WO3/Pt/PEG/SiO2 porous film for hydrogen sensing by the sol-gel method.

Tungsten oxide (W O 3) has been widely used in hydrogen sensing due to its stable chemical properties and high oxygen vacancy diffusion coefficient. However, the response of pure W O 3 to hydrogen is slow, and doping is an effective way to improve the hydrogen sensing performance of W O 3 materials. In this paper, W O 3/P t/P E G/S i O 2 porous film was prepared by the sol-gel method using tungsten powder, H 2 O 2 and C 2 H 5 O H as precursors, polyethylene glycol (PEG) as the pore-forming agent, and tetraethyl orthosilicate (TEOS) as the S i O 2 source material. The sensing properties of the W O 3 composite for hydrogen were characterized by a transmission optical fiber hydrogen sensing system made at home. The process parameters such as water bath time, aging time, W:PEG ratio, and W:TEOS ratio were optimized to improve the sensitivity and response time of the sensing film. The experimental results indicate that the sensitivity is 15.68%, the average response time is 45 s, and the repeatability is up to 98.74% in 16 consecutive tests. The linearity index R 2 is 0.9946 within the hydrogen concentration range of 5000 ppm to 50,000 ppm. The film responds only to H 2 when the concentration of interfering gases (C H 4, CO, C O 2) is 2000 ppm. The hydrogen sensing performance of the optimized film is significantly improved compared with that of the undoped film.

The evolution and formation of centromeric repeats analysis in Vitis vinifera.

MAIN CONCLUSION: Six grape centromere-specific markers for cytogenetics were mined by combining genetic and immunological assays, and the possible evolution mechanism of centromeric repeats was analyzed. Centromeric histone proteins are functionally conserved; however, centromeric repetitive DNA sequences may represent considerable diversity in related species. Therefore, studying the characteristics and structure of grape centromere repeat sequences contributes to a deeper understanding of the evolutionary process of grape plants, including their origin and mechanisms of polyploidization. Plant centromeric regions are mainly composed of repetitive sequences, including SatDNA and transposable elements (TE). In this research, the characterization of centromere sequences in the whole genome of grapevine (Vitis vinifera L.) has been conducted. Five centromeric tandem repeat sequences (Vv1, Vv2, Vv5, Vv6, and Vv8) and one long terminal repeat (LTR) sequence Vv24 were isolated. These sequences had different centromeric distributions, which indicates that grape centromeric sequences may undergo rapid evolution. The existence of extrachromosomal circular DNA (eccDNA) and gene expression in CenH3 subdomain region may provide various potential mechanisms for the generation of new centromeric regions.

BLK positively regulates TLR/IL-1R signaling by catalyzing TOLLIP phosphorylation.

TLR/IL-1R signaling plays a critical role in sensing various harmful foreign pathogens and mounting efficient innate and adaptive immune responses, and it is tightly controlled by intracellular regulators at multiple levels. In particular, TOLLIP forms a constitutive complex with IRAK1 and sequesters it in the cytosol to maintain the kinase in an inactive conformation under unstimulated conditions. However, the underlying mechanisms by which IRAK1 dissociates from TOLLIP to activate TLR/IL-1R signaling remain obscure. Herein, we show that BLK positively regulates TLR/IL-1R-mediated inflammatory response. BLK-deficient mice produce less inflammatory cytokines and are more resistant to death upon IL-1ß challenge. Mechanistically, BLK is preassociated with IL1R1 and IL1RAcP in resting cells. IL-1ß stimulation induces heterodimerization of IL1R1 and IL1RAcP, which further triggers BLK autophosphorylation at Y309. Activated BLK directly phosphorylates TOLLIP at Y76/86/152 and further promotes TOLLIP dissociation from IRAK1, thereby facilitating TLR/IL-1R-mediated signal transduction. Overall, these findings highlight the importance of BLK as an active regulatory component in TLR/IL-1R signaling.

[Estimation and Critical Source Area Identification of Non-point Source Pollution Based on Improved Export Coefficient Models: A Case Study of the Upper Beiyun River Basin].

