MADS-box protein PpDAM6 regulates chilling requirement-mediated dormancy and bud break in peach.

Bud dormancy is crucial for winter survival and is characterized by the inability of the bud meristem to respond to growth-promotive signals before the chilling requirement (CR) is met. However, our understanding of the genetic mechanism regulating CR and bud dormancy remains limited. This study identified PpDAM6 (DORMANCY-ASSOCIATED MADS-box) as a key gene for CR using a genome-wide association study analysis based on structural variations in 345 peach (Prunus persica (L.) Batsch) accessions. The function of PpDAM6 in CR regulation was demonstrated by transiently silencing the gene in peach buds and stably overexpressing the gene in transgenic apple (Malus × domestica) plants. The results showed an evolutionarily conserved function of PpDAM6 in regulating bud dormancy release, followed by vegetative growth and flowering, in peach and apple. The 30-bp deletion in the PpDAM6 promoter was substantially associated with reducing PpDAM6 expression in low-CR accessions. A PCR marker based on the 30-bp indel was developed to distinguish peach plants with non-low and low CR. Modification of the H3K27me3 marker at the PpDAM6 locus showed no apparent change across the dormancy process in low- and non-low- CR cultivars. Additionally, H3K27me3 modification occurred earlier in low-CR cultivars on a genome-wide scale. PpDAM6 could mediate cell-cell communication by inducing the expression of the downstream genes PpNCED1 (9-cis-epoxycarotenoid dioxygenase 1), encoding a key enzyme for ABA biosynthesis, and CALS (CALLOSE SYNTHASE), encoding callose synthase. We shed light on a gene regulatory network formed by PpDAM6-containing complexes that mediate CR underlying dormancy and bud break in peach. A better understanding of the genetic basis for natural variations of CR can help breeders develop cultivars with different CR for growing in different geographical regions.

Serum ASGR2 level: an efficacy biomarker for balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension.

Background: This study aimed to employ plasma proteomics to investigate the molecular changes, pathway alterations, and potential novel biochemical markers associated with balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Methods: Pre- and post-BPA plasma samples from five CTEPH patients in the PRACTICE study were analyzed to identify differentially expressed proteins. Proteomic and bioinformatics analyses were conducted, and the identified proteins were further validated using ELISA assays in a separate cohort of the same study. Correlation and multivariate regression analyses were performed to investigate the associations between these differentially expressed proteins and clinical parameters. Results: Significantly higher serum levels of asialoglycoprotein receptor 2 (ASGR2) were detected in 5 CTEPH patients compared to those in healthy individuals but decreased significantly after successful BPA procedures. The decrease in serum levels of ASGR2 after the completion of BPA procedures was further validated in a separate cohort of 48 patients with CTEPH [0.70 (0.51, 1.11) ng/mL vs. 0.38 (0.27, 0.59) ng/mL, P < 0.001]. Significant associations were found between the pre-BPA ASGR2 level and clinical parameters, including neutrophil percentage (R = 0.285, P < 0.05), platelet (PLT) count (R = 0.386, P < 0.05), and high-density lipoprotein cholesterol (HDL-C) before BPA (R = -0.285, P < 0.05). Significant associations were detected between post-BPA serum ASGR2 levels and lymphocyte percentage (LYM%) (R = 0.306, P < 0.05), neutrophil-to-lymphocyte ratio (R = -0.294, P < 0.05), and pulmonary vascular resistance after BPA (R = -0.35, P < 0.05). Multivariate stepwise regression analysis revealed that pre-BPA ASGR2 levels were associated with HDL-C and PLT count (both P < 0.001), while post-BPA ASGR2 levels were associated with LYM% (P < 0.05). Conclusion: Serum levels of ASGR2 may be a biomarker for the effectiveness of BPA treatment in CTEPH patients. The pre-BPA serum level of ASGR2 in CTEPH patients was associated with HDL-C and the PLT count. The post-BPA serum level of ASGR2 was correlated with the LYM%, which may reflect aspects of immune and inflammatory status.

