adenosine infusion (140 microgxkg(-1)xmin(-1)) induced hyperemia state, CFR was calculated by the ratio of maximal hyperemia and baseline peak diastolic coronary flow velocity (hCFV and bCFV) before and after atorvastatin treatment. RESULTS: (1) Eight weeks later, total cholesterol and LDL-C levels were significantly lower in statin group than in non-statin group and control group [TC (3.83 +/- 0.80) mmol/L vs. (5.30 +/- 1.18) mmol/L vs. (5.32 +/- 1.17) mmol/L, P < 0.05; LDL-C (2.26 +/- 0.64) mmol/L vs. (3.28 +/- 0.85) mmol/L vs. (3.30 +/- 0.82) mmol/L, P < 0.05]. (2)Baseline CFR levels were significantly lower in statin group and non-statin group than that in control group (2.32 +/- 0.30 vs. 2.25 +/- 0.33 vs. 3.15 +/- 0.34, P < 0.05). Compared with non-statin group and statin group before treatment, 8 weeks statin treatment was associated with reduced bCFV [(26.06 +/- 3.22) cm/s vs. (29.02 +/- 3.36) cm/s and (26.06 +/- 3.22) cm/s vs. (28.43 +/- 3.40) cm/s, P < 0.05], increased hCFV [(77.63 +/- 8.96) cm/s vs. (65.17 +/- 7.22) cm/s and (77.63 +/- 8.96) cm/s vs. (64.58 +/- 6.26) cm/s, P < 0.05] and increased CFR (3.07 +/- 0.29 vs. 2.28 +/- 0.35 and 3.07 +/- 0.29 vs. 2.32 +/- 0.30, P < 0.05). bCFV, hCFV and CFR of statin group post treatment were similar to those of controls (P > 0.05). CONCLUSION: Patients with coronary slow flow were associated with lower CFR which could be significantly improved by statin therapy.

The effects of the wenyang huoxue method on coronary heart disease heart failure: A protocol for systematic review.

BACKGROUND: Coronary heart disease (CHD) has become the primary cause of heart failure (HF). Wenyang Huoxue method can significantly improve cardiac function in patients with CHD complicated with HF, but it has not been systematically evaluated for efficacy and safety. METHODS: We will search China National Knowledge Infrastructure Database, Wanfang database, China Biomedical Literature Database, China Science Journal Database PubMed, Excerpt Medica Database, and Cochrane library. Clinical trial registrations, potential grey literature, related conference abstracts, and reference lists of identified studies will also be retrieved. The electronic database will be searched for literatures published from January 2000 to September 2019. Based on the heterogeneity test, data integration is performed using a fixed effect model or a random effects model. Changes in total effective rate in cardiac function will be assessed as primary outcome. 6-minute walk test, left ventricular ejection fraction, and plasma brain natriuretic peptide will be assessed as secondary outcomes. RevMan 5.3.5 will be used for meta-analysis. RESULTS: This study will provide a high-quality comprehensive evaluation of the efficacy and safety of Wenyang Huoxue method for treating patients with CHD complicated with HF. CONCLUSIONS: This systematic review will determine whether Wenyang Huoxue method provides evidence for effective intervention in patients with CHD complicated with HF. ETHICS AND DISSEMINATION: This systematic review and meta-analysis of randomized controlled trials does not require ethical recognition, and the results of this paper will be published in an open access, internationally influential academic journal. TRIAL REGISTRATION NUMBER: CRD42016025957.