Multimodal cell atlas of the ageing human skeletal muscle

Muscle atrophy and functional decline (sarcopenia) are common manifestations of frailty and are critical contributors to morbidity and mortality in older people1. Deciphering the molecular mechanisms underlying sarcopenia has major implications for understanding human ageing2. Yet, progress has been slow, partly due to the difficulties of characterizing skeletal muscle niche heterogeneity (whereby myofibres are the most abundant) and obtaining well-characterized human samples3,4. Here we generate a single-cell/single-nucleus transcriptomic and chromatin accessibility map of human limb skeletal muscles encompassing over 387,000 cells/nuclei from individuals aged 15 to 99 years with distinct fitness and frailty levels. We describe how cell populations change during ageing, including the emergence of new populations in older people, and the cell-specific and multicellular network features (at the transcriptomic and epigenetic levels) associated with these changes. On the basis of cross-comparison with genetic data, we also identify key elements of chromatin architecture that mark susceptibility to sarcopenia. Our study provides a basis for identifying targets in the skeletal muscle that are amenable to medical, pharmacological and lifestyle interventions in late life.

Understanding vegetation phenology responses to easily ignored climate factors in china's mid-high latitudes

Previous studies have primarily focused on the influence of temperature and precipitation on phenology. It is unclear if the easily ignored climate factors with drivers of vegetation growth can effect on vegetation phenology. In this research, we conducted an analysis of the start (SOS) and end (EOS) of the growing seasons in the northern region of China above 30°N from 1982 to 2014, focusing on two-season vegetation phenology. We examined the response of vegetation phenology of different vegetation types to preseason climatic factors, including relative humidity (RH), shortwave radiation (SR), maximum temperature (Tmax), and minimum temperature (Tmin). Our findings reveal that the optimal preseason influencing vegetation phenology length fell within the range of 0-60 days in most areas. Specifically, SOS exhibited a significant negative correlation with Tmax and Tmin in 44.15% and 42.25% of the areas, respectively, while EOS displayed a significant negative correlation with SR in 49.03% of the areas. Additionally, we identified that RH emerged as the dominant climatic factor influencing the phenology of savanna (SA), whereas temperature strongly controlled the SOS of deciduous needleleaf forest (DNF) and deciduous broadleaf forest (DBF). Meanwhile, the EOS of DNF was primarily influenced by Tmax. In conclusion, this study provides valuable insights into how various vegetation types adapt to climate change, offering a scientific basis for implementing effective vegetation adaptation measures.

Inhalation of 2, 4-di-tert-butylphenol-Loaded micelles suppresses respiratory syncytial virus infection in mice

Human respiratory syncytial virus (RSV) is a common cause of respiratory infections in infants, young children, and elderly people. However, there are no effective treatments or vaccines available in most countries. In this study, we explored the anti-RSV potential of 2, 4-Di-tert-butylphenol (2, 4-DTBP), a compound derived from Houttuynia cordata Thunb. To overcome the poor solubility of 2, 4-DTBP, we encapsulated it in polymeric micelles and delivered it by inhalation. We found that 2, 4-DTBP-loaded micelles inhibited RSV infection in vitro and improved survival, lung pathology, and viral clearance in RSV-infected mice. Our results suggested that 2, 4-DTBP-loaded micelle is a promising novel therapeutic agent for RSV infection.

[Analysis of the therapeutic effect of aspiration thrombectomy for early carotid stent thrombosis]

Objective: To investigate the clinical characteristics and the efficacy of thrombus aspiration in patients with early intrastent thrombosis (EST) following carotid artery stenting (CAS). Methods: This study is a retrospective case series, collecting clinical data of five patients who developed EST after CAS in the Department of Neurosurgery, Beijing Chaoyang Hospital, Capital Medical University from January 2021 to September 2023.All patients were male, with an age of (64.0±11.9) years (range:48 to 77 years), accounting for 2.0% (5/244) of CAS procedures during the same period.Among them, three patients did not receive standard dual antiplatelet therapy before the procedure, and one had an inadequate ADP inhibition rate (45.6%).Four patients received XACT carotid stents, while one received a Wallstent carotid stent.All five patients showed significant residual stenosis ranging from 43% to 55% after CAS.Emergency thrombus aspiration was performed in all cases, and data regarding perioperative conditions, vascular patency, and clinical outcomes were collected. Results: The interval between CAS and the occurrence of EST ranged from 3 hours to 14 days.The main clinical symptoms included sudden onset of consciousness disorders and contralateral limb weakness.None of the patients received preoperative intravenous thrombolysis, and thrombus aspiration was performed during the procedure to restore vascular patency.Four cases underwent balloon angioplasty during the procedure, and two cases utilized overlapping stents.Two patients experienced intraoperative embolization of thrombus to the C2 segment.In one case, the embolized thrombus was retrieved using an intracranial thrombectomy stent, while in another case, it was aspirated using a guiding catheter.Postoperatively, all patients had a thrombolysis in cerebral infarction grade of 3, and symptoms improved in four cases.One patient showed no improvement in symptoms, and MRI revealed extensive new infarction in the right frontal and insular regions, adjacent to the right lateral ventricle.Regular follow-up examinations after discharge did not reveal restenosis or embolism within the stent.The follow-up period ranged from 7.6 to 21.2 months, with modified Rankin scale scores of 0 to 1 point in four cases and 2 points in one case, indicating good recovery in all patients. Conclusions: Acute intrastent thrombosis is a rare complication after carotid artery stenting.The combined use of percutaneous thrombus aspiration and endovascular techniques, such as balloon angioplasty and stent overlapping, can rapidly restore vessel patency with favorable outcomes.However, further large-scale clinical studies are needed to confirm the effectiveness of these treatments for acute intrastent thrombosis.

Experimental study of a canine model for a newly designed adjustable prefenestration aortic stent graft

PURPOSE

When performing thoracic aortic endovascular repair (TEVAR) on lesions of the aortic arch, physician- modified fenestration or in situ fenestration is often used to maintain patent branches. We designed a new adjustable prefenestration aortic stent graft that can both isolate pathologies in the aortic arch and obtain patent branches simultaneously. In this study, we use this new type of stent to perform fenestrated TEVAR in a canine's aorta. This study aims to evaluate the safety and feasibility of the new device, which may provide preliminary data for potential human application.

METHODS

Eight Labrador Retriever canines underwent fenestrated TEVAR using the new stent device. Digital subtract angiography (DSA) was performed before and after fenestrated TEVAR to evaluate the safety and feasibility of the procedure. For the device deployment, at the "large curvature" side in the endograft, there is a rectangular prefenestration area (2 × 5 cm) without the polytetrafluoroethylene membrane, and at both longer side edges of the fenestration, there are two slide rails. A moveable membrane that covers the same area as the prefenestration area is initially set at the prefenestration position. A stay line is connected from the distal site of the moveable membrane that controls it to the distal position along the slide rail, which releases the fenestration. After the positioning of the prefenestration is determined, the outer sheath of the delivery system is released, and the stay line at the end of the delivery system is pulled outside the body. The animals were divided into a 1-month group (n = 4) and a 3-month group (n = 4) after the fenestrated TEVAR. Computed tomography (CT) was performed before euthanasia, and video of the DSA during the procedures and CT angiography (CTA) images were then studied.

