[Progress in the Role of Mechanical Stimulus in Cardiac Development].

Mechanical stimulus is critical to cardiovascular development during embryogenesis period.The mechanoreceptors of endocardial cells and cardiac myocytes may sense mechanical signals and initiate signal transduction that induce gene expression at a cellular level,and then translate molecular-level events into tissue-level deformations,thus guiding embryo development.This review summarizes the regulatory roles of mechanical signals in the early cardiac development including the formation of heart tube,looping,valve and septal morphogenesis,ventricular development and maturation.Further,we discuss the potential mechanical transduction mechanisms of platelet endothelial cell adhesion molecule 1-vascular endothelial-cadherin-vascular endothelial growth factor receptor 2 complex,primary cilia,ion channels,and other mechanical sensors that affect some cardiac malformations.

Should a Mechanical or Biological Prosthesis Be Used for a Tricuspid Valve Replacement? A Meta-Analysis.

BACKGROUND AND AIM OF THE STUDY: The prosthesis of choice for a tricuspid valve replacement is still unkown. This meta-analysis was undertaken to review the results of mechanical and bioprosthetic valves in the tricuspid position. METHODS: We identified all relevant studies published in the past 20 years (from January 1, 1995 to December 31, 2014) through the Embase, Current Contents, and PubMed databases. The hazard ratio and its 95% confidence limits were utilized to evaluate time-to-event related effects of surgical procedures. The Q-statistic, Index of Inconsistency test, funnel plots, and Egger's test were used to assess the degree of heterogeneity and publication bias. Random effects models were used, and study quality was also assessed. RESULTS: In our meta-analysis, 22 studies published from 1995 to 2014 were reviewed and 2630 patients and 14,694 follow-up years were analyzed. No statistically significant difference was identified between mechanical and biological valves in terms of survival, reoperation, and prosthetic valve failure. The respective pooled hazard ratio estimates were 0.95 (0.79 to 1.16, p = 0.62, I(2) = 29%), 1.20 (0.84 to 1.71, p = 0.33, I(2) = 0%), and 0.35 (0.06 to 2.01, p = 0.24, I(2) = 0%). A higher risk of thrombosis was found in mechanical tricuspid valve prostheses (3.86, 1.38 to 10.82, p = 0.01, I(2) = 0%). CONCLUSIONS: No statistically significant difference was identified between mechanical and biological valves in terms of survival, reoperation, or prosthetic valve failure, but mechanical tricuspid valve prostheses had a higher risk of thrombosis. doi: 10.1111/jocs.12730 (J Card Surg 2016;31:294-302).

The Role of Interleukin-13 in Patients with Rheumatic Valvular Fibrosis: A Clinical and Histological Study.

BACKGROUND AND AIM OF THE STUDY: Interleukin (IL)-13 is a major inducer of fibrosis in many chronic infectious diseases, yet few studies have reported its role in valvular fibrosis in patients with rheumatic heart disease (RHD). The study aim was to investigate the role of IL-13 in mitral valvular fibrosis in patients with RHD. METHODS: Peripheral blood samples were collected from surgical patients with RHD (n = 18) and from healthy controls (n = 9). Serum levels of IL-13 and interferon (IFN)-gamma were analyzed using ELISA. Rheumatic mitral valves removed from surgical patients with RHD, and normal mitral valves, were obtained at autopsy. The expression and distribution of collagen I, collagen III, and IL-13Ralpha1 were examined by immunohistochemical staining, the degree of which was measured using computed imaging analysis. RESULTS: Higher IL-13 levels were observed in RHD patients (15.16 +/- 9.62 pg/ml; p < 0.05) than in healthy controls (7.78 +/- 3.87 pg/ml). RHD patients had high levels of IFN-gamma (9.95 +/- 0.77 pg/ml; p <0.05) compared to healthy controls (5.95 +/- 0.69 pg/ml). Immunohistochemistry showed that, compared to normal valves, rheumatic mitral valves expressed high levels of collagen I (0.01931 +/- 0.00159 versus 0.01183 +/- 0.00207; p < 0.05), collagen III (0.00726 +/- 0.00078 versus 0.00342 +/- 0.00124; p <0.05), and IL-13Rcxl (0.00454 +/- 0.00086 versus 0.00017 +/- 0.00008; p <0.01). Collagens I and III were each expressed in heart interstitial cells, while IL-13Ralpha1 was expressed in the endothelial cells and smooth muscle cells of the blood vessels, and in interstitial cells. CONCLUSION: Patients with RHD showed increased serum levels of IL-13 compared to healthy controls. IFN-gamma levels were clearly different among RHD patients and healthy controls. The expression of collagens I and III and IL-13Ralpha1 was higher in rheumatic mitral valves compared to normal mitral valves. IL-13 may induce mitral valvular fibrosis in RHD.