Non-point source pollution(NSP) poses a great threat to water ecosystem health. The quantitative estimation of spatial distribution characteristics and accurate identification of critical source areas(CSAs) of NSP are the basis for its efficient and accurate control. The export coefficient model(ECM) has been widely used to assess NSP, but this model should be improved because it ignores pollutant loss in transport processes. In this study, the ECM, which refines the physical transport processes of pollutants through quantifying the loss rate of pollutants in runoff, sediment, and infiltration, was improved to assess NSP and identify CSAs. The simulation accuracy among Johnes ECM, frequent ECM, and improved ECM were analyzed, and the effects of the three models on the simulation results of both spatial distribution characteristics and CSAs were explored. The study showed that:① the simulation error of the improved ECM(-6.79%) was significantly lower than that of the Johnes ECM(50.44%) and the frequent ECM(-84.01%), and this improved ECM increased the simulation accuracy of NSP. ② The spatial distribution characteristics and CSAs of NSP obtained from Johnes, frequent, and improved ECMs were significantly different, and the simulation results of improved ECM were more consistent with the spatial characteristics of NSP in the watershed. The NSP was high in the southeast and low in the northwest of the basin, and the NSP mainly came from urban and cultivated land. ③ Based on the improved ECM, the CSAs of NSP in the basin were mainly distributed in Changping, Shahe, Shigezhuang, the north of Wenquan, and the west of Malianwa Street, accounting for 6.71% of the area. This study can provide an effective tool and scientific reference for the assessment and control of NSP in data-limited regions.

Tyrosine phosphorylation of IRF3 by BLK facilitates its sufficient activation and innate antiviral response.

Viral infection triggers the activation of transcription factor IRF3, and its activity is precisely regulated for robust antiviral immune response and effective pathogen clearance. However, how full activation of IRF3 is achieved has not been well defined. Herein, we identified BLK as a key kinase that positively modulates IRF3-dependent signaling cascades and executes a pre-eminent antiviral effect. BLK deficiency attenuates RNA or DNA virus-induced ISRE activation, interferon production and the cellular antiviral response in human and murine cells, whereas overexpression of BLK has the opposite effects. BLK-deficient mice exhibit lower serum cytokine levels and higher lethality after VSV infection. Moreover, BLK deficiency impairs the secretion of downstream antiviral cytokines and promotes Senecavirus A (SVA) proliferation, thereby supporting SVA-induced oncolysis in an in vivo xenograft tumor model. Mechanistically, viral infection triggers BLK autophosphorylation at tyrosine 309. Subsequently, activated BLK directly binds and phosphorylates IRF3 at tyrosine 107, which further promotes TBK1-induced IRF3 S386 and S396 phosphorylation, facilitating sufficient IRF3 activation and downstream antiviral response. Collectively, our findings suggest that targeting BLK enhances viral clearance via specifically regulating IRF3 phosphorylation by a previously undefined mechanism.

Mesenchymal stem cell-derived extracellular vesicles for treatment of bone loss within periodontitis in pre-clinical animal models: a meta-analysis.

BACKGROUND: Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) represent an effective and promising strategy for periodontitis, although studies remain pre-clinical. Herein, a meta-analysis was conducted to assess the efficacy of MSC-EVs in animal models of periodontitis. METHODS: The PubMed, Web of Science, and Embase electronic databases were searched up to Dec 2022 to retrieve preclinical studies examining the use of MSC-EVs for periodontitis treatment. Meta-analyses and sub-group analyses were performed to assess the effect of MSC-EVs on Bone Volume/Total Volume (BV/TV) or the distance between the cementoenamel junction and alveolar bone crest (CEJ-ABC) in pre-clinical animal models of periodontitis. RESULTS: 11 studies published from Mar 2019 to Oct 2022 met the inclusion criteria. Overall, MSC-EVs contributed to periodontal bone regeneration in the inflammatory bone loss area due to periodontitis, as represented by a weighted mean difference (WMD) of 14.07% (95% CI = 6.73, 21.41%, p < 0.001) for BV/TV and a WMD of -0.12 mm (95% CI= -0.14, -0.11 mm, p < 0.001) for CEJ-ABC. However, sub-analysis suggested that there was no significant difference in CEJ-ABC between studies with bioactive scaffolds and studies without bioactive scaffolds (p = 0.60). CONCLUSIONS: The present study suggests that MSC-EVs may represent an attractive therapy for the treatment of inflammatory bone loss within periodontitis.

A TaSnRK1α Modulates TaPAP6L-Mediated Wheat Cold Tolerance through Regulating Endogenous Jasmonic Acid.