RESULTS

The procedure success rate was 100%, but the total survival rate was only 87.5%. There were no aortic-related deaths during follow-up, and during the operation, there were no stent-graft-related accidents. In addition, no stent-graft migrations were observed in the CTA, and all branch arteries were kept patent by the adjustable fenestration. Finally, histological examination and electron microscope results showed no obvious vascular injury or inflammation.

CONCLUSION

Based on the results of this study, we judge the safety and feasibility of the use of the newly designed adjustable prefenestration aortic stent graft in a fenestrated-TEVAR canine model to be acceptable. Our preliminary data may provide a first reference for evaluating the new stent's potential use in humans.

An injectable signal-amplifying device elicits a specific immune response against malignant glioblastoma

Despite exciting achievements with some malignancies, immunotherapy for hypoimmunogenic cancers, especially glioblastoma (GBM), remains a formidable clinical challenge. Poor immunogenicity and deficient immune infiltrates are two major limitations to an effective cancer-specific immune response. Herein, we propose that an injectable signal-amplifying nanocomposite/hydrogel system consisting of granulocyte-macrophage colony-stimulating factor and imiquimod-loaded antigen-capturing nanoparticles can simultaneously amplify the chemotactic signal of antigen-presenting cells and the "danger" signal of GBM. We demonstrated the feasibility of this strategy in two scenarios of GBM. In the first scenario, we showed that this simultaneous amplification system, in conjunction with local chemotherapy, enhanced both the immunogenicity and immune infiltrates in a recurrent GBM model; thus, ultimately making a cold GBM hot and suppressing postoperative relapse. Encouraged by excellent efficacy, we further exploited this signal-amplifying system to improve the efficiency of vaccine lysate in the treatment of refractory multiple GBM, a disease with limited clinical treatment options. In general, this biomaterial-based immune signal amplification system represents a unique approach to restore GBM-specific immunity and may provide a beneficial preliminary treatment for other clinically refractory malignancies.

Treatment strategies for endoleak after endovascular repair of the abdominal aortic aneurysm: A single center retrospective study

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) is the most frequently used treatment for aneurysm in abdominal aorta. The endoleak after EVAR causes the aneurysm sac to remain enlarged and risk for rupture.

AIMS

The purpose of the study was to assess the efficacy of strategies and techniques for endoleak treatment.

METHODS

This study was a single center retrospective study of 30 patients who had kinds of endoleak. The 30 patients were from a cohort of 597 patients who received EVAR from the Secondary Xiangya Hospital, Central South University between Jan 2014 to Dec 2021, what is follow-up well and diagnosed as endoleak. Data included basic clinical information, aspects of the endoleak treatment techniques, and follow-up findings.

RESULTS

The 30 patients with endoleak were diagnosed by computed tomography angiography or digital subtraction angiography. Age is 69 ± 7.9 yrs. 26 patients are male with only 4 female patients. Immediate endoleak after EVAR is 46.7%and delayed endoleak is 53.3%. The classification of endoleak is type Ⅰ:76.6%; type Ⅱ 26.7%; type Ⅲ:6.7%; type Ⅳ:6.7%; type Ⅴ:13.3%. Different treatment of endoleak includes: screening, endovascular re-intervention and open surgery. There are 3 patients (10.0%) underwent emergency EVAR due to their rupture condition of aneurysm. All the endoleak patients' CTA image characteristics has been reviewed. The follow-up rate is 93.3%. There are 6 patients (21.4%) died during follow-up. No aneurysm sac rupture death has been recorded.

CONCLUSIONS

Endoleak after EVAR is the most frequent complication that directly affects survival and re-intervention rates. Our findings suggested that different treatment strategies based on the individual patient's situation is important for their endoleak treating result.

[Clinical efficacy of entecavir combined with Biejiajian pills and its influence on TCM syndrome scores during the treatment of chronic hepatitis B with hepatic fibrosis and blood stasis syndrome]

Objective: To investigate the clinical efficacy of entecavir combined with Biejiajian pills and its influence on TCM syndrome scores during the treatment of chronic hepatitis B with hepatic fibrosis and blood stasis syndrome by prospective, randomized and controlled study. Methods: Patients with chronic hepatitis B with hepatic fibrosis and blood stasis syndrome were selected as the research subjects and randomly divided into a treatment group and a control group. Entecavir plus Biejiajian pills or entecavir plus a simulant of Biejiajian pills were given for 48 weeks. The changes in liver stiffness measurement (LSM) and TCM syndrome scores before and after treatment were compared between the two groups to analyze the correlation. The data between groups were analyzed by t-test/Wilcoxon rank sum test or χ(2) test. Pearson correlation coefficient was used to analyze the correlation between TCM syndrome scores and LSM values. Results: After 48 weeks of treatment, the LSM values of the two groups were significantly lower than those of the baseline (P < 0.001), liver fibrosis was significantly improved, and the LSM values of the treatment group were lower than those of the control group [(8.67 ± 4.60) kPa and (10.13 ± 4.43) kPa, t = -2.011, P = 0.049]. After 48 weeks of treatment, the TCM syndrome scores of the two groups were significantly reduced compared with the baseline (P < 0.001), and the clinical symptoms were significantly relieved, and the total effective rates of the improvement of the TCM syndrome scores in the two groups were 74.19% and 72.97%, respectively, but the differences between the groups were not statistically significant (χ(2) = 0.013, P = 0.910). Correlation analysis showed that there was no obvious trend between TCM syndrome scores and LSM values. There were no serious adverse reactions associated with the drug during the observation period of this study. Conclusion: Based on antiviral treatment with entecavir, regardless of whether it is combined with the Biejiajian pill, it can effectively reduce the LSM value, improve liver fibrosis, reduce TCM syndrome scores, and alleviate symptoms in patients with chronic hepatitis B with liver fibrosis and blood stasis syndrome. Compared with entecavir alone, the combined Biejia pill has greater efficacy in improving liver fibrosis and a favorable safety profile, meriting its implementation and widespread application.

A control-based observer approach for estimating energy intake during pregnancy

Gestational weight gain outside of Institute of Medicine guidelines poses a risk to both the mother and her unborn child. Behavioral interventions such as Healthy Mom Zone (HMZ) that aim to regulate gestational weight gain require self-monitoring of energy intake, which is often significantly under-reported by participants. This paper describes the use of a control systems approach for energy intake estimation during pregnancy. It relies on an energy balance model that predicts gestational weight based on physical activity and energy intake, the latter treated as an unmeasured disturbance. Two control-based observer formulations relying on Internal Model Control and Model Predictive Control, respectively, are presented in this paper, first for a hypothetical participant, then on data collected from four HMZ participants. Results demonstrate the effectiveness of the method, with generally best results obtained when estimating energy intake over a weekly time period.