Domestication and geographic origin of Oryza sativa in China: insights from multilocus analysis of nucleotide variation of O. sativa and O. rufipogon.

Previous studies have indicated that China is one of the domestication centres of Asian cultivated rice (Oryza sativa), and common wild rice (O. rufipogon) is the progenitor of O. sativa. However, the number of domestication times and the geographic origin of Asian cultivated rice in China are still under debate. In this study, 100 accessions of Asian cultivated rice and 111 accessions of common wild rice in China were selected to examine the relationship between O. sativa and O. rufipogon and thereby infer the domestication and evolution of O. sativa in China through sequence analyses of six gene regions, trnC-ycf6 in chloroplast genomes, cox3 in mitochondrial genomes and ITS, Ehd1, Waxy, Hd1 in nuclear genomes. The results indicated that the two subspecies of O. sativa (indica and japonica) were domesticated independently from different populations of O. rufipogon with gene flow occurring later from japonica to indica; Southern China was the genetic diversity centre of O. rufipogon, and the Pearl River basin near the Tropic of Cancer was the domestication centre of O. sativa in China.

Role of Neuroimmune Interactions in COVID-19-related Cardiovascular Damage.

Coronavirus disease 2019 (COVID-19) has caused a global pandemic impacting over 200 countries/regions and more than 200 million patients worldwide. Among the infected patients, there is a high prevalence of COVID-19-related cardiovascular injuries. However, the specific mechanisms linking cardiovascular damage and COVID-19 remain unclear. The COVID-19 pandemic also has exacerbated the mental health burden of humans. Considering the close association between neuroimmune interactions and cardiovascular disease, this review assessed the complex pathophysiological mechanisms connecting neuroimmune interactions and cardiovascular disease. It was revealed that the mental health burden might be a pivotal accomplice causing COVID-19-associated cardiovascular damage. Specifically, the proinflammatory status of patients with a terrible mood state is closely related to overdrive of the hypothalamus-pituitary-adrenal (HPA) axis, sympathovagal imbalance, and endothelial dysfunction, which lead to an increased risk of developing cardiovascular injury during COVID-19. Therefore, during the prevention and treatment of cardiovascular complications in COVID-19 patients, particular attention should be given to relieve the mental health burden of these patients.

Which is the best prosthesis in an isolated or combined tricuspid valve replacement?

OBJECTIVES: The debate concerning the optimal choice of tricuspid position continues. We compared the long-term results of mechanical and biological prostheses in patients who underwent isolated or combined tricuspid valve replacement, at 2 major cardiac surgical centres in central China. METHODS: From January 1999 to December 2018, 338 patients underwent tricuspid valve replacement. Patients were divided into an isolated group or a combined group according to whether their surgery was combined with a left heart valve surgery. Mechanical tricuspid valve replacement was performed in 142 patients (isolated group: 41 vs combined group: 101), and 196 patients underwent bioprosthetic tricuspid valve replacement (isolated group: 145 vs combined group: 51). Operative results, long-term survival and tricuspid valve-related events were compared. RESULTS: Early mortality in the combined group was higher (n = 6, 4%) than that in the isolated group (n = 3, 2%), but no significant difference was observed between the mechanical and biological subgroups. In the isolated group, there was a higher event-free rate in the biological subgroup than in the mechanical subgroup (P = 0.042) and a similar result was also observed for patients without Ebstein's anomaly (P = 0.039). In the combined group, no significant difference was observed (P = 0.98). Survival rates were similar between the mechanical and biological subgroups in both the isolated (P = 0.54) and combined (P = 0.81) groups. Mechanical valves in isolated tricuspid valve replacement were more prone to valve thrombosis and bleeding. CONCLUSIONS: Every decision regarding tricuspid valve prostheses should be individualized, but biological prostheses may be an optimal choice for patients, especially for patients without Ebstein's anomaly, in isolated tricuspid valve replacement.

