Cytokinin oxidase PpCKX1 plays regulatory roles in development and enhances dehydration and salt tolerance in Physcomitrella patens.

KEY MESSAGE: PpCKX1 localizes to vacuoles and is dominantly expressed in the stem cells. PpCKX1 regulates developmental changes with increased growth of the rhizoid and enhances dehydration and salt tolerance. Cytokinins (CKs) are plant hormones that regulate plant development as well as many physiological processes, such as cell division, leaf senescence, control of shoot/root ratio, and reproductive competence. Cytokinin oxidases/dehydrogenases (CKXs) control CK concentrations by degradation, and thereby influence plant growth and development. In the moss Physcomitrella patens, an evolutionarily early divergent plant, we identified six putative CKXs that, by phylogenetic analysis, form a monophyletic clade. We also observed that ProPpCKX1:GUS is expressed specifically in the stem cells and surrounding cells and that CKX1 localizes to vacuoles, as indicated by Pro35S:PpCKX1-smGFP. Under normal growth conditions, overexpression of PpCKX1 caused many phenotypic changes at different developmental stages, and we suspected that increased growth of the rhizoid could affect those changes. In addition, we present evidence that the PpCKX1-overexpressor plants show enhanced dehydration and salt stress tolerance. Taken together, we suggest that PpCKX1 plays regulatory roles in development and adaptation to abiotic stresses in this evolutionarily early land plant species.

The FBA motif-containing protein AFBA1 acts as a novel positive regulator of ABA response in Arabidopsis.

ABA plays a critical role in regulating seed germination and stomatal movement in response to drought stress. Screening ABA-responsive genes led to the identification of a novel Arabidopsis gene encoding a protein which contained a conserved F-box-associated (FBA) domain, subsequently named ABA-responsive FBA domain-containing protein 1 (AFBA1). Expression of ProAFBA1:GUS revealed that this gene was mainly expressed in guard cells. Expression of AFBA1 increased following the application of exogenous ABA and exposure to salt (NaCl) and drought stresses. Seed germination of the loss-of-function mutant (afba1) was insensitive to ABA, salt or mannitol, whereas AFBA1-overexpressing (Ox) seeds were more sensitive to these stresses than the wild-type seeds. The afba1 plants showed decreased drought tolerance, increased water loss rate and ABA-insensitive stomatal movement compared with the wild-type. In contrast, AFBA1-Ox plants exhibited enhanced drought tolerance and a rapid ABA-induced stomatal closure response. The expression of genes encoding serine/threonine protein phosphatases that are known negative regulators of ABA signaling increased in afba1 plants but decreased in AFBA1-Ox plants. AFBA1 was also found to be localized in the nucleus and to interact with an R2R3-type transcription factor, MYB44, leading to the suggestion that it functions in the stabilization of MYB44. Based on these results, we suggest that AFBA1 functions as a novel positive regulator of ABA responses, regulating the expression of genes involved in ABA signal transduction in Arabidopsis through its interaction with positive regulators of ABA signaling including MYB44, and increasing their stability during ABA-mediated responses.

Single cystathionine ß-synthase domain-containing proteins modulate development by regulating the thioredoxin system in Arabidopsis.

Plant thioredoxins (Trxs) participate in two redox systems found in different cellular compartments: the NADP-Trx system (NTS) in the cytosol and mitochondria and the ferredoxin-Trx system (FTS) in the chloroplast, where they function as redox regulators by regulating the activity of various target enzymes. The identities of the master regulators that maintain cellular homeostasis and modulate timed development through redox regulating systems have remained completely unknown. Here, we show that proteins consisting of a single cystathionine ß-synthase (CBS) domain pair stabilize cellular redox homeostasis and modulate plant development via regulation of Trx systems by sensing changes in adenosine-containing ligands. We identified two CBS domain-containing proteins in Arabidopsis thaliana, CBSX1 and CBSX2, which are localized to the chloroplast, where they activate all four Trxs in the FTS. CBSX3 was found to regulate mitochondrial Trx members in the NTS. CBSX1 directly regulates Trxs and thereby controls H(2)O(2) levels and regulates lignin polymerization in the anther endothecium. It also affects plant growth by regulating photosynthesis-related [corrected] enzymes, such as malate dehydrogenase, via homeostatic regulation of Trxs. Based on our findings, we suggest that the CBSX proteins (or a CBS pair) are ubiquitous redox regulators that regulate Trxs in the FTS and NTS to modulate development and maintain homeostasis under conditions that are threatening to the cell.