[Correlation between pelvic relapses of rectal cancer after radical and R0 resection: A regression model-based analysis]

Objective: To propose a new staging system for presacral recurrence of rectal cancer and explore the factors influencing radical resection of such recurrences based on this staging system. Methods: In this retrospective observational study, clinical data of 51 patients with presacral recurrence of rectal cancer who had undergone surgical treatment in the Department of Gastrointestinal Surgery, Peking University People's Hospital between January 2008 and September 2022 were collected. Inclusion criteria were as follows: (1) primary rectal cancer without distant metastasis that had been radically resected; (2) pre-sacral recurrence of rectal cancer confirmed by multi-disciplinary team assessment based on CT, MRI, positron emission tomography, physical examination, surgical exploration, and pathological examination of biopsy tissue in some cases; and (3) complete inpatient, outpatient and follow-up data. The patients were allocated to radical resection and non-radical resection groups according to postoperative pathological findings. The study included: (1) classification of pre-sacral recurrence of rectal cancer according to its anatomical characteristics as follows: Type I: no involvement of the sacrum; Type II: involvement of the low sacrum, but no other sites; Type III: involvement of the high sacrum, but no other sites; and Type IV: involvement of the sacrum and other sites. (2) Assessment of postoperative presacral recurrence, overall survival from surgery to recurrence, and duration of disease-free survival. (3) Analysis of factors affecting radical resection of pre-sacral recurrence of rectal cancer. Non-normally distributed measures are expressed as median (range). The Mann-Whitney U test was used for comparison between groups. Results: The median follow-up was 25 (2-96) months with a 100% follow-up rate. The rate of metachronic distant metastasis was significantly lower in the radical resection than in the non-radical resection group (24.1% [7/29] vs. 54.5% [12/22], χ²=8.333, P=0.026). Postoperative disease-free survival was longer in the radical resection group (32.7 months [3.0-63.0] vs. 16.1 [1.0-41.0], Z=8.907, P=0.005). Overall survival was longer in the radical resection group (39.2 [3.0-66.0] months vs. 28.1 [1.0-52.0] months, Z=1.042, P=0.354). According to univariate analysis, age, sex, distance between the tumor and anal verge, primary tumor pT stage, and primary tumor grading were not associated with achieving R0 resection of presacral recurrences of rectal cancer (all P>0.05), whereas primary tumor pN stage, anatomic staging of presacral recurrence, and procedure for managing presacral recurrence were associated with rate of R0 resection (all P<0.05). According to multifactorial analysis, the pathological stage of the primary tumor pN1-2 (OR=3.506, 95% CI: 1.089-11.291, P=0.035), type of procedure (transabdominal resection: OR=29.250, 95% CI: 2.789 - 306.811, P=0.005; combined abdominal perineal resection: OR=26.000, 95% CI: 2.219-304.702, P=0.009), and anatomical stage of presacral recurrence (Type III: OR=16.000, 95% CI: 1.542 - 166.305, P = 0.020; type IV: OR= 36.667, 95% CI: 3.261 - 412.258, P = 0.004) were all independent risk factors for achieving radical resection of anterior sacral recurrence after rectal cancer surgery. Conclusion: Stage of presacral recurrences of rectal cancer is an independent predictor of achieving R0 resection. It is possible to predict whether radical resection can be achieved on the basis of the patient's medical history.

Animal study on adjustable pre fenestration aortic stent graft

OBJECTIVES

To isolate aortic arch pathologies and keep the branches superior in arch patent, it always need physicians to do in-vivo fenestration or in-situ fenestration when performing the thoracic endovascular aortic repair (TEVAR). However, both of those fenestration techniques need structure modification of the stent-graft, which may affect their long-term stability. We designed an adjustable pre-fenestration aortic stent-graft to treat pathologies in this area and obtained a patent branch arteries. This study used this new designed stent-graft to perform fenestrated-TEVAR (f-TEVAR) in canine aorta. This study aims to identify its feasibility and safety through animal experiments, which might provide preliminary data for potential human implantation.

METHODS

A total of 8 Labrador Retrievers were underwent f-TEVAR by using the new devices. Digital subtraction angiography was performed before and after f-TEVAR to evaluate the success of the procedures. All the canines were divided into a 4-week group (feeding for 4 weeks after operation) and a 12-week group (feeding for 12 weeks after operation). Computed tomography angiography (CTA) were performed before euthanasia.

RESULTS

The success rate of operation was 100%. During the operation, there was no accident of major bleeding or failure to be released by fenestration. Adjustable fenestration worked well. No stent-graft migration was found in CTA at 4 weeks and 12 weeks after the operation. All branch arteries kept by the adjustable fenestration were patent.

CONCLUSIONS

The result of feasibility and safety of the new designed adjustable pre-fenestration aortic stent-graft in f-TEVAR of canine is acceptable. This study provides a reference for further optimization of this stent and human f-TEVAR implantation involving aortic arch lesions.

Spatiotemporal transcriptomic atlas of mouse organogenesis using DNA nanoball-patterned arrays

Spatially resolved transcriptomic technologies are promising tools to study complex biological processes such as mammalian embryogenesis. However, the imbalance between resolution, gene capture, and field of view of current methodologies precludes their systematic application to analyze relatively large and three-dimensional mid- and late-gestation embryos. Here, we combined DNA nanoball (DNB)-patterned arrays and in situ RNA capture to create spatial enhanced resolution omics-sequencing (Stereo-seq). We applied Stereo-seq to generate the mouse organogenesis spatiotemporal transcriptomic atlas (MOSTA), which maps with single-cell resolution and high sensitivity the kinetics and directionality of transcriptional variation during mouse organogenesis. We used this information to gain insight into the molecular basis of spatial cell heterogeneity and cell fate specification in developing tissues such as the dorsal midbrain. Our panoramic atlas will facilitate in-depth investigation of longstanding questions concerning normal and abnormal mammalian development.

Rolling back human pluripotent stem cells to an eight-cell embryo-like stage

After fertilization, the quiescent zygote experiences a burst of genome activation that initiates a short-lived totipotent state. Understanding the process of totipotency in human cells would have broad applications. However, in contrast to in mice1,2, demonstration of the time of zygotic genome activation or the eight-cell (8C) stage in in vitro cultured human cells has not yet been reported, and the study of embryos is limited by ethical and practical considerations. Here we describe a transgene-free, rapid and controllable method for producing 8C-like cells (8CLCs) from human pluripotent stem cells. Single-cell analysis identified key molecular events and gene networks associated with this conversion. Loss-of-function experiments identified fundamental roles for DPPA3, a master regulator of DNA methylation in oocytes3, and TPRX1, a eutherian totipotent cell homeobox (ETCHbox) family transcription factor that is absent in mice4. DPPA3 induces DNA demethylation throughout the 8CLC conversion process, whereas TPRX1 is a key executor of 8CLC gene networks. We further demonstrate that 8CLCs can produce embryonic and extraembryonic lineages in vitro or in vivo in the form of blastoids5 and complex teratomas. Our approach provides a resource to uncover the molecular process of early human embryogenesis.