Here, a sucrose non-fermenting-1-related protein kinase alpha subunit (TaSnRK1α-1A) is identified as associated with cold stress through integration of genome-wide association study, bulked segregant RNA sequencing, and virus-induced gene silencing. It is confirmed that TaSnRK1α positively regulates cold tolerance by transgenes and ethyl methanesulfonate (EMS) mutants. A plastid-lipid-associated protein 6, chloroplastic-like (TaPAP6L-2B) strongly interacting with TaSnRK1α-1A is screened. Molecular chaperone DJ-1 family protein (TaDJ-1-7B) possibly bridged the interaction of TaSnRK1α-1A and TaPAP6L-2B. It is further revealed that TaSnRK1α-1A phosphorylated TaPAP6L-2B. Subsequently, a superior haplotype TaPAP6L-2B30S /38S is identified and confirmed that both R30S and G38S are important phosphorylation sites that influence TaPAP6L-2B in cold tolerance. Overexpression (OE) and EMS-mutant lines verified TaPAP6L positively modulating cold tolerance. Furthermore, transcriptome sequencing revealed that TaPAP6L-2B-OE lines significantly increased jasmonic acid (JA) content, possibly by improving precursor α-linolenic acid contributing to JA synthesis and by repressing JAR1 degrading JA. Exogenous JA significantly improved the cold tolerance of wheat plants. In summary, TaSnRK1α profoundly regulated cold stress, possibly through phosphorylating TaPAP6L to increase endogenous JA content of wheat plants.

The roles of brassinosteroids and methyl jasmonate on postharvest grape by regulating the interaction between VvDWF4 and VvTIFY 5 A.

Brassinosteroids (BRs) and methyl jasmonate (MeJA) are known for the regulation of plant development, and the crosstalk between them is important for plant growth. However, the interaction between them in the development of postharvest fruit is unresolved. We found that BR treatment enhanced the accumulation of sugar composition and aroma content, reduced the content of organic acids (such as tartaric acid) and promoted the coloring of grape callus. After the application of MeJA, the acidity increased and the sugar content decreased. The physiological data showed that exogenous BR also attenuated the JA inhibition of postharvest ripening in grape. DWF4 is a key enzyme in the BR biosynthetic pathway, and it can effectively regulate the content of endogenous BRs. TIFY 5 A, which belongs to the Jasmonate ZIM-domain (JAZ) family, can be baited by DWF4 through the Y2H experiment. TIFY 5 A represses the expression of dihydroflavonol-4-reductase (DFR) which plays a key role in the synthesis of anthocyanins, while this will be alleviated by VvDWF4. The interaction between TIFY 5 A and DWF4 contributes to the cross talk between JA and BR signalling pathways. This is also verified by the transgenic experimental results. The results in this paper provides a new insight into the relationship between BR and JA signalling pathways, which is important to the regulation of the postharvest ripening of grape.

Screening of superior anti-osteoporotic flavonoids from Epimedii Folium with dual effects of reversing iron overload and promoting osteogenesis.

Iron overload is a risk factor for postmenopausal osteoporosis (PMOP) and lowering iron levels to regulate the labile plasma iron is the preferred therapy. Icariin (ICA), baohuoside I (BHS) and icaritin (ICT) are three flavonoids obtained from Epimedii Folium that are efficient in facilitating osteogenesis. In this study, an active flavonoid with dual effects of reversing iron overload and promoting osteogenesis was screened based on pharmacokinetics, iron complexation properties and the potential to downregulate iron overload, reversing PMOP. As a result, the in vivo absorption of three compounds was ICA > ICT > BHS, while the exposure in muscle and bone was BHS > ICT > ICA. In vitro complexation showed that only ICT complexed with Fe (III) at a 1:1 ratio on 3-OH and the ICT-Fe (III) complex (m/z 424.3750) was identified by UPLC-Q-TOF-MS. In vivo dynamic detection also showed that the concentration of ICT-Fe (III) complexes varied with the concentration of ICT in plasma. The behavioral blunting and bone loss in zebrafish induced by Fe (III) were significantly reversed by ICT in a dose-dependent manner. Pharmacokinetic-pharmacodynamic analysis showed that ICT was negatively correlated with serum ferritin and positively correlated with osteogenic markers including alkaline phosphatase, osteocalcin and osteoprotegerin. Bone loss in ovariectomized rats was significantly altered after ICT intervention, with reduced serum ferritin levels and improved osteogenic marker levels. These results demonstrated that ICT had favorable musculoskeletal penetration and iron complexation capability to shrink labile plasma iron, showing superior performance in anti-PMOP through the dual effects of reversing iron overload and promoting osteogenesis.