An Arabidopsis cell growth defect factor-related protein, CRS, promotes plant senescence by increasing the production of hydrogen peroxide.

Arabidopsis thaliana Cell Growth Defect factor 1 (Cdf1) has been implicated in promotion of proapoptotic Bax-like cell death via the induction of reactive oxygen species (ROS). Here we report a conserved function of a chloroplast-targeting Cdf-related gene Responsive to Senescence (CRS) using CRS overexpression and loss of function in plants as well as CRS heterologous expression in yeast. CRS expression was strongly induced in senescent leaves, suggesting its main functions during plant senescence. CRS expression in yeast mitochondria increased the ROS level and led to cell death in a manner similar to Cdf1. In whole plants, overexpression of CRS caused the loss of chlorophylls (Chls) and the rapid onset of leaf senescence, while the lack of CRS led to the delay of leaf senescence in a loss-of-function mutant, crs. The higher and lower accumulation of H(2)O(2) was correlated with early and late senescence in CRS-overexpressing and crs mutant plants, respectively. Furthermore, expression of senescence-related marker genes and metacaspase genes was induced in CRS-overexpressing plants in response to dark. Our findings suggest that CRS plays a key role in the leaf senescence process that accompanies H(2)O(2) accumulation resulting in cell death promotion.

A cystathionine-ß-synthase domain-containing protein, CBSX2, regulates endothecial secondary cell wall thickening in anther development.

Anther formation and dehiscence are complex pivotal processes in reproductive development. The secondary wall thickening in endothecial cells of the anther is a known prerequisite for successful anther dehiscence. However, many gaps remain in our understanding of the regulatory mechanisms underlying anther dehiscence in planta, including a possible role for jasmonic acid (JA) and H(2)O(2) in secondary wall thickening of endothecial cells. Here, we report that the cystathionine ß-synthase domain-containing protein CBSX2 located in the chloroplast plays a critical role in thickening of the secondary cell walls of the endothecium during anther dehiscence in Arabidopsis. A T-DNA insertion mutant of CBSX2 (cbsx2) showed increased secondary wall thickening of endothecial cells and early anther dehiscence. Consistently, overexpression of CBSX2 resulted in anther indehiscence. Exogenous JA application induced secondary wall thickening and caused flower infertility in the cbsx2 mutant, whereas it partially restored fertility in the CBSX2-overexpressing lines lacking the wall thickening. CBSX2 directly modulated thioredoxin (Trx) in chloroplasts, which affected the level of H(2)O(2) and, consequently, expression of the genes involved in secondary cell wall thickening. Our findings have revealed that CBSX2 modulates the H(2)O(2) status, which is linked to the JA response and in turn controls secondary wall thickening of the endothecial cells in anthers for dehiscence to occur.

[Ilaprazole based bismuth-containing quadruple regimen for the first-line treatment of Helicobacter pylori infection: a multicenter, randomized, controlled clinical study].