The tomato OST1-VOZ1 module regulates drought-mediated flowering

Flowering is a critical agricultural trait that substantially affects tomato fruit yield. Although drought stress influences flowering time, the molecular mechanism underlying drought-regulated flowering in tomato remains elusive. In this study, we demonstrated that loss of function of tomato OPEN STOMATA 1 (SlOST1), a protein kinase essential for abscisic acid (ABA) signaling and abiotic stress responses, lowers the tolerance of tomato plants to drought stress. slost1 mutants also exhibited a late flowering phenotype under both normal and drought stress conditions. We also established that SlOST1 directly interacts with and phosphorylates the NAC (NAM, ATAF and CUC)-type transcription factor VASCULAR PLANT ONE-ZINC FINGER 1 (SlVOZ1), at residue serine 67, thereby enhancing its stability and nuclear translocation in an ABA-dependent manner. Moreover, we uncovered several SlVOZ1 binding motifs from DNA affinity purification sequencing analyses and revealed that SlVOZ1 can directly bind to the promoter of the major flowering-integrator gene SINGLE FLOWER TRUSS to promote tomato flowering transition in response to drought. Collectively, our data uncover the essential role of the SlOST1-SlVOZ1 module in regulating flowering in response to drought stress in tomato and offer insights into a novel strategy to balance drought stress response and flowering.

Cell transcriptomic atlas of the non-human primate Macaca fascicularis

Studying tissue composition and function in non-human primates (NHPs) is crucial to understand the nature of our own species. Here we present a large-scale cell transcriptomic atlas that encompasses over 1 million cells from 45 tissues of the adult NHP Macaca fascicularis. This dataset provides a vast annotated resource to study a species phylogenetically close to humans. To demonstrate the utility of the atlas, we have reconstructed the cell-cell interaction networks that drive Wnt signalling across the body, mapped the distribution of receptors and co-receptors for viruses causing human infectious diseases, and intersected our data with human genetic disease orthologues to establish potential clinical associations. Our M. fascicularis cell atlas constitutes an essential reference for future studies in humans and NHPs.

[Advances in high-content screening applications in toxicology research]

The toxicity data of chemicals and drugs increases rapidly, while the animal experimental-based tests method could not meet the current demand of health risk assessment. The high-throughput screening techniques based on in vitro alternative models, integrating with computational methods and information technology to establish toxicity tests strategy promises to address this problem. High-content screening (HCS) technology uses automated microscopy and quantitative image platforms to perform multi-parameter and high-throughput phenotypic analysis via a visualization and quantification manner, and to quickly and effectively assess toxicity and prioritization of chemicals, which promotes the development of in vitro toxicity tests and computational toxicology. HCS technology has been included as an important tool for Toxicity Testing in the 21^st Century (Tox21) and chemical risk prioritization. Its applications have been widely utilized in the research field of toxicity tests and chemical toxicity mechanisms. In this review, we describe the development of HCS technology, technical points, toxicological applications, and the future directions and challenges of HCS, so as to provide references for the toxicity testing technology and risk assessment methodology.

Gas-Liquid Two-Phase Flow Pattern Identification of a Centrifugal Pump Based on SMOTE and Artificial Neural Network

The accurate identification of the gas-liquid two-phase flow pattern within the impeller of a centrifugal pump is critical to develop a reliable model for predicting the gas-liquid two-phase performance of the centrifugal pump. The influences of the inlet gas volume fraction, the liquid phase flow rate and the pump rotational speed on the flow characteristics of the centrifugal pump were investigated experimentally. Four typical flow patterns in the impeller of the centrifugal pump, i.e., the bubble flow, the agglomerated bubble flow, the gas pocket flow and the segregated flow, were obtained, and the corresponding flow pattern maps were drawn. After oversampling based on the SMOTE algorithm, a four-layer artificial neural network model with two hidden layers was constructed. By selecting the appropriate network super parameters, including the neuron numbers in the hidden layer, the learning rate and the activation function, the different flow patterns in the centrifugal pump impeller were identified. The identification rate of the model increased from 89.91% to 94.88% when the original data was oversampled by the SMOTE algorithm. It is demonstrated that the SMOTE algorithm is an effective method to improve the accuracy of the artificial neural network model. In addition, the Kappa coefficient, the Macro-F1 and the Micro-F1 were 0.93, 0.95 and 0.95, respectively, indicating that the model established in this paper can well identify the flow pattern in the impeller of a centrifugal pump.

[Weighted gene co-expression network analysis of methylated genes in burn scar tissue]

Objective: To investigate the methylated genes in burn scar tissue by weighted gene co-expression network analysis (WGCNA), and to discover molecular markers and therapeutic targets of scar formation. Methods: An observational research method was used. Datasets were downloaded from the National Center for Biotechnology Information Gene Expression Omnibus Database of America. The GSE136906 (n=6) and GSE137134 (n=6) datasets in the same batch were screened out for mRNA sequencing and methylation sequencing respectively, and the dataset GSE108110 (n=9) was incorporated into support vector machine and modeling analysis. The Limma software package was used to identify the differentially expressed genes and differentially methylated genes between scar tissue after burn and normal tissue. WGCNA was used to select the module with strong correlation with clinical features of scar tissue and large number of genes. Functional enrichment analysis of the genes in the module was performed to find genes with abnormal methylation. The receiver operating characteristic (ROC) curve was used to judge diagnostic efficacy of genes with abnormal methylation for scar, and support vector machine (SVM) was used to verify. Results: A total of 10 modules were identified, and the brown module with large number of genes was highly correlated to burn scar tissue formation. The genes in the brown module were mainly concentrated in "regulation of androgen receptor signaling pathway", "cytokine-cytokine receptor interaction", "positive regulation of insulin secretion", and so on. The model showed 35 genes with abnormal methylation status. The ROC curve (area under the curve>0.9) and SVM modeling (accuracy=93.3%) indicated that CCR2, LMO7, STEAP4, NNAT, and TCF7L2 genes had good diagnostic performance for scar. Conclusions: CCR2, LMO7, STEAP4, NNAT, and TCF7L2 can be used as potential targets for burn scar treatment.

G protein coupled estrogen receptor attenuates mechanical stress-mediated apoptosis of chondrocyte in osteoarthritis via suppression of Piezo1

BACKGROUND

Apoptosis of chondrocyte is involved in osteoarthritis (OA) pathogenesis, and mechanical stress plays a key role in this process by activation of Piezo1. However, the negative regulation of signal conduction mediated by mechanical stress is still unclear. Here, we elucidate that the critical role of G protein coupled estrogen receptor (GPER) in the regulation of mechanical stress-mediated signal transduction and chondrocyte apoptosis.

METHODS

The gene expression profile was detected by gene chip upon silencing Piezo1. The expression of GPER in cartilage tissue taken from the clinical patients was detected by RT-PCR and Western blot as well as immunohistochemistry, and the correlation between GPER expression and OA was also investigated. The chondrocytes exposed to mechanical stress were treated with estrogen, G-1, G15, GPER-siRNA and YAP (Yes-associated protein)-siRNA. The cell viability of chondrocytes was measured. The expression of polymerized actin and Piezo1 as well as the subcellular localization of YAP was observed under laser confocal microscope. Western blot confirmed the changes of YAP/ Rho GTPase activating protein 29 (ARHGAP29) /RhoA/LIMK /Cofilin pathway. The knee specimens of osteoarthritis model were stained with safranin and green. OARSI score was used to evaluate the joint lesions. The expressions of GPER and YAP were detected by immunochemistry.

