Newly Isolated Paenibacillus monticola sp. nov., a Novel Plant Growth-Promoting Rhizobacteria Strain From High-Altitude Spruce Forests in the Qilian Mountains, China

Species in the genus Paenibacillus from special habitats have attracted great attention due to their plant growth-promoting traits. A novel plant growth-promoting rhizobacteria (PGPR) species in the genus Paenibacillus was isolated from spruce forest at the height of 3,150 m in the Qilian Mountains, Gansu province, China. The phylogenetic analysis based on 16S rRNA, rpoB, and nifH gene sequences demonstrated that strain LC-T2^T was affiliated in the genus Paenibacillus and exhibited the highest sequence similarity with Paenibacillus donghaensis KCTC 13049^T (97.4%). Average nucleotide identity (ANIb and ANIm) and digital DNA–DNA hybridization (dDDH) between strain LC-T2^T and P. donghaensis KCTC 13049^T were 72.6, 83.3, and 21.2%, respectively, indicating their genetic differences at the species level. These differences were further verified by polar lipids profiles, major fatty acid contents, and several distinct physiological characteristics. Meanwhile, the draft genome analysis provided insight into the genetic features to support its plant-associated lifestyle and habitat adaptation. Subsequently, the effects of volatile organic compound (VOC) emitted from strain LC-T2^T on the growth of Arabidopsis were evaluated. Application of strain LC-T2^T significantly improved root surface area, root projection area, and root fork numbers by 158.3, 158.3, and 241.2%, respectively, compared to control. Also, the effects of LC-T2^T on the growth of white clover (Trifolium repens L.) were further assessed by pot experiment. Application of LC-T2^T also significantly improved the growth of white clover with root fresh weight increased over three-folds compared to control. Furthermore, the viable bacterial genera of rhizosphere soil were detected in each treatment. The number of genera from LC-T2^T-inoculated rhizosphere soil was 1.7-fold higher than that of control, and some isolates were similar to strain LC-T2^T, indicating that LC-T2^T inoculation was effective in the rhizosphere soil of white clover. Overall, strain LC-T2^T should be attributed to a novel PGPR species within the genus Paenibacillus based on phylogenetic relatedness, genotypic features, and phenotypic and inoculation experiment, for which the name Paenibacillus monticola sp. nov. is proposed.

Risk factors for mortality in patients undergoing continuous renal replacement therapy after cardiac surgery

BACKGROUND

To investigate the risk factors for mortality in patients with acute kidney injury requiring continuous renal replacement therapy (AKI-CRRT) after cardiac surgery.

METHODS

In this retrospective study, patients who underwent AKI-CRRT after cardiac surgery in our centre from January 2015 to January 2020 were included. Univariable and multivariable analyses were performed to identify the risk factors for in-hospital mortality.

RESULTS

A total of 412 patients were included in our study. Of these, 174 died after AKI-CRRT, and the remaining 238 were included in the survival control group. Multivariable logistic regression analysis revealed that EuroSCORE > 7 (odds ratio [OR], 3.72; 95% confidence interval [CI], 1.92-7.24; p < 0.01), intraoperative bleeding > 1 L (OR, 2.14; 95% CI, 1.19-3.86; p = 0.01) and mechanical ventilation time > 70 h (OR, 5.03; 95% CI, 2.40-10.54; p < 0.01) were independent risk factors for in-hospital mortality in patients who had undergone AKI-CRRT. Our study also found that the use of furosemide after surgery was a protective factor for such patients (odds ratio, 0.48; 95% confidence interval, 0.25-0.92; p = 0.03).

CONCLUSIONS

In summary, the mortality of patients with AKI-CRRT after cardiac surgery remains high. The EuroSCORE, intraoperative bleeding and mechanical ventilation time were independent risk factors for in-hospital mortality. Continuous application of furosemide may be associated with a better outcome.

[Effects and mechanisms of Supplemented Gegen Qinlian Decoction Formula against podocyte pyroptosis and insulin resistance in model rats with diabetic kidney disease]

This study explored the in vivo effects and mechanisms of the modern classical prescription Supplemented Gegen Qinlian Decoction Formula(SGDF) against diabetic kidney disease(DKD). Sixty rats were randomly divided into the normal group, model group, SGDF group, and rosiglitazone(ROS) group. The modified DKD rat model was established by employing the following three methods: exposure to high-fat diet, unilateral nephrectomy, and intraperitoneal injection of streptozotocin(STZ). After modeling, rats in the four groups were treated with double distilled water, SGDF suspension, and ROS suspension, respectively, by gavage every day. At the end of the 6 th week of drug administration, all the rats were sacrificed for collecting urine, blood, and kidney tissue, followed by the examination of rat general conditions, urine and blood biochemical indicators, glomerulosclerosis-related indicators, podocyte pyroptosis markers, insulin resistance(IR)-related indicators, and key molecules in the insulin receptor substrate(IRS) 1/phosphatidylinositol-3-kinase(PI3 K)/serine threonine kinase(Akt) signaling pathway. The results showed that SGDF and ROS improved the general conditions, some renal function indicators and glomerulosclerosis of DKD model rats without affecting the blood glucose(BG). Besides, they ameliorated the expression characteristics and levels of podocyte pyroptosis markers, alleviated IR, and up-regulated the protein expression levels of the key molecules in IRS1/PI3 K/Akt pathway to varying degrees. In conclusion, similar to ROS, SGDF relieves DKD by targeting multiple targets in vivo. Specifically, it exerts the therapeutic effects by alleviating podocyte pyroptosis and IR. This study has preliminarily provided the pharmacological evidence for the research and development of new drugs for the treatment of DKD based on SGDF.