Water-solubility croconic acid-bisindole dye with morpholine ring for tumor NIRF/PA imaging and photothermal therapy activated by lysosome pH-response.

A novel croconic acid-bisindole dye CR-630 with a morpholine ring showed good water-solubility and obvious lysosome-targeting. The protonation of the nitrogen atom in the indole and lysosome-targeting of morpholine ring let it exhibit stronger pH-responsive NIR/PA imaging and photothermal effect in the lysosome acidic microenvironment (pH 4.0-5.5) than in the tumor acidic microenvironment. In the animal study, compound CR-630 could NIRF/PA image in the tumor tissues in 1.5-2.0 h, effectively inhibit the growth of the tumor, and even ablate the tumor at the drug dose of 1 mg/kg. It also demonstrated good biosafety. This study gives a new idea to develop water-solubility organic dyes with lysosome targeting, stronger pH-responsive NIRF/PA imaging and PTT for breast cancer.

Efficient degradation of micropollutants in CoCaAl-LDO/peracetic acid (PAA) system: An organic radical dominant degradation process.

As a novel strategy, peracetic acid (PAA) based advanced oxidation processes (AOPs) are being used in micropollutant elimination due to their high oxidation and low toxicity. In this study, Co2Ca1Al1-LDO as a kind of layered double oxides (LDOs) was successfully synthesized, and it is the first time to apply Co2Ca1Al1-LDO for activating PAA. The Co2Ca1Al1-LDO/PAA system showed excellent removal efficiencies for various micropollutants with removal ratios ranging from 90.4% to 100% and k values from 0.087 min-1 to 0.298 min-1. In the degradation period, various reactive oxygen species (ROS) are involved in the system, while organic radicals (R-O•) with a high concentration of 5.52 × 10-13 M are the dominant ROS in the contaminants degradation process. Compared to other ROS, R-O• had the largest contribution ratio (more than 85%) to pollutant degradation. Further analysis demonstrated that C1, C2, C3, C4, C5, C6 and N11 concentrated on the aniline group of SMX are the main attack sites based on the density functional theory (DFT) results, which is consistent with the degradation products. The toxicity of contaminants was obviously reduced after removing in this system. Furthermore, Co2Ca1Al1-LDO showed good reusability and stability, and Co2Ca1Al1-LDO/PAA system had excellent removal ability in actual water bodies containing inorganic anions, showing good application potential. Importantly, this study explored the feasibility of applying LDO catalysts in PAA-based AOPs for micropollutants elimination, providing new insights for subsequent research.

Assessment of 'Cabernet Sauvignon' Grape Quality Half-Véraison to Maturity for Grapevines Grown in Different Regions.

Grapes are widely cultivated around the world and their quality has distinct regional characteristics. In this study, the qualitative characteristics of the 'Cabernet Sauvignon' grape variety in seven regions, from half-véraison to maturity, were analyzed comprehensively at physiological and transcriptional levels. The results indicated that the quality traits of 'Cabernet Sauvignon' grapes in different regions were significantly different with obvious regionality. Total phenols, anthocyanins, and titratable acids were the main factors of the regionality of berry quality, which were very sensitive to changes in the environment. It should be noted that the changes in titrating acids and total anthocyanin of berries vary greatly from half-véraison to maturity between regions. Moreover, the transcriptional analysis showed that the co-expressed genes between regions characterized the core transcriptome of berry development, while the unique genes of each region reflected the regionality of berries. The differentially expressed genes (DEGs) between half-véraison and maturity can be used to demonstrate that the environment of the regions could promote or inhibit gene expression. The functional enrichment suggested that these DEGs help to understand the interpretation of the plasticity of the quality composition of grapes according to the environment. Taken together, the information generated by this study could contribute to the development of viticultural practices aimed at making better use of native varieties for the development of wines with regional characteristics.

Characterization of Simple Sequence Repeat (SSR) Markers Mined in Whole Grape Genomes.