RESULTS

Expression profiles of Piezo1- silenced chondrocytes showed that GPER expression was significantly upregulated. Moreover, GPER was negatively correlated with cartilage degeneration during OA pathogenesis. In addition, we uncovered that GPER directly targeted YAP and broadly restrained mechanical stress-triggered actin polymerization. Mechanism studies revealed that GPER inhibited mechanical stress-mediated RhoA/LIMK/cofilin pathway, as well as the actin polymerization, by promoting expression of YAP and ARHGAP29, and the YAP nuclear localization, eventually causing the inhibition of Piezo1. YAP was obviously decreased in degenerated cartilage. Silencing YAP caused significantly increased actin polymerization and activation of Piezo1, and an increase of chondrocyte apoptosis. In addition, intra-articular injection of G-1 to OA rat effectively attenuated cartilage degeneration.

CONCLUSION

We propose a novel regulatory mechanism underlying mechanical stress-mediated apoptosis of chondrocyte and elucidate the potential application value of GPER as therapy targets for OA.

Mediator tail module subunits MED16 and MED25 differentially regulate abscisic acid signaling in Arabidopsis

MED25 has been implicated as a negative regulator of the abscisic acid (ABA) signaling pathway. However, it is unclear whether other Mediator subunits could associate with MED25 to participate in the ABA response. Here, we used affinity purification followed by mass spectrometry to uncover Mediator subunits that associate with MED25 in transgenic plants. We found that at least 26 Mediator subunits, belonging to the head, middle, tail, and CDK8 kinase modules, were co-purified with MED25 in vivo. Interestingly, the tail module subunit MED16 was identified to associate with MED25 under both mock and ABA treatments. We further showed that the disruption of MED16 led to reduced ABA sensitivity compared to the wild type. Transcriptomic analysis revealed that the expression of several ABA-responsive genes was significantly lower in med16 than those in wild type. Furthermore, we discovered that MED16 may possibly compete with MED25 to interact with the key transcription factor ABA INSENSITIVE 5 (ABI5) to positively regulate ABA signaling. Consistently, med16 and med25 mutants displayed opposite phenotypes in ABA response, cuticle permeability, and differential ABI5-mediated EM1 and EM6 expression. Together, our data indicate that MED16 and MED25 differentially regulate ABA signaling by antagonistically affecting ABI5-mediated transcription in Arabidopsis.

[Application of fecal DNA methylation biomarkers detection in gastric cancer screening]

Objective: Explore the feasibility of fecal gene methylation for screening gastric cancer and its relationship with clinical characteristics of gastric cancer patients. Methods: One hundred and fifty-six stool samples of patients in general surgery or digestive department of the First Affiliated Hospital of Soochow University from August 2018 to December 2019 were collected, detailed clinical information of gastric cancer patients were recorded. All patients and normal controls were divided into two sets including train sets (n=52)and test sets (n=104). Stool DNA was extracted for detection of methylation (SDC2, SFRP2, RASSF2 and TERT). Meanwhile, hemoglobin in stool samples were detected by immunoassays. A logistic regression model was built to analyze the sensitivity and specificity of single fecal DNA biomarker in detecting gastric cancer by Ct values of each stool-based DNA biomarker; Based on Akaike information criterion (AIC), the gastric cancer early screening model was constructed with each biomarker and the combinations, and evaluate the performance of the model in the test sets. Results: The accuracy of each stool biomarkers and their ranks were showed as SDC2(71.2%)>TERT(67.3%)=RASSF2(67.3%)>Hb(63.5%)>SFRP2(61.5%). By stepwise regression analysis, a combination composed of the methylation of SDC2 and TERT, fecal occult blood testing was well-behaved in the screening of gastric cancer.This combination showed a sensitivity of 66.7% for gastric cancer in train sets and test sets at the specificity of 78.9%. In different stages and parts of gastric cancer samples, the combination of this marker has the highest sensitivity in stage I gastric cancer(78.6%) and gastric body cancer(75.0%). Conclusion: The methylation of SDC2, SFRP2, TERT, RASSF2 has higher accuracy rate in the screening of gastric cancer, which is a potential fecal biomarker of gastric cancer.

[Guidance of magnetic resonance imaging for target area delineation of postoperative presacral recurrence of rectal cancer]

Objective: Presacral recurrence of rectal cancer have altered the adjacent structures of original pelvic organs due to the previous radical surgery of rectal cancer, and the boundary between recurrent tumor tissues and pelvic internal structures is not clear. Conventional CT examination has poor soft tissue resolution, which makes it difficult to accurately delineate the target area of radiotherapy. This study aimed to explore the guiding role of magnetic resonance imaging (MRI) in delineating the target area of presacral recurrence after radical resection of rectal cancer. Methods: A descriptive case series research method was adopted. From May 2014 to May 2019, the clinical data of 30 patients with presacral recurrence after radical resection of rectal cancer were collected, who were admitted to Peking University People's Hospital, confirmed by pathology or discussed by multidisciplinary team (MDT), with complete MRI, CT and case information. According to the gross tumor volume (GTV) with presacral recurrence outlined in CT and MRI images, including presacral recurrent lesions (GTVT) and metastatic lymph nodes (GTVN), the GTV volume was calculated, and the tumor boundary and diameter were measured. The differences between MRI and CT were compared. Results: The volume of GTVT-CT was larger than that of GTVT-MR in all the 30 patients. The median volume of GTVT-CT was 67.86 (range 5.12-234.10) cm(3), which was significantly larger than 43.02 (range 3.42-142.50) cm(3) of GTVT-MR with statistically significant difference (Z=-4.288, P<0.001). The mean volume of GTVN outlined by CT and MRI was (0.43±0.11) cm(3) and (0.40±0.10) cm(3) respectively without statistically significant difference (t=1.550, P=0.132). The mean values of boundary and radial line of the presacral lesions on CT images were all longer than those on MRI images. The vertical diameter of GTVT on CT and MRI images was (6.66±2.92) cm and (5.17±2.40) cm (t=5.466, P<0.001); the anterior boundary was (3.24±2.51) cm and (2.69±2.48) cm (t=4.685, P<0.001); the anteroposterior diameter was (4.92±2.02) cm and (4.04±1.57) cm (t=6.210, P<0.001); the left boundary was (3.05±1.00) cm and (2.64±0.78) cm (t=2.561, P=0.016); the right boundary was 2.66 (0.00-4.23) cm and 1.82 (-1.10-3.59) cm (Z=-3.950, P<0.001); the transverse diameter was (5.01±1.78) cm and (3.82±1.29) cm (t=4.648, P<0.001), respectively, whose differences were all statistically significant. MRI was superior to CT in judging the involvement of anterior organs, such as intestine, prostate, bladder and the posterior sacrum. Fifteen patients received radiotherapy according to the target area guided by MRI and 10 patients obtained clinical symptom relief. Conclusion: Compared with CT, the GTV of postoperative presacral recurrence of rectal cancer outlined in MRI images is smaller, and MRI can determine the boundary between tumor and surrounding normal tissues more precisely, so it can show the invasion range of tumor more accurately and guide the accurate implementation of radiotherapy.