Interleukin-6 and pulmonary hypertension: from physiopathology to therapy.

Pulmonary hypertension (PH) is a progressive, pulmonary vascular disease with high morbidity and mortality. Unfortunately, the pathogenesis of PH is complex and remains unclear. Existing studies have suggested that inflammatory factors are key factors in PH. Interleukin-6 (IL-6) is a multifunctional cytokine that plays a crucial role in the regulation of the immune system. Current studies reveal that IL-6 is elevated in the serum of patients with PH and it is negatively correlated with lung function in those patients. Since IL-6 is one of the most important mediators in the pathogenesis of inflammation in PH, signaling mechanisms targeting IL-6 may become therapeutic targets for this disease. In this review, we detailed the potential role of IL-6 in accelerating PH process and the specific mechanisms and signaling pathways. We also summarized the current drugs targeting these inflammatory pathways to treat PH. We hope that this study will provide a more theoretical basis for targeted treatment in patients with PH in the future.

The Role of Glutamine and Glutaminase in Pulmonary Hypertension.

Pulmonary hypertension (PH) refers to a clinical and pathophysiological syndrome in which pulmonary vascular resistance and pulmonary arterial pressure are increased due to structural or functional changes in pulmonary vasculature caused by a variety of etiologies and different pathogenic mechanisms. It is followed by the development of right heart failure and even death. In recent years, most studies have found that PH and cancer shared a complex common pathological metabolic disturbance, such as the shift from oxidative phosphorylation to glycolysis. During the shifting process, there is an upregulation of glutamine decomposition driven by glutaminase. However, the relationship between PH and glutamine hydrolysis, especially by glutaminase is yet unclear. This review aims to explore the special linking among glutamine hydrolysis, glutaminase and PH, so as to provide theoretical basis for clinical precision treatment in PH.

Comparative Effectiveness of Exercise Training for Patients With Chronic Thromboembolic Pulmonary Hypertension After Pulmonary Endarterectomy: A Systematic Review and Meta-Analysis.

Background: Patients with chronic thromboembolic pulmonary hypertension (CTEPH) still experience reduced exercise capacity despite pulmonary endarterectomy (PEA). Exercise training improves the exercise capacity and quality of life (QoL) in patients with PH, but data on the effects of exercise training on these patients are scarce. The aim of this meta-analysis and systematic review was to evaluate the effectiveness and safety of exercise training in CTEPH after PEA. Methods: We searched the relevant literature published before January 2020 for the systematic review and meta-analysis using the PubMed, EMBASE, and Cochrane Library databases. The primary outcome was a change in the 6-min walking distance (6 MWD). We also assessed the effect of exercise on the peak oxygen uptake (VO2) or peak VO2/kg, oxygen uptake anaerobic threshold, workload, oxygen pulse, hemodynamics, arterial blood gases, oxygen saturation, N-terminal pro-brain-type natriuretic peptide (NT-proBNP), quality of life (QoL) and pulmonary function tests. Results: We included 4 studies with 208 exercise-training participants. In the pooled analysis, short-term exercise training can improve the 6 MWD of 58.89 m (95% CI: 46.26-71.52 m, P < 0.0001). There was a significant increase in the peak VO2/kg or peak VO2 after exercise training (3.15 ml/min/kg, 95% CI: 0.82-5.48, P = 0.008; 292.69 ml/min, 95% CI: 24.62-560.75, P = 0.032, respectively). After exercise training, the maximal workload and O2 pulse significantly improved. Three months of exercise training increased the right ventricular ejection fraction by 3.53% (95% CI: 6.31-11.94, P < 0.00001, I 2 = 0) independently of PEA surgery. In addition, NT-proBNP plasma levels significantly improved with exercise training after PEA [weighted mean difference (WMD): -524.79 ng/L, 95% CI: 705.16 to -344.42, P < 0.0001, I 2 = 0]. The partial pressure of oxygen and pH improved progressively over 12 weeks of exercise training (WMD: 4 mmHg, 95% CI: 1.01-8.33, P = 0.01; WMD: 0.03, 95% CI: 0.02-0.04, P < 0.0001, respectively). Subscales of the QoL measured by the SF-36 questionnaire had also improved. In addition, exercise training was well-tolerated with a low dropout rate, and no major adverse events occurred during exercise training. Conclusion: Exercise training may be associated with a significant improvement in the exercise capacity and QoL among CTEPH patients after PEA and was proven to be safe. However, more large-scale multicentre studies are needed to confirm the effectiveness and safety of exercise training in CTEPH patients after PEA. PROSPERO registration number: CRD42021235275.