SSR (simple sequence repeat) DNA markers are widely used for genotype DNA identification, QTL mapping, and analyzing genetic biodiversity. However, SSRs in grapes are still in their early stages, with a few primer pairs accessible. With the whole-genome sequencing (WGS) of several grape varieties, characterization of grape SSR changed to be necessary not only to genomics but to also help SSR development and utility. Based on this, we identified the whole-genome SSR of nine grape cultivars ('PN40024', 'Cabernet Sauvignon', 'Carménère', 'Chardonnay', 'Merlot', 'Riesling', 'Zinfandel', 'Shine Muscat', and 'Muscat Hamburg') with whole-genome sequences released publicly and found that there are great differences in the distribution of SSR loci in different varieties. According to the difference in genome size, the number of SSRs ranged from 267,385 (Cabernet Sauvignon) to 627,429 (Carménère), the density of the SSR locus in the genome of nine cultivars was generally 1 per Kb. SSR motif distribution characteristic analysis of these grape cultivars showed that the distribution patterns among grape cultivars were conservative, mainly enriched in A/T. However, there are some differences in motif types (especially tetranucleotides, pentanucleotides, and hexanucleotides), quantity, total length, and average length in different varieties, which might be related to the size of the assembled genome or the specificity of variety domestication. The distribution characteristics of SSRs were revealed by whole-genome analysis of simple repeats of grape varieties. In this study, 32 pairs of primers with lower polymorphism have been screened, which provided an important research foundation for the development of molecular markers of grape variety identification and the construction of linkage maps of important agronomic traits for crop improvement.

Risk of gout attack not increased in patients with thalassemia: a population-based cohort study.

The incidence of gout arthritis in patients with thalassemia and the association between them was indefinite. We aimed to give epidemiological evidence regarding the association between thalassemia and gout arthritis. This retrospective cohort study extracted data relating to the risk of gout arthritis from patients diagnosed with thalassemia between 2000 and 2013. We selected the control group at a ratio of 1:4 by propensity score matching (PSM). Univariable and multivariable Cox proportional hazard regression models were performed to analyze the association between thalassemia and gout arthritis and to evaluate the hazard ratio (HR) of gout arthritis after exposure with thalassemia. The sensitivity analysis was performed to avoid the mislabeled thalassemia disease, the transfusion-dependent thalassemia was classified to compare the risk of gout arthritis. The secondary outcome for the risk of gout arthritis with antigout drugs treatment was also evaluated between study groups. In the age and sex matched cohort, the majority of thalassemia patients were women (62.03%) and aged younger than 30 years old (44.79%). There were 138 (4.2%) and 500 (3.8%) incident cases of gout arthritis in the thalassemia and non-thalassemia group. After PSM, the incidence rate, per 100 person-years, of gout arthritis was 0.48 (95% CI 0.42 to 0.56) and 0.60 (95% CI 0.51 to 0.72) in non-thalassemia individuals and patients with thalassemia, respectively. In the Cox proportional hazard regression, patients with thalassemia had no significant increase in the risk of gout arthritis (adjusted HR, 1.00; 95%CI: 0.80 to 1.25) after adjusting demographic variables and comorbidities. The Kaplan-Meier curve showed that the cumulative incidence of gout arthritis was not a significant difference in the thalassemia group than in the comparison group (p > 0.05). The sensitivity analysis showed the consistent results about the risk of gout arthritis in patients with thalassemia. Our study indicated that there was no significant increase in the risk of gout arthritis in subjects with thalassemia.Future research needs to clarify the biological mechanisms behind this connection.

NIR C-Myc Pu22 G-quadruplex probe as a photosensitizer for bioimaging and antitumor study.

Despite the fact that C-Myc G-quadruplex in the oncogene promoter regions is one of the crucial targets of antitumor drugs, the selectivities and proliferation inhibitions of its probes towards tumor cells remain a big challenge. Until now, no effective C-Myc G-quadruplex probes have been reported as a photosensitizer to increase their antitumor activities. Here, the first NIR C-Myc G-quadruplex probe PDS-SQ has been designed, comprising a G-quadruplex binder PDS and a squaraine dye SQ as a photosensitizer. Conjugate PDS-SQ could selectively NIR image C-Myc Pu22 G-quadruplex in tumor cells, and show stronger antitumor activity in the irradiation by a chemo-photodynamic method than in the dark. The study provides a new way to develop the novel NIR C-Myc G-quadruplex probes with more potent antitumor activities.