CDK8 is associated with RAP2.6 and SnRK2.6 and positively modulates abscisic acid signaling and drought response in Arabidopsis

CDK8 is a key subunit of Mediator complex, a large multiprotein complex that is a fundamental part of the conserved eukaryotic transcriptional machinery. However, the biological functions of CDK8 in plant abiotic stress responses remain largely unexplored. Here, we demonstrated CDK8 as a critical regulator in the abscisic acid (ABA) signaling and drought response pathways in Arabidopsis. Compared to wild-type, cdk8 mutants showed reduced sensitivity to ABA, impaired stomatal apertures and hypersensitivity to drought stress. Transcriptomic and chromatin immunoprecipitation analysis revealed that CDK8 positively regulates the transcription of several ABA-responsive genes, probably through promoting the recruitment of RNA polymerase II to their promoters. We discovered that both CDK8 and SnRK2.6 interact physically with an ERF/AP2 transcription factor RAP2.6, which can directly bind to the promoters of RD29A and COLD-REGULATED 15A (COR15A) with GCC or DRE elements, thereby promoting their expression. Importantly, we also showed that CDK8 is essential for the ABA-induced expression of RAP2.6 and RAP2.6-mediated upregulation of ABA-responsive genes, indicating that CDK8 could link the SnRK2.6-mediated ABA signaling to RNA polymerase II to promote immediate transcriptional response to ABA and drought signals. Overall, our data provide new insights into the roles of CDK8 in modulating ABA signaling and drought responses.

Mediator Complex: A Pivotal Regulator of ABA Signaling Pathway and Abiotic Stress Response in Plants

As an evolutionarily conserved multi-protein complex, the Mediator complex modulates the association between transcription factors and RNA polymerase II to precisely regulate gene transcription. Although numerous studies have shown the diverse functions of Mediator complex in plant development, flowering, hormone signaling, and biotic stress response, its roles in the Abscisic acid (ABA) signaling pathway and abiotic stress response remain largely unclear. It has been recognized that the phytohormone, ABA, plays a predominant role in regulating plant adaption to various abiotic stresses as ABA can trigger extensive changes in the transcriptome to help the plants respond to environmental stimuli. Over the past decade, the Mediator complex has been revealed to play key roles in not only regulating the ABA signaling transduction but also in the abiotic stress responses. In this review, we will summarize current knowledge of the Mediator complex in regulating the plants’ response to ABA as well as to the abiotic stresses of cold, drought and high salinity. We will particularly emphasize the involvement of multi-functional subunits of MED25, MED18, MED16, and CDK8 in response to ABA and environmental perturbation. Additionally, we will discuss potential research directions available for further deciphering the role of Mediator complex in regulating ABA and other abiotic stress responses.

[Clinicopathological features and prognosis in patients with presacral recurrent rectal cancer]

Objective: To investigate the clinicopathological features and prognostic factors in patients with presacral recurrent rectal cancer (PRRC). Methods: PRRC was defined as recurrence of rectal cancer after radical surgery involving posteriorly the presacral soft tissue, the sacrum/coccyx, and/or sacral nerve root. The diagnosis is confirmed with clinical symptoms (pain of pelvis/back/lower limb, bloody stools, increased frequency of defecation, and abnormal secretions), physical examination of perineal or pelvic masses, radiological findings, colonoscopy with histopathological biopsy, and the evaluation by multi-disciplinary team (MDT). Inclusion criteria: (1) primary rectal cancer undergoing radical surgery without distant metastasis; (2) PRRC was diagnosed; (3) complete inpatient, outpatient and follow-up data. According to the above criteria, clinical data of 72 patients with PRRC in Peking University People's Hospital from January 2008 to December 2017 were retrospectively analyzed. The clinicopathological features and follow-up data were summarized. Cox proportional hazard models was used to analyze the prognostic factors of PRRC. Results: Among 72 patients, 45 were male and 27 were female with a male-to-female ratio of 1.7:1.0. The median age at recurrence was 58 (34 to 83) years and the median interval from surgery to recurrence was 2.0 (0.2 to 17.0) years. The main symptom was pain in 48.6% (35/72) of patients. In addition, gastrointestinal symptoms were found in 25.0% (18/72) of patients. The presacral recurrent sites were presacral fascia in 36 (50.0%) patients, lower sacrum (S3~S5 or coccyx) in 25 (34.7%) patients, and higher sacrum (S1~S2) in 11 (15.3%) patients. Forty-seven (65.3%) patients underwent radical surgery (abdominal resection, abdominoperineal resection, sacrectomy, abdominosacral resection), 12 (16.7%) underwent non-radical surgery (colostomy, cytoreductive surgery), and 13 (18.1%) did not undergo any surgery but only receive palliative chemoradiotherapy and nutritional support treatment. Thirty-three (45.8%) patients received radiotherapy and/or chemotherapy (oxaliplatin, 5-fluorouracil, capecitabine, irinotecan, etc.). All the patients received follow-up, and the median follow-up time was 19 (2 to 72) months. The median overall survival time was 14 (1 to 65) months. The 1- and 3-year overall survival rates were 67.1% and 32.0%, respectively. Univariate analysis showed that age at recurrence (P=0.031) and radical resection (P<0.001) were associated with prognosis. Multivariate analysis demonstrated that radical resection was independent factor of good prognosis (RR=0.140, 95%CI: 0.061-0.322, P<0.001). Conclusions: Patients tend to develop presacral recurrent rectal cancer within 2 years after primary surgery. The main symptom is pain. Patients undergoing radical resection have a relatively good prognosis.

[Comparison of clinical efficacy among different surgical methods for presacral recurrent rectal cancer]