OBJECTIVE: To explore the effects of 7-day quadruple regimen as the first-line therapy strategy for Helicobacter pylori(H. pylori)infection and compare the eradication rate of ilaprazole versus esoprazole-based regimen. METHODS: A total of 440 patients with H. pylori infection, who had never received H. pylori eradication treatment, were enrolled from 10 domestic hospitals from October 2010 to July 2011. Diagnosed as chronic gastritis or duodenal ulcer according to their endoscopic examination results, they were randomized into ilaprazole and(or) esoprazole-based bismuth-containing quadruple regimen group with amoxicillin and clarithromycin (n = 110 each). After a 7-day eradication treatment, all patients with duodenal ulcer received PPI (ilaprazole and(or) esoprazole) treatment for 14 days and (13)C urea breath test was performed at least 28 days after the end of therapy. The patients with failed eradication treatment underwent endoscopy examination and biopsy. H. pylori culture and detection of antibiotic-resistant genes were also performed. RESULTS: In gastritis patients, the eradication rate (per-protocol, PP value) were 78.2% (79/101) and 82.0% (82/100) in ilaprazole and esoprazole groups (P = 0.50) while the (intention-to-treat) ITT value of eradication rate were 71.8% (79/110) and 74.5% (82/110) in ilaprazole and esoprazole groups respectively (P = 0.65). And there was no statistical difference (P > 0.05). In duodenal patients, the eradication rate (PP) were 92.1% (93/101) and 91.4% (96/105) in ilaprazole and esoprazole group (P = 0.86) while the ITT value of eradication rate were 84.5% (93/110) and 87.3% (96/110) in ilaprazole and esoprazole groups respectively (P = 0.56). And no significant difference existed between two groups in gastritis and duodenal ulcer patients (P > 0.05). In total, the eradication rate was 80.1% (161/201) (PP) and 73.2% (161/220) (ITT), 91.7% (189/206) (PP) and 85.9% (189/220) (ITT) in chronic gastritis and duodenal ulcer patients respectively. The symptomatic improvements of stomachache, burning, belching and nausea remained almost unchanged. No severe side effect was observed. The point mutations for clarithromycin resistance were detected in all 53 H. pylori strains (100%) isolated from the patients with failed eradication treatment. CONCLUSIONS: The eradication rate of PPI based bismuth-containing quadruple regimen as the first-line treatment is satisfactory in chronic gastritis and duodenal ulcer patients. No significant difference exists between the effects of ilaprazole and esoprazole-based groups. And the treatment failure may be attributed mainly to the clarithromycin resistance of H. pylori.

[Jinghuaweikang capsules combined with triple therapy in the treatment of Helicobacter pylori associated gastritis and duodenal ulcer and analysis of antibiotic resistance: a multicenter, randomized, controlled, clinical study].

OBJECTIVE: To explore the efficacy of Jinghuaweikang capsules plus triple therapy (LACJ) in treatment of Helicobacter pylori (H. pylori) associated gastritis or duodenal ulcer, compare it with bismuth-containing quadruple therapy (LACB) and standard triple therapy (LAC) and analyze the antibiotic sensitivity of gastric mucosal H. pylori strains from the failed patients. METHODS: A total of 565 patients with H. pylori infection were recruited from 11 hospitals from January 2010 to June 2011. There were 336 males and 229 females. They underwent gastroendoscopy examination due to upper gastrointestinal symptoms and had never received H. pylori eradication therapies. Duodenal ulcer patients were divided randomly into LACJ therapy group, LACB therapy group and LAC therapy group while gastritis patients LACJ therapy group and LACB therapy group. Group LAC received lansoprazole 30 mg + amoxicillin 1000 mg + clarithromycin 500 mg, twice a day, for 7 d (d1-7). Group LACJ: LAC therapy plus Jinghuaweikang, 3 capsules, twice a day, for 7 d (d1-7) then Jinghuaweikang, 3 capsules, twice a day, for 14 d (d8-21). Group LACB: LAC plus bismuth potassium citrate 220 mg, twice a day, for 7 d (d1-7) and then bismuth potassium citrate 220 mg, twice a day, for 14 d (d8-21). All duodenal ulcer patients received lansoprazole (30 mg, once a day) for 14 days after the first 7-day of treatment (d 8-21). At least 28 days after the end of treatment, all patients underwent (13)C urea breath test. Gastric mucosa was collected under endoscopy from the failed patients. The detection technique of gene chip was employed to detect antibiotics resistant gene from mucosa. RESULTS: The eradication rates of duodenal ulcer patients in groups LACJ, LACB and LAC were as follows: per-protocol (PP), 80.2% (77/96), 89.9% (89/99) and 72.2% (70/97) (P = 0.007), intention-to-treat (ITT), 78.6% (77/98), 88.1% (89/101) and 70.0% (70/100) (P = 0.007). No statistical differences existed between groups LACJ and LACB or LAC (all P > 0.05). But there were statistical differences between groups LACB and LAC (both P = 0.002). The eradication rates of PP and ITT of chronic gastritis patients in groups LACJ and LACB were as follows: 75.8% (97/128), 74.6% (97/130) vs 83.8% (109/130), 80.1% (109/136) (both P > 0.05). The symptomatic improvements of abdominal pain, burning and acid reflux of duodenal ulcer patients in group LACJ were higher than those in groups LACB and LAC. There were statistical differences between groups LACJ and LAC (all P < 0.05). The symptomatic improvements of bloating and belching for chronic gastritis patients in group LACJ were higher than those of group LACB. But no significant difference existed between two groups (all P > 0.05). Sixty samples of gastric mucosa were collected from the failed patients. The detection rates of antibiotic-resistant gene to clarithromycin and amoxicillin were 60.0% (36/36) and 18.3% (11/60) respectively. CONCLUSIONS: The efficacy of LACJ for the treatment of H. pylori infection patients is similar to LACB and superior to LAC. And the symptomatic improvement of patients is better than the other two regimens. The main cause of treatment failure is antibiotic resistance of H. pylori strains.

