OTUD1 promotes isoprenaline- and myocardial infarction-induced heart failure by targeting PDE5A in cardiomyocytes.

Heart failure represents a major cause of death worldwide. Recent research has emphasized the potential role of protein ubiquitination/deubiquitination protein modification in cardiac pathology. Here, we investigate the role of the ovarian tumor deubiquitinase 1 (OTUD1) in isoprenaline (ISO)- and myocardial infarction (MI)-induced heart failure and its molecular mechanism. OTUD1 protein levels were raised markedly in murine cardiomyocytes after MI and ISO treatment. OTUD1 deficiency attenuated myocardial hypertrophy and cardiac dysfunction induced by ISO infusion or MI operation. In vitro, OTUD1 knockdown in neonatal rat ventricular myocytes (NRVMs) attenuated ISO-induced injuries, while OTUD1 overexpression aggravated the pathological changes. Mechanistically, LC-MS/MS and Co-IP studies showed that OTUD1 bound directly to the GAF1 and PDEase domains of PDE5A. OTUD1 was found to reverse K48 ubiquitin chain in PDE5A through cysteine at position 320 of OTUD1, preventing its proteasomal degradation. PDE5A could inactivates the cGMP-PKG-SERCA2a signaling axis which dysregulate the calcium handling in cardiomyocytes, and leading to the cardiomyocyte injuries. In conclusion, OTUD1 promotes heart failure by deubiquitinating and stabilizing PDE5A in cardiomyocytes. These findings have identified PDE5A as a new target of OTUD1 and emphasize the potential of OTUD1 as a target for treating heart failure.

Structural characterization and in vitro hypoglycaemic activity of glucomannan from Anemarrhena asphodeloides Bunge.

A new polysaccharide (AABP-2B) was obtained from Anemarrhena asphodeloides Bunge after purification by gradient alcohol precipitation and DEAE-52 cellulose column chromatography. AABP-2B was confirmed to be a homogeneous polysaccharide with a molecular weight of 5800 Da and was composed of mannose and glucose at a molar ratio of 7.2 : 2.8. Structural analysis demonstrated that the backbone of AABP-2B was mainly composed of 4)-ß-D-Manp-(1, 4,6)-ß-D-Glcp-(1 and 3,6)-ß-D-Manp-(1. The hypoglycaemic effect of AABP-2B was evaluated by its inhibition of α-glucosidase activities and insulin resistance in a HepG2 cell model. The results showed that AABP-2B displayed α-glucosidase inhibitory activities and could significantly improve glucose consumption by activating the IRS-1/PI3K/Akt signalling pathway in insulin-resistant HepG2 cells. Hence, AABP-2B may have potential as a functional food or medicine for diabetes therapy.

Maize NAC-domain retained splice variants act as dominant negatives to interfere with the full-length NAC counterparts.

The plant-specific NAC transcription factors play diverse roles in various stress signaling. Alternative splicing is particularly prevalent in plants under stress. However, the investigation of cadmium (Cd) on the differential expression of the splice variants of NACs is in its infancy. Here, we identified three Cd-induced intron retention splice NAC variants which only contained the canonical NAC domain, designated as nacDomains, derived from three Cd-upregulated maize NACs. Subcellular localization analysis indicated that both nacDomain and its full-length NAC counterpart co-localized in the nucleus as manifested in the BiFC assay, thus implied that nacDomains and their corresponding NACs form heterodimers through the identical NAC domain. Further chimeric reporter/effector transient expression assay and Cd-tolerance assay in tobacco leaves collectively indicated that nacDomain-NAC heterodimers were involved in the regulation of NAC function. The results obtained here were in accordance with the model of dominant negative, which suggested that nacDomain act as the dominant negative to antagonize the regulation of NAC on its target gene expression and the Cd-tolerance function performance of NAC transcription factor. These findings proposed a novel insight into understanding the molecular mechanisms of Cd response in plants.