Objective: To investigate the efficacy and prognosis of three surgical methods for presacral recurrent rectal cancer (PRRC). Methods: A retrospective cohort study was carried out. Case inclusion criteria: (1) primary rectal cancer without distant metastasis and undergoing radical surgery; (2) patients undergoing radical surgery after the diagnosis of PRRC; (3) complete inpatient, outpatient and follow-up data. Clinical data of 47 patients meeting the above criteria who underwent operation at the Department of Gastrointestinal Surgery, The Peking University People's Hospital from January 2008 to December 2017 were reviewed and analyzed retrospectively. Of the 47 patients, 31 were male and 16 were female; the mean age was 57 years old; 9 (19.1%) were low differentiation or signet ring cell carcinoma, 38 (80.9%) were medium differentiation; 19 (40.4%) received neoadjuvant therapy. According to operative procedure, 22 patients were in the abdominal/abdominoperineal resection group, 15 in the sacrectomy group and 10 in the abdominosacral resection group. The operative data, postoperative data and prognosis were compared among the three groups. Survival curve was conducted using the Kaplan-Meier method, and log-rank test was used to compare survival difference among three groups. Results: There were no significant differences in baseline data among three groups (all P>0.05). All the 47 patients completed the radical resection successfully. The mean operation time was (4.7±2.1) hours, the median intraoperative blood loss was 600 ml, and the median postoperative hospitalization time was 17 days. Fifteen cases (31.9%) had perioperative complications, of which 3 cases were grade III-IV. There was no perioperative death. The mean operative time was (7.4±1.6) hours in the abdominosacral resection group, (4.9±1.6) hours in the abdominal/abdominoperineal resection group, and (3.0±1.1) hours in the sacroectomy group, with a significant difference (F=25.071, P<0.001). There were no significant differences in intraoperative blood loss, postoperative hospitalization days and perioperative complications among the three groups (all P>0.05). The median follow-up period of all the patients was 24 months, 12 cases (25.5%) developed postoperative dysfunction. The incidence of postoperative dysfunction in the abdominosacral resection group was 5/10, which was higher than 4/15 in the sacrectomy group and 3/22 (13.6%) in the abdominoperineal resection group with statistically significant difference (χ(2)=9.307, P=0.010). The 1-year and 3-year overall survival rates were 86.1% and 40.2% respectively. The 1-year overall survival rates were 86.0%, 86.7% and 83.3%, and the 3-year overall survival rates were 33.2%, 40.0% and 62.5% in the abdominal/abdominoperineal resection group, sacrectomy group and abdominosacral resection group, respectively, whose difference was not statistically significant (χ(2)=0.222, P=0.895). Conclusions: Abdominal/abdominoperineal resection, sacrectomy and abdominosacral resection are all effective for PRRC. Intraoperative function protection should be concerned for patients undergoing abdominosacral resection.

The stability of care preferences following acute illness: a mixed methods prospective cohort study of frail older people

Background

Patient preferences are integral to person-centred care, but preference stability is poorly understood in older people, who may experience fluctuant illness trajectories with episodes of acute illness. We aimed to describe, and explore influences on the stability of care preferences in frail older people following recent acute illness.

Methods

Mixed-methods prospective cohort study with dominant qualitative component, parallel data collection and six-month follow up. Study population: age ≥ 65, Rockwood Clinical Frailty score ≥ 5, recent acute illness requiring acute assessment/hospitalisation. Participants rated the importance of six preferences (to extend life, improve quality of life, remain independent, be comfortable, support ‘those close to me’, and stay out of hospital) at baseline, 12 and 24 weeks using a 0–4 scale, and ranked the most important. A maximum-variation sub-sample additionally contributed serial in-depth qualitative interviews. We described preference stability using frequencies and proportions, and undertook thematic analysis to explore influences on preference stability.

Results

90/192 (45%) of potential participants consented. 82/90 (91%) answered the baseline questionnaire; median age 84, 63% female. Seventeen undertook qualitative interviews. Most participants consistently rated five of the six preferences as important (range 68–89%). ‘Extend life’ was rated important by fewer participants (32–43%). Importance ratings were stable in 61–86% of cases. The preference ranked most important was unstable in 82% of participants.

Preference stability was supported by five influences: the presence of family support; both positive or negative care experiences; preferences being concordant with underlying values; where there was slowness of recovery from illness; and when preferences linked to long term goals. Preference change was related to changes in health awareness, or life events; if preferences were specific to a particular context, or multiple concurrent preferences existed, these were also more liable to change.

Conclusions

Preferences were largely stable following acute illness. Stability was reinforced by care experiences and the presence of family support. Where preferences were unstable, this usually related to changing health awareness. Consideration of these influences during preference elicitation or advance care planning will support delivery of responsive care to meet preferences. Obtaining longer-term data across diverse ethnic groups is needed in future research.

Biomechanical effect of asymmetric mandibular prognathism treated with BSSRO and USSRO on temporomandibular joints: a three-dimensional finite element analysis

Asymmetric mandibular prognathism is a clinically common skeletal dentomaxillofacial deformity. Unilateral sagittal split ramus osteotomy (USSRO) is an effective alternative procedure to bilateral sagittal split ramus osteotomy (BSSRO) for some patients. However, the biomechanical effect of temporomandibular joint (TMJ) of USSRO has not been fully studied. This study aims to evaluate the stress distribution changes in the TMJ of asymmetric mandibular prognathism treated with BSSRO/USSRO, to validate the clinical feasibility of USSRO. Nineteen patients with mandibular prognathism patients who were treated with BSSRO (n=12) and USSRO (n=7) had preoperative and postoperative computed tomographic scanning. Preoperative and postoperative 3-dimensional finite element analysis (FEA) of functional TMJ movements were made on one BSSRO patient and one USSRO patient. In all patients, the ANB angle and mandibular deviation were significantly improved postoperatively. There was no significant difference in the postoperative ANB angle and mandibular deviation between the BSSRO group and the USSRO group. In two preoperative FEA models, the maximum stresses of non-deviation side TMJ structures were greater than the deviation side during functional movements. The unbalanced stress distribution was corrected postoperatively in both BSSRO/USSRO FE models. Both BSSRO/USSRO can improve the ANB angle and mandibular deviation. The bilateral TMJ structure in patients with asymmetric mandibular prognathism had unbalanced stress, which could be significantly improved with the USSRO as effectively as BSSRO.

β-Catenin safeguards the ground state of mousepluripotency by strengthening the robustness of the transcriptional apparatus

Mouse embryonic stem cells cultured with MEK (mitogen-activated protein kinase kinase) and GSK3 (glycogen synthase kinase 3) inhibitors (2i) more closely resemble the inner cell mass of preimplantation blastocysts than those cultured with SL [serum/leukemia inhibitory factor (LIF)]. The transcriptional mechanisms governing this pluripotent ground state are unresolved. Release of promoter-proximal paused RNA polymerase II (Pol2) is a multistep process necessary for pluripotency and cell cycle gene transcription in SL. We show that β-catenin, stabilized by GSK3 inhibition in medium with 2i, supplies transcriptional coregulators at pluripotency loci. This selectively strengthens pluripotency loci and renders them addicted to transcription initiation for productive gene body elongation in detriment to Pol2 pause release. By contrast, cell cycle genes are not bound by β-catenin, and proliferation/self-renewal remains tightly controlled by Pol2 pause release under 2i conditions. Our findings explain how pluripotency is reinforced in the ground state and also provide a general model for transcriptional resilience/adaptation upon network perturbation in other contexts.