Survival in severe pulmonary hypertension due to chronic lung disease: influence of in-hospital platelet distribution width.

Platelet distribution width has been recognized as risk predictors of idiopathic pulmonary arterial hypertension. This study aims to investigate whether in-hospital platelet distribution width would be useful to predict all-cause death in patients with severe pulmonary hypertension due to chronic lung diseases (CLD-PH). Early in-hospital platelet distribution width was measured in 67 severe CLD-PH patients who were confirmed by right heart catheterization and followed up. Event-free survival was estimated using the Kaplan-Meier method and analyzed with the log-rank test. Cox proportional hazards models were performed to determine the association between the platelet distribution width level and all-cause death. During median of 2.4 (2.5, 3.7) years of follow-up, 44 patients died. A significant association was noted between in-hospital platelet distribution width level and the adjusted risk of all-cause mortality (hazard ratio: 1.245; 95% confidence interval: 1.117-1.386, P < 0.001). Compared with those with platelet distribution width <16.1%, the hazard ratio for all-cause death increased by 5.278 (95% confidence interval: 2.711-10.276, P < 0.0001) among patients with platelet distribution width ≥16.1%. Higher levels of platelet distribution width were also associated with increased risk of all-cause death. In-hospital platelet distribution width was independently associated with all-cause death in patients with severe CLD-PH. This potentially could be used to estimate the severity of severe CLD-PH.

[Role of JAK2/STAT3 signaling pathway in microglia activation after hypoxic-ischemic brain damage].

Hypoxic-ischemic encephalopathy (HIE) is the leading cause of neonatal death and neurodevelopmental disorders in infants. Part of patients have different degrees of neurological sequelae, such as cerebral palsy, cognitive and motor function development disorders. Hypoxia-ischemia may activate JAK2/STAT3 signaling pathway, which leads to the microglia activation and neuroinflammation. Down-Regulating JAK2/STAT3 signaling pathway can inhibit microglia activation and regulate the inflammatory injury of nervous system. At present, the treatment of hypoxic ischemic encephalopathy is limited, so the study of regulatory mechanism about microglia activation has important value for the treatment of hypoxic-ischemic encephalopathy. This paper summarizes the role of JAK2/STAT3 signaling pathway in microglia activation and analyzes the relationship between them, in order to provide new ideas and strategies for treatment on hypoxic-ischemic encephalopathy.

[Advances on selective posterior rhizotomy for lower limb function in patients with cerebral palsy].

Cerebral palsy is a common clinical syndrome of neurological disability in childhood, which seriously affects the quality of life of children and their families, and brings a heavy economic burden to the society. Domestic and foreign scholars had a long history of the application of selective posterior rhizotomy for the treatment of spastic cerebral palsy or mixed cerebral palsy with limb paralysis. It is effective in improving the lower extremity spasm of patients with cerebral palsy, and there are few cases with recurrences. After rehabilitation therapy, the muscle strength of patients with cerebral palsy was significantly improved compared with the previous one. The range of motion was significantly improved after operation, and there is no rebounded in aspect of joint activety in the long-term follow-up. The overall gait of the patient was significant improved. The author thought that selective posterior rhizotomy is effective in improving the motor function of lower limbs in patients with cerebral palsy, and it is worth being spread. However, it has to follow the principle of selecting appropriate cases before surgery, precise operation during operation, and timely and effective rehabilitation treatment after surgery, in order to achieve a better curative effect.