Physiological and biochemical responses of Ulva prolifera and Ulva linza to cadmium stress.

Responses of Ulva prolifera and Ulva linza to Cd(2+) stress were studied. We found that the relative growth rate (RGR), Fv/Fm, and actual photochemical efficiency of PSII (Yield) of two Ulvaspecies were decreased under Cd(2+) treatments, and these reductions were greater in U. prolifera than in U. linza. U. prolifera accumulated more cadmium than U. linza under Cd(2+) stress. While U. linza showed positive osmotic adjustment ability (OAA) at a wider Cd(2+) range than U. prolifera. U. linza had greater contents of N, P, Na(+), K(+), and amino acids than U. prolifera. A range of parameters (concentrations of cadmium, Ca(2+), N, P, K(+), Cl(-), free amino acids (FAAs), proline, organic acids and soluble protein, Fv/Fm, Yield, OAA, and K(+)/Na(+)) could be used to evaluate cadmium resistance in Ulva by correlation analysis. In accordance with the order of the absolute values of correlation coefficient, contents of Cd(2+) and K(+), Yield, proline content, Fv/Fm, FAA content, and OAA value of Ulva were more highly related to their adaptation to Cd(2+) than the other eight indices. Thus, U. linza has a better adaptation to Cd(2+) than U. prolifera, which was due mainly to higher nutrient content and stronger OAA and photosynthesis in U. linza.

[Comparison of seed oil physicochemical characteristics among three cultivars of Jatropha curcas L].

Taking the cultivars Nanyou 1, 2, and 3 of barbadosnut (Jatropha curcas L. ) with different genotypes that can grow and seed normally at the inshore land in Hainan as test materials, the characters of their seeds and the physicochemical characteristics of their seed oils were analyzed and compared. No significant differences were observed in the seed length, width, thickness, and surface area among the cultivars, but Nanyou 2 had greater 1000 seed mass and lower unsound kernel percentage than Nanyou 1 and Nanyou 3, suggesting that the seed satiation of Nanyou 2 was good and the fecundity was excellent. The kernel oil content of Nanyou 3 was significantly higher than that of Nanyou 1 and Nanyou 2, and there was no significant difference between Nanyou 1 and Nanyou 2. The seed oil peroxide value, refractive index, and saponification value of the three cultivars had no significant differences, but the acid value for Nanyou 2 was much lower than that for Nanyou 1 and Nanyou 3. The seed oil iodine value of the three cultivars was all below 100, and was significantly lower for Nanyou 2 than for Nanyou 1 and Nanyou 3. The fatty acids in the three cultivars seed oils were mainly oleic acid, palmitic acid, linoleic acid, stearic acid, and margaric acid, and dominated by unsaturated fatty acids. The contents of saturated fatty acids in Nanyou 2 seed oil were relatively higher than those in Nanyou 1 and Nanyou 3 seed oils, indicating that comparing with Nanyou 1, cultivars Nanyou 2 and Nanyou 3 had relatively good potential for application.

Silicate improves growth and ion absorption and distribution in aloe vera under salt stress.

Si 2.0 mmol/L in irrigation solution alleviated significantly the inhibition of NaCl stress of 100 or 200 mmol/L to aloe growth. Exogenously applied Si decreased significantly Na(+) and Cl(-) contents, increased K(+) content and K(+)/Na(+) ratio and selectivity ratio of absorption (AS(K, Na)) and of translocation (TS(K, Na)) to K(+) and Na(+) in aloe plant under both NaCl 100 and 200 mmol/L stresses for 30 d. In this way, the ion homeostasis in aloe plant under NaCl stress was maintained, as was proved by X-ray microanalysis of root tip and leaf across sections. One of the mechanisms to achieve this may be the significant enhancement of H(+)-ATPase activities by the addition of silicate in plasma membrane and tonoplast, H(+)-pyrophosphatase (H(+)-PPase) activity in tonoplast isolated from aloe root tips under NaCl stress.