Ischemic colitis after receiving the second dose of a COVID-19 inactivated vaccine: A case report.

BACKGROUND: The outbreak of the coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 has been the most important clinical challenge worldwide since January 2020. COVID-19 inactivated vaccines play a crucial role in reducing the rates of morbidity and mortality. CASE SUMMARY: We presented a 48-year-old woman from Haidian District, Beijing, China who developed ischemic colitis after receiving the second dose of COVID-19 inactivated vaccine. Computed tomography of the abdomen showed edema and bowel wall thickening with hypodensity in the sigmoid colon and descending colon. Colonoscopy revealed hyperemia, edema and erosion of the mucosa with superficial ulceration and a yellow-white coating at the descending colon and sigmoid colon. The symptoms were relieved after 1 wk of receiving pinaverium bromide (50 mg, tid) and aspirin enteric-coated tablets (0.1 g, qd). CONCLUSION: The possible occurrence of ischemic colitis should be considered after administration of the COVID-19 inactivated vaccines.

[Effect of Abl-interacting protein 1 overexpression upon human gastric cancer cell proliferation in vitro].

OBJECTIVE: To investigate the expression of Abl-interacting protein 1 (ABI1) in normal gastric mucosal cell line GES-1 and gastric cancer cell line AGS, and the effects of ABI1 gene overexpression upon the proliferation of human gastric cancer cell AGS in vitro. METHODS: Firstly the ABI1 expression in GES-1 and AGS cells were identified by immunohistochemistry, immunofluorescence, RT-PCR, real-time PCR and Western blot. Secondly human gastric cancer cell line AGS was cultured and transfected with recombinant MSCV-GFP-ABI1 plasmid or blank plasmid MSCV-GPF. Real-time PCR and Western blot were used to detect the mRNA and protein expression of ABI1. And lastly the cell proliferation was detected by CCK-8 assay. RESULTS: ABI1 was expressed both in normal gastric mucosal cell line GES-1 and in gastric cancer cell line AGS. Compared to GES-1 cells, the ABI1 expression in AGS cells was lowered significantly. There were no significant differences in the ABI1 mRNA and protein expression between the AGS and AGS-MSCV-GFP groups. Compared to those of the AGS group, the ABI1 mRNA expression levels of the AGS-MSCV-GFP-ABI1 group increased by 1.87 times (P = 0.002). The protein expression levels of the AGS-MSCV-GFP-ABI1 group were remarkably higher than those of the AGS and AGS-MSCV-GFP groups (P = 0.002). CCK-8 assay showed that there were no significant differences in the proliferation rates at different time points between the AGS and AGS-MSCV-GFP groups. However, the proliferation rates at the time points of 24, 48, 72 and 96 hours of the AGS-MSCV-GFP-ABI1 were 1.46 +/- 0.31, 4.75 +/- 0.12, 6.62 +/- 0.32 and 8.96 +/- 0.27 respectively. And they were significantly lower than the proliferation rates of the AGS and AGS-MSCV-GFP groups (P < 0.01). CONCLUSION: ABI1 gene is down-regulated in gastric cancer cells. The ABI1 overexpression effectively inhibits the proliferation in human gastric cancer cell lines. It suggests that ABI1 may be involved in gastric cancer pathogenesis by regulating the proliferation of gastric carcinomas cells.

Arabidopsis histidine-containing phosphotransfer factor 4 (AHP4) negatively regulates secondary wall thickening of the anther endothecium during flowering.