Piezo1 activates the NLRP3 inflammasome in nucleus pulposus cell-mediated by Ca2+/NF-κB pathway

Studying and understanding the mechanism of inflammation in nucleus pulposus is the key to understand and prevent intervertebral disc degeneration. We propose a model of mechanical sensitive ion channel Piezo1 mediated inflammation of nucleus pulposus cells. Piezo1 can up-regulate the level of interleukin-1β (IL-1β) in nucleus pulposus cells once it is activated. It is suggested that Piezo1 may mediate inflammation by activating Nod-like receptor protein 3 (NLRP3) inflammasome to accelerate the production and maturation of IL-1β. The primary objective of this study was to explore whether Piezo1 activates NLRP3 inflammasome in nucleus pulposus cells. Piezo1 sensitization was induced by mechanical stretch following which we analyzed the priming and assembly of NLRP3 inflammasome and also studied if the downstream Ca²⁺/NF-κB pathway mediated this activation in nucleus pulposus cells. The expression of Piezo1 and NLRP3 inflammasome increased in a time-dependent manner upon mechanical stretch. Piezo1 activation promoted NLRP3 inflammasome assembly, which was demonstrated by the upregulation of caspase-1 activation and IL-1β production. Transfection of Piezo1-siRNA reversed this process. The inhibition of Ca²⁺/NF-κB pathway reduced Piezo1-dependent activation of NLRP3 inflammasome. Thus, we propose that activation of NLRP3 inflammasome in nucleus pulposus cells mediated by Piezo1 through the Ca²⁺/NF-κB pathway is a novel pathogenesis for the progress of intervertebral disc degeneration. As per our knowledge this is the first study which has provided evidence linking Piezo1-mediated inflammation in nucleus pulposus cells with the production of NLRP3 inflammasome.

MYB Superfamily in Brassica napus: Evidence for Hormone-Mediated Expression Profiles, Large Expansion, and Functions in Root Hair Development

MYB proteins are involved in diverse important biological processes in plants. Herein, we obtained the MYB superfamily from the allotetraploid Brassica napus, which contains 227 MYB-related (BnMYBR/Bn1R-MYB), 429 R2R3-MYB (Bn2R-MYB), 22 R1R2R3-MYB (Bn3R-MYB), and two R1R2R2R1/2-MYB (Bn4R-MYB) genes. Phylogenetic analysis classified the Bn2R-MYBs into 43 subfamilies, and the BnMYBRs into five subfamilies. Sequence characteristics and exon/intron structures within each subfamily of the Bn2R-MYBs and BnMYBRs were highly conserved. The whole superfamily was unevenly distributed on 19 chromosomes and underwent unbalanced expansion in B. napus. Allopolyploidy between B. oleracea and B. rapa mainly contributed to the expansion in their descendent B. napus, in which B. rapa-derived genes were more retained. Comparative phylogenetic analysis of 2R-MYB proteins from nine Brassicaceae and seven non-Brassicaceae species identified five Brassicaceae-specific subfamilies and five subfamilies that are lacking from the examined Brassicaceae species, which provided an example for the adaptive evolution of the 2R-MYB gene family alongside angiosperm diversification. Ectopic expression of four Bn2R-MYBs under the control of the viral CaMV35S and/or native promoters could rescue the lesser root hair phenotype of the Arabidopsis thaliana wer mutant plants, proving the conserved negative roles of the 2R-MYBs of the S15 subfamily in root hair development. RNA-sequencing data revealed that the Bn2R-MYBs and BnMYBRs had diverse transcript profiles in roots in response to the treatments with various hormones. Our findings provide valuable information for further functional characterizations of B. napusMYB genes.

Odorranalectin modified PEG-PLGA/PEG-PBLG curcumin-loaded nanoparticle for intranasal administration

Curcumin (Cur) is a promising drug for neurological diseases. Nevertheless, the application of Cur has been limited due to its difficulty in penetrating blood-brain barrier (BBB). Intranasal drug delivery, a noninvasive alternative delivery of Cur, can effectively help Cur cross BBB and inert into central nervous system directly. Odorranalectin (OL) which is the smallest lectin can prolong the residence time of Cur in the nasal mucosa and promote cellular uptake. In this work, a nasal delivery system incorporating OL modified Cur-loaded nanoparticles (Cur-OL-NPs) was developed and expected to bypass BBB and promote the absorption of Cur. We conjugated OL to polyethylene glycol-poly (lactic-co-glycolic acid) (PEG-PLGA), and combined polyethylene glycol-poly (γ-benzyl-L-glutamate) (PEG-PBLG) and OL-PEG-PLGA to prepare nanoparticles to improve the stability, bioavailability and targeting of Cur. Compared with unmodified NPs, increased efficiency of Cur-OL-NPs cellular uptake by Calu-3 cells had been obtained with no severe toxicity. Furthermore, in vivo pharmacokinetic studies also showed that Cur-OL-NPs had higher relative bioavailability. Thus, it is concluded that the results indicated that OL-NPs as carriers of Cur had a promising future in nasal drug delivery system.

MiR-29a promotes osteogenic differentiation of mesenchymal stem cells via targeting HDAC4

OBJECTIVE

To investigate the role of miR-29a in regulating the differentiation mesenchymal stem cells into osteoblasts.

MATERIALS AND METHODS

For the first step, the changes of expression of miR-29a during the process of mesenchymal stem cells (MSCs) differentiation into osteoblast were detected. Then, we infected the MSCs with mimics or inhibitors of miR-29a to explore the roles of miR-29a in the differentiation. Further, the prediction and verification of the possible target genes of miR-29a were achieved by bioinformatics analysis and luciferase reporter assay.

RESULTS

MiR-29a was up-regulated during the process of MSCs differentiation into osteoblasts. Overexpression or inhibition of miR-29a using mimics or inhibitors had no significant effect on cell proliferation. Furthermore, the differentiation was enhanced when miR-29a was artificially overexpressed in vitro, whereas silencing of miR-29a attenuated this process. It was evidenced by alkaline phosphatase (ALP) staining, matrix mineralization, and increased expression of osteoblast-specific genes. Furthermore, we determined that the gene HDAC4 might be a direct target of miR-29a.

CONCLUSIONS

In the current study, miR-29a promotes osteogenesis via suppressing HDAC4, indicating that targeting miR-29a may be feasible in the management of osteoporosis.

Genome-wide survey and expression analyses of the GRAS gene family in Brassica napus reveals their roles in root development and stress response

Genome-wide identification, classification, expression analyses, and functional characterization of GRAS genes in oil crop, Brassica napus, indicate their importance in root development and stress response. GRAS proteins are a plant-specific transcription factor gene family involved in tissues development and stress response. We classified 87 putative GRAS genes in the Brassica napus genome (BnGRASs) into 13 subfamilies by phylogenetic analysis. The C-terminal GRAS domains of Brassica napus (B. napus) proteins were less conserved among subfamilies, but were conserved within each subfamily. A series of analyses revealed that 89.7% of the BnGRASs did not have intron insertions, and 24 specific-motifs were found at the N-terminal. A highly conserved microRNA 171 (miRNA171) target was observed specifically in the HAM subfamily across land plants. A total of 868 pairs of interaction proteins were predicted, the primary of which were transcription factors involved in transcriptional regulation and signal transduction. Integrated comparative analysis of GRAS genes across 26 species of algae, mosses, ferns, gymnosperms, and angiosperms revealed that this gene family originated in early mosses and was classified into 19 subfamilies, 14 of which may have originated prior to bryophyte evolution. RNA-Seq analysis demonstrated that most BnGRASs were widely expressed in different tissues/organs at different stages in B. napus, and 24 BnGRASs were highly/specifically expressed in roots. Results from a qRT-PCR analysis suggested that two BnGRASs belonging to SCR and LISCL subfamilies potentially have important roles in the stress response of roots.