Single aromatics sulfonamide substituted dibenzothiazole squaraines for tumor NIR imaging and efficient photodynamic therapy at low drug dose.

On the base of the zwiterionic dibenzothiazole squaraine SQ, five cationic aromatics sulfonamide substituted dibenzothiazole squaraines SQ-D1 âˆ¼ 5 have been designed and synthesized. Through the formation of the cationic compound, a higher rigid structure and the addition of the strong electron-withdrawing group (-CN), an ideal photosensitizer SQ-D2 has been gotten. In all the sulfonaminosquaraines, compound SQ-D2 exhibited the highest ROS generation efficacy and photostability. It also showed the highest photo-cytotoxicity (IC50 = 0.25 ± 0.08 µM), very low dark-cytotoxicity and the excellent cell uptake. In animal study, it not only showed the effective tumor retention and the easy removal from the body, but also exhibited the effective PDT efficacy at low drug dose (0.15 mg/kg) and the good biocompatibility. Furthermore, photosensitizer SQ-D2 as a single component exhibited greater potential than clinically approved photosensitizer m-THPC and some nanomaterials with photosensitizers in PDT therapy towards human breast cancer. This work provides a new perspective to develop the ideal photosensitizer of the squaraine dyes.

miR3633a-GA3ox2 Module Conducts Grape Seed-Embryo Abortion in Response to Gibberellin.

Seedlessness is one of the important quality and economic traits favored by grapevine consumers, which are mainly affected by phytohormones, especially gibberellin (GA). GA is widely utilized in seedless berry production and could effectively induce grape seed embryo abortion. However, the molecular mechanism underlying this process, like the role of RNA silencing in the biosynthesis pathway of GA remains elusive. Here, Gibberellin 3-ß dioxygenase2 (GA3ox2) as the last key enzyme in GA biosynthesis was predicated as a potential target gene for miR3633a, and two of them were identified as a GA response in grape berries. We also analyzed the promoter regions of genes encoding GA biosynthesis and found the hormone-responsive elements to regulate grape growth and development. The cleavage interaction between VvmiR3633a and VvGA3ox2 was validated by RLM-RACE and the transient co-transformation technique in tobacco in vivo. Interestingly, during GA-induced grape seed embryo abortion, exogenous GA promoted the expression of VvmiR3633a, thereby mainly repressing the level of VvGA3ox2 in seed embryos. We also observed a negative correlation between down-regulated VvGA20ox2/VvGA3ox2 and up-regulated VvGA2ox3/VvGA2ox1, of which GA inactivation was greater than GA synthesis, inhibited active GA content, accompanied by the reduction of VvSOD and VvCAT expression levels and enzymatic activities. These series of changes might be the main causes of grape seed embryo abortion. In conclusion, we have preliminarily drawn a schematic mode of GA-mediated VvmiR3633a and related genes regulatory network during grape seed abortion induced by exogenous GA. Our findings provide novel insights into the GA-responsive roles of the VvmiR3633a-VvGA3ox2 module in the modulation of grape seed-embryo abortion, which has implications for the molecular breeding of high-quality seedless grape berries.

Receptor-like protein kinase BAK1 promotes K+ uptake by regulating H+-ATPase AHA2 under low potassium stress.

Potassium (K+) is one of the essential macronutrients for plant growth and development. However, the available K+ concentration in soil is relatively low. Plant roots can perceive low K+ (LK) stress, then enhance high-affinity K+ uptake by activating H+-ATPases in root cells, but the mechanisms are still unclear. Here, we identified the receptor-like protein kinase Brassinosteroid Insensitive 1-Associated Receptor Kinase 1 (BAK1) that is involved in LK response by regulating the Arabidopsis (Arabidopsis thaliana) plasma membrane H+-ATPase isoform 2 (AHA2). The bak1 mutant showed leaf chlorosis phenotype and reduced K+ content under LK conditions, which was due to the decline of K+ uptake capacity. BAK1 could directly interact with the AHA2 C terminus and phosphorylate T858 and T881, by which the H+ pump activity of AHA2 was enhanced. The bak1 aha2 double mutant also displayed a leaf chlorosis phenotype that was similar to their single mutants. The constitutively activated form AHA2Δ98 and phosphorylation-mimic form AHA2T858D or AHA2T881D could complement the LK sensitive phenotypes of both aha2 and bak1 mutants. Together, our data demonstrate that BAK1 phosphorylates AHA2 and enhances its activity, which subsequently promotes K+ uptake under LK conditions.