Cytokinins are essential hormones in plant development. Arabidopsis histidine-containing phosphotransfer proteins (AHPs) are mediators in a multistep phosphorelay pathway for cytokinin signaling. The exact role of AHP4 has not been elucidated. In this study, we demonstrated young flower-specific expression of AHP4, and compared AHP4-overexpressing (Ox) trangenic Arabidopsis lines and an ahp4 knock-out line. AHP4-Ox plants had reduced fertility due to a lack of secondary cell wall thickening in the anther endothecium and inhibition of IRREGURAR XYLEMs (IRXs) expression in young flowers. Conversely, ahp4 anthers had more lignified anther walls than the wild type, and increased IRXs expression. Our study indicates that AHP4 negatively regulates thickening of the secondary cell wall of the anther endothecium, and provides new insight into the role of cytokinins in formation of secondary cell walls via the action of AHP4.

[Diagnostic value of antineutrophil cytoplasmic antibodies in patients with ulcerative colitis: a meta-analysis].

OBJECTIVE: To evaluate the diagnostic value of antineutrophil cytoplasmic antibodies (ANCA) in patients with ulcerative colitis (UC). METHODS: Articles related to diagnosis of UC by ANCA test, published before November 2007, were retrieved in the databanks such as Chinese BioMedical Disc, Chinese Medical Current Contents, China National Knowledge Infrastructure, and VIP databank. Related journals were searched manually. Meta-analysis was performed by summary receiver operating characteristic curve recommended by Diagnostic and Screening Group of the Cochrane Collaboration Web with the parameters such as sensitivity, specificity, accuracy, predictive values and likelihood ratio. RESULTS: Totally 10 studies including 381 patients met the inclusion criteria. Meta-analysis showed that the sensitivity and specificity of ANCA to the diagnosis of UC were 52.2% and 99.0% respectively. The positive and negative predictive values (PPV and NPV) were 98.0% and 68.7% respectively. Meanwhile, the positive and negative likelihood ratio (+LR and -LR) were 52.2 and 0.5, respectively. CONCLUSIONS: ANCA is an immunological index related to UC. Positive ANCA helps diagnose UC, but is not sensible enough to screen UC.

Upregulation of microRNA 181c expression in gastric cancer tissues and plasma.

OBJECTIVE: To test the microRNA-181c (miR-181c) expression in tissues and plasma of gastric cancer (GC) cases, analyze any correlations, and explore the possibility of miR-181c as a potential molecular marker for GC diagnosis. MATERIALS AND METHODS: Relative miR-181c expression levels in cancers and plasma from 30 GC patients was tested using reverse transcription?real-time fluorescent quantitation PCR and compared to that in samples from 30 gastric ulcer and 30 chronic gastritis patients. RESULTS: The miR-181c expression level in the GC tissues was significantly higher than that in the gastric ulcer and chronic gastritis tissues (P = 0.000), as was the miR-181c expression level in the GC plasma (P = 0.000). We determined that miR-181c expression in GC plasma was positively correlated to its expression in the GC tissues (P = 0.000). CONCLUSIONS: The expression of miR-181c is upregulated in GC tissues and plasma, and the miR-181c expression level in GC plasma is positively correlated to that in the corresponding cancer tissues. Plasma miR-181c is possibly a new serological marker for GC diagnosis.

An Arabidopsis R2R3-MYB transcription factor, AtMYB20, negatively regulates type 2C serine/threonine protein phosphatases to enhance salt tolerance.

We have characterized the function of a plant R2R3-MYB transcription factor, Arabidopsis thaliana MYB20 (AtMYB20). Transgenic plants overexpressing AtMYB20 (AtMYB20-OX) enhanced salt stress tolerance while repression lines (AtMYB20-SRDX) were more vulnerable to NaCl than wild-type plants. Following NaCl treatment, the expressions of ABI1, ABI2 and AtPP2CA, which encode type 2C serine/threonine protein phosphatases (PP2Cs) that act as negative regulators in abscisic acid (ABA) signaling, were suppressed in AtMYB20-OX but induced in AtMYB20-SRDX. The electrophoretic mobility shift assay results revealed that AtMYB20 binds to the promoter regions containing the MYB recognition sequence (TAACTG) and an ACGT core element of ABI1 and AtPP2CA. These findings suggest that AtMYB20 down-regulates the expression of PP2Cs, the negative regulator of ABA signaling, and enhances salt tolerance.