S‑allyl‑cysteine sulfoxide (alliin) alleviates myocardial infarction by modulating cardiomyocyte necroptosis and autophagy

S-allyl-cysteine sulfoxide (alliin) is the main organosulfur component of garlic and its preparations. The present study aimed to examine the protective effect of alliin on cardiac function and the underlying mechanism in a mouse model of myocardial infarction (MI). Notably, alliin treatment preserved heart function, attenuated the area of infarction in the myocardium of mice and reduced lesions in the myocardium, including cardiomyocyte fibrosis and death. Further mechanistic experiments revealed that alliin inhibited necroptosis but promoted autophagy in vitro and in vivo. Cell viability assays showed that alliin dose-dependently reduced the necroptotic index and inhibited the expression of necroptosis-related receptor-interacting protein 1, receptor-interacting protein 3 and tumor necrosis factor receptor-associated factor 2, whereas the levels of Beclin 1 and microtubule-associated protein 1 light chain 3, which are associated with autophagy, exhibited an opposite trend upon treatment with alliin. In addition, the level of peroxisome proliferator-activated receptor γ was increased by alliin. Collectively, these findings demonstrate that alliin has the potential to protect cardiomyocytes from necroptosis following MI and that this protective effect occurs via the enhancement of autophagy.

Genetic evidence for panmixia of Japanese eel (Anguilla japonica) populations in China

The Japanese eel population has dramatically declined since the 1970s. In order to conserve this species, the background genetic structure affecting these populations should be well documented. Previous genetic studies of this species have produced seemingly conflicting results, ranging from no detectable heterogeneity to small, but statistically significant variance. This study investigates the population structure of Japanese glass eels collected from 10 localities in China in 2009 using a mitochondrial DNA (mtDNA) control region and 19 polymorphic microsatellite loci. Results revealed evidence of low genetic differentiation using both mtDNA (FST = 0.001, P = 0.291) and microsatellite data (FST = 0.003, P = 0.008). Pairwise F-statistic values generated from mtDNA and microsatellite DNA were similar, showing little evidence of significant genetic differentiation. The minimum spanning haplotype network constructed using mtDNA control regions produced no clear phylogeographic structure. The Mantel test revealed no significant correlation with distances for both mtDNA and microsatellite DNA. Therefore, our results suggest a panmictic population of Japanese eels in China, which should be conserved as a single management unit.

Sodium chloride improves photosynthesis and water status in the succulent xerophyte Zygophyllum xanthoxylum

Zygophyllum xanthoxylum, a C(3) woody species, is a succulent xerophyte that is well adapted to arid environments. Our previous investigations showed that Na(+) has a positive effect on the growth of Z. xanthoxylum under drought conditions, which was closely related to high Na(+) accumulation in leaves. To reveal the physiological mechanisms underlying how Na(+) accumulation improves the drought resistance of Z. xanthoxylum, 3-week-old seedlings were treated with a series of additional external NaCl concentrations (5-150 mM) in sand culture experiments. Seedlings were also subjected to water deficit (30% of field water capacity) in the presence or absence of additional NaCl (50 mM) in pot experiments. The results indicated that 50 mM NaCl could mitigate deleterious impacts of water deficit on the growth of Z. xanthoxylum, by improving the relative water content, inducing a significant drop in leaf water potential and, concomitantly, increasing leaf turgor pressure and chlorophyll concentrations resulting in an enhancement of overall plant photosynthetic activity (i.e., photosynthetic rate and water use efficiency). Furthermore, NaCl (50 mM) could alleviate the inhibitory effect of water deficit on the activity of photosystem II in Z. xanthoxylum. The contribution of Na(+) to the total osmotic potential varied from 8% in the control to 13% in plants subjected to water deficit and, surprisingly, to 28% in plants grown in the presence of 50 mM NaCl under water deficit; however, the contribution of K(+) significantly decreased from 13 to 8%. These findings suggest that, under arid environments, Z. xanthoxylum is able to accumulate a high concentration of Na(+) in its leaves and use it directly for osmotic adjustment, which was coupled with an improvement in leaf hydration and photosynthetic activity.

Study on the amount of binding of anti-tumor metal complexes to different target sites of dGMP using trans-[en(2)Os(eta2-H(2))(CF(3)SO(3))](CF(3)SO(3)) in a competitive mode

In order to investigate the binding sites and the amount of binding of a number of anti-tumor metal complexes (cisplatin, Cp(2)TiCl(2) and (CH(3))(2)SnCl(2)) to target molecule DNA mononucleotides in aqueous solution, a 1H NMR recognition probe, trans-[en(2)Os(eta2-H(2))(CF(3)SO(3))](CF(3)SO(3)), was used in a competitive mode. The minimum percentages of binding of anti-tumor metal complexes to different sites of dGMP were also determined.