Long noncoding RNA X-inactive specific transcript regulates NLR family pyrin domain containing 3/caspase-1-mediated pyroptosis in diabetic nephropathy.

BACKGROUND: NLRP3-mediated pyroptosis is recognized as an essential modulator of renal disease pathology. Long noncoding RNAs (lncRNAs) are active participators of diabetic nephropathy (DN). X inactive specific transcript (XIST) expression has been reported to be elevated in the serum of DN patients. AIM: To evaluate the mechanism of lncRNA XIST in renal tubular epithelial cell (RTEC) pyroptosis in DN. METHODS: A DN rat model was established through streptozotocin injection, and XIST was knocked down by tail vein injection of the lentivirus LV sh-XIST. Renal metabolic and biochemical indices were detected, and pathological changes in the renal tissue were assessed. The expression of indicators related to inflammation and pyroptosis was also detected. High glucose (HG) was used to treat HK2 cells, and cell viability and lactate dehydrogenase (LDH) activity were detected after silencing XIST. The subcellular localization and downstream mechanism of XIST were investigated. Finally, a rescue experiment was carried out to verify that XIST regulates NLR family pyrin domain containing 3 (NLRP3)/caspase-1-mediated RTEC pyroptosis through the microRNA-15-5p (miR-15b-5p)/Toll-like receptor 4 (TLR4) axis. RESULTS: XIST was highly expressed in the DN models. XIST silencing improved renal metabolism and biochemical indices and mitigated renal injury. The expression of inflammation and pyroptosis indicators was significantly increased in DN rats and HG-treated HK2 cells; cell viability was decreased and LDH activity was increased after HG treatment. Silencing XIST inhibited RTEC pyroptosis by inhibiting NLRP3/caspase-1. Mechanistically, XIST sponged miR-15b-5p to regulate TLR4. Silencing XIST inhibited TLR4 by promoting miR-15b-5p. miR-15b-5p inhibition or TLR4 overexpression averted the inhibitory effect of silencing XIST on HG-induced RTEC pyroptosis. CONCLUSION: Silencing XIST inhibits TLR4 by upregulating miR-15b-5p and ultimately inhibits renal injury in DN by inhibiting NLRP3/caspase-1-mediated RTEC pyroptosis.

Phosphorylation of the plasma membrane H+-ATPase AHA2 by BAK1 is required for ABA-induced stomatal closure in Arabidopsis.

Stomatal opening is largely promoted by light-activated plasma membrane-localized proton ATPases (PM H+-ATPases), while their closure is mainly modulated by abscisic acid (ABA) signaling during drought stress. It is unknown whether PM H+-ATPases participate in ABA-induced stomatal closure. We established that BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) interacts with, phosphorylates and activates the major PM Arabidopsis H+-ATPase isoform 2 (AHA2). Detached leaves from aha2-6 single mutant Arabidopsis thaliana plants lost as much water as bak1-4 single and aha2-6 bak1-4 double mutants, with all three mutants losing more water than the wild-type (Columbia-0 [Col-0]). In agreement with these observations, aha2-6, bak1-4, and aha2-6 bak1-4 mutants were less sensitive to ABA-induced stomatal closure than Col-0, whereas the aha2-6 mutation did not affect ABA-inhibited stomatal opening under light conditions. ABA-activated BAK1 phosphorylated AHA2 at Ser-944 in its C-terminus and activated AHA2, leading to rapid H+ efflux, cytoplasmic alkalinization, and reactive oxygen species (ROS) accumulation, to initiate ABA signal transduction and stomatal closure. The phosphorylation-mimicking mutation AHA2S944D driven by its own promoter could largely compensate for the defective phenotypes of water loss, cytoplasmic alkalinization, and ROS accumulation in both aha2-6 and bak1-4 mutants. Our results uncover a crucial role of AHA2 in cytoplasmic alkalinization and ABA-induced stomatal closure during the plant's response to drought stress.