Sequential hydrophile and lipophile solubilization as an efficient method for decellularization of porcine aortic valve leaflets: Structure, mechanical property and biocompatibility study.

Antigenicity of xenogeneic tissues is the major obstacle to increased use of these materials in clinical medicine. Residual xenoantigens in decellularized tissue elicit the immune response after implantation, causing graft failure. With this in mind, the potential use is proposed of three protein solubilization-based protocols for porcine aortic valve leaflets decellularization. It was demonstrated that hydrophile solubilization alone achieved incomplete decellularization; lipophile solubilization alone (LSA) completely removed all cells and two most critical xenoantigens - galactose-α(1,3)-galactose (α-Gal) and major histocompatibility complex I (MHC I) - but caused severe alterations of the structure and mechanical properties; sequential hydrophile and lipophile solubilization (SHLS) resulted in a complete removal of cells, α-Gal and MHC I, and good preservation of the structure and mechanical properties. In contrast, a previously reported method using Triton X-100, sodium deoxycholate and IGEPAL CA-630 resulted in a complete removal of all cells and MHC I, but with remaining α-Gal epitope. LSA- and SHLS-treated leaflets showed significantly reduced leucocyte activation (polymorphonuclear elastase) upon interaction with human blood in vitro. When implanted subdermally in rats for 6 weeks, LSA- or SHLS-treated leaflets were presented with more biocompatible implants and all four decellularized leaflets were highly resistant to calcification. These findings illustrate that the SHLS protocol could be considered as a promising decellularization method for the decellularization of xenogeneic tissues in tissue engineering and regenerative medicine. Copyright © 2016 John Wiley & Sons, Ltd.

Analysis of amylose accumulation during seed development in maize.

Starch, which includes amylose and amylopectin, is the most important component in maize (Zea mays L.) seeds. The accumulation of amylose in maize seeds was examined in this study. The percentage of amylose content gradually increased in seeds from day 10 to day 25 after pollination, which is consistent with the changes of GBSS activity. The transcripts of GBSSI were detected in both the endosperm and embryo of wild-type maize. However, its transcripts, GBSS activity, and amylose were not detected in either the endosperm or embryo of waxy maize. These results indicate that the accumulation of amylose is controlled by GBSSI expression in the seeds of maize.

Overexpression of AeNHX1, a root-specific vacuolar Na+/H+ antiporter from Agropyron elongatum, confers salt tolerance to Arabidopsis and Festuca plants.

Agropyron elongatum, a species in grass family, has a strong tolerance to salt stress. To study the molecular mechanism of Agropyron elongatum in salt tolerance, we isolated a homolog of Na(+)/H(+) antiporters from the root tissues of Agropyron plants. Sequence analysis revealed that this gene encodes a putative vacuolar Na(+)/H(+) antiporter and was designated as AeNHX1. The AeNHX1-GFP fusion protein was clearly targeted to the vacuolar membrane in a transient transfection assay. Northern analysis indicated that AeNHX1 was expressed in a root-specific manner. Expression of AeNHX1 in yeast Na(+)/H(+) antiporter mutants showed function complementation. Further, overexpression of AeNHX1 promoted salt tolerance of Arabidopsis plants, and improved osmotic adjustment and photosynthesis which might be responsible for normal development of transgenic plants under salt stress. Similarly, AeNHX1 also functioned in transgenic Festuca plants. The results suggest that this gene might function in the roots of Agropyron plants, and its expression is involved in the improvement of salt tolerance.